.app{min-height:100vh;display:flex;flex-direction:column;background:linear-gradient(135deg,#667eea,#764ba2);position:relative;overflow-x:hidden}.app:before{content:"";position:fixed;top:0;left:0;right:0;bottom:0;background:radial-gradient(circle at 20% 80%,rgba(120,119,198,.3) 0,transparent 50%),radial-gradient(circle at 80% 20%,rgba(255,119,198,.3) 0,transparent 50%),radial-gradient(circle at 40% 40%,rgba(120,219,255,.2) 0,transparent 50%);pointer-events:none;z-index:0}.app-header{position:relative;z-index:1000;background:hsla(0,0%,100%,.1);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-bottom:1px solid hsla(0,0%,100%,.2);padding:12px 0;isolation:isolate}.header-content{max-width:1400px;margin:0 auto;padding:0 24px;display:flex;align-items:center;justify-content:space-between}.header-main{text-align:center;flex:1 1}.app-title{font-size:42px;font-weight:700;color:#fff;margin-bottom:6px;text-shadow:0 2px 20px rgba(0,0,0,.3);display:flex;align-items:center;justify-content:center;gap:14px}.app-title i{font-size:36px;color:gold;filter:drop-shadow(0 2px 10px rgba(255,215,0,.5))}.app-subtitle{font-size:16px;color:hsla(0,0%,100%,.9);margin:0;font-weight:400;text-shadow:0 1px 10px rgba(0,0,0,.2)}.app-main{flex:1 1;position:relative;z-index:1;padding:16px 24px 0;max-width:1400px;margin:0 auto;min-height:calc(100vh - 100px);display:flex;flex-direction:column;align-items:center;justify-content:flex-start}.app-main>.menu-container{flex:1 1;display:flex;align-items:center;width:100%}.app-main>.menu-container .menu-container{grid-template-columns:1fr 280px;grid-gap:24px;gap:24px;padding-top:8px}.app-main>.menu-container .menu-container,.menu-container{display:grid;max-width:1200px;margin:0 auto;width:100%;align-items:start}.menu-container{grid-template-columns:1fr 300px;grid-gap:32px;gap:32px;padding-top:0}.menu-main{display:flex;flex-direction:column;gap:20px;min-width:0}.menu-actions{display:flex;justify-content:flex-start;margin:0;gap:10px;flex-wrap:wrap}.menu-actions-desktop{display:none}.menu-actions-mobile{display:flex}.leaderboard-btn{background:linear-gradient(135deg,gold,#ffed4e);color:#8b6914;border:none;border-radius:6px;padding:6px 12px;font-size:11px;font-weight:600;cursor:pointer;transition:all .3s ease;display:flex;align-items:center;gap:3px;box-shadow:0 2px 8px rgba(255,215,0,.3);white-space:nowrap}.leaderboard-btn:hover{transform:translateY(-1px);box-shadow:0 4px 12px rgba(255,215,0,.4)}.leaderboard-btn i{font-size:10px}.quick-start-btn{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;border-radius:6px;padding:6px 12px;font-size:11px;font-weight:600;cursor:pointer;transition:all .3s ease;display:flex;align-items:center;gap:3px;box-shadow:0 2px 8px rgba(102,126,234,.3);white-space:nowrap}.quick-start-btn:hover{transform:translateY(-1px);box-shadow:0 4px 12px rgba(102,126,234,.4)}.menu-sidebar{width:100%;display:flex;flex-direction:column;gap:10px;position:-webkit-sticky;position:sticky;top:12px;height:-moz-fit-content;height:fit-content;max-height:calc(100vh - 140px);overflow-y:auto}.compact-stats{background:hsla(0,0%,100%,.95);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-radius:8px;padding:10px;box-shadow:0 4px 20px rgba(0,0,0,.1);border:1px solid hsla(0,0%,100%,.2)}.compact-stats h3{font-size:12px;font-weight:700;color:#212529;margin-bottom:6px;display:flex;align-items:center;gap:3px}.compact-stats-grid{display:grid;grid-template-columns:1fr 1fr;grid-gap:4px;gap:4px}.compact-stat-item{text-align:center;padding:6px 4px;background:hsla(0,0%,100%,.5);border-radius:4px;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.compact-stat-value{font-size:14px;font-weight:700;color:#667eea;margin-bottom:1px;line-height:1.1}.compact-stat-label{font-size:8px;color:#6c757d;font-weight:500;text-transform:uppercase;letter-spacing:.3px;line-height:1.1}.game-features{background:hsla(0,0%,100%,.95);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-radius:8px;padding:10px;box-shadow:0 4px 20px rgba(0,0,0,.1);border:1px solid hsla(0,0%,100%,.2)}.game-features h3{font-size:12px;font-weight:700;color:#212529;margin-bottom:6px;display:flex;align-items:center;gap:3px}.features-list{display:flex;flex-direction:column;gap:3px}.feature-item{display:flex;align-items:center;gap:5px;font-size:9px;color:#495057;padding:1px 0;line-height:1.2}.feature-item i{color:#667eea;width:10px;text-align:center;font-size:8px;flex-shrink:0}.game-container{display:grid;grid-template-columns:minmax(400px,1fr) 350px;grid-gap:32px;gap:32px;max-width:1400px;margin:0 auto;align-items:start}.game-info{grid-column:1/-1;justify-content:space-between;background:hsla(0,0%,100%,.95);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-radius:20px;padding:20px 32px;box-shadow:0 8px 32px rgba(0,0,0,.1);border:1px solid hsla(0,0%,100%,.2);margin-bottom:24px}.game-info,.game-stats{display:flex;align-items:center}.game-stats{gap:32px}.stat-item{display:flex;align-items:center;gap:10px;font-size:16px;font-weight:500;color:#495057;padding:8px 16px;background:hsla(0,0%,100%,.5);border-radius:12px;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.stat-item i{font-size:18px;color:#6c757d}.difficulty-badge{background:linear-gradient(135deg,#ff6b6b,#ee5a24);color:#fff;padding:10px 20px;border-radius:25px;font-size:14px;font-weight:600;text-transform:uppercase;letter-spacing:.5px;box-shadow:0 4px 15px rgba(238,90,36,.3)}.game-board-container{display:flex;justify-content:center;align-items:flex-start}.game-sidebar{width:100%;max-width:350px;display:flex;flex-direction:column;gap:20px;margin-bottom:20px}.game-sidebar::-webkit-scrollbar{width:6px}.game-sidebar::-webkit-scrollbar-track{background:transparent}.game-sidebar::-webkit-scrollbar-thumb{background:rgba(102,126,234,.3);border-radius:3px}.game-sidebar::-webkit-scrollbar-thumb:hover{background:rgba(102,126,234,.5)}.completion-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.8);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);display:flex;align-items:center;justify-content:center;z-index:1000;animation:fadeIn .3s ease-out}.completion-modal{background:linear-gradient(135deg,#fff,#f8f9fa);border-radius:24px;padding:40px;max-width:500px;width:90%;text-align:center;box-shadow:0 20px 60px rgba(0,0,0,.3);animation:bounceIn .5s ease-out}.completion-header{margin-bottom:30px}.completion-header i{font-size:64px;color:gold;margin-bottom:16px;filter:drop-shadow(0 4px 20px rgba(255,215,0,.5));animation:bounce 2s infinite}.completion-header h2{font-size:32px;font-weight:700;color:#212529;margin:0;background:linear-gradient(135deg,#667eea,#764ba2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.completion-stats{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:20px;gap:20px;margin-bottom:30px}.completion-stat{background:linear-gradient(135deg,#f8f9fa,#e9ecef);border-radius:12px;padding:20px;border:1px solid #dee2e6}.stat-label{color:#6c757d;text-transform:uppercase;letter-spacing:.5px;margin-bottom:8px}.stat-value{font-size:24px;color:#212529;font-family:Roboto Mono,monospace}.completion-actions{display:flex;gap:12px;justify-content:center;flex-wrap:wrap}.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 24px;border:none;border-radius:12px;font-size:16px;font-weight:600;cursor:pointer;transition:all .3s ease;text-decoration:none}.btn-primary{background:linear-gradient(135deg,#28a745,#20c997);color:#fff;box-shadow:0 4px 15px rgba(40,167,69,.3)}.btn-primary:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(40,167,69,.4)}.btn-secondary{background:linear-gradient(135deg,#6c757d,#5a6268);color:#fff;box-shadow:0 4px 15px hsla(208,7%,46%,.3)}.btn-secondary:hover{transform:translateY(-2px);box-shadow:0 6px 20px hsla(208,7%,46%,.4)}@keyframes bounce{0%,20%,50%,80%,to{transform:translateY(0)}40%{transform:translateY(-10px)}60%{transform:translateY(-5px)}}@media (min-width:1200px){.app-main{padding:20px;max-width:none}.menu-container{gap:24px;grid-template-columns:60% 40%;padding-top:0;min-height:calc(100vh - 100px);max-width:none;width:100%}.menu-actions-desktop{display:none}.menu-actions-mobile{display:flex;gap:10px}.menu-actions-mobile .leaderboard-btn,.menu-actions-mobile .quick-start-btn{padding:8px 16px;font-size:12px;border-radius:8px;gap:4px}.menu-actions-mobile .leaderboard-btn i,.menu-actions-mobile .quick-start-btn i{font-size:11px}.difficulty-grid{grid-template-columns:repeat(3,1fr);gap:10px}.difficulty-card{min-height:90px;padding:12px}.difficulty-info h3{font-size:13px}.difficulty-desc{font-size:10px;-webkit-line-clamp:1}.compact-stats{padding:12px}.compact-stats h3{font-size:13px;margin-bottom:8px}.compact-stat-value{font-size:15px}.compact-stat-label{font-size:9px}.game-features{padding:12px}.game-features h3{font-size:13px;margin-bottom:8px}.feature-item{font-size:10px;padding:2px 0}.game-container{grid-template-columns:7fr 3fr;gap:32px}.game-board,.game-container{width:100%;max-width:none;margin:0}.game-info{padding:24px 40px}.game-stats{gap:40px}.stat-item{padding:10px 20px;font-size:17px}.game-sidebar{width:100%;max-width:none}}@media (min-width:1400px) and (max-width:1600px){.app-main{padding:20px;max-width:none}.game-container{grid-template-columns:7fr 3fr;gap:28px}.game-board,.game-container{width:100%;max-width:none;margin:0}.game-board{padding:20px}.game-sidebar{width:100%;max-width:none}}@media (min-width:1600px){.app-main{padding:32px 20px;width:100%;max-width:none}.game-container{grid-template-columns:7fr 3fr;gap:40px}.game-board,.game-container{width:100%;max-width:none;margin:0}.game-sidebar{width:100%;max-width:none}}@media (max-width:1199px) and (min-width:769px){.menu-container{grid-template-columns:1fr;gap:16px;min-height:auto}.menu-actions-desktop{display:none}.menu-actions-mobile{display:flex;justify-content:center}.menu-sidebar{width:100%;display:grid;grid-template-columns:1fr 1fr;grid-gap:12px;gap:12px;position:static;max-height:none}.difficulty-grid{grid-template-columns:repeat(6,1fr);gap:8px}.difficulty-card{min-height:80px;padding:10px}.game-container{grid-template-columns:1fr;gap:24px;width:100%}.game-sidebar{width:100%;max-width:100%;display:grid;grid-template-columns:1fr 1fr;grid-gap:20px;gap:20px;position:static}.game-info{padding:18px 28px}.game-stats{gap:28px;flex-wrap:wrap}.stat-item{padding:8px 16px;font-size:15px}}@media (max-width:768px){.app-main{padding:16px 20px;align-items:center;justify-content:flex-start;min-height:calc(100vh - 100px)}.menu-container{grid-template-columns:1fr;gap:20px;padding-top:0;min-height:auto;width:100%;max-width:100%;margin:0 auto}.menu-main{gap:16px;width:100%;max-width:100%;display:flex;flex-direction:column;align-items:center}.menu-actions-desktop{display:none}.menu-actions-mobile{display:flex;flex-direction:row;gap:12px;justify-content:center;width:100%;max-width:400px}.menu-sidebar{width:100%;max-width:500px;order:-1;gap:16px;position:static;max-height:none;margin:0 auto}.compact-stats-grid{grid-template-columns:repeat(4,1fr);gap:8px}.compact-stat-item{padding:8px 4px}.compact-stat-value{font-size:13px}.compact-stat-label{font-size:8px}.features-list{display:flex;flex-direction:column;gap:4px}.feature-item{font-size:9px;gap:4px}.difficulty-grid{grid-template-columns:repeat(3,1fr);gap:10px;max-width:500px;margin:0 auto}.difficulty-card{min-height:85px;padding:12px}.difficulty-icon{width:24px;height:24px;margin-bottom:6px}.difficulty-icon i{font-size:10px}.difficulty-info h3{font-size:11px;margin-bottom:3px}.difficulty-desc{font-size:8px;margin-bottom:3px}.difficulty-clues{font-size:7px}.leaderboard-btn,.quick-start-btn{padding:8px 16px;font-size:12px;flex:1 1}.app-header{padding:12px 0;position:relative;z-index:1000}.header-content{padding:0 20px;flex-direction:row;justify-content:space-between;align-items:center;position:relative}.header-main{flex:1 1;text-align:center}.app-title{font-size:28px;gap:8px;margin-bottom:4px}.app-title i{font-size:24px}.app-subtitle{font-size:13px}.header-controls{position:relative;z-index:10002;flex-shrink:0}.game-container{grid-template-columns:1fr;gap:24px;max-width:100%;width:100%;margin:0 auto}.game-sidebar{display:flex;position:static}.game-info,.game-sidebar{width:100%;max-width:100%;flex-direction:column;gap:20px;margin:0 auto}.game-info{text-align:center;padding:20px 24px;border-radius:16px}.game-stats{flex-wrap:wrap;justify-content:center;gap:16px}.stat-item{font-size:14px;padding:8px 16px;background:hsla(0,0%,100%,.7);min-width:120px}.difficulty-badge{padding:10px 20px;font-size:13px}.completion-modal{padding:24px 20px;margin:20px;border-radius:20px;max-width:calc(100vw - 40px)}.completion-header h2{font-size:26px}.completion-stats{grid-template-columns:1fr;gap:16px}.completion-actions{flex-direction:column;gap:16px}}@media (max-width:480px){.header-content{padding:0 16px;align-items:center}.header-main{margin-top:0}.app-title{font-size:24px;margin-bottom:4px;gap:6px}.app-title i{font-size:20px}.app-subtitle{font-size:12px}.app-main{padding:12px 8px;align-items:center;justify-content:flex-start}.menu-container{gap:16px;width:100%;max-width:100%;margin:0}.menu-main{gap:12px;width:100%;max-width:100%;align-items:center}.menu-actions-mobile{gap:8px;max-width:100%}.menu-sidebar{max-width:100%;gap:12px}.difficulty-grid{grid-template-columns:repeat(2,1fr);gap:8px;max-width:100%}.difficulty-card{min-height:80px;padding:10px}.difficulty-icon{width:20px;height:20px;margin-bottom:4px}.difficulty-icon i{font-size:8px}.difficulty-info h3{font-size:10px;margin-bottom:2px}.difficulty-desc{font-size:7px;margin-bottom:2px}.difficulty-clues{font-size:6px}.leaderboard-btn,.quick-start-btn{padding:6px 12px;font-size:11px}.game-container{margin:0;width:100%}.game-container,.game-info,.game-sidebar{gap:16px;max-width:100%}.game-info{padding:16px 20px;width:84%;margin:0}.game-stats{gap:12px}.stat-item{min-width:100px;padding:6px 12px;font-size:13px}.completion-modal{padding:20px 16px;margin:16px;max-width:calc(100vw - 32px);max-height:90vh;overflow-y:auto}.completion-header h2{font-size:22px}.completion-stats{gap:12px}}@media (max-width:360px){.app-main{padding:8px 12px}.header-content{padding:0 12px}.menu-container{gap:12px}.menu-main,.menu-sidebar{gap:10px}.difficulty-grid{gap:6px}.difficulty-card{min-height:75px;padding:8px}.leaderboard-btn,.quick-start-btn{padding:5px 10px;font-size:10px}.game-info{padding:12px 16px}.stat-item{min-width:80px;padding:4px 8px;font-size:12px}}@media (prefers-color-scheme:dark){.app{background:linear-gradient(135deg,#2c3e50,#34495e)}.app-header{background:rgba(0,0,0,.2);border-bottom-color:hsla(0,0%,100%,.1)}.game-info{background:rgba(0,0,0,.3);color:#ecf0f1}.stat-item{color:#bdc3c7}.completion-modal{background:linear-gradient(135deg,#34495e,#2c3e50);color:#ecf0f1}.completion-stat{background:linear-gradient(135deg,#3c4043,#2c3e50);border-color:#4a5568}.stat-value{color:#ecf0f1}}@media (prefers-contrast:high){.app{background:#fff}.app-subtitle,.app-title{color:#000;text-shadow:none}.game-info{background:#fff}.btn,.game-info{border:2px solid #000}}.main-function-area{background:hsla(0,0%,100%,.1);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:16px;padding:32px;margin-bottom:32px;border:1px solid hsla(0,0%,100%,.2)}.main-function-container{display:grid;grid-template-columns:1fr 350px;grid-gap:40px;gap:40px;max-width:1200px;margin:0 auto;align-items:start}.difficulty-section,.main-actions-section{display:flex;flex-direction:column}.main-actions-section{gap:24px}.quick-actions{display:flex;gap:12px}.quick-actions .leaderboard-btn,.quick-actions .quick-start-btn{flex:1 1;padding:12px 18px;font-size:14px;border-radius:8px;font-weight:600;transition:all .3s ease}.user-stats{background:hsla(0,0%,100%,.1);border-radius:12px;padding:20px;border:1px solid hsla(0,0%,100%,.15)}.user-stats h3{color:#fff;font-size:18px;font-weight:600;margin-bottom:16px;display:flex;align-items:center;gap:8px}.user-stats h3 i{color:gold;font-size:16px}.stats-grid{display:grid;grid-template-columns:1fr 1fr;grid-gap:16px;gap:16px}.stat-item{text-align:center;background:hsla(0,0%,100%,.08);border-radius:8px;padding:12px 8px;border:1px solid hsla(0,0%,100%,.1)}.stat-value{font-size:20px;font-weight:700;color:#fff;margin-bottom:4px}.stat-label{font-size:12px;color:hsla(0,0%,100%,.8);font-weight:500}.feature-introduction{width:100%;background:hsla(0,0%,100%,.08);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:16px;padding:32px;margin-bottom:32px;border:1px solid hsla(0,0%,100%,.15)}.feature-container{max-width:1200px;margin:0 auto}.features-section h3{color:#fff;font-size:24px;font-weight:700;margin-bottom:20px;display:flex;align-items:center;gap:12px;justify-content:center}.features-section h2,.modes-section h2{color:#fff}.features-section h2 i,.modes-section h2 i{color:gold;margin-right:10px}.features-section h3 i{color:gold;font-size:20px}.features-grid{display:grid;grid-template-columns:repeat(4,1fr);grid-gap:20px;gap:20px}.feature-card{background:hsla(0,0%,100%,.1);border-radius:12px;padding:24px;border:1px solid hsla(0,0%,100%,.2);transition:all .3s ease;text-align:center}.feature-card:hover{transform:translateY(-4px);background:hsla(0,0%,100%,.15);box-shadow:0 8px 32px rgba(0,0,0,.2)}.feature-card i{font-size:32px;color:gold;margin-bottom:16px;display:block}.feature-card h4{color:#fff;font-size:18px;font-weight:600;margin-bottom:12px}.feature-card p{color:hsla(0,0%,100%,.8);font-size:14px;line-height:1.6;margin:0}.game-mode-introduction{width:100%;background:hsla(0,0%,100%,.06);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:16px;padding:32px;margin-bottom:32px;border:1px solid hsla(0,0%,100%,.12)}.mode-container{max-width:1200px;margin:0 auto}.modes-section h3{color:#fff;font-size:24px;font-weight:700;margin-bottom:20px;display:flex;align-items:center;gap:12px;justify-content:center}.modes-section h3 i{color:gold;font-size:20px}.modes-grid{display:grid;grid-template-columns:repeat(4,1fr);grid-gap:20px;gap:20px}.mode-card{background:hsla(0,0%,100%,.1);border:1px solid hsla(0,0%,100%,.2);border-radius:12px;padding:24px;text-align:center;position:relative;overflow:hidden}.mode-card:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,hsla(0,0%,100%,.1),transparent);transition:left .6s ease}.mode-card:hover:before{left:100%}.mode-card:hover{background:hsla(0,0%,100%,.15);transform:translateY(-6px) scale(1.02);box-shadow:0 12px 24px rgba(0,0,0,.2)}.mode-card i{font-size:40px;color:gold;margin-bottom:16px;display:block}.mode-card h4,.mode-card i{position:relative;z-index:1}.mode-card h4{color:#fff;font-size:18px;font-weight:600;margin:0 0 12px}.mode-card p{color:hsla(0,0%,100%,.85);font-size:14px;margin:0;line-height:1.5;position:relative;z-index:1}@media (max-width:1024px){.features-grid,.modes-grid{grid-template-columns:repeat(2,1fr);gap:16px}}@media (max-width:768px){.feature-introduction,.game-mode-introduction,.sudoku-strategy{padding:20px 16px;margin-bottom:20px;width:100%;max-width:100%}.feature-container,.mode-container,.strategy-container{max-width:100%;margin:0;padding:0}.main-function-area{padding:20px 16px;margin-bottom:20px;width:100%;max-width:100%}.main-function-container{grid-template-columns:1fr;gap:20px;max-width:100%;margin:0}.stats-grid{grid-template-columns:1fr 1fr;gap:12px}.quick-actions{flex-direction:column;gap:12px}.features-grid,.modes-grid{grid-template-columns:1fr;gap:16px;max-width:100%;margin:0 auto}.feature-card,.mode-card{padding:20px;max-width:100%;margin:0 auto}.feature-card i,.mode-card i{font-size:28px}.feature-card h4,.mode-card h4{font-size:16px}.feature-card p,.mode-card p{font-size:13px}.features-section h3,.modes-section h3{font-size:20px;flex-direction:column;gap:8px}.strategy-title{font-size:24px;flex-direction:column;gap:8px}.techniques-grid{grid-template-columns:1fr;gap:16px}.step-item,.technique-card{flex-direction:column;align-items:center;text-align:center;gap:12px}.tips-grid{grid-template-columns:1fr;gap:16px}.strategy-cta{padding:24px 16px;text-align:center}}@media (max-width:480px){.feature-introduction,.game-mode-introduction,.main-function-area,.sudoku-strategy{padding:16px 12px;margin-bottom:16px}.main-function-area{border-radius:0}.main-function-container{gap:16px;width:95%}.stats-grid{grid-template-columns:1fr 1fr;gap:8px}.quick-actions{gap:8px}.features-grid,.modes-grid{gap:12px}.feature-card,.mode-card{padding:16px 12px}.feature-card i,.mode-card i{font-size:24px}.feature-card h4,.mode-card h4{font-size:14px}.feature-card p,.mode-card p{font-size:12px}.features-section h3,.modes-section h3{font-size:18px}.strategy-title{font-size:20px}.step-item,.technique-card{padding:16px 12px;gap:8px}.tips-grid{gap:12px}.tip-card{padding:16px 12px}.strategy-cta{padding:20px 12px}.cta-button{padding:12px 24px;font-size:14px}}@media (max-width:360px){.feature-introduction,.game-mode-introduction,.main-function-area,.sudoku-strategy{padding:12px 8px;margin-bottom:12px}.stats-grid{gap:6px}.features-grid,.modes-grid{gap:8px}.feature-card,.mode-card,.step-item,.technique-card,.tip-card{padding:12px 8px}.strategy-cta{padding:16px 8px}}.cell{width:100%;height:100%;background:#fff;border:2px solid #dee2e6;display:flex;align-items:center;justify-content:center;cursor:pointer;transition:all .3s ease;position:relative;-webkit-user-select:none;-moz-user-select:none;user-select:none;border-radius:4px}.cell:hover{background:#f8f9fa;border-color:#adb5bd;transform:scale(1.02)}.cell.given{font-weight:700;color:#2e7d32}.cell.given .cell-value{text-shadow:0 1px 2px rgba(46,125,50,.2)}.cell.selected{background:linear-gradient(135deg,#e3f2fd,#bbdefb);border:2px solid #2196f3;z-index:10;transform:scale(1.05)}.cell.highlighted{background-color:#f0f0f0;border-color:#969696}.cell.conflict{background:linear-gradient(135deg,#fff3e0,#f44336);border-color:#f44336;z-index:2}.cell.wrong{background:linear-gradient(135deg,#fff3e0,#ffcc02);border-color:#ff9800;color:#e65100;z-index:2}.cell-value{font-size:22px;font-weight:700;font-family:Roboto Mono,monospace;color:#495057;line-height:1;text-shadow:0 1px 2px rgba(0,0,0,.1)}.cell.border-top{border-top:2px solid #343a40}.cell.border-bottom{border-bottom:2px solid #343a40}.cell.border-left{border-left:2px solid #343a40}.cell.border-right{border-right:2px solid #343a40}@media (min-width:1200px){.cell{border-radius:6px}.cell-value{font-size:24px}.cell.border-bottom,.cell.border-left,.cell.border-right,.cell.border-top{border-width:2px}}@media (max-width:1199px) and (min-width:769px){.cell-value{font-size:20px}}@media (max-width:768px){.cell{border-radius:3px}.cell-value{font-size:18px}.cell.border-bottom,.cell.border-left,.cell.border-right,.cell.border-top{border-width:2px}.cell:hover{transform:scale(1.01)}.cell.selected{transform:scale(1.03)}}@media (max-width:480px){.cell-value{font-size:16px}}@media (max-width:360px){.cell-value{font-size:15px}}@media (prefers-contrast:high){.cell{border:2px solid #000;background:#fff}.cell.given{background:#f0f0f0;color:#000}.cell.selected{background:#ff0;border-color:#000}.cell.border-bottom,.cell.border-left,.cell.border-right,.cell.border-top{border-color:#000;border-width:6px}}@media (prefers-reduced-motion:reduce){.cell,.cell.selected,.cell:hover{transition:none;transform:none;animation:none}}@media (hover:none) and (pointer:coarse){.cell:hover{background:#fff;border-color:#dee2e6;transform:none;box-shadow:0 1px 3px rgba(0,0,0,.1)}.cell:active{background:#e9ecef;transform:scale(.98);box-shadow:0 1px 2px rgba(0,0,0,.1)}}.difficulty-selector{max-width:100%;margin:0;padding:0}.selector-header{text-align:left;margin-bottom:12px}.selector-header h2{font-size:20px;font-weight:700;color:#212529;margin-bottom:4px;background:linear-gradient(135deg,#667eea,#764ba2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;text-shadow:0 2px 4px rgba(0,0,0,.1);line-height:1.2}.selector-header p{font-size:12px;color:#6c757d;margin:0;font-weight:400;line-height:1.3}.difficulty-grid{display:grid;grid-template-columns:repeat(3,1fr);grid-gap:8px;gap:8px;margin-bottom:12px}.difficulty-card{background:linear-gradient(135deg,#fff,#f8f9fa);border:2px solid #dee2e6;border-radius:8px;padding:10px;cursor:pointer;transition:all .3s ease;position:relative;overflow:hidden;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);box-shadow:0 2px 12px rgba(0,0,0,.08);min-height:85px;display:flex;flex-direction:column;justify-content:center;text-align:center;animation:fadeInUp .6s ease-out forwards;opacity:0;transform:translateY(20px)}.difficulty-card:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,hsla(0,0%,100%,.4),transparent);transition:left .5s ease}.difficulty-card:hover:before{left:100%}.difficulty-card:hover:not(.selected){transform:translateY(-4px) scale(1.01);border-color:var(--accent-color);box-shadow:0 8px 25px rgba(0,0,0,.12)}.difficulty-card:active{transform:translateY(-2px) scale(1.005)}.difficulty-card.easy{--accent-color:#28a745}.difficulty-card.medium{--accent-color:#ffc107}.difficulty-card.hard{--accent-color:#fd7e14}.difficulty-card.extreme{--accent-color:#dc3545}.difficulty-card.nightmare{--accent-color:#6f42c1}.difficulty-card.diabolical{--accent-color:#000}.difficulty-card.selected{border-color:var(--accent-color)!important}.difficulty-card.selected,.difficulty-card.selected:hover{box-shadow:0 0 0 3px rgba(var(--accent-color),.3)!important;transform:translateY(0)!important}.difficulty-card.selected .difficulty-icon{animation:selectedIconPulse 2s ease-in-out infinite}.difficulty-icon{width:32px;height:32px;border-radius:50%;background:linear-gradient(135deg,var(--accent-color),hsla(0,0%,100%,.2));display:flex;align-items:center;justify-content:center;margin:0 auto 8px;box-shadow:0 2px 8px rgba(0,0,0,.2);position:relative;overflow:hidden;flex-shrink:0}.difficulty-icon:before{content:"";position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:linear-gradient(45deg,transparent,hsla(0,0%,100%,.3),transparent);transform:rotate(45deg);animation:iconShine 3s ease-in-out infinite}.difficulty-icon i{font-size:14px;color:#fff;text-shadow:0 1px 3px rgba(0,0,0,.3);z-index:1}.difficulty-info{flex:1 1;display:flex;flex-direction:column;justify-content:center}.difficulty-info h3{font-size:14px;font-weight:700;color:#212529;margin-bottom:4px;line-height:1.2}.difficulty-desc{color:#6c757d;margin-bottom:4px;font-size:11px;line-height:1.2;display:-webkit-box;-webkit-line-clamp:1;-webkit-box-orient:vertical;overflow:hidden}.difficulty-clues{color:var(--accent-color);font-weight:600;font-size:10px;margin:0}.difficulty-indicator{position:absolute;top:8px;right:8px;color:var(--accent-color);font-size:16px}.variant-section{margin:12px 0;background:hsla(0,0%,100%,.95);border-radius:12px;padding:16px;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.variant-section h3{font-size:16px;font-weight:700;color:#fff;margin-bottom:12px;text-align:center;background:linear-gradient(135deg,#667eea,#764ba2);padding:8px;border-radius:8px}.variant-grid{display:flex;flex-direction:row;gap:12px}.variant-card{background:linear-gradient(135deg,#f8f9fa,#fff);border:1px solid #dee2e6;border-radius:8px;padding:12px;display:flex;align-items:center;flex:1 1;transition:all .3s ease;cursor:pointer}.variant-card:hover{transform:translateY(-2px);box-shadow:0 4px 12px rgba(0,0,0,.1);border-color:#667eea}.variant-card i{font-size:18px;color:#667eea;width:24px;text-align:center}.variant-card h4{font-size:14px;font-weight:600;color:#212529;margin-bottom:2px}.variant-card p{font-size:12px;color:#6c757d;margin:0}.start-section{display:flex;flex-direction:column;gap:16px;margin-top:16px}.start-btn{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;border-radius:12px;padding:14px 24px;font-size:16px;font-weight:700;cursor:pointer;transition:all .3s ease;display:flex;align-items:center;justify-content:center;gap:8px;position:relative;overflow:hidden;box-shadow:0 4px 15px rgba(102,126,234,.4);text-transform:uppercase;letter-spacing:1px}.start-btn:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,hsla(0,0%,100%,.2),transparent);transition:left .5s ease}.start-btn:hover:before{left:100%}.start-btn:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(102,126,234,.6)}.start-btn:active{transform:translateY(0)}.start-btn i{animation:playPulse 2s ease-in-out infinite}.tips{background:linear-gradient(135deg,#ffeaa7,#fdcb6e);border-radius:12px;padding:16px;position:relative;overflow:hidden;border:2px solid #fdcb6e}.tips:before{content:"";position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle,hsla(0,0%,100%,.1) 1px,transparent 0),radial-gradient(circle,hsla(0,0%,100%,.05) 1px,transparent 0);background-size:20px 20px,40px 40px;animation:sparkle 4s linear infinite;pointer-events:none}.tips h4{font-size:14px;font-weight:700;color:#8b6914;margin-bottom:8px;display:flex;align-items:center;gap:6px}.tips h4 i{animation:lightbulbGlow 2s ease-in-out infinite}.tips ul{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:1fr;grid-gap:4px;gap:4px}.tips li{font-size:12px;color:#8b6914;position:relative;padding:4px 0 4px 16px;transition:all .3s ease}.tips li:before{content:"⭐";position:absolute;left:0;animation:sparkle 3s ease-in-out infinite}.tips li:nth-child(2):before{animation-delay:.5s}.tips li:nth-child(3):before{animation-delay:1s}.tips li:nth-child(4):before{animation-delay:1.5s}.tips li:hover{transform:translateX(4px);color:#6c5914}@keyframes fadeInUp{0%{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}@keyframes iconShine{0%,to{transform:rotate(45deg) translateX(-200%)}50%{transform:rotate(45deg) translateX(200%)}}@keyframes playPulse{0%,to{transform:scale(1)}50%{transform:scale(1.1)}}@keyframes lightbulbGlow{0%,to{color:#f39c12;text-shadow:0 0 5px #f39c12}50%{color:#e67e22;text-shadow:0 0 10px #e67e22}}@keyframes sparkle{0%,to{opacity:.8;transform:scale(1)}50%{opacity:1;transform:scale(1.2)}}.difficulty-card:first-child{animation-delay:.1s}.difficulty-card:nth-child(2){animation-delay:.2s}.difficulty-card:nth-child(3){animation-delay:.3s}.difficulty-card:nth-child(4){animation-delay:.4s}.difficulty-card:nth-child(5){animation-delay:.5s}.difficulty-card:nth-child(6){animation-delay:.6s}@media (max-width:768px){.difficulty-grid{grid-template-columns:repeat(2,1fr);gap:8px}.difficulty-card{min-height:80px;padding:10px}.difficulty-icon{width:24px;height:24px;margin-bottom:6px}.difficulty-info h3{font-size:12px}.difficulty-desc{font-size:10px}.difficulty-clues{font-size:9px}.variant-grid{grid-template-columns:1fr}.variant-card{padding:10px}.variant-card i{font-size:16px}.variant-card h4{font-size:13px}.variant-card p{font-size:11px}.start-btn{padding:12px 20px;font-size:14px}.tips{padding:12px}.tips h4{font-size:13px}.tips li{font-size:11px}}@media (max-width:480px){.selector-header h2{font-size:18px}.selector-header p{font-size:11px}.difficulty-card{min-height:75px;padding:8px}.difficulty-icon{width:20px;height:20px}.difficulty-icon i{font-size:12px}.difficulty-info h3{font-size:11px}.difficulty-desc{font-size:9px}.difficulty-clues{font-size:8px}.variant-section{margin:12px 0;padding:12px}.variant-section h3{font-size:14px}.start-btn{padding:10px 16px;font-size:13px}.start-btn i{font-size:12px}}@media (min-width:1200px){.difficulty-grid{grid-template-columns:repeat(4,1fr);gap:12px}.difficulty-card{min-height:100px;padding:16px}.difficulty-info h3{font-size:16px}.difficulty-desc{font-size:12px}}.game-board{max-width:calc(100vh * .9);position:relative;background:linear-gradient(135deg,#f8f9fa,#e9ecef);box-shadow:0 12px 40px rgba(0,0,0,.15);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.game-board.paused{filter:blur(8px)}.pause-overlay{top:50%;left:50%;transform:translate(-50%,-50%);z-index:100;gap:12px;color:#495057;font-size:24px;pointer-events:none;background:hsla(0,0%,100%,.9);padding:24px 32px;border-radius:16px}.pause-overlay i{color:#6c757d}.sudoku-grid{padding:12px;background:#343a40;border-radius:16px;box-shadow:inset 0 2px 8px rgba(0,0,0,.3),0 4px 20px rgba(0,0,0,.1)}.sudoku-grid,.sudoku-row{grid-gap:3px;gap:3px}.sudoku-row:nth-child(3n):not(:last-child){margin-bottom:6px}.sudoku-row .cell:nth-child(3n):not(:last-child){margin-right:6px}.number-input{width:100%;max-width:50px;background:hsla(0,0%,100%,.5);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.number-btn{margin:5px 0;border-radius:16px;font-size:22px;transition:all .3s ease;box-shadow:0 2px 8px rgba(0,0,0,.1)}.number-btn:before{transition:left .5s ease}.number-btn:hover:not(:disabled){transform:translateY(-3px);box-shadow:0 6px 20px rgba(33,150,243,.4)}.number-btn:active:not(:disabled){transform:translateY(-1px);box-shadow:0 3px 10px rgba(33,150,243,.3)}@keyframes pulse{0%,to{transform:scale(1)}50%{transform:scale(1.05)}}@keyframes selectedPulse{0%,to{box-shadow:0 0 0 3px rgba(var(--accent-color),.3);transform:translateY(0) scale(1)}50%{box-shadow:0 0 0 6px rgba(var(--accent-color),.2);transform:translateY(0) scale(1.02)}}@keyframes selectedIconPulse{0%,to{transform:scale(1);box-shadow:0 2px 8px rgba(0,0,0,.2)}50%{transform:scale(1.1);box-shadow:0 4px 16px rgba(0,0,0,.3)}}.timer{background:linear-gradient(135deg,#667eea,#764ba2);border-radius:16px;padding:20px;display:flex;align-items:center;gap:16px;color:#fff;box-shadow:0 8px 32px rgba(102,126,234,.3);border:1px solid hsla(0,0%,100%,.2);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);position:relative;overflow:hidden}.timer:before{content:"";position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle,hsla(0,0%,100%,.1) 1px,transparent 0);background-size:20px 20px;animation:sparkleFloat 8s linear infinite;pointer-events:none}.timer-icon{flex-shrink:0;width:32px;height:32px;background:hsla(0,0%,100%,.2);border-radius:50%;display:flex;align-items:center;justify-content:center;border:2px solid hsla(0,0%,100%,.3);position:relative;z-index:1}.timer-icon i{font-size:20px;color:#fff;text-shadow:0 1px 3px rgba(0,0,0,.3);animation:timerPulse 2s ease-in-out infinite}.timer-content{flex:1 1;position:relative;z-index:1}.timer-text{font-size:28px;font-weight:700;font-family:Roboto Mono,monospace;color:#fff;text-shadow:0 2px 4px rgba(0,0,0,.3);line-height:1}.timer-label{font-size:14px;color:hsla(0,0%,100%,.9);font-weight:500;text-transform:uppercase;letter-spacing:1px}.game-controls{background:hsla(0,0%,100%,.95);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-radius:16px;padding:24px;box-shadow:0 8px 32px rgba(0,0,0,.1);border:1px solid hsla(0,0%,100%,.2)}.controls-title{font-size:18px;font-weight:700;color:#212529;margin-bottom:20px;display:flex;align-items:center;gap:10px}.controls-title,.controls-title i{background:linear-gradient(135deg,#667eea,#764ba2);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.controls-title i{font-size:16px}.control-buttons{display:flex;flex-direction:column;gap:12px;margin-bottom:24px}.control-btn{display:flex;align-items:center;justify-content:center;gap:10px;padding:14px 20px;border:none;border-radius:12px;font-size:14px;font-weight:600;cursor:pointer;transition:all .3s ease;position:relative;overflow:hidden;text-transform:uppercase;letter-spacing:.5px}.control-btn:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,hsla(0,0%,100%,.2),transparent);transition:left .5s ease}.control-btn:hover:not(:disabled):before{left:100%}.pause-btn{background:linear-gradient(135deg,#ffc107,#ffb300);color:#8b6914;box-shadow:0 4px 15px rgba(255,193,7,.3)}.pause-btn:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 20px rgba(255,193,7,.4)}.reset-btn{background:linear-gradient(135deg,#dc3545,#c82333);color:#fff;box-shadow:0 4px 15px rgba(220,53,69,.3)}.reset-btn:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 20px rgba(220,53,69,.4)}.menu-btn{background:linear-gradient(135deg,#6c757d,#5a6268);color:#fff;box-shadow:0 4px 15px hsla(208,7%,46%,.3)}.menu-btn:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 6px 20px hsla(208,7%,46%,.4)}.control-btn:disabled{opacity:.6;cursor:not-allowed;transform:none!important;box-shadow:none!important}.control-btn i{font-size:16px}.control-tips{background:linear-gradient(135deg,#f8f9fa,#e9ecef);border-radius:12px;padding:16px;border:1px solid #dee2e6}.control-tips h4{font-size:14px;font-weight:700;color:#495057;margin-bottom:12px;display:flex;align-items:center;gap:8px}.control-tips h4 i{color:#667eea;font-size:12px}.tips-list{display:flex;flex-direction:column;gap:8px}.tip-item{display:flex;align-items:center;justify-content:space-between;gap:12px;font-size:12px;color:#6c757d;padding:4px 0}.tip-item kbd{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;padding:2px 6px;border-radius:4px;font-size:11px;font-weight:600;box-shadow:0 2px 4px rgba(102,126,234,.3);min-width:32px;text-align:center}.tip-item span{flex:1 1;text-align:right}.hint-system{background:hsla(0,0%,100%,.95);-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border-radius:16px;padding:24px;box-shadow:0 8px 32px rgba(0,0,0,.1);border:1px solid hsla(0,0%,100%,.2)}.hint-header h3{font-size:18px;font-weight:700;color:#212529;margin-bottom:20px;display:flex;align-items:center;gap:10px;background:linear-gradient(135deg,#667eea,#764ba2);-webkit-background-clip:text;background-clip:text}.hint-header h3,.hint-header h3 i{-webkit-text-fill-color:transparent}.hint-header h3 i{background:linear-gradient(135deg,#ffc107,#ffb300);-webkit-background-clip:text;background-clip:text;font-size:16px;animation:lightbulbGlow 2s ease-in-out infinite}.selected-cell-info{background:linear-gradient(135deg,#e3f2fd,#f3e5f5);border-radius:12px;padding:16px;margin-bottom:16px;border:1px solid rgba(102,126,234,.2)}.cell-position{font-size:14px;font-weight:600;color:#495057;margin-bottom:12px;text-align:center}.candidates-label{font-size:12px;color:#6c757d;font-weight:600;margin-bottom:8px;text-transform:uppercase;letter-spacing:.5px}.candidates-grid{display:flex;flex-wrap:wrap;gap:6px;justify-content:center}.candidate-number{display:inline-flex;align-items:center;justify-content:center;width:32px;height:32px;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border-radius:8px;font-size:14px;font-weight:700;font-family:Roboto Mono,monospace;box-shadow:0 2px 8px rgba(102,126,234,.3);transition:all .3s ease}.candidate-number:hover{transform:scale(1.1);box-shadow:0 4px 12px rgba(102,126,234,.4)}.no-candidates{color:#dc3545;font-size:12px;font-style:italic;text-align:center;padding:8px}.smart-hint{background:linear-gradient(135deg,#fff3cd,#ffeaa7);border-radius:12px;padding:16px;margin-bottom:16px;border:1px solid gold;position:relative;overflow:hidden}.smart-hint:before{content:"";position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle,rgba(255,215,0,.1) 1px,transparent 0);background-size:15px 15px;animation:sparkleFloat 6s linear infinite;pointer-events:none}.hint-type{font-size:14px;font-weight:700;color:#8b6914;text-transform:uppercase;letter-spacing:.5px}.hint-description,.hint-type{margin-bottom:8px;position:relative;z-index:1}.hint-description{font-size:13px;color:#856404;line-height:1.4}.hint-suggestion{font-size:13px;font-weight:600;color:#8b6914;background:hsla(0,0%,100%,.6);padding:8px 12px;border-radius:8px;border:1px solid rgba(255,215,0,.3);position:relative;z-index:1}.no-selection{text-align:center;padding:32px 16px;color:#6c757d}.no-selection i{font-size:48px;color:#dee2e6;margin-bottom:16px;animation:bounceGentle 2s ease-in-out infinite}.no-selection p{font-size:14px;margin:0;font-style:italic}.difficulty-analysis{background:linear-gradient(135deg,#f8f9fa,#e9ecef);border-radius:12px;padding:16px;border:1px solid #dee2e6}.difficulty-analysis h4{font-size:14px;font-weight:700;color:#495057;margin-bottom:12px;text-align:center}.analysis-stats{display:flex;flex-direction:column;gap:8px}.stat-row{display:flex;justify-content:space-between;align-items:center;font-size:12px;padding:4px 0;border-bottom:1px solid rgba(0,0,0,.1)}.stat-row:last-child{border-bottom:none}.stat-row span:first-child{color:#6c757d;font-weight:500}.stat-row span:last-child{color:#495057;font-weight:700;font-family:Roboto Mono,monospace}@keyframes sparkleFloat{0%{transform:translateX(-50%) translateY(-50%) rotate(0deg)}to{transform:translateX(-50%) translateY(-50%) rotate(1turn)}}@keyframes timerPulse{0%,to{transform:scale(1);opacity:1}50%{transform:scale(1.1);opacity:.8}}@keyframes bounceGentle{0%,to{transform:translateY(0)}50%{transform:translateY(-8px)}}@media (min-width:1200px){.game-sidebar{max-width:380px;gap:24px}.timer{padding:24px}.timer-text{font-size:28px}.game-controls,.hint-system{padding:28px}}@media (max-width:1199px) and (min-width:769px){.game-sidebar{width:100%;max-width:100%;display:grid;grid-template-columns:1fr 1fr;grid-gap:20px;gap:20px;position:static;max-height:none}.hint-system{grid-column:1/-1}}@media (max-width:768px){.game-sidebar{width:100%;max-width:100%;display:flex;gap:16px;position:static;max-height:none}.game-sidebar,.timer{flex-direction:column}.timer{padding:16px;text-align:center;gap:12px}.timer-icon{width:40px;height:40px}.timer-icon i{font-size:16px}.timer-text{font-size:28px}.timer-label{font-size:12px}.game-controls{padding:20px}.controls-title{font-size:16px;margin-bottom:16px}.control-buttons{gap:10px;margin-bottom:20px}.control-btn{padding:12px 16px;font-size:13px}.control-btn i{font-size:14px}.control-tips{padding:14px}.tip-item{font-size:11px}.tip-item kbd{font-size:10px;padding:1px 4px;min-width:28px}.hint-system{padding:20px}.hint-header h3{font-size:16px;margin-bottom:16px}.selected-cell-info{padding:14px;margin-bottom:14px}.candidates-grid{gap:4px}.candidate-number{width:28px;height:28px;font-size:12px}.smart-hint{margin-bottom:14px}.difficulty-analysis,.smart-hint{padding:14px}}@media (max-width:480px){.game-sidebar{gap:12px}.timer{padding:12px;gap:8px}.timer-icon{width:32px;height:32px}.timer-icon i{font-size:14px}.timer-text{font-size:24px}.timer-label{font-size:11px}.game-controls{padding:16px}.controls-title{font-size:15px;margin-bottom:12px}.control-buttons{gap:8px;margin-bottom:16px}.control-btn{padding:10px 12px}.control-btn,.control-btn i{font-size:12px}.hint-system{padding:16px}.hint-header h3{font-size:15px;margin-bottom:12px}.candidate-number{width:24px;height:24px;font-size:11px}}@media (prefers-color-scheme:dark){.game-controls{background:rgba(0,0,0,.3);color:#ecf0f1}.controls-title,.hint-system{color:#ecf0f1}.hint-system{background:rgba(0,0,0,.3)}.hint-header h3{color:#ecf0f1}.selected-cell-info{background:rgba(0,0,0,.2);border-color:rgba(102,126,234,.3)}.control-tips,.difficulty-analysis{background:rgba(0,0,0,.2);border-color:#4a5568}.smart-hint{background:rgba(255,215,0,.1);border-color:rgba(255,215,0,.3)}}.language-selector{position:relative;z-index:10001;isolation:isolate}.language-button{display:flex;align-items:center;gap:8px;padding:8px 12px;background:linear-gradient(135deg,hsla(0,0%,100%,.15),hsla(0,0%,100%,.05));backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border:1px solid hsla(0,0%,100%,.2);border-radius:12px;color:#fff;font-size:14px;font-weight:500;cursor:pointer;transition:all .3s ease;min-width:100px;box-shadow:0 4px 15px rgba(0,0,0,.1);position:relative;overflow:hidden}.language-button:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,hsla(0,0%,100%,.2),transparent);transition:left .5s ease}.language-button:hover:before{left:100%}.language-button:hover{background:linear-gradient(135deg,hsla(0,0%,100%,.25),hsla(0,0%,100%,.15));border-color:hsla(0,0%,100%,.3);transform:translateY(-1px);box-shadow:0 6px 20px rgba(0,0,0,.15)}.language-button:focus{outline:2px solid hsla(0,0%,100%,.5);outline-offset:2px}.language-button:active{transform:translateY(0);box-shadow:0 2px 8px rgba(0,0,0,.1)}.language-flag{font-size:18px;line-height:1;filter:drop-shadow(0 1px 2px rgba(0,0,0,.2))}.language-name{font-weight:600;text-shadow:0 1px 2px rgba(0,0,0,.1);flex:1 1}.language-button i{font-size:12px;color:hsla(0,0%,100%,.8);transition:transform .3s ease}.language-button[aria-expanded=true] i{transform:rotate(180deg)}.language-dropdown{position:absolute;top:calc(100% + 8px);right:0;min-width:200px;background:linear-gradient(135deg,hsla(0,0%,100%,.95),rgba(248,249,250,.95));backdrop-filter:blur(20px);-webkit-backdrop-filter:blur(20px);border:1px solid hsla(0,0%,100%,.2);border-radius:16px;box-shadow:0 12px 40px rgba(0,0,0,.15);z-index:10002;animation:languageDropdownSlideIn .3s ease-out;overflow:hidden}.language-dropdown-header{display:flex;align-items:center;gap:8px;padding:12px 16px;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;font-size:14px;font-weight:600;text-shadow:0 1px 2px rgba(0,0,0,.1)}.language-dropdown-header i{font-size:16px;color:hsla(0,0%,100%,.9)}.language-options{padding:8px 0;max-height:300px}.language-options::-webkit-scrollbar{width:6px}.language-options::-webkit-scrollbar-track{background:transparent}.language-options::-webkit-scrollbar-thumb{background:rgba(102,126,234,.3);border-radius:3px}.language-options::-webkit-scrollbar-thumb:hover{background:rgba(102,126,234,.5)}.language-option{display:flex;align-items:center;gap:12px;width:100%;padding:12px 16px;border:none;background:transparent;color:#495057;font-size:14px;font-weight:500;text-align:left;cursor:pointer;transition:all .2s ease;position:relative;overflow:hidden}.language-option:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(102,126,234,.1),transparent);transition:left .3s ease}.language-option:hover:before{left:100%}.language-option:hover{background:linear-gradient(135deg,rgba(102,126,234,.08),rgba(118,75,162,.08));color:#667eea;transform:translateX(4px)}.language-option:focus{outline:none;background:linear-gradient(135deg,rgba(102,126,234,.12),rgba(118,75,162,.12));color:#667eea}.language-option.active{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;font-weight:600}.language-option.active:hover{background:linear-gradient(135deg,#5a6fd8,#6a4190);transform:translateX(0)}.language-option .language-flag{font-size:20px;filter:drop-shadow(0 1px 3px rgba(0,0,0,.1))}.language-option .language-name{flex:1 1}.language-option i.fa-check{color:hsla(0,0%,100%,.9);font-size:12px}.language-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.2);backdrop-filter:blur(2px);-webkit-backdrop-filter:blur(2px);z-index:10000;animation:languageOverlayFadeIn .3s ease-out}@keyframes languageDropdownSlideIn{0%{opacity:0;transform:translateY(-10px) scale(.95)}to{opacity:1;transform:translateY(0) scale(1)}}@keyframes languageOverlayFadeIn{0%{opacity:0}to{opacity:1}}@media (min-width:1200px){.language-button{padding:10px 16px;font-size:15px;min-width:120px}.language-dropdown{min-width:220px}.language-option{padding:14px 20px;font-size:15px}.language-flag{font-size:20px}.language-option .language-flag{font-size:22px}}@media (max-width:768px){.language-button{padding:6px 10px;font-size:13px;min-width:80px;border-radius:10px}.language-flag{font-size:16px}.language-name{display:none}.language-dropdown{right:-8px;min-width:180px;border-radius:12px}.language-dropdown-header,.language-option{padding:10px 14px;font-size:13px}.language-option .language-flag{font-size:18px}.language-overlay{backdrop-filter:blur(5px);-webkit-backdrop-filter:blur(5px);background:rgba(0,0,0,.3)}}@media (max-width:480px){.language-button{padding:4px 8px;font-size:12px;min-width:60px;border-radius:8px}.language-button i{font-size:10px}.language-flag{font-size:14px}.language-dropdown{right:-12px;min-width:160px;top:calc(100% + 4px)}.language-dropdown-header{padding:8px 12px;font-size:12px}.language-dropdown-header i{font-size:14px}.language-option{padding:8px 12px;font-size:12px}.language-option .language-flag{font-size:16px}}@media (prefers-color-scheme:dark){.language-button{background:linear-gradient(135deg,rgba(0,0,0,.3),rgba(0,0,0,.2));border-color:hsla(0,0%,100%,.15);color:#ecf0f1}.language-button:hover{background:linear-gradient(135deg,rgba(0,0,0,.4),rgba(0,0,0,.3));border-color:hsla(0,0%,100%,.25)}.language-dropdown{background:linear-gradient(135deg,rgba(44,62,80,.95),rgba(52,73,94,.95));border-color:hsla(0,0%,100%,.1)}.language-option{color:#bdc3c7}.language-option:hover{background:linear-gradient(135deg,rgba(102,126,234,.2),rgba(118,75,162,.2));color:#ecf0f1}.language-overlay{background:rgba(0,0,0,.4)}}@media (prefers-contrast:high){.language-button{background:#fff;border:2px solid #000;color:#000}.language-button:hover{background:#f0f0f0}.language-dropdown{background:#fff;border:2px solid #000}.language-dropdown-header{background:#000;color:#fff}.language-option{color:#000}.language-option:hover{background:#e0e0e0}.language-option.active{background:#000;color:#fff}}@media (prefers-reduced-motion:reduce){.language-button,.language-dropdown,.language-option{transition:none;animation:none}.language-button:before,.language-option:before{display:none}.language-button i{transition:none}}.sudoku-strategy{width:100%;background:hsla(0,0%,100%,.05);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-radius:16px;padding:40px;border:1px solid hsla(0,0%,100%,.1)}.strategy-container{max-width:1200px;margin:0 auto}.strategy-header{text-align:center;margin-bottom:40px}.strategy-title{color:#fff;font-size:32px;font-weight:700;margin-bottom:12px;display:flex;align-items:center;justify-content:center;gap:16px}.strategy-title i{color:gold;font-size:28px}.strategy-subtitle{color:hsla(0,0%,100%,.9);font-size:18px;margin:0;font-weight:400}.strategy-content{display:flex;flex-direction:column;gap:40px}.pro-tips h3,.solving-steps h3,.techniques-section h3{color:#fff;font-size:24px;font-weight:700;margin-bottom:24px;display:flex;align-items:center;gap:12px}.pro-tips h3 i,.solving-steps h3 i,.techniques-section h3 i{color:gold;font-size:20px}.techniques-grid{display:grid;grid-template-columns:1fr 1fr;grid-gap:20px;gap:20px}.technique-card{background:hsla(0,0%,100%,.08);border-radius:12px;padding:20px;border:1px solid hsla(0,0%,100%,.15);display:flex;gap:16px;align-items:flex-start;transition:all .3s ease}.technique-card:hover{background:hsla(0,0%,100%,.12);transform:translateY(-2px)}.technique-icon{flex-shrink:0;width:48px;height:48px;background:rgba(255,215,0,.2);border-radius:50%;display:flex;align-items:center;justify-content:center;border:2px solid rgba(255,215,0,.3)}.technique-icon i{color:gold;font-size:20px}.technique-content h4{color:#fff;font-size:16px;font-weight:600;margin-bottom:8px}.technique-content p{color:hsla(0,0%,100%,.8);font-size:14px;line-height:1.6;margin:0}.steps-list{display:flex;flex-direction:column;gap:20px}.step-item{display:flex;gap:20px;align-items:flex-start;background:hsla(0,0%,100%,.08);border-radius:12px;padding:20px;border:1px solid hsla(0,0%,100%,.15);transition:all .3s ease}.step-item:hover{background:hsla(0,0%,100%,.12)}.step-number{flex-shrink:0;width:32px;height:32px;background:linear-gradient(135deg,gold,#ffed4e);color:#8b6914;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:16px}.step-content h4{color:#fff;font-size:16px;font-weight:600;margin-bottom:8px}.step-content p{color:hsla(0,0%,100%,.8);font-size:14px;line-height:1.6;margin:0}.tips-grid{display:grid;grid-template-columns:repeat(2,1fr);grid-gap:20px;gap:20px}.tip-card{background:hsla(0,0%,100%,.08);border-radius:12px;padding:20px;border:1px solid hsla(0,0%,100%,.15);text-align:center;transition:all .3s ease}.tip-card:hover{background:hsla(0,0%,100%,.12);transform:translateY(-2px)}.tip-card i{font-size:24px;color:gold;margin-bottom:12px;display:block}.tip-card h4{color:#fff;font-size:16px;font-weight:600;margin-bottom:8px}.tip-card p{color:hsla(0,0%,100%,.8);font-size:14px;line-height:1.6;margin:0}.strategy-cta{text-align:center;background:hsla(0,0%,100%,.1);border-radius:16px;padding:32px;border:1px solid hsla(0,0%,100%,.2)}.strategy-cta h3{color:#fff;font-size:24px;font-weight:700;margin-bottom:12px}.strategy-cta p{color:hsla(0,0%,100%,.9);font-size:16px;margin-bottom:24px}.cta-button{background:linear-gradient(135deg,#ff6b6b,#ee5a52);color:#fff;border:none;border-radius:12px;padding:16px 32px;font-size:16px;font-weight:600;cursor:pointer;transition:all .3s ease;display:inline-flex;align-items:center;gap:12px;box-shadow:0 4px 16px hsla(0,100%,71%,.3)}.cta-button:hover{transform:translateY(-2px);box-shadow:0 8px 24px hsla(0,100%,71%,.4)}.cta-button i{font-size:18px}.skip-link{position:absolute;top:-40px;left:6px;background:#000;color:#fff;padding:8px;z-index:1000;text-decoration:none;border-radius:4px;font-weight:600}.skip-link:focus{top:6px}.visually-hidden{position:absolute!important;clip:rect(1px,1px,1px,1px)!important;padding:0!important;border:0!important;height:1px!important;width:1px!important;overflow:hidden!important}.feature-card:focus,.mode-card:focus,.tip-card:focus,button:focus{outline:2px solid gold;outline-offset:2px}h1{font-size:2.5rem;font-weight:700;line-height:1.2}h2{font-size:2rem;line-height:1.3}h2,h3{font-weight:600}h3{font-size:1.5rem;line-height:1.4}h4{font-size:1.25rem;font-weight:500;line-height:1.5}.mode-card{cursor:pointer;transition:all .3s ease}.mode-card:focus,.mode-card:hover{transform:translateY(-4px);box-shadow:0 8px 25px rgba(0,0,0,.2)}.features-grid[role=list],.modes-grid[role=list],.steps-list,.techniques-grid[role=list],.tips-grid[role=list]{list-style:none;padding:0;margin:0}@media (max-width:768px){h1{font-size:2rem}h2{font-size:1.75rem}h3{font-size:1.25rem}h4{font-size:1.1rem}}@media (max-width:480px){h1{font-size:1.75rem}h2{font-size:1.5rem}h3{font-size:1.1rem}}.game-board{display:flex;flex-direction:row;align-items:center;gap:24px;padding:24px;background:hsla(0,0%,100%,.8);border-radius:20px;-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border:1px solid hsla(0,0%,100%,.2);box-shadow:0 8px 32px rgba(0,0,0,.1);width:100%;margin:0 auto}.game-board.paused{pointer-events:none;position:relative}.pause-overlay{position:absolute;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.8);display:flex;flex-direction:column;align-items:center;justify-content:center;color:#fff;font-size:20px;font-weight:600;z-index:1000;border-radius:20px;-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px)}.pause-overlay i{font-size:48px;margin-bottom:16px}.sudoku-grid{display:grid;grid-template-rows:repeat(9,1fr);grid-gap:0;gap:0;border:2px solid #495057;border-radius:12px;overflow:hidden;background:#495057;width:100%;aspect-ratio:1}.sudoku-row{display:grid;grid-template-columns:repeat(9,1fr);grid-gap:0;gap:0}.sudoku-row:nth-child(3n):not(:last-child){border-bottom:2px solid #495057}.sudoku-row .cell:nth-child(3n):not(:last-child){margin-right:3px}.number-input{display:flex;flex-direction:column;gap:8px;max-width:60px;padding:12px;background:hsla(0,0%,100%,.9);border-radius:16px;-webkit-backdrop-filter:blur(20px);backdrop-filter:blur(20px);border:2px solid hsla(0,0%,100%,.3)}.number-btn{width:50px;height:50px;margin:2px 0;border:2px solid #dee2e6;border-radius:12px;background:linear-gradient(135deg,#fff,#f8f9fa);color:#495057;font-size:20px;font-weight:700;font-family:Roboto Mono,monospace;cursor:pointer;transition:all .2s cubic-bezier(.4,0,.2,1);display:flex;align-items:center;justify-content:center;position:relative;overflow:hidden;-webkit-tap-highlight-color:transparent;-webkit-touch-callout:none;-webkit-user-select:none;-moz-user-select:none;user-select:none}.number-btn:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,hsla(0,0%,100%,.4),transparent);transition:left .3s ease}.number-btn:hover:not(:disabled):before{left:100%}.number-btn:hover:not(:disabled){background:linear-gradient(135deg,#e3f2fd,#bbdefb);border-color:#2196f3;transform:translateY(-1px)}.number-btn:active:not(:disabled){transform:translateY(0);background:linear-gradient(135deg,#bbdefb,#90caf9)}.number-btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important}.number-btn.erase-btn{background:linear-gradient(135deg,#ffebee,#ffcdd2);border-color:#f44336;color:#d32f2f}.number-btn.erase-btn:hover:not(:disabled){background:linear-gradient(135deg,#ffcdd2,#ef9a9a);border-color:#d32f2f}.number-btn.erase-btn:active:not(:disabled){background:linear-gradient(135deg,#ef9a9a,#e57373)}@media (max-width:768px){.game-board{gap:16px;padding:16px;margin:0 8px}.sudoku-grid{width:100%}.number-input{flex-direction:row;flex-wrap:wrap;justify-content:center;max-width:100%;width:100%;gap:6px;padding:12px}.number-btn{width:44px;height:44px;font-size:16px;margin:2px;border-radius:10px;touch-action:manipulation}.number-btn:active:not(:disabled){transform:scale(.95);transition:transform .1s ease}}@media (max-width:480px){.game-board{gap:12px;padding:12px;margin:0 4px}.sudoku-grid{border-width:2px}.number-input{gap:4px;padding:8px}.number-btn{width:38px;height:38px;font-size:14px;margin:1px;border-width:1px;border-radius:8px}.number-btn i{font-size:12px}}@media (max-width:360px){.game-board{gap:8px;padding:8px;margin:0 2px}.number-input{gap:3px;padding:6px}.number-btn{width:32px;height:32px;font-size:12px;margin:1px}.number-btn i{font-size:10px}}@media (max-width:768px){.game-container{grid-template-columns:1fr;gap:16px;max-width:100%;width:100%;margin:0;padding:0 8px;max-height:calc(100vh - 120px);overflow-y:auto}.game-board-container{width:100%;display:flex;justify-content:center;margin-bottom:env(keyboard-inset-height,0)}.game-sidebar{width:100%;max-width:100%;display:flex;flex-direction:column;gap:12px;position:static;margin:0;padding-bottom:env(safe-area-inset-bottom,16px)}}@media (max-width:480px){.game-container{gap:12px;padding:0 4px;max-height:calc(100vh - 100px)}.game-board-container{margin-bottom:env(keyboard-inset-height,16px);width:95%}.game-sidebar{gap:8px;padding-bottom:env(safe-area-inset-bottom,12px)}}@media (hover:none) and (pointer:coarse){.number-btn:hover:not(:disabled){background:linear-gradient(135deg,#fff,#f8f9fa);border-color:#dee2e6;transform:none;box-shadow:0 2px 8px rgba(0,0,0,.08)}.number-btn:hover:not(:disabled):before{left:-100%}.number-btn:active:not(:disabled){background:linear-gradient(135deg,#e3f2fd,#bbdefb);border-color:#2196f3;transform:scale(.95);box-shadow:0 2px 12px rgba(33,150,243,.3)}.number-btn.erase-btn:hover:not(:disabled){background:linear-gradient(135deg,#ffebee,#ffcdd2);border-color:#f44336}.number-btn.erase-btn:active:not(:disabled){background:linear-gradient(135deg,#ffcdd2,#ef9a9a);transform:scale(.95)}}@supports (-webkit-touch-callout:none){.game-board{max-height:calc(100vh - env(safe-area-inset-top) - env(safe-area-inset-bottom) - 120px)}.number-btn{-webkit-appearance:none;border-radius:12px}}@media (-webkit-min-device-pixel-ratio:2),(min-resolution:192dpi){.number-btn{border-width:.5px}.sudoku-grid{border-width:1.5px}.sudoku-row:nth-child(3n):not(:last-child){border-bottom-width:1.5px}}@media (min-width:2560px){.app-main{padding:60px 80px;width:100%;max-width:none}.game-container{grid-template-columns:7fr 3fr;gap:60px}.game-board,.game-container{width:100%;max-width:none;margin:0}.game-board{padding:32px;gap:32px}.cell{width:90%;height:90%}.cell-value,.number-btn{font-size:24px}.number-btn{width:60px;height:60px}.game-sidebar{width:100%;max-width:none;gap:32px}.timer{padding:32px}.timer-text{font-size:36px}.game-controls,.hint-system{padding:32px}}@media (min-width:1920px) and (max-width:2559px){.app-main{padding:50px 60px;width:100%;max-width:none}.game-container{grid-template-columns:7fr 3fr;gap:50px}.game-board,.game-container{width:100%;max-width:none;margin:0}.game-board{padding:28px;gap:28px}.sudoku-grid{max-width:500px}.cell-value,.number-btn{font-size:22px}.number-btn{width:55px;height:55px}.game-sidebar{width:100%;max-width:none;gap:28px}}@media (min-width:1024px) and (max-width:1199px){.app-main{padding:20px;width:100%;max-width:none}.game-container{grid-template-columns:7fr 3fr;gap:32px}.game-board,.game-container{width:100%;max-width:none;margin:0}.game-sidebar{width:100%;max-width:none;display:grid;grid-template-columns:1fr 1fr;grid-gap:24px;gap:24px;position:static;max-height:none}.hint-system{grid-column:1/-1}.difficulty-grid{grid-template-columns:repeat(6,1fr);gap:12px}.difficulty-card{min-height:90px;padding:12px}}@media (min-width:415px) and (max-width:480px){.app-main{padding:12px 16px}.difficulty-grid{grid-template-columns:repeat(2,1fr);gap:10px;max-width:100%}.difficulty-card{min-height:85px;padding:12px}.game-board{gap:14px;padding:14px;margin:0 6px}.sudoku-grid{width:min(420px,calc(100vw - 28px));border-width:2px}.number-input{gap:6px;padding:10px}.number-btn{width:40px;height:40px;font-size:15px;margin:1px;border-width:1px;border-radius:8px}}@media (min-width:361px) and (max-width:414px){.app-main{padding:12px}.difficulty-grid{grid-template-columns:repeat(2,1fr);gap:8px;max-width:100%}.difficulty-card{min-height:80px;padding:10px}.game-board{flex-direction:column;gap:12px;padding:12px;margin:0 4px}.sudoku-grid{width:320px;border-width:2px}.number-input{gap:4px;padding:8px}.number-btn{width:32px;height:32px;font-size:14px;margin:1px;border-width:1px;border-radius:8px}.number-btn i{font-size:11px}}@media (min-width:321px) and (max-width:360px){.app-main{padding:10px 8px}.difficulty-grid{grid-template-columns:repeat(2,1fr);gap:6px;max-width:100%}.difficulty-card{min-height:75px;padding:8px}.difficulty-icon{width:18px;height:18px;margin-bottom:3px}.difficulty-icon i{font-size:7px}.difficulty-info h3{font-size:9px;margin-bottom:2px}.difficulty-desc{font-size:6px;margin-bottom:2px}.difficulty-clues{font-size:5px}.game-board{gap:8px;padding:8px;margin:0 2px}.sudoku-grid{width:min(340px,calc(100vw - 16px))}.number-input{gap:3px;padding:6px}.number-btn{width:32px;height:32px;font-size:12px;margin:1px}.number-btn i{font-size:10px}}@media (min-width:280px) and (max-width:320px){.app-main{padding:8px 4px}.app-title{font-size:20px}.app-subtitle{font-size:10px}.difficulty-grid{grid-template-columns:repeat(2,1fr);gap:4px;max-width:100%}.difficulty-card{min-height:65px;padding:6px}.difficulty-icon{width:16px;height:16px;margin-bottom:2px}.difficulty-icon i{font-size:6px}.difficulty-info h3{font-size:8px;margin-bottom:1px}.difficulty-desc{font-size:5px;margin-bottom:1px}.difficulty-clues{font-size:4px}.game-board{gap:6px;padding:6px;margin:0 1px}.sudoku-grid{width:min(280px,calc(100vw - 12px))}.cell-value{font-size:12px}.number-input{gap:2px;padding:4px}.number-btn{width:28px;height:28px;font-size:10px;margin:1px}.number-btn i{font-size:8px}}@media (min-width:768px) and (max-width:1024px) and (orientation:landscape){.game-container{grid-template-columns:7fr 3fr;gap:24px;max-height:calc(100vh - 100px)}.game-board,.game-container{width:100%;max-width:none;margin:0}.game-sidebar{width:100%;max-width:none;flex-shrink:0;max-height:calc(100vh - 100px);overflow-y:auto;display:flex;flex-direction:column;gap:16px}}@media (max-width:768px) and (max-height:500px) and (orientation:landscape){.app-header{padding:6px 0}.app-main{padding:6px 12px}.game-container{grid-template-columns:1fr auto;gap:12px;max-height:calc(100vh - 60px)}.game-board{gap:8px;padding:8px}.sudoku-grid{width:min(320px,calc(100vh - 120px));max-width:min(320px,calc(100vh - 120px))}.cell-value{font-size:14px}.number-input{flex-direction:column;max-width:40px;gap:2px;padding:4px}.number-btn{width:32px;height:32px;font-size:12px;margin:1px}.game-sidebar{width:200px;max-width:200px;flex-shrink:0;max-height:calc(100vh - 60px);overflow-y:auto;gap:8px}.timer{padding:8px;gap:8px}.timer-text{font-size:18px}.game-controls{padding:8px}.control-btn{padding:6px 8px;font-size:10px}.hint-system{padding:8px}}.leaderboard-modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.8);display:flex;align-items:center;justify-content:center;z-index:10000;padding:20px}.leaderboard-modal{background:linear-gradient(135deg,#fff,#f8f9fa);border-radius:20px;box-shadow:0 20px 60px rgba(0,0,0,.3);width:100%;max-width:900px;max-height:90vh;overflow:hidden;display:flex;flex-direction:column}.leaderboard-header{display:flex;align-items:center;justify-content:space-between;padding:24px 32px;background:linear-gradient(135deg,#667eea,#764ba2);color:#fff}.leaderboard-header h2{font-size:24px;font-weight:700;margin:0;display:flex;align-items:center;gap:12px}.close-btn{background:hsla(0,0%,100%,.2);border:none;border-radius:50%;width:40px;height:40px;color:#fff;font-size:18px;cursor:pointer;transition:all .2s ease}.close-btn:hover{background:hsla(0,0%,100%,.3);transform:scale(1.1)}.leaderboard-tabs{display:flex;background:#f8f9fa;border-bottom:1px solid #dee2e6}.tab-btn{flex:1 1;padding:16px 24px;background:none;border:none;font-size:14px;font-weight:500;color:#6c757d;cursor:pointer;transition:all .2s ease;display:flex;align-items:center;justify-content:center;gap:8px}.tab-btn:hover{background:rgba(102,126,234,.1);color:#667eea}.tab-btn.active{background:#fff;color:#667eea;border-bottom:3px solid #667eea}.leaderboard-content,.leaderboard-view{flex:1 1;overflow:hidden;display:flex;flex-direction:column}.difficulty-tabs{display:flex;padding:16px 24px 0;gap:8px;overflow-x:auto}.difficulty-tab{padding:8px 16px;background:hsla(0,0%,100%,.8);border:2px solid transparent;border-radius:20px;font-size:13px;font-weight:500;color:#6c757d;cursor:pointer;transition:all .2s ease;display:flex;align-items:center;gap:6px;white-space:nowrap}.difficulty-tab:hover{border-color:var(--difficulty-color);color:var(--difficulty-color)}.difficulty-tab.active{background:var(--difficulty-color);color:#fff;border-color:var(--difficulty-color)}.difficulty-tab .count{font-size:11px;opacity:.8}.leaderboard-list{flex:1 1;padding:16px 24px 24px;overflow-y:auto}.leaderboard-item{display:flex;align-items:center;gap:16px;padding:16px;background:#fff;border-radius:12px;box-shadow:0 2px 8px rgba(0,0,0,.1);margin-bottom:12px;transition:all .2s ease}.leaderboard-item:hover{transform:translateY(-2px);box-shadow:0 4px 16px rgba(0,0,0,.15)}.leaderboard-item.champion{background:linear-gradient(135deg,#fff9c4,#fff3cd);border:2px solid gold}.rank{width:40px;text-align:center;font-weight:700;font-size:16px;color:#495057}.champion-crown{color:gold;font-size:20px;animation:crownGlow 2s ease-in-out infinite}@keyframes crownGlow{0%,to{transform:scale(1)}50%{transform:scale(1.1)}}.player-info{flex:1 1}.player-name{font-size:16px;font-weight:600;color:#212529;margin-bottom:4px;display:flex;align-items:center;gap:8px}.champion-badge{background:linear-gradient(135deg,gold,#ffed4e);color:#8b6914;padding:2px 8px;border-radius:10px;font-size:10px;font-weight:700;text-transform:uppercase}.player-stats{display:flex;gap:16px;font-size:12px;color:#6c757d}.player-stats span{display:flex;align-items:center;gap:4px}.score-info{text-align:right}.score{font-size:18px;font-weight:700;color:#28a745;margin-bottom:4px}.pk-stats{display:flex;gap:12px;font-size:11px;color:#6c757d}.pk-stats span{display:flex;align-items:center;gap:2px}.pk-wins{color:#28a745}.pk-losses{color:#dc3545}.pk-btn{background:linear-gradient(135deg,#ff6b6b,#ee5a24);color:#fff;border:none;border-radius:8px;padding:8px 12px;font-size:12px;font-weight:600;cursor:pointer;transition:all .2s ease;display:flex;align-items:center;gap:4px}.pk-btn:hover:not(:disabled){transform:translateY(-1px);box-shadow:0 4px 12px hsla(0,100%,71%,.4)}.pk-btn:disabled{opacity:.5;cursor:not-allowed}.empty-leaderboard{text-align:center;padding:60px 20px;color:#6c757d}.empty-leaderboard i{font-size:48px;margin-bottom:16px;opacity:.5}.join-form{padding:32px;text-align:center}.join-header{margin-bottom:32px}.join-header i{font-size:48px;color:gold;margin-bottom:16px}.join-header h3{font-size:24px;font-weight:700;color:#212529;margin-bottom:8px}.join-header p{color:#6c757d;font-size:16px}.game-summary{background:#f8f9fa;border-radius:12px;padding:24px;margin-bottom:32px}.summary-item{display:flex;justify-content:space-between;align-items:center;padding:8px 0;border-bottom:1px solid #dee2e6}.summary-item:last-child{border-bottom:none}.summary-item.score-preview{font-weight:700;font-size:16px;color:#28a745}.summary-item .label{color:#6c757d;font-weight:500}.summary-item .value{font-weight:600;color:#212529;display:flex;align-items:center;gap:6px}.nickname-input{display:flex;gap:12px;max-width:400px;margin:0 auto}.nickname-input input{flex:1 1;padding:12px 16px;border:2px solid #dee2e6;border-radius:8px;font-size:16px;transition:border-color .2s ease}.nickname-input input:focus{outline:none;border-color:#667eea}.join-btn{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;border-radius:8px;padding:12px 20px;font-size:14px;font-weight:600;cursor:pointer;transition:all .2s ease;display:flex;align-items:center;gap:8px}.join-btn:hover:not(:disabled){transform:translateY(-1px);box-shadow:0 4px 12px rgba(102,126,234,.4)}.join-btn:disabled{opacity:.5;cursor:not-allowed}.pk-modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.8);display:flex;align-items:center;justify-content:center;z-index:10001;padding:20px}.pk-modal{background:#fff;border-radius:16px;box-shadow:0 20px 60px rgba(0,0,0,.3);width:100%;max-width:500px;overflow:hidden}.pk-header{background:linear-gradient(135deg,#ff6b6b,#ee5a24);color:#fff;padding:20px 24px;text-align:center}.pk-header h3{margin:0;font-size:20px;font-weight:700;display:flex;align-items:center;justify-content:center;gap:8px}.pk-content{padding:24px;text-align:center}.pk-content p{font-size:16px;color:#495057;margin-bottom:24px}.pk-comparison{display:flex;align-items:center;gap:16px;margin-bottom:24px}.challenger,.target{flex:1 1;padding:16px;background:#f8f9fa;border-radius:8px}.challenger h4,.target h4{margin:0 0 8px;font-size:14px;font-weight:600;color:#495057}.stats{font-size:12px;color:#6c757d}.stats div{margin-bottom:4px}.vs{font-size:18px;font-weight:700;color:#ff6b6b}.pk-actions{display:flex;gap:12px;padding:0 24px 24px}.cancel-btn,.confirm-btn{flex:1 1;padding:12px 20px;border:none;border-radius:8px;font-size:14px;font-weight:600;cursor:pointer;transition:all .2s ease}.cancel-btn{background:#6c757d;color:#fff}.cancel-btn:hover{background:#5a6268}.confirm-btn{background:linear-gradient(135deg,#ff6b6b,#ee5a24);color:#fff;display:flex;align-items:center;justify-content:center;gap:8px}.confirm-btn:hover{transform:translateY(-1px);box-shadow:0 4px 12px hsla(0,100%,71%,.4)}@media (max-width:768px){.leaderboard-modal{margin:10px;max-height:calc(100vh - 20px)}.leaderboard-header{padding:16px 20px}.leaderboard-header h2{font-size:20px}.tab-btn{padding:12px 16px;font-size:13px}.difficulty-tabs{padding:12px 16px 0}.leaderboard-list{padding:12px 16px 16px}.leaderboard-item{padding:12px;gap:12px}.player-stats{gap:12px}.join-form{padding:20px}.nickname-input,.pk-comparison{flex-direction:column}.pk-comparison{gap:12px}.vs{transform:rotate(90deg)}}@media (max-width:480px){.leaderboard-item{flex-direction:column;align-items:flex-start;gap:8px}.rank{width:auto;text-align:left}.score-info{text-align:left;width:100%;display:flex;justify-content:space-between;align-items:center}.pk-btn{align-self:flex-end}}.cell.same-number{background-color:#e8f4f8!important;color:#1976d2!important;font-weight:600!important;border:2px dashed #64b5f6!important;transition:all .15s ease-out;z-index:2}.cell.same-number .cell-value{color:#1976d2!important;text-shadow:0 0 2px rgba(25,118,210,.3)}@keyframes conflictPulse{0%,to{background-color:rgba(244,67,54,.1);border-color:rgba(244,67,54,.3)}50%{background-color:rgba(244,67,54,.15);border-color:rgba(244,67,54,.4)}}@keyframes wrongShake{0%,to{transform:translateX(0);background-color:rgba(244,67,54,.08)}25%{transform:translateX(-2px);background-color:rgba(244,67,54,.12)}75%{transform:translateX(2px);background-color:rgba(244,67,54,.12)}}.cell.selected{background-color:#e3f2fd!important;border:2px solid #2196f3!important;transition:all .12s ease-out;box-shadow:0 0 0 1px rgba(33,150,243,.2)}@media (prefers-reduced-motion:reduce){.cell{transition:none!important}.cell,.cell.conflict{animation:none!important}.cell.conflict{background-color:rgba(244,67,54,.1)!important}.cell.wrong{animation:none!important;background-color:rgba(244,67,54,.08)!important}}.victory-modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.8);display:flex;align-items:center;justify-content:center;z-index:1000;-webkit-backdrop-filter:blur(5px);backdrop-filter:blur(5px)}.victory-modal{background:linear-gradient(135deg,#667eea,#764ba2);border-radius:20px;max-width:650px;max-height:90vh;overflow-y:auto;position:relative;box-shadow:0 20px 40px rgba(0,0,0,.3);animation:victoryModalAppear .5s ease-out}@keyframes victoryModalAppear{0%{opacity:0;transform:scale(.7) translateY(-50px)}to{opacity:1;transform:scale(1) translateY(0)}}.confetti-container{position:absolute;top:0;left:0;right:0;bottom:0;pointer-events:none;overflow:hidden;border-radius:20px}.confetti{position:absolute;width:8px;height:8px;background:gold;animation:confettiFall 3s linear}.confetti-0{background:gold;left:10%;animation-delay:0s}.confetti-1{background:#ff6b35;left:25%;animation-delay:.2s}.confetti-2{background:#f7931e;left:40%;animation-delay:.4s}.confetti-3{background:#9acd32;left:60%;animation-delay:.6s}.confetti-4{background:#87ceeb;left:80%;animation-delay:.8s}@keyframes confettiFall{0%{transform:translateY(-100vh) rotate(0deg);opacity:1}to{transform:translateY(100vh) rotate(2turn);opacity:0}}.victory-header{position:relative;padding:20px;text-align:right}.victory-header .close-btn{background:hsla(0,0%,100%,.2);border:none;border-radius:50%;width:40px;height:40px;color:#fff;font-size:18px;cursor:pointer;transition:all .3s ease}.victory-header .close-btn:hover{background:hsla(0,0%,100%,.3);transform:scale(1.1)}.victory-content{padding:0 30px 30px;color:#fff;text-align:center}.victory-title h2{font-size:2.5em;margin:0 0 10px;text-shadow:2px 2px 4px rgba(0,0,0,.3);animation:titlePulse 2s ease-in-out infinite}@keyframes titlePulse{0%,to{transform:scale(1)}50%{transform:scale(1.05)}}.victory-subtitle{font-size:1.2em;margin:0 0 30px;opacity:.9}.score-display{margin:30px 0;display:flex;justify-content:center}.score-canvas{max-width:100%;height:auto;border-radius:15px;box-shadow:0 10px 20px rgba(0,0,0,.2)}.victory-actions{gap:20px}.primary-actions,.victory-actions{display:flex;flex-direction:column}.primary-actions{gap:15px}.join-leaderboard-section{display:flex;gap:10px;align-items:center}.nickname-input{flex:1 1;padding:12px 16px;border:2px solid hsla(0,0%,100%,.3);border-radius:25px;background:hsla(0,0%,100%,.1);color:#fff;font-size:16px;outline:none;transition:all .3s ease}.nickname-input::placeholder{color:hsla(0,0%,100%,.7)}.nickname-input:focus{border-color:hsla(0,0%,100%,.6);background:hsla(0,0%,100%,.15)}.join-leaderboard-btn,.view-leaderboard-btn{padding:12px 24px;border:none;border-radius:25px;font-size:16px;font-weight:600;cursor:pointer;transition:all .3s ease;display:flex;align-items:center;gap:8px;justify-content:center}.join-leaderboard-btn{background:linear-gradient(45deg,gold,orange);color:#333}.join-leaderboard-btn:hover:not(:disabled){transform:translateY(-2px);box-shadow:0 5px 15px rgba(255,215,0,.4)}.join-leaderboard-btn:disabled{opacity:.5;cursor:not-allowed}.view-leaderboard-btn{background:hsla(0,0%,100%,.2);color:#fff;border:2px solid hsla(0,0%,100%,.3)}.view-leaderboard-btn:hover{background:hsla(0,0%,100%,.3);transform:translateY(-2px)}.share-actions{border-top:1px solid hsla(0,0%,100%,.2);padding-top:20px}.share-toggle-btn{width:100%;padding:12px 24px;border:2px solid hsla(0,0%,100%,.3);border-radius:25px;background:hsla(0,0%,100%,.1);color:#fff;font-size:16px;font-weight:600;cursor:pointer;transition:all .3s ease;display:flex;align-items:center;gap:8px;justify-content:center}.share-toggle-btn:hover{background:hsla(0,0%,100%,.2);transform:translateY(-2px)}.share-options{display:grid;grid-template-columns:repeat(2,1fr);grid-gap:12px;gap:12px;margin-top:15px;animation:shareOptionsSlide .3s ease-out}@keyframes shareOptionsSlide{0%{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}.share-btn{padding:10px 16px;border:none;border-radius:20px;font-size:14px;font-weight:600;cursor:pointer;transition:all .3s ease;display:flex;align-items:center;gap:6px;justify-content:center}.share-btn.facebook{background:#1877f2;color:#fff}.share-btn.twitter{background:#1da1f2;color:#fff}.share-btn.download{background:#28a745;color:#fff}.share-btn.pk{background:#ff6b35;color:#fff}.share-btn:hover{transform:translateY(-2px);box-shadow:0 4px 12px rgba(0,0,0,.2)}@media (max-width:768px){.victory-modal{margin:20px;max-width:calc(100vw - 40px)}.victory-content{padding:0 20px 20px}.victory-title h2{font-size:2em}.join-leaderboard-section{flex-direction:column}.nickname-input{width:100%}.share-options{grid-template-columns:1fr}}.header-controls{display:flex;align-items:center;gap:16px;position:relative;z-index:10001!important;isolation:isolate;pointer-events:auto}.solitaire-link:hover i{color:gold;filter:drop-shadow(0 2px 4px rgba(255,215,0,.3))}@media (min-width:1200px){.nav-link{padding:10px 20px;font-size:15px}.nav-link i{font-size:18px}}@media (max-width:768px){.nav-link{padding:6px 12px;font-size:13px;border-radius:10px}.nav-link i{font-size:14px}}@media (max-width:480px){.nav-link{padding:4px 8px;border-radius:8px}.nav-link,.nav-link i{font-size:12px}}@media (prefers-color-scheme:dark){.nav-link{background:linear-gradient(135deg,rgba(0,0,0,.3),rgba(0,0,0,.2));border-color:hsla(0,0%,100%,.15);color:#ecf0f1}.nav-link:hover{background:linear-gradient(135deg,rgba(0,0,0,.4),rgba(0,0,0,.3));border-color:hsla(0,0%,100%,.25)}.solitaire-link i{color:hsla(0,0%,100%,.8)}.solitaire-link:hover i{color:gold}}@media (prefers-contrast:high){.nav-link{background:#fff;border:2px solid #000;color:#000}.nav-link:hover{background:#f0f0f0}.solitaire-link i,.solitaire-link:hover i{color:#000}}@media (prefers-reduced-motion:reduce){.nav-link{transition:none}.nav-link:before{display:none}}.nav-link{display:flex;align-items:center;gap:8px;padding:8px 16px;background:linear-gradient(135deg,hsla(0,0%,100%,.15),hsla(0,0%,100%,.05));backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border:1px solid hsla(0,0%,100%,.2);border-radius:12px;color:#fff;font-size:14px;font-weight:500;text-decoration:none;cursor:pointer;transition:all .3s ease;box-shadow:0 4px 15px rgba(0,0,0,.1);position:relative;overflow:hidden}.nav-link:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,hsla(0,0%,100%,.2),transparent);transition:left .5s ease}.nav-link:hover:before{left:100%}.nav-link:hover{background:linear-gradient(135deg,hsla(0,0%,100%,.25),hsla(0,0%,100%,.15));border-color:hsla(0,0%,100%,.3);transform:translateY(-1px);box-shadow:0 6px 20px rgba(0,0,0,.15);color:#fff;text-decoration:none}.nav-link:focus{outline:2px solid hsla(0,0%,100%,.5);outline-offset:2px}.nav-link:active{transform:translateY(0);box-shadow:0 2px 8px rgba(0,0,0,.1)}.nav-link i{font-size:16px;filter:drop-shadow(0 1px 2px rgba(0,0,0,.2))}.solitaire-link i{color:hsla(0,0%,100%,.9);background:linear-gradient(135deg,#ff6b6b,#ffd93d 25%,#6bcf7f 50%,#4d9de0 75%,#e15759);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;animation:cardColorShift 3s ease-in-out infinite;text-shadow:none;filter:drop-shadow(0 2px 4px rgba(0,0,0,.3))}.solitaire-link:hover i{animation:cardColorShift 1s ease-in-out infinite,cardBounce .6s ease-in-out infinite;transform:scale(1.1)}@keyframes cardColorShift{0%,to{background:linear-gradient(135deg,#ff6b6b,#ffd93d 25%,#6bcf7f 50%,#4d9de0 75%,#e15759);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}25%{background:linear-gradient(135deg,#ffd93d,#6bcf7f 25%,#4d9de0 50%,#e15759 75%,#ff6b6b);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}50%{background:linear-gradient(135deg,#6bcf7f,#4d9de0 25%,#e15759 50%,#ff6b6b 75%,#ffd93d);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}75%{background:linear-gradient(135deg,#4d9de0,#e15759 25%,#ff6b6b 50%,#ffd93d 75%,#6bcf7f);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}}@keyframes cardBounce{0%,to{transform:scale(1.1) translateY(0)}50%{transform:scale(1.1) translateY(-2px)}}