:root{color-scheme:light;--ink:#243e33;--green:#375c4c;--muted:#5c7067;--paper:#f5f8f4;--white:#fff;--line:#ccdad0;--sage:#dcece0;--selected:#bad7c3;--error:#8d233b;--error-bg:#ffe6ec;--focus:#8b5625;font-family:ui-sans-serif,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:16px;color:var(--ink);background:var(--paper)}*{box-sizing:border-box}body{margin:0}a{color:var(--green);text-underline-offset:4px}a:hover{text-decoration-thickness:2px}button,select{font:inherit;color:inherit;cursor:pointer}button{border:1px solid var(--line);border-radius:9px;background:var(--white);min-height:44px;padding:9px 13px;font-weight:600;transition:background .15s,color .15s}button:hover{background:var(--sage)}button:disabled{opacity:.48;cursor:default}button:focus-visible,select:focus-visible,a:focus-visible{outline:3px solid var(--focus);outline-offset:3px}button.primary{background:var(--green);color:var(--white);border-color:var(--green)}button.primary:hover{background:#284536}select{border:1px solid var(--line);border-radius:8px;background:var(--white);min-height:40px;padding:5px 28px 5px 12px}svg{width:20px;height:20px;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}::selection{background:var(--selected);color:var(--ink)}.site-header{border-bottom:1px solid var(--line);background:var(--white)}.header-inner{max-width:1040px;margin:auto;min-height:68px;padding:12px 26px;display:flex;align-items:center;justify-content:space-between;gap:24px}.brand{display:flex;align-items:center;gap:9px;font-weight:750;text-decoration:none;font-size:18px;white-space:nowrap}.brand img{display:block}.site-nav{display:flex;gap:24px;font-size:14px}.site-nav a{text-decoration:none}.site-nav a[aria-current=page]{text-decoration:underline}.game-shell{width:min(100% - 36px,504px);margin:25px auto 0}.game-heading{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:14px}h1{font-size:29px;line-height:1.18;letter-spacing:-.025em;margin:0;font-weight:750}.game-settings{display:flex;align-items:center;gap:17px}.timer-label{display:flex;align-items:center;gap:5px;color:var(--muted);font-variant-numeric:tabular-nums;font-size:15px}.sudoku-board{display:grid;grid-template-columns:repeat(9,1fr);aspect-ratio:1;width:100%;border:2px solid var(--green);border-radius:3px;overflow:hidden;background:var(--white)}.cell{min-width:0;min-height:0;border:0;border-radius:0;border-right:1px solid var(--line);border-bottom:1px solid var(--line);padding:0;font-size:clamp(21px,4vw,29px);font-weight:550;color:#3a6955;background:var(--white);position:relative;line-height:1;font-variant-numeric:tabular-nums}.cell:nth-child(3n){border-right:2px solid var(--green)}.cell:nth-child(9n){border-right:0}.cell:nth-child(n+19):nth-child(-n+27),.cell:nth-child(n+46):nth-child(-n+54){border-bottom:2px solid var(--green)}.cell:nth-child(n+73){border-bottom:0}.cell.given{font-weight:750;color:var(--ink)}.cell.peer{background:#f0f5f0}.cell.same-number{background:var(--sage)}.cell.selected{background:var(--selected);box-shadow:inset 0 0 0 2px var(--green)}.cell.error{color:var(--error);background:var(--error-bg)}.cell.hinted:after{content:"";position:absolute;width:4px;height:4px;background:var(--green);border-radius:50%;bottom:5px;right:5px}.cell:focus-visible{outline:0;box-shadow:inset 0 0 0 3px var(--focus);z-index:1}.number-pad{display:grid;grid-template-columns:repeat(9,1fr);gap:5px;margin-top:13px}.number-pad button{padding:8px 0;font-size:23px;font-weight:600;min-height:49px}.game-actions{display:grid;grid-template-columns:repeat(4,1fr);gap:7px;margin-top:10px}.game-actions button{display:flex;align-items:center;justify-content:center;gap:6px;font-size:14px;padding:9px 6px}.game-actions svg{width:17px;height:17px}.game-actions #hint-count{font-size:12px;border-radius:50%;padding:1px 5px;background:var(--sage)}.game-feedback{margin:10px 0 0;min-height:40px;font-size:13px;text-align:center;color:var(--muted)}.game-feedback p{margin:3px 0;line-height:1.4}.save-status{font-size:12px}.inline-panel,.completion{padding:17px 0;border-top:1px solid var(--line);margin-top:12px}.inline-panel p{margin-top:0}.inline-panel>div{display:flex;gap:8px}.completion{display:flex;align-items:center;gap:13px}.completion h2{font-size:22px;margin:0 0 4px}.completion p{margin:0;font-size:14px}.completion button{margin-left:auto}.completion[hidden],.inline-panel[hidden]{display:none}.sudoku-board.completed{animation:solved .65s ease-out}@keyframes solved{50%{border-color:#d09f30;box-shadow:0 0 0 5px #efdfab}}.game-intro{max-width:650px;margin:42px auto 47px;padding:0 25px;font-size:15px;line-height:1.75;color:var(--muted)}.intro-links{display:flex;flex-wrap:wrap;gap:14px 26px}.intro-links a{font-weight:650}.site-footer{border-top:1px solid var(--line);font-size:12px;color:var(--muted)}.footer-inner{max-width:1040px;margin:auto;padding:22px 26px;display:flex;gap:20px;align-items:center;flex-wrap:wrap}.footer-inner>span{margin-right:auto}.analytics-toggle{font-size:12px;font-weight:400;min-height:32px;padding:4px 0;border:0;background:transparent;text-decoration:underline;text-underline-offset:3px}.page-content{max-width:760px;margin:47px auto 60px;padding:0 28px;line-height:1.75}.page-heading{margin-bottom:30px}.page-heading h1{font-size:38px}.lead{font-size:19px;color:var(--muted);line-height:1.65}.content-section{margin:34px 0}.content-section h2,.page-content>h2{font-size:24px;letter-spacing:-.015em;line-height:1.3;margin-bottom:14px}.content-section h3{font-size:19px;line-height:1.4;margin-bottom:8px}.rule-list,.tip-list{padding-left:23px}.rule-list li,.tip-list li{padding:4px 0}.rules-figure{margin:25px 0}.rules-figure img{width:100%;max-width:430px;height:auto;display:block;margin:auto}.rules-figure figcaption{font-size:13px;color:var(--muted);text-align:center;margin-top:10px}.faq-list details{border-top:1px solid var(--line);padding:15px 0}.faq-list summary{cursor:pointer;font-weight:650}.faq-list details p{color:var(--muted);margin-bottom:0}.game-list{margin-top:32px}.game-card{border-top:1px solid var(--line);padding:26px 0;display:flex;gap:23px}.game-number{font-size:28px;font-weight:650;color:var(--muted);min-width:26px;line-height:1.3}.game-detail h2{margin:0 0 9px;font-size:25px;line-height:1.25}.game-detail p{margin:7px 0}.game-fit{color:var(--muted)}.source-link{font-size:14px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}body::-webkit-scrollbar{width:9px}body::-webkit-scrollbar-thumb{background:#b6c9bc;border-radius:5px}body::-webkit-scrollbar-track{background:var(--paper)}@media(max-width:580px){.header-inner{min-height:58px;padding:10px 18px;gap:14px}.brand{font-size:16px}.brand img{width:25px;height:25px}.site-nav{gap:13px;font-size:12px}.game-shell{margin-top:18px;width:calc(100% - 28px);max-width:454px}.game-heading{margin-bottom:12px}h1{font-size:27px}.game-settings{gap:10px}.game-settings select{font-size:14px;min-height:38px;padding-left:9px}.timer-label svg{display:none}.timer-label{font-size:14px}.number-pad{gap:4px;margin-top:11px}.number-pad button{font-size:21px;min-height:46px}.game-actions{gap:5px}.game-actions button{font-size:12px;gap:4px;min-height:44px}.game-actions svg{width:15px;height:15px}.game-feedback{font-size:12px}.game-intro{margin-top:29px}.page-content{padding:0 22px;margin-top:29px}.page-heading h1{font-size:32px}.lead{font-size:17px}.game-card{gap:16px}.footer-inner{padding:18px}.completion{flex-wrap:wrap}.completion button{margin-left:0}.intro-links{display:block}.intro-links a{display:block;margin:8px 0}}@media(max-width:360px){.brand span{font-size:14px}.site-nav{gap:9px;font-size:11px}.header-inner{padding-left:14px;padding-right:14px}.game-heading h1{font-size:24px}.game-settings{gap:7px}.game-actions svg{display:none}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important}}
.skip-link{position:absolute;top:-80px;left:15px;z-index:10;background:var(--white);padding:10px 15px}.skip-link:focus{top:10px}.controls-list>div{display:grid;grid-template-columns:85px 1fr;gap:15px;padding:10px 0;border-top:1px solid var(--line)}.controls-list dt{font-weight:650}.controls-list dd{margin:0;color:var(--muted)}kbd{font:inherit;font-size:.85em;border:1px solid var(--line);border-radius:4px;background:var(--white);padding:1px 5px}.footer-inner nav{display:flex;gap:15px;flex-wrap:wrap}.source-note{font-size:13px;color:var(--muted)}
.board-row{display:contents}.board-row:nth-child(3n) .cell{border-bottom:2px solid var(--green)}.board-row:last-child .cell{border-bottom:0}
@media(min-width:581px){.header-inner{min-height:60px}.game-shell{max-width:454px;margin-top:18px}.game-heading{margin-bottom:12px}}