:root{color-scheme:dark;--ink:#f4f1eb;--muted:#aaa69d;--night:#100e0a;--panel:#1a1711;--line:#454034;--lime:#c9f45b;--blue:#75bff2;--sand:#e5b96b;--display:"Arial Black","Helvetica Neue",Arial,sans-serif;--body:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif}*{box-sizing:border-box}html{min-width:280px;background:var(--night)}body{min-height:100vh;margin:0;color:var(--ink);background:radial-gradient(circle at 82% 5%,rgba(229,185,107,.11),transparent 30rem),var(--night);font-family:var(--body);line-height:1.5}a{color:inherit}button{color:inherit;font:inherit}.site-header,main,footer{width:min(1080px,calc(100% - 40px));margin-inline:auto}.site-header{display:flex;align-items:center;justify-content:space-between;min-height:78px;border-bottom:1px solid var(--line)}.brand{display:inline-flex;align-items:center;gap:11px;font-weight:850;text-decoration:none}.brand-mark{display:grid;width:34px;height:34px;place-items:center;color:var(--night);background:var(--lime);border-radius:9px;font-family:var(--display)}.site-header p{margin:0;color:var(--muted);font-size:.7rem;font-weight:800;letter-spacing:.13em;text-transform:uppercase}.site-header p span,.eyebrow{color:var(--sand)}.intro{display:grid;grid-template-columns:1fr minmax(260px,400px);gap:60px;align-items:end;padding:58px 0 36px}.intro>p{margin-bottom:3px;color:var(--muted)}.eyebrow{margin:0 0 10px;font-size:.72rem;font-weight:850;letter-spacing:.18em;text-transform:uppercase}h1,h2,p{margin-top:0}h1{margin-bottom:0;font-family:var(--display);font-size:clamp(3.5rem,8vw,6.5rem);line-height:.86;letter-spacing:-.07em}.game-shell{max-width:900px;margin-inline:auto;overflow:hidden;background:var(--panel);border:1px solid var(--line);border-radius:17px}.difficulty{display:grid;grid-template-columns:repeat(3,1fr);gap:1px;background:var(--line);border-bottom:1px solid var(--line)}.difficulty button{display:grid;gap:1px;min-height:58px;padding:10px 16px;text-align:left;background:var(--panel);border:0;cursor:pointer}.difficulty button[aria-pressed="true"]{color:var(--night);background:var(--sand)}.difficulty strong{font-size:.82rem}.difficulty span{color:var(--muted);font-size:.66rem}.difficulty button[aria-pressed="true"] span{color:#563d16}.game-bar{display:grid;grid-template-columns:auto 1fr auto auto;gap:18px;align-items:center;padding:13px 16px;border-bottom:1px solid var(--line)}.game-bar>div{display:grid}.game-bar span{color:var(--muted);font-size:.58rem;font-weight:850;letter-spacing:.12em;text-transform:uppercase}.game-bar strong{color:var(--lime);font:850 1.2rem/1 ui-monospace,SFMono-Regular,Menlo,monospace}.game-bar p{margin:0;color:var(--muted);font-size:.73rem;text-align:center}.mistakes{text-align:right}.game-bar>button{min-height:39px;padding:0 13px;background:transparent;border:1px solid #5b5547;border-radius:8px;font-size:.72rem;font-weight:800;cursor:pointer}.game-bar>button:hover,.game-bar>button:focus-visible{color:var(--night);background:var(--lime);border-color:var(--lime)}.play-area{display:grid;grid-template-columns:minmax(0,610px) minmax(170px,1fr);gap:20px;align-items:center;padding:20px}.board{display:grid;grid-template-columns:repeat(9,1fr);aspect-ratio:1;background:#5e5748;border:3px solid #b8ad92;touch-action:manipulation}.cell{position:relative;display:grid;min-width:0;padding:0;place-items:center;color:var(--blue);background:#15130f;border:0;border-right:1px solid #454034;border-bottom:1px solid #454034;font-family:var(--display);font-size:clamp(1rem,4.2vw,2rem);cursor:pointer}.cell:nth-child(9n+3),.cell:nth-child(9n+6){border-right:3px solid #8b816b}.cell:nth-child(n+19):nth-child(-n+27),.cell:nth-child(n+46):nth-child(-n+54){border-bottom:3px solid #8b816b}.cell:nth-child(9n){border-right:0}.cell:nth-child(n+73){border-bottom:0}.cell--related{background:#201e18}.cell--same{background:#293324}.cell--selected{background:#3a4327;outline:3px solid var(--lime);outline-offset:-3px;z-index:2}.cell--given{color:var(--ink)}.cell--error{color:#ff766f;background:#3b201d}.cell__value{font:inherit}.cell__notes{position:absolute;inset:2px;display:grid;grid-template-columns:repeat(3,1fr);grid-template-rows:repeat(3,1fr);color:#a9c9dc;font:600 clamp(.42rem,1.4vw,.68rem)/1 var(--body)}.cell__notes i{display:grid;place-items:center;font-style:normal}.number-pad{display:grid;grid-template-columns:repeat(3,1fr);gap:7px}.number-pad button{aspect-ratio:1;padding:0;color:var(--night);background:var(--sand);border:1px solid #ffdd9c;border-radius:9px;font:850 1.3rem/1 var(--display);cursor:pointer}.number-pad button:hover,.number-pad button:focus-visible{background:var(--lime);border-color:var(--lime)}.number-pad .tool{display:grid;aspect-ratio:auto;min-height:54px;padding:5px;place-items:center;color:var(--ink);background:#29251c;border-color:#5d5646;font-family:var(--body)}.number-pad .tool[aria-pressed="true"]{color:var(--night);background:var(--blue);border-color:var(--blue)}.tool strong{font-size:.73rem}.tool span{color:var(--muted);font-size:.6rem}.tool[aria-pressed="true"] span{color:#17394d}.rules{display:grid;grid-template-columns:1fr 1fr;gap:clamp(50px,9vw,110px);padding:90px 0}.rules h2{margin:0;font-family:var(--display);font-size:clamp(2rem,4vw,3.8rem);line-height:.98;letter-spacing:-.05em}.rules>p{margin:0;color:var(--muted)}footer{display:flex;justify-content:space-between;padding:28px 0 42px;color:var(--muted);border-top:1px solid var(--line);font-size:.8rem}footer a{color:var(--ink);font-weight:750;text-decoration:none}footer p{margin:0}@media(max-width:760px){.site-header,main,footer{width:min(100% - 20px,620px)}.site-header{min-height:64px}.intro{grid-template-columns:1fr;gap:16px;padding:34px 0 25px}.play-area{grid-template-columns:1fr;padding:10px}.number-pad{grid-template-columns:repeat(6,1fr);gap:5px}.number-pad button{aspect-ratio:auto;min-height:48px}.number-pad .tool{min-height:48px}.rules{grid-template-columns:1fr;gap:22px;padding:72px 0 82px}}@media(max-width:470px){.intro h1{font-size:3.8rem}.intro>p{font-size:.9rem}.difficulty button{padding:8px}.game-bar{grid-template-columns:auto auto auto;gap:8px;padding:9px}.game-bar p{grid-column:1/-1;grid-row:2}.game-bar>button{padding-inline:8px}.play-area{padding:7px}.board{border-width:2px}.cell{font-size:clamp(1rem,6vw,1.55rem)}.cell__notes{font-size:clamp(.38rem,2.2vw,.56rem)}.number-pad{grid-template-columns:repeat(6,1fr)}.number-pad button{min-height:44px}.tool strong{font-size:.62rem}.rules{padding-top:68px}footer{display:block}footer p{margin-top:6px}}@media(prefers-reduced-motion:reduce){*{transition:none!important}}