:root{--paper:#fffaf0;--paper-deep:#f7e7c6;--panel:#fffdfa;--shelf:#fff4d9;--ink:#2b251d;--muted:#736651;--line:#dfc895;--green-deep:#2f6844;--green-dark:#183b29;--gold:#e7bb52;--white:#fff;--danger:#a8493d}
*{box-sizing:border-box}html{color-scheme:light}body{margin:0;min-width:320px;background:linear-gradient(#2f684406 1px,transparent 1px),var(--paper);background-size:100% 28px;color:var(--ink);font-family:"Yu Gothic","Hiragino Kaku Gothic ProN","Noto Sans JP",system-ui,sans-serif;line-height:1.7}button,input{font:inherit}a{color:var(--green-deep)}[hidden]{display:none!important}button,a{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,input:focus-visible{outline:3px solid var(--gold);outline-offset:3px}.skip-link{position:fixed;top:8px;left:8px;z-index:100;padding:8px 12px;background:var(--green-dark);color:white;transform:translateY(-160%)}.skip-link:focus{transform:none}.site-header{border-bottom:1px solid #dfc895e6;background:#fffdfaf5}.header-inner{display:flex;align-items:center;gap:24px;width:min(1320px,calc(100% - 32px));min-height:58px;margin:auto}.site-logo{flex:0 0 auto;color:var(--green-dark);font-family:Georgia,"Times New Roman",serif;font-size:22px;font-weight:800;letter-spacing:.035em;text-decoration:none}.site-nav{display:flex;flex:1 1 auto;gap:4px;overflow-x:auto;scrollbar-width:thin}.site-nav a{flex:0 0 auto;padding:7px 9px;border-radius:5px;color:var(--ink);font-size:13px;font-weight:700;text-decoration:none;white-space:nowrap}.site-nav a:hover{background:var(--shelf);color:var(--green-deep)}.page-shell{width:min(1100px,calc(100% - 32px));margin:18px auto 42px}main{min-width:0}main:focus{outline:none}.ad-rail{display:none}.hero{margin:0 0 14px;padding:12px 4px 4px}.eyebrow{margin:0 0 4px;color:var(--green-deep);font-size:11px;font-weight:900;letter-spacing:.17em}h1,h2,p{overflow-wrap:anywhere}h1{margin:0;color:var(--green-dark);font-family:Georgia,"Yu Mincho","Hiragino Mincho ProN",serif;font-size:clamp(30px,4.1vw,42px);line-height:1.16;letter-spacing:.015em}h2{margin:0;color:var(--green-dark);font-size:clamp(21px,2.8vw,28px);line-height:1.35}.hero>p:last-child{margin:8px 0 0;color:var(--muted);font-size:15px;font-weight:700}.panel{border:1px solid var(--line);border-radius:8px;background:#fffdfaf7;box-shadow:0 12px 30px #2d33231a}.intro{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:20px 22px;margin-bottom:18px}.intro p{margin:7px 0 0;color:var(--muted)}button{min-height:44px;padding:9px 18px;border:1px solid var(--green-deep);border-radius:6px;background:var(--green-deep);color:white;box-shadow:0 4px 0 var(--green-dark);font-weight:900;cursor:pointer;flex-shrink:0}button:hover{background:var(--green-dark)}button:active{box-shadow:none;transform:translateY(2px)}button:disabled{opacity:.62;cursor:default}.game{padding:14px 18px 18px;margin-bottom:18px}.game-heading{display:flex;align-items:center;justify-content:space-between;gap:8px}.game-heading h2{font-size:22px}#phase{padding:3px 10px;border-radius:20px;background:var(--shelf);font-size:12px;white-space:nowrap}.metrics{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin:10px 0}.metrics p{display:flex;justify-content:space-between;gap:4px;margin:0;padding:5px 10px;border:1px solid var(--line);border-radius:5px;background:var(--paper);font-size:12px}.metrics strong{font-size:16px;color:var(--green-dark);font-variant-numeric:tabular-nums}.game-body{display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:18px;align-items:center}.stage{margin:0;padding:12px;border-radius:6px;background:var(--green-dark);color:var(--paper)}.dig-site{position:relative;max-width:420px;aspect-ratio:1.2;margin:auto;overflow:hidden;border:4px solid #997447;border-radius:5px;background:#31553c;box-shadow:inset 0 0 36px #0005}#fossil{display:block;position:absolute;inset:0;width:100%;height:100%;fill:none;stroke:#f9eac5;stroke-width:8;stroke-linejoin:round;stroke-linecap:round}.tiles{position:absolute;inset:0;display:grid;grid-template-columns:repeat(3,1fr);grid-template-rows:repeat(3,1fr)}.tile{position:relative;display:flex;flex-direction:column;align-items:center;justify-content:center;border:1px solid #5c402b;color:#fffaf0;isolation:isolate;overflow:hidden}.tile::before{position:absolute;inset:0;z-index:-1;content:"";background:radial-gradient(ellipse at 22% 28%,#d0a971 0 2px,transparent 3px),radial-gradient(ellipse at 76% 77%,#493728 0 2px,transparent 3px),#8b6040;background-size:24px 29px,37px 33px,auto;transition:opacity .3s}.tile[data-layers="1"]::before{opacity:.57}.tile[data-layers="0"]{border-color:#eee3}.tile[data-layers="0"]::before{opacity:0}.tile strong{padding:0 6px;border-radius:4px;background:#503323e6;font-size:clamp(17px,2vw,22px);line-height:1.5;letter-spacing:.05em}.tile small{padding:0 4px;background:#503323e6;font-size:10px;border-radius:3px}.tile.dug::after{content:"✦ · ✧ ·";position:absolute;inset:10%;color:#f2d898;pointer-events:none;animation:crumbs .5s ease-out both}.tile[data-layers="0"] strong,.tile[data-layers="0"] small{display:none}.stage figcaption{text-align:center;font-size:11px;margin-top:6px;min-height:19px}.controls{min-width:0}form{padding:14px;border:1px solid var(--line);border-radius:6px;background:var(--shelf)}label{display:block;margin-bottom:6px;font-size:14px;font-weight:900;color:var(--green-dark)}.input-row{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:8px}input{min-width:0;width:100%;min-height:44px;padding:7px 10px;border:2px solid var(--green-deep);border-radius:6px;color:var(--ink);font-size:20px;background:white}#hint{min-height:40px;margin:6px 0 0;font-size:12px;color:var(--muted)}#hint.error{color:var(--danger)}.play-note{font-size:13px;color:var(--muted);margin:12px 0}.result{border:2px solid var(--green-deep);border-radius:6px;background:var(--shelf);padding:16px}.result h2{font-size:24px}.result p{margin:8px 0;font-size:14px}.section{padding:18px 20px;margin-bottom:18px}.section ol{padding-left:1.4em;margin:10px 0 0}.section>p:last-child{font-size:13px;color:var(--muted)}.related>div{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:8px;margin-top:10px}.related a{padding:10px 12px;border:1px solid var(--line);border-radius:5px;background:var(--paper);font-weight:800;text-decoration:none}.site-footer{padding:24px 16px 28px;border-top:1px solid var(--line);background:var(--green-dark);color:white;text-align:center}.site-footer nav{display:flex;flex-wrap:wrap;justify-content:center;gap:8px 18px}.site-footer a{color:white;font-size:13px;font-weight:700}.site-footer p{margin:14px 0 0;color:#ffffffc7;font-size:12px}.is-playing #howto,.is-playing #related{display:none}.is-playing .hero{padding-top:4px;margin-bottom:10px}.is-playing .hero>p:last-child{font-size:13px;margin-top:4px}.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}@keyframes crumbs{from{opacity:1;transform:translateY(0)}to{opacity:0;transform:translateY(45px)}}
@media(max-width:760px){.header-inner{display:block;width:min(100% - 24px,720px);padding:8px 0 6px}.site-logo{display:inline-block;margin-bottom:4px}.site-nav{width:100%}.site-nav a{padding:6px 8px;font-size:12px}.page-shell{width:min(100% - 24px,720px);margin-top:10px}.hero{padding-top:5px}.hero>p:last-child{font-size:13px}.intro{display:block;padding:16px}.intro button{margin-top:14px}.game{padding:12px}.game-body{grid-template-columns:1fr;gap:10px}.dig-site{max-width:300px}.stage{padding:8px}.related>div{grid-template-columns:1fr}.play-note{margin:6px 0;font-size:12px}.play-note br{display:none}.metrics p{padding:4px 6px;font-size:11px}.metrics strong{font-size:14px}.result{padding:12px}.result h2{font-size:22px}form{padding:10px}#hint{min-height:20px}.is-playing .page-shell{margin-bottom:18px}}@media(max-width:430px){.page-shell{width:calc(100% - 20px)}.game-heading h2{font-size:20px}.dig-site{max-width:270px}.tile strong{font-size:19px}.tile small{font-size:9px}.section{padding:16px}.metrics{gap:5px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
/* The prepared board is visible before input is enabled. */
.is-ready .hero{padding-top:4px;margin-bottom:10px}.is-ready .hero>p:last-child{font-size:13px;margin-top:4px}.is-ready .intro{padding:10px 16px;margin-bottom:10px}.is-ready .intro h2{font-size:18px}.is-ready .intro p{display:none}.is-ready .game-body{grid-template-columns:1fr}.is-ready .controls{display:none}.is-ready .stage{width:100%;max-width:600px;margin:auto}.is-ready .intro button{margin-top:0}.is-ready .intro{display:flex;gap:12px;align-items:center;justify-content:space-between}
@media(max-width:760px){.is-ready .intro{padding:8px 12px}.is-ready .intro h2{font-size:16px}.is-ready .intro button{padding:8px 12px;font-size:13px}.is-ready .stage{max-width:100%}.is-ready .page-shell{margin-bottom:18px}}
.is-ready .dig-site{max-width:320px}@media(max-width:760px){.is-ready .dig-site{max-width:270px}}