:root{--paper:#f5f2ea;--paper-deep:#ebe6da;--ink:#18263a;--muted:#7d8490;--line:#cbd0d2;--blue:#315f88;--blue-soft:#dce9f1;--blue-pale:#edf4f7;--gold:#d7a74e;--danger:#bd554a;--white:#fffef9}*{box-sizing:border-box}html{background:var(--paper);-webkit-tap-highlight-color:transparent;min-height:100%}body{background:radial-gradient(circle at 15% -10%, #ffffffeb, transparent 35rem), linear-gradient(180deg, #f8f6f0 0%, var(--paper) 60%, #f0ece3 100%);min-height:100%;color:var(--ink);font-synthesis:none;margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif}button,select,input{font:inherit}button{color:inherit}button:focus-visible,a:focus-visible{outline-offset:3px;outline:3px solid #315f8861}.app-shell{width:min(100%,580px);min-height:100vh;padding:0 20px calc(22px + env(safe-area-inset-bottom));margin:0 auto}.topbar{justify-content:space-between;align-items:center;height:76px;display:flex}.brand{color:var(--ink);letter-spacing:-.035em;font-family:Georgia,Songti SC,serif;font-size:19px;font-weight:680;text-decoration:none;display:inline-block}.header-actions{gap:9px;display:flex}.round-button{cursor:pointer;background:#ffffff7a;border:1px solid #18263a21;border-radius:50%;place-items:center;width:40px;height:40px;font-size:22px;font-weight:400;display:grid;box-shadow:0 2px 12px #212c360a}.game-heading{justify-content:space-between;align-items:flex-end;padding:12px 2px 18px;display:flex}.eyebrow{color:var(--blue);letter-spacing:.18em;text-transform:uppercase;margin:0 0 4px;font-size:11px;font-weight:800}h1,h2,p{margin-top:0}h1{letter-spacing:-.06em;margin-bottom:0;font-family:Georgia,Songti SC,STSong,serif;font-size:clamp(38px,9vw,50px);font-weight:650;line-height:1}.difficulty-chip{color:var(--blue);cursor:pointer;background:#ffffff7a;border:1px solid #315f8838;border-radius:999px;margin-bottom:2px;padding:8px 12px 8px 14px;font-size:13px;font-weight:750}.difficulty-chip span{margin-left:7px}.score-strip{background:#ffffff80;border:1px solid #18263a1a;border-radius:16px;grid-template-columns:1fr 1px 1fr 1px 1fr auto;align-items:center;min-height:59px;margin-bottom:17px;padding:8px 10px 8px 18px;display:grid;box-shadow:0 8px 30px #232e380a}.score-strip>div{flex-direction:column;gap:1px;display:flex}.score-strip span{color:var(--muted);letter-spacing:.08em;font-size:10px;font-weight:650}.score-strip strong{font-variant-numeric:tabular-nums;letter-spacing:.02em;font-size:16px}.score-strip>i{background:#18263a1a;width:1px;height:23px}.pause-button{background:var(--ink);color:#fff;cursor:pointer;border:0;border-radius:12px;width:38px;height:38px;font-size:13px}.board-wrap{background:var(--ink);border-radius:10px;width:100%;padding:5px;position:relative;box-shadow:0 15px 40px 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button.selected-option{border-color:var(--blue);background:var(--blue-pale)}.win-backdrop{align-items:center}.win-modal{text-align:center;border-radius:24px;padding:32px 25px 25px}.win-badge{background:var(--blue);color:#fff;width:62px;height:62px;box-shadow:0 0 0 9px var(--blue-soft);border-radius:50%;place-items:center;margin:0 auto 18px;font-size:28px;display:grid}.win-stats{color:var(--muted);justify-content:center;gap:30px;margin:20px 0;font-size:12px;display:flex}.win-stats strong{color:var(--ink);margin-top:2px;font-size:21px;display:block}.primary-button{background:var(--ink);color:#fff;cursor:pointer;border:0;border-radius:14px;width:100%;height:50px;font-weight:750}.text-button{color:var(--blue);cursor:pointer;background:0 0;border:0;margin-top:10px;padding:10px 20px;font-weight:750}.toast{left:50%;bottom:calc(24px + env(safe-area-inset-bottom));z-index:80;background:var(--ink);color:#fff;pointer-events:none;opacity:0;border-radius:999px;max-width:calc(100% - 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