:root{--sky-top:#e0f7fa;--sky-bottom:#b7e3f5;--river:#4682b4;--river-deep:#2f5f8a;--land:#9acd32;--land-deep:#6b8e23;--sun:#fc0;--ink:#1f3648;--card:#fff;--muted:#5c7a8c;--good:#3f9e7d;--bad:#d9924d}*{box-sizing:border-box}html,body{margin:0;padding:0}body{color:var(--ink);background:linear-gradient(180deg, var(--sky-top) 0%, var(--sky-bottom) 100%) fixed;min-height:100vh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif}.shell{max-width:480px;padding:16px 12px calc(24px + env(safe-area-inset-bottom));flex-direction:column;gap:14px;margin:0 auto;display:flex}.card{background:var(--card);border-radius:14px;padding:12px;box-shadow:0 2px 10px #1f364814}.center-card{text-align:center}h1{margin:4px 0;font-size:1.5rem;font-weight:650}h2,p{margin:8px 0}.muted{color:var(--muted);font-size:.9rem}button{font:inherit;color:var(--ink);cursor:pointer;touch-action:manipulation;background:#eef6fa;border:1px solid #cfe3ee;border-radius:10px;padding:10px 16px}button.primary{background:var(--river);border-color:var(--river-deep);color:#fff;width:100%;padding:12px 20px;font-weight:600}button.secondary{width:100%;padding:12px 20px}button:active{transform:translateY(1px)}button.ghost{color:var(--muted);background:0 0;border:none;padding:2px 6px;font-size:.8rem}.home-head{text-align:center}.elo-card{flex-direction:column;align-items:center;gap:2px;padding:22px 12px;display:flex}.elo-value{color:var(--river-deep);font-size:2.6rem;font-weight:650;line-height:1.1}.elo-sub{font-size:.8rem}.home-link{margin-top:6px}.session{flex-direction:column;gap:12px;display:flex}.session-head{color:var(--muted);justify-content:space-between;align-items:center;padding:0 4px;font-size:.9rem;display:flex}.session-dots{gap:4px;display:flex}.dot{background:#cfe3ee;border-radius:50%;width:8px;height:8px;display:inline-block}.dot.done{background:var(--river)}.dot.now{background:var(--sun)}.puzzle{flex-direction:column;gap:12px;display:flex}.matrix{grid-template-columns:repeat(3,1fr);gap:6px;display:grid}.matrix-cell{aspect-ratio:1;background:#f6fbfd;border:1px solid #e2eef5;border-radius:8px;display:flex}.matrix-missing{background:#eaf4f9;border-style:dashed;border-color:#a9cde0}.panel-svg{width:100%;height:100%;display:block}.options{grid-template-columns:repeat(3,1fr);gap:8px;display:grid}.option{aspect-ratio:1;background:var(--card);border:2px solid #d6e7f0;border-radius:12px;padding:6px}.option:disabled{cursor:default;opacity:1}.option-correct{border-color:var(--good);box-shadow:0 0 0 2px #3f9e7d59}.option-wrong{border-color:var(--bad)}.option-dim{opacity:.45}.explain{background:#f2f9f6}.explain-head{margin-bottom:4px;font-weight:600}.explain ul{margin:4px 0 0;padding-left:20px}.explain li{margin:4px 0}.shell.wide{max-width:920px}.browse-head{align-items:center;gap:12px;display:flex}.browse-head h1{margin:0}.browse-intro{margin-top:0}.browse-section{flex-direction:column;gap:8px;margin-top:8px;display:flex}.section-title{margin:6px 0 0;font-size:1.05rem;font-weight:600}.cat-blurb{max-width:60ch;margin:0}.cat-grid{grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:12px;display:grid}.cat-card{flex-direction:column;gap:8px;display:flex}.cat-tag{margin:0;font-size:.78rem}.cat-explain{color:var(--muted);margin:0;padding-left:18px;font-size:.82rem}.cat-explain li{margin:2px 0}.matrix.mini{gap:3px}.mini-answer{border-color:var(--good);background:#eef7f2;border-style:dashed}