:root{--bg:#f7f8fb;--ink:#14213d;--mute:#5b6577;--line:#d9dde7;--card:#fff;--grid:#e9ecf3;--c-math:#2f6fde;--c-physics:#d6453d;--c-language:#2e9e5b;--c-misc:#b7791f;color-scheme:light dark}
@media (prefers-color-scheme:dark){:root{--bg:#10151f;--ink:#e8ecf4;--mute:#9aa5b8;--line:#2c3649;--card:#171e2b;--grid:#19212f;--c-math:#6b9bff;--c-physics:#ff6b61;--c-language:#4fcf86;--c-misc:#e9b44c}}
*{box-sizing:border-box}
body{margin:0;min-height:100vh;display:flex;flex-direction:column;background-color:var(--bg);background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:32px 32px;color:var(--ink);font:17px/1.55 "Avenir Next","Segoe UI",system-ui,sans-serif;padding:env(safe-area-inset-top,0) 0 env(safe-area-inset-bottom,0)}
main{flex:1}
.wrap{max-width:1000px;margin:0 auto;padding:0 20px}
header{border-bottom:1px solid var(--line);background:var(--bg)}
.bar{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 24px;padding-top:12px;padding-bottom:12px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink);text-decoration:none;font-weight:700;font-size:19px;letter-spacing:-.01em}
nav{display:flex;flex-wrap:wrap;gap:4px 18px;font-size:15px}
nav a{color:var(--mute);text-decoration:none}nav a:hover{color:var(--ink);text-decoration:underline}
h1{font-size:clamp(30px,6vw,46px);line-height:1.1;letter-spacing:-.02em;margin:44px 0 12px}
.lead{max-width:34em;color:var(--mute);font-size:18px;margin:0 0 30px}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:16px;margin-bottom:48px}
.card{display:flex;gap:16px;align-items:flex-start;background:var(--card);border:1px solid var(--line);border-left:5px solid var(--accent);border-radius:14px;padding:18px;color:inherit;text-decoration:none;transition:transform .15s,box-shadow .15s}
.card:hover{transform:translateY(-2px);box-shadow:0 6px 18px rgba(20,33,61,.12)}
.card img{flex:none;width:64px;height:64px}
.card h2{font-size:20px;line-height:1.25;margin:2px 0 4px}
.card p{margin:0;color:var(--mute);font-size:15.5px}
.card .meta{margin-top:8px;font-size:14px;color:var(--ink);font-weight:600}
.back{display:inline-block;margin-top:24px;color:var(--mute);font-size:15px;text-decoration:none}.back:hover{color:var(--ink);text-decoration:underline}
.pagehead{display:flex;gap:18px;align-items:center;margin:14px 0 26px}
.pagehead img{width:72px;height:72px;flex:none}
.pagehead h1{margin:0 0 4px;font-size:clamp(26px,5vw,38px)}
.pagehead p{margin:0;color:var(--mute)}
.empty{border:2px dashed var(--line);border-radius:14px;padding:26px;color:var(--mute);margin-bottom:48px;background:var(--card)}
.empty b{display:block;color:var(--ink);margin-bottom:4px}
footer{border-top:1px solid var(--line);padding:16px 0;color:var(--mute);font-size:14px;background:var(--bg)}
a:focus-visible{outline:2px solid var(--c-math);outline-offset:3px;border-radius:6px}
@media (prefers-reduced-motion:reduce){.card{transition:none}.card:hover{transform:none}}