:root{--bg:#fbfaf8;--ink:#1d2430;--muted:#5d6978;--card:#fff;--line:#e4e1da;--accent:#c2570a}
@media(prefers-color-scheme:dark){:root{--bg:#0f141a;--ink:#e6edf3;--muted:#9aa7b6;--card:#161d26;--line:#26303c;--accent:#ff9d3d}}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;display:flex;flex-direction:column;min-height:100vh}
.bar{display:flex;justify-content:space-between;align-items:flex-end;gap:12px;flex-wrap:wrap;padding:16px 20px 6px}
.bar h1{font-size:1.5rem;margin:.1em 0 0}.crumb{font-size:13px;color:var(--muted);text-decoration:none}
.actions{display:flex;gap:8px;flex-wrap:wrap}
button,.btn{font:inherit;font-size:14px;padding:6px 12px;border-radius:8px;border:1px solid var(--line);background:var(--card);color:var(--ink);cursor:pointer}
button:hover,.btn:hover{border-color:var(--accent)}.primary{background:var(--accent);border-color:var(--accent);color:#fff}
.hint{margin:0;padding:0 20px 12px;color:var(--muted);font-size:14px;max-width:980px}.hint a{color:var(--accent)}
main{flex:1;display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1.2fr);gap:14px;padding:0 20px 20px;min-height:0}
@media(max-width:900px){main{grid-template-columns:1fr}.preview iframe{min-height:70vh}}
.editor{display:flex;flex-direction:column;gap:8px;min-width:0}
.tabs{display:flex;gap:4px;flex-wrap:wrap}
.tabs button{font:13px ui-monospace,Menlo,Consolas,monospace;padding:4px 10px;border-radius:6px 6px 0 0}
.tabs button[aria-selected=true]{background:var(--ink);color:var(--bg);border-color:var(--ink)}
.namebar{display:flex;gap:8px;align-items:center;color:var(--muted);font-size:13px}
.namebar input{flex:1;font:13px ui-monospace,Menlo,Consolas,monospace;padding:4px 8px;border:1px solid var(--line);border-radius:6px;background:var(--card);color:var(--ink)}
.namebar input:disabled{opacity:.6}
#text{flex:1;min-height:360px;resize:vertical;font:13.5px/1.5 ui-monospace,Menlo,Consolas,monospace;padding:12px;border-radius:8px;border:1px solid var(--line);background:#141a22;color:#e6edf3;tab-size:4}
.row{display:flex;gap:8px}
.problems{list-style:none;margin:0;padding:0;font-size:13px}
.problems li{padding:6px 10px;border-radius:6px;margin-top:4px;background:color-mix(in srgb,#d33 12%,transparent);color:var(--ink)}
.problems li.ok{background:color-mix(in srgb,#2a2 14%,transparent)}
.preview{min-width:0}.preview iframe{width:100%;height:100%;min-height:600px;border:1px solid var(--line);border-radius:10px;background:var(--card)}