:root{--fg:#1d2433;--muted:#5b6475;--bg:#f6f7f9;--card:#fff;--accent:#0b5cad;--bad:#a4262c;color-scheme:light}
*{box-sizing:border-box}
body{margin:0;font:16px/1.5 system-ui,-apple-system,"Segoe UI",sans-serif;color:var(--fg);background:var(--bg)}
header,footer{padding:12px 20px;color:var(--muted);font-size:14px}
header{background:var(--card);border-bottom:1px solid #e3e6eb;display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px}
header strong{color:var(--fg)}
main{max-width:640px;margin:24px auto;padding:24px;background:var(--card);border-radius:8px;border:1px solid #e3e6eb}
@media (max-width:680px){main{margin:16px;padding:16px}}
h1{font-size:24px;margin-top:0}
a{color:var(--accent)}
.button,button{display:inline-block;background:var(--accent);color:#fff;border:0;border-radius:6px;padding:10px 18px;font:inherit;text-decoration:none;cursor:pointer}
.problem{color:var(--bad);font-weight:600}
.note{background:#fff4ce;padding:8px 12px;border-radius:6px}
.tap{font:600 32px/1.2 ui-monospace,Consolas,monospace;letter-spacing:2px;background:#eef4fb;padding:16px;border-radius:8px;text-align:center;word-break:break-all}
dt{color:var(--muted);font-size:14px}dd{margin:0 0 12px}
main.wide{max-width:1200px}
.scroll{overflow-x:auto}
table{border-collapse:collapse;width:100%;font-size:14px}
th,td{text-align:left;vertical-align:top;padding:8px;border-bottom:1px solid #e3e6eb}
th{color:var(--muted);font-weight:600;white-space:nowrap}
.sub{color:var(--muted);font-size:12px}
.pill{display:inline-block;padding:2px 8px;border-radius:10px;font-size:12px;font-weight:600;white-space:nowrap}
.pill.ok{background:#dff6dd;color:#107c10}.pill.warn{background:#fff4ce;color:#7a5c00}.pill.bad{background:#fde7e9;color:var(--bad)}
.tabs{font-size:14px}