:root {
  --bg: #f6f7f9; --card: #fff; --ink: #1d2330; --muted: #6b7280; --line: #e3e6eb; --accent: #2563eb;
  --hard: #15803d; --hard-bg: #dcfce7; --medium: #b45309; --medium-bg: #fef3c7;
  --easy: #475569; --easy-bg: #e2e8f0; --hold: #b91c1c; --hold-bg: #fee2e2;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #111418; --card: #1a1f26; --ink: #e6e9ee; --muted: #9aa3af; --line: #2b323c; --accent: #60a5fa;
    --hard: #4ade80; --hard-bg: #14321f; --medium: #fbbf24; --medium-bg: #3a2b0c;
    --easy: #cbd5e1; --easy-bg: #2a323d; --hold: #f87171; --hold-bg: #3b1515; }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink);
  font: 14px/1.55 -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", "Segoe UI", sans-serif; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
header { padding: 20px 16px 8px; max-width: 1400px; margin: 0 auto; }
header h1 { margin: 0 0 4px; font-size: 22px; }
header .sub { color: var(--muted); }
main { padding: 8px 16px 40px; max-width: 1400px; margin: 0 auto; }
table { border-collapse: collapse; width: 100%; background: var(--card); border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
th, td { padding: 9px 12px; border-bottom: 1px solid var(--line); text-align: right; white-space: nowrap; }
th:first-child, td:first-child, th:last-child, td:last-child { text-align: left; }
th { background: var(--bg); font-weight: 600; color: var(--muted); font-size: 13px; }
tr:last-child td { border-bottom: none; }
td.date a { font-weight: 600; font-size: 15px; }
.tablewrap { overflow-x: auto; }
.bar { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 8px 0 16px; position: sticky; top: 0;
  background: var(--bg); padding: 8px 0; z-index: 5; }
.chip { border: 1px solid var(--line); background: var(--card); color: var(--ink); border-radius: 999px; padding: 5px 12px; cursor: pointer; font: inherit; }
.chip.on { border-color: var(--accent); color: var(--accent); font-weight: 600; }
select, input[type=search] { border: 1px solid var(--line); background: var(--card); color: var(--ink); border-radius: 8px; padding: 6px 10px; font: inherit; }
input[type=search] { min-width: 220px; flex: 1; max-width: 360px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(360px, 1fr)); gap: 12px; }
@media (max-width: 420px) { .grid { grid-template-columns: 1fr; } input[type=search] { min-width: 0; } }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 12px 14px; display: flex; flex-direction: column; gap: 6px; min-width: 0; }
.top { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; color: var(--muted); font-size: 13px; }
.lv { font-weight: 700; font-size: 12px; padding: 2px 8px; border-radius: 6px; text-transform: uppercase; }
.lv.hard { color: var(--hard); background: var(--hard-bg); } .lv.medium { color: var(--medium); background: var(--medium-bg); }
.lv.easy { color: var(--easy); background: var(--easy-bg); } .lv.hold { color: var(--hold); background: var(--hold-bg); }
.task { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: 12.5px; word-break: break-all; }
.zh { font-size: 14px; } .en { color: var(--muted); font-size: 12.5px; }
.lbl { color: var(--muted); font-size: 12px; margin-right: 4px; }
.holdr { color: var(--hold); font-size: 13px; }
.meta { color: var(--muted); font-size: 12px; word-break: break-all; }
details { font-size: 12px; color: var(--muted); } details summary { cursor: pointer; }
details div { word-break: break-all; margin-top: 4px; }
.play { align-self: flex-start; border: 1px solid var(--accent); color: var(--accent); background: transparent; border-radius: 8px; padding: 5px 12px; cursor: pointer; font: inherit; }
video { width: 100%; border-radius: 8px; background: #000; aspect-ratio: 1920 / 1200; }
.more { text-align: center; color: var(--muted); padding: 24px; }
.login { position: fixed; inset: 0; background: var(--bg); display: flex; align-items: center; justify-content: center; z-index: 50; }
.login form { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 28px; width: min(340px, 92vw); display: flex; flex-direction: column; gap: 10px; }
.login h2 { margin: 0; } .login p { margin: 0; color: var(--muted); }
.login input { border: 1px solid var(--line); background: var(--bg); color: var(--ink); border-radius: 8px; padding: 9px 10px; font: inherit; }
.login button { background: var(--accent); color: #fff; border: 0; border-radius: 8px; padding: 9px; font: inherit; cursor: pointer; }
.login .err { color: var(--hold); min-height: 1.2em; }
.empty { color: var(--muted); padding: 40px 0; text-align: center; }