/* nano-vllm-omni drills · hints — shared styles (light + dark) */
:root {
  --bg: #f7f6f2;
  --surface: #ffffff;
  --surface-2: #f0eee8;
  --border: #dedad0;
  --text: #22211e;
  --muted: #6b675e;
  --accent: #2f6fdb;
  --accent-soft: #e3ecfb;
  --code-bg: #f3f1ec;
  --l1: #2e8b57;
  --l1-soft: #e4f3ea;
  --l2: #b7791f;
  --l2-soft: #fbf0dc;
  --l3: #c0392b;
  --l3-soft: #fbe5e2;
  --ok: #2e8b57;
  --bad: #c0392b;
  --ax-t: #2f6fdb;
  --ax-h: #d9822b;
  --ax-w: #2e9e6b;
  --hl: #ffcf4d;
  --hl-soft: #fff3c4;
  --shadow: 0 1px 2px rgba(0, 0, 0, .05), 0 2px 8px rgba(0, 0, 0, .04);
  --radius: 10px;
  --font: "PingFang SC", "Hiragino Sans GB", "Noto Sans CJK SC", "Source Han Sans SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", "SFMono-Regular", "Cascadia Code", Menlo, Consolas, "Noto Sans Mono CJK SC", monospace;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #17181b;
    --surface: #1f2125;
    --surface-2: #26282d;
    --border: #363a41;
    --text: #e6e4df;
    --muted: #a19d94;
    --accent: #7aa7ff;
    --accent-soft: #23314d;
    --code-bg: #24262b;
    --l1: #5cc98b;
    --l1-soft: #1d3327;
    --l2: #e6b25c;
    --l2-soft: #3a2f1b;
    --l3: #f08070;
    --l3-soft: #3d2320;
    --ok: #5cc98b;
    --bad: #f08070;
    --ax-t: #7aa7ff;
    --ax-h: #f0a35e;
    --ax-w: #5ccf9a;
    --hl: #d9a520;
    --hl-soft: #3d3418;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #17181b;
  --surface: #1f2125;
  --surface-2: #26282d;
  --border: #363a41;
  --text: #e6e4df;
  --muted: #a19d94;
  --accent: #7aa7ff;
  --accent-soft: #23314d;
  --code-bg: #24262b;
  --l1: #5cc98b;
  --l1-soft: #1d3327;
  --l2: #e6b25c;
  --l2-soft: #3a2f1b;
  --l3: #f08070;
  --l3-soft: #3d2320;
  --ok: #5cc98b;
  --bad: #f08070;
  --ax-t: #7aa7ff;
  --ax-h: #f0a35e;
  --ax-w: #5ccf9a;
  --hl: #d9a520;
  --hl-soft: #3d3418;
  --shadow: 0 1px 2px rgba(0, 0, 0, .4);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15.5px/1.75 var(--font);
  overflow-x: hidden;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ------------------------------------------------------------ top bar */
.topbar {
  position: sticky; top: 0; z-index: 20;
  display: flex; align-items: center; gap: 12px;
  padding: 8px 16px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}
.topbar .home { font-weight: 600; color: var(--text); white-space: nowrap; }
.topbar .spacer { flex: 1; }
.topbar .nav a { margin-left: 10px; white-space: nowrap; }
.btn {
  appearance: none; border: 1px solid var(--border); background: var(--surface);
  color: var(--text); border-radius: 8px; padding: 4px 10px; font: inherit; font-size: 13px;
  cursor: pointer; line-height: 1.5;
}
.btn:hover { border-color: var(--accent); }
.btn:disabled { opacity: .4; cursor: default; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }

/* ------------------------------------------------------------ layout */
.page { max-width: 920px; margin: 0 auto; padding: 24px 16px 80px; }
.hero { margin: 8px 0 20px; }
.hero .kicker { color: var(--muted); font-size: 13px; letter-spacing: .04em; }
.hero h1 { font-size: 28px; line-height: 1.3; margin: 4px 0 10px; }
.hero .lede { color: var(--muted); margin: 0 0 12px; }
.badges { display: flex; flex-wrap: wrap; gap: 6px; margin: 8px 0; }
.badge {
  display: inline-flex; align-items: center; gap: 4px;
  border: 1px solid var(--border); background: var(--surface);
  border-radius: 999px; padding: 1px 10px; font-size: 12.5px; color: var(--muted);
}
.badge b { color: var(--text); font-weight: 600; }
.badge.diff-易 b { color: var(--ok); }
.badge.diff-中 b { color: var(--l2); }
.badge.diff-难 b { color: var(--bad); }
.done-toggle { margin-left: auto; }
.done-toggle input { margin-right: 6px; }

.toc {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 10px 14px; margin: 16px 0 24px; font-size: 14px;
}
.toc b { font-size: 13px; color: var(--muted); }
.toc ol { margin: 4px 0 0; padding-left: 20px; columns: 2; column-gap: 24px; }
@media (max-width: 640px) { .toc ol { columns: 1; } }

h2 {
  font-size: 21px; margin: 40px 0 12px; padding-top: 8px;
  border-top: 1px solid var(--border);
  scroll-margin-top: 60px;
}
h3 { font-size: 17px; margin: 24px 0 8px; scroll-margin-top: 60px; }
h4 { font-size: 15.5px; margin: 18px 0 6px; }
p, ul, ol { margin: 8px 0; }
li { margin: 2px 0; }
hr { border: 0; border-top: 1px dashed var(--border); margin: 20px 0; }
blockquote {
  margin: 12px 0; padding: 6px 14px; border-left: 3px solid var(--accent);
  background: var(--accent-soft); border-radius: 0 8px 8px 0;
}
blockquote p { margin: 4px 0; }

code {
  font-family: var(--mono); font-size: .86em;
  background: var(--code-bg); border: 1px solid var(--border);
  padding: 0 4px; border-radius: 4px;
}
pre {
  background: var(--code-bg); border: 1px solid var(--border); border-radius: 8px;
  padding: 10px 12px; overflow-x: auto; font-size: 13px; line-height: 1.55;
  margin: 10px 0;
}
pre code { background: none; border: 0; padding: 0; font-size: inherit; }

.table-wrap { overflow-x: auto; margin: 10px 0; }
table { border-collapse: collapse; font-size: 13.5px; min-width: 60%; background: var(--surface); }
th, td { border: 1px solid var(--border); padding: 5px 9px; text-align: left; vertical-align: top; }
th { background: var(--surface-2); font-weight: 600; }
td code, th code { font-size: .9em; }

/* ------------------------------------------------------------ callouts */
.callout {
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface);
  padding: 10px 14px; margin: 14px 0; box-shadow: var(--shadow);
}
.callout > .callout-title { font-weight: 600; margin-bottom: 4px; }
.callout.analogy { border-left: 4px solid var(--ax-h); }
.callout.warn { border-left: 4px solid var(--bad); }
.callout.info { border-left: 4px solid var(--accent); }
.callout.ok { border-left: 4px solid var(--ok); }

/* ------------------------------------------------------------ hint levels */
details.hint {
  border: 1px solid var(--border); border-radius: var(--radius); margin: 14px 0;
  background: var(--surface); box-shadow: var(--shadow);
}
details.hint > summary {
  cursor: pointer; list-style: none; padding: 10px 14px; font-weight: 600;
  display: flex; align-items: center; gap: 10px; border-radius: var(--radius);
}
details.hint > summary::-webkit-details-marker { display: none; }
details.hint > summary::after { content: "展开 ▸"; margin-left: auto; font-size: 12px; color: var(--muted); font-weight: 400; }
details.hint[open] > summary::after { content: "收起 ▾"; }
details.hint[open] > summary { border-bottom: 1px solid var(--border); border-radius: var(--radius) var(--radius) 0 0; }
details.hint > .body { padding: 6px 16px 14px; }
.lvl { display: inline-block; border-radius: 6px; padding: 0 8px; font-size: 12px; font-weight: 700; }
details.hint.l1 > summary { background: var(--l1-soft); }
details.hint.l2 > summary { background: var(--l2-soft); }
details.hint.l3 > summary { background: var(--l3-soft); }
details.hint.l1 .lvl { background: var(--l1); color: #fff; }
details.hint.l2 .lvl { background: var(--l2); color: #fff; }
details.hint.l3 .lvl { background: var(--l3); color: #fff; }
.spoiler-note { font-size: 12px; color: var(--muted); font-weight: 400; }

details.answer {
  border: 1px dashed var(--border); border-radius: 8px; margin: 10px 0; background: var(--surface-2);
}
details.answer > summary { cursor: pointer; padding: 6px 12px; color: var(--accent); font-size: 14px; }
details.answer > .body { padding: 2px 14px 10px; }

/* ------------------------------------------------------------ stepper */
.stepper {
  border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface);
  margin: 16px 0; box-shadow: var(--shadow); overflow: hidden;
}
.stepper > .st-head {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  padding: 8px 12px; background: var(--surface-2); border-bottom: 1px solid var(--border);
}
.stepper .st-title { font-weight: 600; }
.stepper .st-count { color: var(--muted); font-size: 13px; font-family: var(--mono); }
.stepper .st-ctrl { margin-left: auto; display: flex; gap: 6px; }
.stepper .st-dots { display: flex; flex-wrap: wrap; gap: 4px; padding: 8px 12px 0; }
.stepper .st-dot {
  width: 22px; height: 22px; border-radius: 50%; border: 1px solid var(--border);
  background: var(--surface); font-size: 11px; cursor: pointer; color: var(--muted); padding: 0;
  font-family: var(--mono);
}
.stepper .st-dot.on { background: var(--accent); border-color: var(--accent); color: #fff; }
.stepper .st-dot.seen:not(.on) { border-color: var(--accent); color: var(--accent); }
.stepper .step { padding: 8px 14px 12px; }
.stepper .step > .step-title { font-weight: 600; margin: 4px 0 6px; color: var(--accent); }
.stepper.js .step { display: none; }
.stepper.js .step.active { display: block; animation: fadein .18s ease; }
.stepper:not(.js) .step + .step { border-top: 1px dashed var(--border); }
.stepper .st-diagram { padding: 10px 12px 0; }
@keyframes fadein { from { opacity: .3; } to { opacity: 1; } }

/* ------------------------------------------------------------ diagrams */
.diagram { overflow-x: auto; }
.diagram svg { display: block; max-width: 100%; height: auto; margin: 0 auto; }
.diagram svg text { fill: var(--text); font-family: var(--font); }
.diagram svg .muted-text { fill: var(--muted); }
.diagram svg .node rect, .diagram svg .node ellipse, .diagram svg .node circle {
  fill: var(--surface); stroke: var(--border); stroke-width: 1.5; transition: fill .2s, stroke .2s;
}
.diagram svg .node.state rect { fill: var(--surface-2); }
.diagram svg .node.hl rect, .diagram svg .node.hl ellipse, .diagram svg .node.hl circle {
  fill: var(--hl-soft); stroke: var(--hl); stroke-width: 2.5;
}
.diagram svg .edge { stroke: var(--muted); stroke-width: 1.4; fill: none; transition: stroke .2s; }
.diagram svg .edge.submit { stroke-dasharray: 5 4; stroke: var(--ax-h); }
.diagram svg .edge.hl { stroke: var(--hl); stroke-width: 3; }
.diagram svg .arrowhead { fill: var(--muted); }

/* grids of cells (block tables, positions, buffers) */
.cells { display: inline-flex; flex-wrap: wrap; gap: 3px; vertical-align: middle; }
.cell {
  min-width: 26px; height: 26px; padding: 0 4px; border: 1px solid var(--border); border-radius: 5px;
  display: inline-flex; align-items: center; justify-content: center;
  font: 12px/1 var(--mono); background: var(--surface);
}
.cell.t, .ax-t { color: var(--ax-t); }
.cell.h, .ax-h { color: var(--ax-h); }
.cell.w, .ax-w { color: var(--ax-w); }
.cell.t { background: color-mix(in srgb, var(--ax-t) 14%, var(--surface)); border-color: var(--ax-t); }
.cell.h { background: color-mix(in srgb, var(--ax-h) 14%, var(--surface)); border-color: var(--ax-h); }
.cell.w { background: color-mix(in srgb, var(--ax-w) 14%, var(--surface)); border-color: var(--ax-w); }
.cell.on { background: var(--hl-soft); border-color: var(--hl); }
.cell.off { opacity: .45; }
.cell.bad { background: var(--l3-soft); border-color: var(--bad); color: var(--bad); }
.cell.ok { background: var(--l1-soft); border-color: var(--ok); color: var(--ok); }
.cell.gap { border-style: dashed; }
.ok-text { color: var(--ok); font-weight: 600; }
.bad-text { color: var(--bad); font-weight: 600; }
.muted { color: var(--muted); }
.small { font-size: 13px; }

/* ------------------------------------------------------------ footer nav */
.pager {
  display: flex; justify-content: space-between; gap: 12px; margin-top: 48px;
  border-top: 1px solid var(--border); padding-top: 16px; font-size: 14px;
}
.pager a {
  display: block; max-width: 48%; padding: 8px 12px; border: 1px solid var(--border);
  border-radius: 8px; background: var(--surface);
}
.pager a small { display: block; color: var(--muted); }
.pager .next { text-align: right; margin-left: auto; }

/* ------------------------------------------------------------ index */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 12px; margin: 12px 0 24px; }
.card {
  position: relative; display: block; border: 1px solid var(--border); background: var(--surface);
  border-radius: var(--radius); padding: 12px 14px; color: var(--text); box-shadow: var(--shadow);
  transition: border-color .15s, transform .15s;
}
.card:hover { border-color: var(--accent); text-decoration: none; transform: translateY(-1px); }
.card .num { font: 12px var(--mono); color: var(--muted); }
.card .id { font: 700 13px var(--mono); color: var(--accent); margin-left: 6px; }
.card .ttl { font-weight: 600; margin: 4px 0 6px; line-height: 1.45; }
.card .meta { font-size: 12.5px; color: var(--muted); }
.card.done { opacity: .7; }
.card.done .ttl::before { content: "✓ "; color: var(--ok); }
.card .chk { position: absolute; top: 10px; right: 12px; }
.track-head { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; }
.track-head h2 { border: 0; margin-bottom: 0; }
.track-head .muted { font-size: 14px; }
.progress { height: 8px; background: var(--surface-2); border-radius: 999px; overflow: hidden; border: 1px solid var(--border); }
.progress > div { height: 100%; background: var(--ok); width: 0; transition: width .3s; }
.legend { display: flex; flex-wrap: wrap; gap: 10px; font-size: 13.5px; }
.legend span { display: inline-flex; gap: 6px; align-items: center; }

@media (max-width: 640px) {
  body { font-size: 15px; }
  .hero h1 { font-size: 23px; }
  .topbar .nav .lbl { display: none; }
}

@media print {
  .topbar, .pager, .st-ctrl, .st-dots { display: none !important; }
  details { open: true; }
  .stepper.js .step { display: block !important; }
}