:root {
  --bg: #fafaf8;
  --surface: #ffffff;
  --ink: #1b1b1f;
  --ink-2: #4b4b55;
  --ink-3: #8a8a96;
  --line: #e6e5e0;
  --accent: #2f6fed;
  --accent-soft: #e8f0ff;
  --ok: #1a7f4b;
  --ok-soft: #e3f5ea;
  --radius: 14px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101114;
    --surface: #17181c;
    --ink: #ececf1;
    --ink-2: #b4b4c0;
    --ink-3: #7c7c8a;
    --line: #26272d;
    --accent: #7aa2ff;
    --accent-soft: #1b2540;
    --ok: #5fd08e;
    --ok-soft: #12301f;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg);
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
.wrap { max-width: 760px; margin: 0 auto; padding: 0 22px; }

/* header */
.hero {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding: 36px 0 32px;
}
.back { display: inline-block; font-size: 14px; color: var(--ink-3); margin-bottom: 22px; }
.app-id {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 15px; font-weight: 600; color: var(--ink-2);
  letter-spacing: .02em; text-transform: uppercase;
}
.app-icon {
  display: inline-grid; place-items: center;
  width: 40px; height: 40px; border-radius: 10px;
  background: var(--accent-soft); font-size: 22px;
}
h1 { font-size: clamp(30px, 5vw, 42px); line-height: 1.15; margin: 14px 0 8px; letter-spacing: -.02em; }
.meta { margin: 0; color: var(--ink-3); font-size: 15px; }
.meta time { color: var(--ink-2); font-weight: 500; }

/* body */
.intro { font-size: 19px; color: var(--ink-2); margin: 36px 0 28px; }
.intro p { margin: 0 0 14px; }

.toc {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px 18px;
  margin-bottom: 40px;
}
.toc ol { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 4px 20px; }
.toc a { display: flex; gap: 10px; font-size: 14.5px; color: var(--ink-2); padding: 4px 0; }
.toc a span { color: var(--ink-3); font-variant-numeric: tabular-nums; font-weight: 600; }
.toc a:hover { color: var(--accent); text-decoration: none; }

section {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 0 18px;
  padding: 30px 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 24px;
}
section:last-child { border-bottom: 1px solid var(--line); }
.num {
  font-size: 13px; font-weight: 700; color: var(--ink-3);
  letter-spacing: .08em; padding-top: 6px; font-variant-numeric: tabular-nums;
}
h2 { font-size: 22px; margin: 0 0 10px; letter-spacing: -.01em; line-height: 1.3; }
.body p { margin: 0 0 14px; }
.body p:last-child { margin-bottom: 0; }
.body ul { margin: 0 0 14px; padding-left: 22px; }
.body li { margin: 6px 0; }

.badge {
  display: inline-block;
  font-size: 13px; font-weight: 600;
  color: var(--ok); background: var(--ok-soft);
  padding: 4px 11px; border-radius: 999px;
  margin: 0 0 14px;
}
.badge::before { content: "✓ "; }

dl { margin: 4px 0 16px; padding: 4px 0; display: grid; grid-template-columns: max-content 1fr; gap: 10px 22px; }
dt { font-weight: 600; }
dd { margin: 0; color: var(--ink-2); }

.tbl { overflow-x: auto; margin: 4px 0 16px; border: 1px solid var(--line); border-radius: 10px; }
table { border-collapse: collapse; width: 100%; font-size: 15.5px; background: var(--surface); }
th, td { text-align: left; padding: 10px 14px; vertical-align: top; border-bottom: 1px solid var(--line); }
th { font-size: 13px; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-3); background: var(--bg); }
tr:last-child td { border-bottom: none; }

/* index cards */
.cards { display: grid; gap: 12px; margin: 36px 0; }
.card {
  display: grid; grid-template-columns: 40px 1fr auto; align-items: center; gap: 18px;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px 24px; color: var(--ink);
  transition: border-color .15s, transform .15s, box-shadow .15s;
}
.card:hover { border-color: var(--accent); text-decoration: none; transform: translateY(-1px); box-shadow: 0 6px 20px rgba(0,0,0,.06); }
.card .num { font-size: 13px; font-weight: 700; color: var(--ink-3); letter-spacing: .08em; font-variant-numeric: tabular-nums; }
.card .meta { display: grid; gap: 2px; min-width: 0; }
.card strong { font-size: 21px; letter-spacing: -.01em; line-height: 1.25; }
.card small { color: var(--ink-3); font-size: 14.5px; }
.card .side { display: grid; gap: 4px; justify-items: end; text-align: right; white-space: nowrap; }
.card .go { color: var(--accent); font-size: 14px; font-weight: 600; }
.card:hover .go { text-decoration: underline; }

footer {
  display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
  padding: 40px 22px 60px; color: var(--ink-3); font-size: 14px;
}

@media (max-width: 560px) {
  body { font-size: 16px; }
  section { grid-template-columns: 1fr; gap: 6px; padding: 26px 0; }
  .num { padding-top: 0; }
  dl { grid-template-columns: 1fr; gap: 2px 0; }
  dd { margin-bottom: 10px; }
  .card { grid-template-columns: 1fr; gap: 8px; padding: 18px 20px; }
  .card .num { display: none; }
  .card .side { justify-items: start; text-align: left; white-space: normal; }
}