:root {
  --bg: #f6f7fb;
  --bg-soft: #ffffff;
  --card: #ffffff;
  --text: #14161c;
  --muted: #5b6472;
  --line: #e4e7ee;
  --brand: #1f6feb;
  --brand-2: #0ea5a5;
  --brand-soft: #eef4ff;
  --radius: 18px;
  --shadow: 0 1px 2px rgba(16, 24, 40, .04), 0 12px 32px rgba(16, 24, 40, .07);
  --max: 900px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1017;
    --bg-soft: #12161f;
    --card: #151a24;
    --text: #eef1f6;
    --muted: #9aa4b4;
    --line: #232a37;
    --brand: #6ea8ff;
    --brand-2: #4fd1c5;
    --brand-soft: #16203a;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 14px 34px rgba(0, 0, 0, .35);
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }
h1, h2, h3 { overflow-wrap: break-word; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 20px; }

.site-header {
  position: sticky; top: 0; z-index: 20;
  background: var(--bg);
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--line);
}

.site-header .bar {
  display: flex; align-items: center; gap: 14px;
  min-height: 62px; flex-wrap: wrap;
}

.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; letter-spacing: -.01em; }
.brand:hover { text-decoration: none; }
.brand-mark { width: 30px; height: 30px; flex: 0 0 auto; display: block; object-fit: contain; }

.nav { display: flex; gap: 4px; margin-left: auto; flex-wrap: wrap; }
.nav a {
  color: var(--muted); font-size: 14.5px; font-weight: 500;
  padding: 8px 12px; border-radius: 10px;
}
.nav a:hover { background: var(--brand-soft); color: var(--brand); text-decoration: none; }
.nav a[aria-current="page"] { color: var(--brand); background: var(--brand-soft); }

.hero { padding: 56px 0 28px; text-align: center; }
.hero .kicker {
  display: inline-block; font-size: 12.5px; font-weight: 700; letter-spacing: .08em;
  text-transform: uppercase; color: var(--brand);
  background: var(--brand-soft); padding: 6px 12px; border-radius: 999px;
}
.hero h1 { font-size: clamp(28px, 5vw, 42px); line-height: 1.15; letter-spacing: -.02em; margin: 18px 0 12px; }
.hero p { color: var(--muted); font-size: 17px; max-width: 620px; margin: 0 auto; }

.cards { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); padding: 22px 0 8px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; box-shadow: var(--shadow); display: flex; flex-direction: column; gap: 8px;
  transition: transform .18s ease, border-color .18s ease;
}
.card:hover { transform: translateY(-2px); border-color: color-mix(in srgb, var(--brand) 35%, var(--line)); }
.card h2 { font-size: 17.5px; margin: 0; letter-spacing: -.01em; }
.card p { margin: 0; color: var(--muted); font-size: 14.5px; }
.card .go { margin-top: auto; padding-top: 8px; font-weight: 600; font-size: 14.5px; }

main { padding: 8px 0 64px; }

.page-head { padding: 40px 0 10px; }
.page-head h1 { font-size: clamp(26px, 4.4vw, 36px); letter-spacing: -.02em; margin: 0 0 10px; line-height: 1.2; }
.page-head .meta { color: var(--muted); font-size: 14.5px; }

.panel {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: clamp(20px, 4vw, 36px); margin-top: 22px;
}

.toc {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 14px;
  padding: 16px 18px; margin: 0 0 26px;
}
.toc strong { display: block; font-size: 13px; letter-spacing: .06em; text-transform: uppercase; color: var(--muted); margin-bottom: 8px; }
.toc ol { margin: 0; padding-left: 20px; columns: 2; column-gap: 26px; font-size: 14.5px; }
.toc li { break-inside: avoid; margin-bottom: 4px; }
@media (max-width: 620px) { .toc ol { columns: 1; } }

h2 { font-size: 20px; letter-spacing: -.01em; margin: 34px 0 10px; scroll-margin-top: 84px; }
h3 { font-size: 16.5px; margin: 22px 0 6px; }
p, li { color: var(--text); }
p { margin: 0 0 12px; }
ul, ol { margin: 0 0 14px; padding-left: 22px; }
li { margin-bottom: 7px; }
li > ul { margin-top: 7px; }
strong { font-weight: 650; }

.note {
  border-left: 3px solid var(--brand); background: var(--brand-soft);
  border-radius: 10px; padding: 14px 16px; margin: 18px 0; font-size: 15px;
}
.note p:last-child { margin-bottom: 0; }

table { width: 100%; border-collapse: collapse; margin: 14px 0 18px; font-size: 14.8px; }
th, td { text-align: left; padding: 11px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-size: 13px; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); font-weight: 700; }
tr:last-child td { border-bottom: 0; }
.table-scroll { overflow-x: auto; }

.site-footer { border-top: 1px solid var(--line); background: var(--bg-soft); padding: 26px 0 34px; }
.site-footer .inner { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; justify-content: space-between; color: var(--muted); font-size: 14px; }
.site-footer nav { display: flex; gap: 14px; flex-wrap: wrap; }

@media (max-width: 620px) {
  .site-header .bar {
    flex-direction: column; align-items: center; justify-content: center;
    text-align: center; gap: 6px;
    min-height: auto; padding-top: 12px; padding-bottom: 8px;
  }
  .brand { justify-content: center; text-align: center; }
  .brand-mark { width: 34px; height: 34px; }
  .nav { margin-left: 0; width: 100%; justify-content: center; }
  .site-footer { padding: 22px 0 28px; }
  .site-footer .inner {
    flex-direction: column; align-items: center; justify-content: center; text-align: center;
  }
  .site-footer nav { justify-content: center; }
  .hero { padding: 34px 0 16px; }
  .hero h1 { font-size: clamp(25px, 7vw, 34px); }
}