:root {
  --brand: #0e7c8a;
  --brand-dark: #0a5f6a;
  --accent: #20c6d7;
  --warm: #ef4c68;
  --ink: #191a1f;
  --body: #33363d;
  --muted: #6b7280;
  --line: #e3e8ea;
  --bg: #ffffff;
  --panel: #f6f8f9;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #f2f4f5;
    --body: #c8ced4;
    --muted: #949ba4;
    --line: #2a2f35;
    --bg: #16181c;
    --panel: #1e2126;
    --brand: #2fb3c4;
    --brand-dark: #63d3e0;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--body);
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-text-size-adjust: 100%;
}

.wrap { max-width: 720px; margin: 0 auto; padding: 0 20px; }

/* ---------- header ---------- */
.site-head {
  border-bottom: 1px solid var(--line);
  background: var(--panel);
}
.site-head .wrap { padding-top: 18px; padding-bottom: 14px; }
.brand {
  display: inline-block;
  font-size: 19px;
  font-weight: 700;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: -0.01em;
}
.brand span { color: var(--brand); }
.tagline { margin: 2px 0 0; font-size: 14px; color: var(--muted); }

.site-nav { margin-top: 12px; display: flex; flex-wrap: wrap; gap: 6px 14px; }
.site-nav a {
  font-size: 14px;
  color: var(--body);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}
.site-nav a:hover { color: var(--brand); border-bottom-color: var(--brand); }
.site-nav a[aria-current="page"] { color: var(--brand); font-weight: 600; }

/* ---------- type ---------- */
main { padding: 32px 0 8px; }
h1 {
  font-size: 30px;
  line-height: 1.25;
  color: var(--ink);
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}
h2 {
  font-size: 21px;
  line-height: 1.3;
  color: var(--ink);
  margin: 34px 0 10px;
  letter-spacing: -0.01em;
}
p { margin: 0 0 16px; }
.lead { font-size: 18.5px; color: var(--body); }
a { color: var(--brand); }
a:hover { color: var(--brand-dark); }

ol, ul { margin: 0 0 16px; padding-left: 22px; }
li { margin-bottom: 8px; }
li::marker { color: var(--brand); }

/* ---------- illustration ---------- */
.hero-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 480px;
  margin: 0 auto 26px;
}

/* ---------- callout ---------- */
.note {
  background: var(--panel);
  border-left: 3px solid var(--brand);
  border-radius: 0 8px 8px 0;
  padding: 14px 16px;
  margin: 0 0 18px;
  font-size: 16px;
}
.note strong { color: var(--ink); }
.note--warn { border-left-color: var(--warm); }

/* ---------- tool link ---------- */
.tool {
  display: block;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px 18px;
  margin: 0 0 18px;
  text-decoration: none;
  background: var(--bg);
  transition: border-color .15s ease;
}
.tool:hover { border-color: var(--brand); }
.tool b { display: block; color: var(--brand); font-size: 16.5px; margin-bottom: 2px; }
.tool span { display: block; color: var(--muted); font-size: 14.5px; }

/* ---------- hub cards ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
  margin: 24px 0 8px;
  padding: 0;
  list-style: none;
}
.cards li { margin: 0; }
.cards a {
  display: block;
  height: 100%;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px;
  text-decoration: none;
  background: var(--panel);
  transition: border-color .15s ease, transform .15s ease;
}
.cards a:hover { border-color: var(--brand); transform: translateY(-2px); }
.cards img { width: 100%; height: auto; display: block; margin-bottom: 12px; }
.cards b { display: block; color: var(--ink); font-size: 16.5px; line-height: 1.35; margin-bottom: 4px; }
.cards span { display: block; color: var(--muted); font-size: 14.5px; line-height: 1.5; }

/* ---------- more list ---------- */
.more { border-top: 1px solid var(--line); margin-top: 40px; padding-top: 22px; }
.more h2 { margin-top: 0; font-size: 17px; }
.more ul { list-style: none; padding: 0; }
.more li { margin-bottom: 7px; font-size: 15.5px; }

/* ---------- footer ---------- */
.site-foot {
  border-top: 1px solid var(--line);
  margin-top: 44px;
  padding: 22px 0 40px;
  font-size: 14px;
  color: var(--muted);
}
.site-foot p { margin: 0 0 8px; }
.site-foot a { color: var(--muted); }
.site-foot a:hover { color: var(--brand); }

@media (max-width: 520px) {
  body { font-size: 16.5px; }
  h1 { font-size: 26px; }
  main { padding-top: 24px; }
}