:root {
  color-scheme: light dark;
  --background: #f5f7fa;
  --surface: #ffffff;
  --text: #172033;
  --muted: #586275;
  --border: #d9dee8;
  --accent: #2563d8;
  --accent-strong: #174aa8;
  --nav: #172033;
  --nav-text: #ffffff;
  --radius: 8px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #0d121b;
    --surface: #151d29;
    --text: #f4f7fb;
    --muted: #aeb8c8;
    --border: #303b4c;
    --accent: #74a7ff;
    --accent-strong: #a9c8ff;
    --nav: #080c13;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-size: 17px;
  line-height: 1.62;
}

a { color: var(--accent); }
a:hover { color: var(--accent-strong); }

.site-header {
  background: var(--nav);
  color: var(--nav-text);
  border-bottom: 1px solid color-mix(in srgb, var(--nav-text) 18%, transparent);
}

.nav {
  max-width: 1040px;
  min-height: 64px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  color: var(--nav-text);
  font-size: 21px;
  font-weight: 750;
  text-decoration: none;
}

.nav-links { display: flex; gap: 22px; }
.nav-links a { color: #dbe6f8; text-decoration: none; font-size: 15px; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: #ffffff; text-decoration: underline; }

main {
  width: min(100% - 32px, 880px);
  margin: 46px auto 72px;
}

.hero { margin-bottom: 32px; }
.hero h1 { margin: 0 0 8px; font-size: clamp(34px, 7vw, 54px); line-height: 1.08; }
.hero p { max-width: 700px; margin: 0; color: var(--muted); font-size: 19px; }

.document, .support-grid article {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: clamp(24px, 5vw, 46px);
}

.document h2 { margin-top: 36px; font-size: 24px; line-height: 1.25; }
.document h2:first-child { margin-top: 0; }
.document h3 { margin-top: 26px; font-size: 19px; }
.document ul { padding-left: 24px; }
.document li + li { margin-top: 8px; }
.effective { color: var(--muted); font-size: 15px; }

.support-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.support-grid article { padding: 26px; }
.support-grid h2 { margin: 0 0 8px; font-size: 21px; }
.support-grid p { margin: 0; color: var(--muted); }

.button {
  display: inline-block;
  margin-top: 18px;
  padding: 10px 16px;
  color: #ffffff;
  background: #2563d8;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 650;
}

.button:hover { color: #ffffff; background: #174aa8; }

.notice {
  border-left: 4px solid var(--accent);
  background: color-mix(in srgb, var(--accent) 9%, var(--surface));
  padding: 16px 18px;
  margin: 24px 0;
}

footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 14px;
}

.footer-inner {
  max-width: 1040px;
  margin: 0 auto;
  padding: 28px 24px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}

.footer-links { display: flex; gap: 18px; flex-wrap: wrap; }

@media (max-width: 680px) {
  .nav { align-items: flex-start; flex-direction: column; padding-block: 16px; }
  .nav-links { width: 100%; justify-content: space-between; gap: 12px; }
  .support-grid { grid-template-columns: 1fr; }
  main { margin-top: 32px; }
}