:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-soft: #f5f5f7;
  --text: #1d1d1f;
  --text-secondary: #6e6e73;
  --line: #d2d2d7;
  --accent: #0066cc;
  --max: 680px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #000000;
    --bg-soft: #1d1d1f;
    --text: #f5f5f7;
    --text-secondary: #a1a1a6;
    --line: #424245;
    --accent: #2997ff;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", "Segoe UI", Roboto, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

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

header.site {
  border-bottom: 1px solid var(--line);
}

header.site .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 52px;
}

.brand {
  color: var(--text);
  font-weight: 600;
  font-size: 19px;
  letter-spacing: -0.01em;
}

.brand:hover {
  text-decoration: none;
}

nav.site {
  display: flex;
  gap: 20px;
  font-size: 14px;
}

nav.site a {
  color: var(--text-secondary);
}

nav.site a[aria-current="page"] {
  color: var(--text);
}

main {
  padding: 48px 0 64px;
}

h1 {
  font-size: 40px;
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-weight: 700;
  margin: 0 0 12px;
}

h2 {
  font-size: 24px;
  line-height: 1.25;
  letter-spacing: -0.01em;
  font-weight: 600;
  margin: 40px 0 12px;
}

h3 {
  font-size: 19px;
  font-weight: 600;
  margin: 28px 0 8px;
}

p,
ul,
ol {
  margin: 0 0 16px;
}

ul,
ol {
  padding-left: 22px;
}

li {
  margin-bottom: 6px;
}

.lead {
  font-size: 21px;
  line-height: 1.4;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.meta {
  font-size: 14px;
  color: var(--text-secondary);
}

.button {
  display: inline-block;
  background: var(--text);
  color: var(--bg);
  border-radius: 980px;
  padding: 11px 22px;
  font-size: 17px;
  font-weight: 500;
}

.button:hover {
  text-decoration: none;
  opacity: 0.85;
}

.features {
  list-style: none;
  padding: 0;
  margin: 40px 0;
  border-top: 1px solid var(--line);
}

.features li {
  padding: 18px 0;
  margin: 0;
  border-bottom: 1px solid var(--line);
}

.features strong {
  display: block;
  font-weight: 600;
  margin-bottom: 2px;
}

.features span {
  color: var(--text-secondary);
}

.note {
  background: var(--bg-soft);
  border-radius: 14px;
  padding: 18px 20px;
  font-size: 15px;
  color: var(--text-secondary);
}

.note p:last-child {
  margin-bottom: 0;
}

.toc {
  font-size: 15px;
  background: var(--bg-soft);
  border-radius: 14px;
  padding: 18px 20px 18px 40px;
}

.toc li {
  margin-bottom: 4px;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
  margin: 0 0 20px;
}

th,
td {
  text-align: left;
  vertical-align: top;
  padding: 10px 12px 10px 0;
  border-bottom: 1px solid var(--line);
}

th {
  font-weight: 600;
}

.table-scroll {
  overflow-x: auto;
}

address {
  font-style: normal;
}

footer.site {
  border-top: 1px solid var(--line);
  padding: 20px 0 32px;
  font-size: 12px;
  color: var(--text-secondary);
}

footer.site .wrap {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 20px;
}

footer.site nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

footer.site a {
  color: var(--text-secondary);
}

@media (max-width: 600px) {
  body {
    font-size: 16px;
  }

  main {
    padding: 32px 0 48px;
  }

  h1 {
    font-size: 32px;
  }

  h2 {
    font-size: 21px;
  }

  .lead {
    font-size: 19px;
  }

  nav.site {
    gap: 14px;
  }
}