:root {
  color-scheme: light dark;
  --accent: #108a7a;
  --accent-strong: #066c60;
  --ink: #17201f;
  --muted: #5f6f6b;
  --line: #dce7e4;
  --surface: #ffffff;
  --surface-soft: #f5faf8;
  --shadow: 0 18px 46px rgba(16, 138, 122, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  background: var(--surface-soft);
  color: var(--ink);
}

body {
  margin: 0;
  line-height: 1.72;
}

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

a:hover {
  text-decoration: underline;
}

.page {
  width: min(960px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 56px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 10px 0 26px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: inherit;
}

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

.app-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  color: #ffffff;
  font-weight: 800;
  letter-spacing: 0;
  background:
    radial-gradient(circle at 72% 24%, rgba(255, 255, 255, 0.72), transparent 22%),
    linear-gradient(145deg, #34d399, #108a7a 55%, #2563eb);
  box-shadow: 0 12px 28px rgba(16, 138, 122, 0.24);
}

.brand-title {
  display: block;
  font-size: 17px;
  font-weight: 700;
}

.brand-subtitle {
  display: block;
  margin-top: -2px;
  color: var(--muted);
  font-size: 13px;
}

.nav {
  display: flex;
  gap: 14px;
  color: var(--muted);
  font-size: 15px;
}

.hero,
.doc-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
}

.hero {
  padding: clamp(28px, 6vw, 58px);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent-strong);
  font-size: 14px;
  font-weight: 700;
}

h1 {
  margin: 0;
  max-width: 760px;
  font-size: clamp(34px, 6vw, 58px);
  line-height: 1.08;
  letter-spacing: 0;
}

.lead {
  max-width: 720px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 16px;
  border-radius: 10px;
  border: 1px solid var(--line);
  color: var(--ink);
  background: var(--surface);
  font-weight: 700;
}

.button.primary {
  border-color: transparent;
  color: #ffffff;
  background: var(--accent);
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.tile {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
}

.tile h2 {
  margin: 0 0 8px;
  font-size: 20px;
}

.tile p {
  margin: 0;
  color: var(--muted);
}

.doc-card {
  padding: clamp(24px, 5vw, 46px);
}

.meta {
  margin: 16px 0 30px;
  color: var(--muted);
  font-size: 14px;
}

.toc {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px 18px;
  padding: 16px;
  margin: 24px 0 34px;
  border-radius: 12px;
  background: var(--surface-soft);
}

section {
  padding-top: 8px;
  margin-top: 24px;
  border-top: 1px solid var(--line);
}

h2 {
  margin: 0 0 10px;
  font-size: 22px;
  line-height: 1.28;
  letter-spacing: 0;
}

p,
li {
  color: var(--muted);
}

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

.notice {
  padding: 14px 16px;
  border-radius: 12px;
  background: rgba(16, 138, 122, 0.09);
  color: var(--accent-strong);
}

.footer {
  margin-top: 28px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

@media (max-width: 720px) {
  .topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .nav {
    width: 100%;
    justify-content: space-between;
  }

  .grid,
  .toc {
    grid-template-columns: 1fr;
  }

  .hero,
  .doc-card {
    border-radius: 14px;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #eef7f4;
    --muted: #a9bbb6;
    --line: #27403a;
    --surface: #101816;
    --surface-soft: #0a100f;
    --shadow: none;
  }
}