*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #f9f9fb;
  --surface: #ffffff;
  --text: #111118;
  --muted: #6b6b80;
  --faint: #9999aa;
  --border: #e4e4ec;
  --accent: #6366f1;
  --accent-light: #eef2ff;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.page {
  max-width: 680px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}

/* Back link */
.back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
  margin-bottom: 40px;
  letter-spacing: 0.01em;
  transition: color 0.15s ease;
}

.back:hover {
  color: var(--accent);
}

.back svg {
  width: 14px;
  height: 14px;
}

/* Header */
.doc-header {
  margin-bottom: 40px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border);
}

.app-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-light);
  padding: 3px 10px;
  border-radius: 20px;
  margin-bottom: 14px;
}

.doc-header h1 {
  font-size: 1.9rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  color: var(--text);
  margin-bottom: 10px;
}

.doc-meta {
  font-size: 0.82rem;
  color: var(--faint);
}

/* Content */
.doc-body h2 {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
  margin-top: 36px;
  margin-bottom: 10px;
}

.doc-body h2:first-child {
  margin-top: 0;
}

.doc-body p {
  color: var(--muted);
  margin-bottom: 12px;
}

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

.doc-body ul {
  color: var(--muted);
  padding-left: 20px;
  margin-bottom: 12px;
}

.doc-body li {
  margin-bottom: 6px;
}

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

.doc-body a:hover {
  text-decoration: underline;
}

.callout {
  background: #fffbeb;
  border-left: 3px solid #f59e0b;
  border-radius: 0 8px 8px 0;
  padding: 12px 16px;
  margin: 16px 0;
  font-size: 0.875rem;
  color: #78490a;
}

.section-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 32px 0;
}

/* Footer */
.doc-footer {
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--faint);
}

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

@media (max-width: 600px) {
  .page {
    padding: 32px 20px 60px;
  }

  .doc-header h1 {
    font-size: 1.5rem;
  }
}