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

:root {
  --bg: #ffffff;
  --surface: #f7f6f3;
  --surface-hover: #efefec;
  --border: #e9e9e7;
  --text-primary: #37352f;
  --text-secondary: #787774;
  --text-tertiary: #b0aeaa;
  --accent: #2eaadc;
  --radius: 10px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  min-height: 100vh;
}

/* ── Nav ── */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
}

.nav-inner {
  max-width: 640px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 52px;
}

.nav-logo {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.2px;
}

.nav-links {
  display: flex;
  gap: 4px;
}

.nav-link {
  font-size: 13.5px;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 6px 10px;
  border-radius: 6px;
  transition: background 0.15s ease, color 0.15s ease;
}

.nav-link:hover {
  background: var(--surface);
  color: var(--text-primary);
}

.nav-link.active {
  color: var(--text-primary);
  background: var(--surface);
}

/* ── Page layout ── */
.page {
  max-width: 640px;
  margin: 0 auto;
  padding: 56px 24px 80px;
}

/* ── Page header ── */
.page-header {
  margin-bottom: 40px;
}

.page-title {
  font-size: 26px;
  font-weight: 600;
  letter-spacing: -0.4px;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.page-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ── Divider ── */
.divider {
  height: 1px;
  background: var(--border);
  margin: 32px 0;
}

/* ── Prose ── */
.prose p {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

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

/* ── Section label ── */
.section-label {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  margin-bottom: 14px;
}

/* ── Tag / Chip ── */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  font-size: 12px;
  padding: 3px 10px;
  border-radius: 20px;
  background: var(--surface);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

/* ── Card ── */
.card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  transition: background 0.15s ease;
}

.card:hover {
  background: var(--surface);
}

.card + .card {
  margin-top: 10px;
}

.card-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.card-meta {
  font-size: 12px;
  color: var(--text-tertiary);
  margin-bottom: 10px;
}

.card-desc {
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--text-secondary);
}

.card-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 12.5px;
  color: var(--accent);
  text-decoration: none;
  margin-top: 12px;
  transition: opacity 0.15s ease;
}

.card-link:hover {
  opacity: 0.75;
}

/* ── Social icons ── */
.social-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text-secondary);
  text-decoration: none;
  transition: background 0.15s ease, color 0.15s ease, transform 0.1s ease;
  border: 1px solid var(--border);
}

.social-btn:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
  transform: translateY(-1px);
}

.social-btn:active {
  transform: translateY(0);
}

.social-btn svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* ── Footer ── */
.footer {
  text-align: center;
  margin-top: 56px;
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ── Contact row ── */
.contact-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: color 0.15s ease;
}

.contact-row:first-child {
  border-top: 1px solid var(--border);
}

.contact-row:hover .contact-label {
  color: var(--text-primary);
}

.contact-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--surface);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--text-secondary);
}

.contact-icon svg {
  width: 16px;
  height: 16px;
}

.contact-label {
  font-size: 14px;
  color: var(--text-secondary);
  transition: color 0.15s ease;
  flex: 1;
}

.contact-arrow {
  color: var(--text-tertiary);
  font-size: 16px;
}

@media (max-width: 480px) {
  .page { padding: 40px 16px 64px; }
  .page-title { font-size: 22px; }
  .nav-inner { padding: 0; }
}