/** Platform 2040 Header Toolkit v1
 * Apps own semantic header markup and navigation; this stylesheet supplies the
 * shared visual and responsive contract.
 */
[data-platform-header] {
  --platform-header-bg: rgba(246, 245, 241, .97);
  --platform-header-border: var(--line, #d8ddd7);
  --platform-header-ink: var(--ink, #18201b);
  --platform-header-muted: var(--muted, #5d6961);
  --platform-header-accent: var(--brand, #d90b32);
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  width: 100%;
  min-height: 52px;
  gap: 12px;
  padding: 8px 16px;
  border-bottom: 1px solid var(--platform-header-border);
  color: var(--platform-header-ink);
  background: var(--platform-header-bg);
  font-family: Manrope, Inter, system-ui, sans-serif;
  backdrop-filter: blur(14px);
}

[data-platform-header][data-platform-header-theme="dark"] {
  --platform-header-bg: rgba(10, 12, 15, .97);
  --platform-header-border: var(--line, #29313a);
  --platform-header-ink: var(--text, #eef2f4);
  --platform-header-muted: var(--muted, #a7b1ba);
}

[data-platform-brand] {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 8px;
  color: var(--platform-header-ink);
  font-size: 14px;
  font-weight: 800;
  text-decoration: none;
  white-space: nowrap;
}

[data-platform-brand] img {
  width: 28px;
  height: 28px;
  flex: 0 0 auto;
  border-radius: 6px;
  object-fit: contain;
}

[data-platform-nav] {
  display: flex;
  flex: 1 1 auto;
  min-width: 0;
  align-items: stretch;
  gap: 2px;
  overflow-x: auto;
  scrollbar-width: none;
}

[data-platform-nav]::-webkit-scrollbar { display: none; }

[data-platform-nav] a {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  min-height: 34px;
  padding: 6px 9px;
  border-bottom: 2px solid transparent;
  color: var(--platform-header-muted);
  font-size: 12px;
  font-weight: 700;
  line-height: 1;
  text-decoration: none;
  white-space: nowrap;
}

[data-platform-nav] a:hover,
[data-platform-nav] a:focus-visible {
  color: var(--platform-header-ink);
  background: color-mix(in srgb, var(--platform-header-accent) 8%, transparent);
}

[data-platform-nav] a:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--platform-header-accent) 25%, transparent);
  outline-offset: 1px;
}

[data-platform-nav] a[aria-current="page"] {
  border-bottom-color: var(--platform-header-accent);
  color: var(--platform-header-ink);
}

[data-platform-auth-slot] {
  flex: 0 0 auto;
  min-width: 88px;
  min-height: 32px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  color: var(--platform-header-muted);
  white-space: nowrap;
}

[data-platform-auth-slot] .ar-user-email[data-profile-link] {
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
}

[data-platform-nav] [hidden] { display: none !important; }

[data-platform-header-state="error"] [data-platform-auth-slot] {
  color: #8b1028;
  font-size: 12px;
  font-weight: 700;
}

@media (max-width: 720px) {
  [data-platform-header] { gap: 6px; padding-inline: 10px; }
  [data-platform-brand-label] { display: none; }
  [data-platform-nav] a { padding-inline: 7px; }
  [data-platform-auth-slot] { min-width: 72px; }
  [data-platform-auth-slot] .ar-user-email { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  [data-platform-header] * { scroll-behavior: auto !important; }
}