/* Shared top navigation — chat UI and Platform Overview */

:root {
  --header-h: 72px;
  --nav-purple-deep: #4e2a84;
  --nav-purple-mid: #6b3fa8;
  --nav-purple-glow: rgba(78, 42, 132, 0.18);
  --nav-cream: #faf7f2;
  --nav-cream-dark: #f0ebe3;
  --nav-ink-muted: #5c5468;
  --nav-white: #ffffff;
  --nav-font-display: "Fraunces", Georgia, serif;
  --nav-font-body: "Source Serif 4", Georgia, serif;
  --nav-ease-out: cubic-bezier(0.22, 1, 0.36, 1);
}

.site-header {
  height: var(--header-h);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
  border-bottom: 1px solid rgba(78, 42, 132, 0.1);
  background: rgba(250, 247, 242, 0.92);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 1100;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.875rem;
  text-decoration: none;
  color: inherit;
}

a.brand:hover .brand-title {
  color: var(--nav-purple-mid);
}

.brand-logo {
  display: block;
  height: 40px;
  width: auto;
  max-width: 56px;
  object-fit: contain;
  flex-shrink: 0;
  border-radius: 6px;
}

.brand-title {
  font-family: var(--nav-font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--nav-purple-deep);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.brand-sub {
  font-family: var(--nav-font-body);
  font-size: 0.75rem;
  color: var(--nav-ink-muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin: 0;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav-pill,
.nav-link-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 36px;
  font-family: var(--nav-font-body);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--nav-purple-deep);
  background: var(--nav-white);
  border: 1px solid rgba(78, 42, 132, 0.2);
  border-radius: 999px;
  padding: 0.45rem 1rem;
  text-decoration: none;
  white-space: nowrap;
  transition: all 0.2s var(--nav-ease-out);
  box-sizing: border-box;
}

.nav-pill:hover,
.nav-link-btn:hover {
  background: var(--nav-cream-dark);
  border-color: var(--nav-purple-mid);
  color: var(--nav-purple-deep);
}

.nav-pill--active {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  font-family: var(--nav-font-body);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--nav-white);
  background: var(--nav-purple-deep);
  border: 1px solid var(--nav-purple-deep);
  border-radius: 999px;
  padding: 0.45rem 1rem;
  white-space: nowrap;
  box-shadow: 0 4px 16px var(--nav-purple-glow);
}

.new-session-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  min-height: 36px;
  font-family: var(--nav-font-body);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--nav-purple-deep);
  background: var(--nav-white);
  border: 1px solid rgba(78, 42, 132, 0.2);
  border-radius: 999px;
  padding: 0.45rem 1rem;
  cursor: pointer;
  transition: all 0.2s var(--nav-ease-out);
}

.new-session-btn:hover {
  background: var(--nav-purple-deep);
  color: var(--nav-white);
  border-color: var(--nav-purple-deep);
  box-shadow: 0 4px 16px var(--nav-purple-glow);
}

.session-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 36px;
  font-family: var(--nav-font-body);
  font-size: 0.8rem;
  color: var(--nav-ink-muted);
  padding: 0.45rem 0.875rem;
  border-radius: 999px;
  background: var(--nav-white);
  border: 1px solid rgba(78, 42, 132, 0.12);
}

.session-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #3dba6d;
  flex-shrink: 0;
}