header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--color-bg) 86%, transparent);
  border-bottom: 1px solid var(--color-border);
}

.header-wrap {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--sp4);
  padding-block: var(--sp3);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: var(--sp3);
  min-width: 0;
}

.logo-mark {
  width: 2rem;
  height: 2rem;
  border-radius: 0.75rem;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  box-shadow: var(--shadow-sm);
  flex-shrink: 0;
}

.logo-text {
  min-width: 0;
}

.logo-title {
  display: block;
  font-family: var(--fh);
  font-size: var(--text-lg);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
}

.logo-subtitle {
  display: block;
  margin-top: 0.2rem;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.header-nav {
  display: flex;
  justify-content: center;
  gap: var(--sp2);
  flex-wrap: wrap;
}

.header-nav a {
  font-size: var(--text-sm);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--sp2);
}

.contact-chip {
  white-space: nowrap;
  color: var(--color-primary);
  background: var(--color-primary-hl);
}

.theme-btn {
  width: 2.5rem;
  height: 2.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.theme-btn:hover {
  background: var(--color-surface-offset);
}

.theme-btn svg {
  width: 1rem;
  height: 1rem;
}

@media (max-width: 760px) {
  .header-wrap {
    grid-template-columns: auto auto;
    grid-template-areas:
      "logo actions"
      "nav nav";
    align-items: start;
  }

  .logo {
    grid-area: logo;
  }

  .header-nav {
    grid-area: nav;
    justify-content: flex-start;
  }

  .header-actions {
    grid-area: actions;
    justify-content: flex-end;
    flex-wrap: wrap;
  }
}