/* Header layout & branding for BODNARUK-PROF-HOM Anatolii Bodnaruk */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
}

.header-brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
}

.logo-emblem {
  position: relative;
  width: 42px;
  height: 42px;
  border-radius: 18px;
  background: radial-gradient(circle at 20% 20%, var(--color-accent-coral), transparent 55%),
              radial-gradient(circle at 80% 80%, var(--color-primary), transparent 55%),
              var(--color-neutral-50);
  box-shadow: var(--shadow-medium);
  overflow: hidden;
}

.logo-frame {
  position: absolute;
  inset: 8px 7px 10px 7px;
  border-radius: 14px;
  border: 2px solid rgba(18, 32, 51, 0.14);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.8);
}

.logo-sparkle {
  position: absolute;
  top: 5px;
  right: 4px;
  width: 12px;
  height: 12px;
  background:
    radial-gradient(circle at 50% 0%, #ffffff 0, #ffffff 35%, transparent 36%),
    radial-gradient(circle at 50% 100%, rgba(255, 255, 255, 0.7) 0, transparent 60%);
  transform: rotate(18deg);
  border-radius: 4px;
  opacity: 0.9;
}

.logo-chip {
  position: absolute;
  left: 6px;
  bottom: 5px;
  width: 18px;
  height: 18px;
  border-radius: 999px;
  background: conic-gradient(from 180deg, var(--color-primary), var(--color-accent-sand), var(--color-accent-coral), var(--color-primary));
  box-shadow: 0 6px 14px rgba(12, 26, 75, 0.4);
}

.logo-chip::after {
  content: "";
  position: absolute;
  inset: 4px;
  border-radius: inherit;
  background: radial-gradient(circle at 30% 20%, #ffffff, #ffece6);
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.logo-title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.03em;
}

.logo-subtitle {
  font-size: var(--font-size-xs);
  color: var(--color-text-soft);
}

/* Navigation */
.primary-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.nav-link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-soft);
  padding: 0.35rem 0.15rem;
  position: relative;
}

.nav-link::after {
  content: "";
  position: absolute;
  inset-inline: 0;
  bottom: -0.25rem;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent-coral));
  opacity: 0;
  transform: scaleX(0.5);
  transform-origin: center;
  transition: opacity var(--transition-normal), transform var(--transition-normal);
}

.nav-link:hover::after,
.nav-link:focus-visible::after {
  opacity: 1;
  transform: scaleX(1);
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--color-text);
}

.nav-item-cta {
  margin-left: var(--space-3);
}

.header-cta {
  font-size: var(--font-size-xs);
}

/* Mobile navigation toggle */
.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-2);
  padding: 0.4rem 0.75rem;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(15, 31, 56, 0.12);
  background-color: rgba(255, 255, 255, 0.9);
  font-size: var(--font-size-xs);
  font-weight: 500;
}

.nav-toggle-box {
  position: relative;
  width: 18px;
  height: 14px;
}

.nav-toggle-line {
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent-coral));
  transition: transform var(--transition-normal), opacity var(--transition-normal), top var(--transition-normal), bottom var(--transition-normal);
}

.nav-toggle-line:first-child {
  top: 2px;
}

.nav-toggle-line:last-child {
  bottom: 2px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:first-child {
  top: 6px;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:last-child {
  bottom: 6px;
  transform: rotate(-45deg);
}

.nav-toggle-label {
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.nav-toggle:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Mobile nav overlay */
.mobile-nav-overlay {
  position: fixed;
  inset: 0;
  background: linear-gradient(145deg, rgba(11, 26, 54, 0.5), rgba(11, 26, 54, 0.3));
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 30;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.mobile-nav-overlay.is-visible {
  opacity: 1;
  pointer-events: auto;
}

/* Mobile navigation panel */
@media (max-width: 768px) {
  .primary-nav {
    position: fixed;
    inset-inline: 0;
    top: 64px;
    background: rgba(255, 255, 255, 0.98);
    border-bottom: 1px solid var(--color-border-subtle);
    box-shadow: 0 18px 40px rgba(6, 22, 61, 0.18);
    transform: translateY(-110%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
  }

  .primary-nav.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-list {
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-4);
    gap: var(--space-3);
  }

  .nav-item-cta {
    width: 100%;
    margin-left: 0;
    margin-top: var(--space-2);
  }

  .header-cta {
    width: 100%;
    justify-content: center;
  }

  .nav-toggle {
    display: inline-flex;
  }
}

@media (max-width: 480px) {
  .logo-subtitle {
    display: none;
  }
}

@media (min-width: 769px) {
  .mobile-nav-overlay {
    display: none;
  }
}