/* ==========================================================================
   Header / Top Bar Styles
   ========================================================================== */

.header {
  height: var(--header-height);
  background: var(--glass-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  padding: 0 1.75rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 90;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.mobile-menu-btn {
  display: none;
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  background: var(--bg-surface-elevated);
  color: var(--text-primary);
  align-items: center;
  justify-content: center;
}

.page-breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.breadcrumb-root {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.breadcrumb-separator {
  color: var(--text-muted);
  font-size: 0.8rem;
}

.breadcrumb-current {
  font-size: 0.95rem;
  color: var(--text-primary);
  font-weight: 600;
}

/* Header Right Actions */
.header-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Exam Countdown Badge */
.countdown-badge {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: linear-gradient(135deg, rgba(79, 70, 229, 0.1), rgba(6, 182, 212, 0.1));
  border: 1px solid rgba(79, 70, 229, 0.2);
  padding: 0.45rem 0.9rem;
  border-radius: var(--radius-full);
  color: var(--primary);
  font-weight: 600;
  font-size: 0.82rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.countdown-badge:hover {
  border-color: var(--primary);
  box-shadow: 0 2px 8px var(--primary-glow);
}

.countdown-pulse {
  width: 8px;
  height: 8px;
  background: var(--primary);
  border-radius: 50%;
  box-shadow: 0 0 0 0 rgba(79, 70, 229, 0.7);
  animation: pulse-ring 2s infinite;
}

@keyframes pulse-ring {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(79, 70, 229, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 6px rgba(79, 70, 229, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(79, 70, 229, 0); }
}

/* Global Search Trigger */
.search-trigger-btn {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-md);
  color: var(--text-muted);
  font-size: 0.82rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.search-trigger-btn:hover {
  border-color: var(--border-focus);
  color: var(--text-primary);
}

.search-kbd {
  font-size: 0.68rem;
  font-weight: 700;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  padding: 0.1rem 0.35rem;
  color: var(--text-secondary);
}

/* Header Icon Buttons */
.header-icon-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  background: var(--bg-surface-elevated);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
  position: relative;
}

.header-icon-btn:hover {
  background: var(--border-color);
  color: var(--text-primary);
  transform: translateY(-1px);
}

/* Theme Switcher Special styling */
.theme-toggle-btn svg {
  transition: transform var(--transition-normal);
}

.theme-toggle-btn:hover svg {
  transform: rotate(20deg);
}

@media (max-width: 900px) {
  .mobile-menu-btn {
    display: flex;
  }
}

@media (max-width: 600px) {
  .header {
    padding: 0 0.85rem;
  }
  .page-breadcrumb .breadcrumb-root,
  .page-breadcrumb .breadcrumb-separator {
    display: none;
  }
  .countdown-badge {
    font-size: 0.75rem;
    padding: 0.35rem 0.65rem;
  }
  .search-trigger-btn span {
    display: none;
  }
  .search-trigger-btn {
    padding: 0.45rem;
    min-width: 36px;
    justify-content: center;
  }
}