/* ============================================
   ISO Download Station - Layout
   ============================================ */

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg-primary);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  height: var(--header-height);
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.header-logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-text-primary);
  white-space: nowrap;
  text-decoration: none;
}

.header-logo:hover {
  color: var(--color-text-primary);
}

.header-logo-icon {
  width: 32px;
  height: 32px;
  color: var(--color-accent-primary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-left: auto;
}

/* Search */
.header-search {
  flex: 1;
  max-width: 480px;
  position: relative;
}

.header-search-input {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  padding-left: 40px;
  background: var(--color-bg-search);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.3s ease;
}

.header-search-input:focus {
  border-color: var(--color-accent-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.header-search-input::placeholder {
  color: var(--color-text-muted);
}

.header-search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  width: 18px;
  height: 18px;
  color: var(--color-text-muted);
  pointer-events: none;
}

/* Theme toggle */
.theme-toggle {
  width: 38px;
  height: 38px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  transition: background-color 0.2s ease, color 0.2s ease;
}

.theme-toggle:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

/* Main Content */
.main-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-lg);
  min-height: calc(100vh - var(--header-height) - 60px);
}

/* Breadcrumb */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-md) 0;
  flex-wrap: wrap;
  font-size: var(--font-size-sm);
  overflow-x: auto;
  white-space: nowrap;
  -webkit-overflow-scrolling: touch;
}

.breadcrumb-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--color-text-muted);
  text-decoration: none;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: color 0.2s ease, background-color 0.2s ease;
}

.breadcrumb-item:hover {
  color: var(--color-text-primary);
  background: var(--color-bg-tertiary);
}

.breadcrumb-item.current {
  color: var(--color-text-primary);
  font-weight: 500;
}

.breadcrumb-separator {
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
  flex-shrink: 0;
}

/* Content Grid */
.content-grid {
  display: grid;
  gap: var(--spacing-md);
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  padding: var(--spacing-md) 0;
}

.content-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--spacing-md);
}

.content-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
}

.content-count {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  background: var(--color-bg-tertiary);
  padding: 4px 12px;
  border-radius: var(--radius-xl);
}

/* Footer */
.footer {
  text-align: center;
  padding: var(--spacing-lg);
  color: var(--color-text-muted);
  font-size: var(--font-size-sm);
  border-top: 1px solid var(--color-border);
  margin-top: var(--spacing-3xl);
  transition: border-color 0.3s ease;
}

/* Loading & Empty States */
.loading-state,
.empty-state {
  grid-column: 1 / -1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-3xl) var(--spacing-lg);
  text-align: center;
  color: var(--color-text-muted);
}

.loading-state svg,
.empty-state svg {
  width: 64px;
  height: 64px;
  margin-bottom: var(--spacing-lg);
  opacity: 0.4;
}

.empty-state h3 {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-sm);
}

/* Skeleton loading */
.skeleton {
  background: linear-gradient(90deg, var(--color-bg-tertiary) 25%, var(--color-bg-secondary) 50%, var(--color-bg-tertiary) 75%);
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-md);
}

@keyframes skeleton-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}