/**
 * Table of Contents Styles
 * 
 * Styling for the sticky TOC sidebar component
 * Uses site variables and theme support
 */

/* Container */
.article-toc {
    position: sticky;
    top: 84px; /* var(--header-height) + 20px spacing */
    max-height: calc(100vh - 104px);
    overflow-y: auto;
    padding: 0;
    background-color: transparent;
    font-size: var(--font-size-sm);
    line-height: var(--line-height-normal);
}

/* Custom scrollbar for TOC */
.article-toc::-webkit-scrollbar {
    width: 3px;
}

.article-toc::-webkit-scrollbar-track {
    background: transparent;
}

.article-toc::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: var(--radius-sm);
}

.article-toc::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-muted);
}

/* Header */
.article-toc__header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-4);
    padding-bottom: var(--spacing-3);
    border-bottom: 1px solid var(--color-border);
}

.article-toc__title {
    margin: 0;
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-semibold);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.article-toc__toggle {
    display: none;
    padding: var(--spacing-1);
    background: none;
    border: none;
    cursor: pointer;
    color: var(--color-text-muted);
    transition: color var(--transition-fast), transform var(--transition-fast);
    border-radius: var(--radius-sm);
}

.article-toc__toggle:hover {
    color: var(--color-text);
    background-color: var(--color-bg-secondary);
}

.article-toc__toggle--active {
    transform: rotate(180deg);
}

/* List */
.article-toc__list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.article-toc__list--nested {
    margin-top: var(--spacing-1);
    margin-left: 0;
    padding-left: var(--spacing-4);
    border-left: 1px solid var(--color-border-light);
}

.article-toc__list--collapsed {
    display: none;
}

/* Items */
.article-toc__item {
    margin: 0;
    padding: 0;
}

.article-toc__item + .article-toc__item {
    margin-top: var(--spacing-1);
}

/* Links */
.article-toc__link {
    display: block;
    padding: var(--spacing-2) var(--spacing-3);
    color: var(--color-text-secondary);
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    line-height: var(--line-height-normal);
    position: relative;
    font-size: var(--font-size-sm);
}

.article-toc__link:hover {
    color: var(--color-text);
    background-color: var(--color-bg-secondary);
}

.article-toc__link--active {
    color: var(--color-primary);
    background-color: var(--color-primary-light);
    font-weight: var(--font-weight-medium);
}

/* Active link keeps its style on hover */
.article-toc__link--active:hover {
    color: var(--color-primary);
    background-color: var(--color-primary-light);
}

/* Active indicator line */
.article-toc__link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 2px;
    height: 0;
    background-color: var(--color-primary);
    border-radius: var(--radius-sm);
    transition: height var(--transition-fast);
}

.article-toc__link--active::before {
    height: 60%;
}

/* Level-specific styling */
.article-toc__item--level-2 .article-toc__link {
    font-weight: var(--font-weight-medium);
}

.article-toc__item--level-3 .article-toc__link {
    font-size: var(--font-size-xs);
}

.article-toc__item--level-4 .article-toc__link {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

.article-toc__item--level-4 .article-toc__link:hover {
    color: var(--color-text-secondary);
}

/* Mobile styles */
@media (max-width: 768px) {
    .article-toc {
        position: relative;
        top: 0;
        max-height: none;
        margin-bottom: var(--spacing-6);
        padding: var(--spacing-4);
        background-color: var(--color-bg-secondary);
        border-radius: var(--radius-lg);
        border: 1px solid var(--color-border);
    }
    
    .article-toc__toggle {
        display: flex;
    }
    
    .article-toc__list--collapsed {
        display: none;
    }
    
    .article-toc__header {
        margin-bottom: var(--spacing-3);
    }
}

/* Tablet styles */
@media (min-width: 769px) and (max-width: 1024px) {
    .article-toc {
        font-size: var(--font-size-xs);
    }
    
    .article-toc__link {
        padding: var(--spacing-1) var(--spacing-2);
    }
}

/* Print styles */
@media print {
    .article-toc {
        display: none;
    }
}

/* Focus styles for accessibility */
.article-toc__link:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

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

/* Dark theme is handled automatically via CSS variables */