/* Chapter Index - Optimized, Compact & Minimal Design */

/* Container */
.chapter-index {
    max-width: 680px;
    margin: 0 auto;
    padding: 0.75rem 0.5rem;
}

/* Controls */
.index-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    padding: 0 0.25rem;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.4rem 0.6rem;
    font-size: 0.8125rem;
    color: var(--fg-600, #666);
    text-decoration: none;
    border-radius: 4px;
    transition: color 0.15s, background 0.15s;
}

.back-link:hover {
    color: var(--fg-900, #1a1a1a);
    background: var(--bg-50, rgba(0,0,0,0.02));
}

.back-link span {
    font-weight: 500;
}

.controls-right {
    display: flex;
    gap: 0.375rem;
    align-items: center;
}

.icon-btn {
    position: relative;
    padding: 0.4rem 0.55rem;
    font-size: 0.875rem;
    color: var(--fg-600, #666);
    background: transparent;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: color 0.15s, background 0.15s;
}

.icon-btn:hover:not(:disabled) {
    color: var(--fg-900, #1a1a1a);
    background: var(--bg-50, rgba(0,0,0,0.02));
}

.icon-btn:hover:not(:disabled)::after {
    opacity: 1;
    transform: translateY(0);
}

.icon-btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

/* Helper text tooltip - order button only */
.order-btn::after {
    content: 'Toggle Order';
    position: absolute;
    top: calc(100% + 0.25rem);
    right: 0;
    padding: 0.25rem 0.5rem;
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--fg-700, #444);
    background: var(--bg-100, rgba(0,0,0,0.06));
    border-radius: 3px;
    white-space: nowrap;
    opacity: 0;
    transform: translateY(-2px);
    transition: opacity 0.15s, transform 0.15s;
    pointer-events: none;
}

/* Chapter List */
.chapter-list {
    padding: 0 0.25rem;
}

/* Group */
.chapter-index-group {
    margin-bottom: 1.25rem;
}

/* Section Headers */
/* Free section: has free/purchased badges AND no unpurchased badges */
.chapter-index-group:has(.price-badge.free):not(:has(.price-badge.unpurchased))::before,
.chapter-index-group:has(.price-badge.purchased):not(:has(.price-badge.unpurchased))::before {
    content: 'Free Chapters';
    display: block;
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--fg-500, #888);
    padding: 0.5rem 0.5rem 0.35rem;
    margin-bottom: 0.25rem;
    opacity: 0.7;
}

/* Advanced section: has at least one unpurchased badge */
.chapter-index-group:has(.price-badge.unpurchased)::before {
    content: 'Advanced Chapters';
    display: block;
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--fg-500, #888);
    padding: 0.5rem 0.5rem 0.35rem;
    margin-bottom: 0.25rem;
    opacity: 0.7;
}

/* Only show section header on first group of each type */
.chapter-index-group:has(.price-badge.free):not(:has(.price-badge.unpurchased)) ~ .chapter-index-group:has(.price-badge.free):not(:has(.price-badge.unpurchased))::before,
.chapter-index-group:has(.price-badge.purchased):not(:has(.price-badge.unpurchased)) ~ .chapter-index-group:has(.price-badge.purchased):not(:has(.price-badge.unpurchased))::before {
    display: none;
}

.chapter-index-group:has(.price-badge.unpurchased) ~ .chapter-index-group:has(.price-badge.unpurchased)::before {
    display: none;
}

.chapter-group-name {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--fg-700, #444);
    padding: 0.25rem 0.5rem;
    margin-bottom: 0.2rem;
    display: flex;
    align-items: baseline;
    gap: 0.25rem;
}

.chapter-count {
    font-size: 0.625rem;
    font-weight: 500;
    color: var(--fg-500, #888);
    opacity: 0.65;
    margin-left: auto;
}

.chapter-group-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

/* Chapter Item */
.chapter-item {
    margin-bottom: 0;
}

.chapter-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 0.5rem;
    text-decoration: none;
    color: var(--fg-900, #1a1a1a);
    border-radius: 2px;
    transition: background 0.1s ease, transform 0.1s ease;
    position: relative;
}

.chapter-link:hover {
    background: var(--bg-50, rgba(0,0,0,0.02));
    transform: translateX(1px);
}

.chapter-link:active {
    transform: translateX(0);
}

/* Current Chapter Indicator */
.current-chapter .chapter-link {
    background: var(--bg-100, rgba(0,0,0,0.04));
}

.current-chapter .chapter-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 2px;
    height: 60%;
    background: var(--fg-700, #444);
    border-radius: 0 1px 1px 0;
}

.current-chapter .chapter-title {
    font-weight: 600;
}

.current-chapter .chapter-link:hover {
    background: var(--bg-100, rgba(0,0,0,0.05));
}

/* Price Badge */
.price-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 20px;
    height: 20px;
    padding: 0 0.275rem;
    font-size: 0.625rem;
    font-weight: 700;
    border-radius: 2px;
    flex-shrink: 0;
    letter-spacing: -0.25px;
}

.price-badge.purchased {
    background: var(--success-100, rgba(40,167,69,0.12));
    color: var(--success-700, #1e7e34);
}

.price-badge.free {
    background: transparent;
    color: var(--fg-400, #999);
    font-weight: 500;
}

.price-badge.unpurchased {
    background: var(--accent-100, rgba(0,123,255,0.1));
    color: var(--accent-700, #0056b3);
}

/* Chapter Info */
.chapter-info {
    flex: 1;
    min-width: 0;
    line-height: 1;
}

.chapter-title {
    font-size: 0.8125rem;
    font-weight: 500;
    line-height: 1.35;
    color: inherit;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.chapter-subtitle {
    font-size: 0.6875rem;
    color: var(--fg-500, #888);
    line-height: 1.25;
    margin-top: 0.125rem;
    opacity: 0.8;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Load More Button */
.load-more-wrap {
    text-align: center;
    margin: 0.5rem 0 0.25rem;
}

.load-more-btn {
    position: relative;
    padding: 0.3rem 0.875rem;
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--fg-500, #888);
    background: transparent;
    border: none;
    cursor: pointer;
    border-radius: 2px;
    transition: all 0.12s ease;
    opacity: 0.65;
}

.load-more-btn::before {
    content: 'Load More';
}

.load-more-btn:hover:not(:disabled) {
    color: var(--fg-700, #444);
    background: var(--bg-50, rgba(0,0,0,0.025));
    opacity: 1;
}

.load-more-btn:active:not(:disabled) {
    background: var(--bg-100, rgba(0,0,0,0.04));
}

.load-more-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

/* Loading Indicator */
.loading-indicator {
    text-align: center;
    padding: 1rem;
    color: var(--fg-500, #888);
    font-size: 0.875rem;
}

/* Error */
.error {
    color: var(--error, #dc3545);
    text-align: center;
    padding: 1rem;
    font-size: 0.8125rem;
}

/* Hidden */
.hidden {
    display: none !important;
}

/* Dark Mode */
:root[data-mode="dark"] .back-link {
    color: var(--fg-400, #aaa);
}

:root[data-mode="dark"] .back-link:hover {
    color: var(--fg-200, #e0e0e0);
    background: var(--bg-800, rgba(255,255,255,0.04));
}

:root[data-mode="dark"] .icon-btn {
    color: var(--fg-400, #aaa);
}

:root[data-mode="dark"] .icon-btn:hover:not(:disabled) {
    color: var(--fg-200, #e0e0e0);
    background: var(--bg-800, rgba(255,255,255,0.04));
}

:root[data-mode="dark"] .order-btn::after {
    color: var(--fg-300, #ccc);
    background: var(--bg-700, rgba(255,255,255,0.08));
}

:root[data-mode="dark"] .chapter-index-group::before {
    color: var(--fg-400, #aaa);
}

:root[data-mode="dark"] .chapter-group-name {
    color: var(--fg-300, #ccc);
}

:root[data-mode="dark"] .chapter-link {
    color: var(--fg-200, #e0e0e0);
}

:root[data-mode="dark"] .chapter-link:hover {
    background: var(--bg-800, rgba(255,255,255,0.03));
}

:root[data-mode="dark"] .current-chapter .chapter-link {
    background: var(--bg-800, rgba(255,255,255,0.05));
}

:root[data-mode="dark"] .current-chapter .chapter-link::before {
    background: var(--fg-300, #ccc);
}

:root[data-mode="dark"] .current-chapter .chapter-link:hover {
    background: var(--bg-800, rgba(255,255,255,0.07));
}

:root[data-mode="dark"] .price-badge.purchased {
    background: var(--success-900, rgba(40,167,69,0.18));
    color: var(--success-300, #5cb85c);
}

:root[data-mode="dark"] .price-badge.free {
    background: transparent;
    color: var(--fg-600, #666);
}

:root[data-mode="dark"] .price-badge.unpurchased {
    background: var(--accent-900, rgba(0,123,255,0.18));
    color: var(--accent-300, #6ca6f5);
}

:root[data-mode="dark"] .chapter-subtitle {
    color: var(--fg-500, #888);
}

:root[data-mode="dark"] .load-more-btn {
    color: var(--fg-500, #888);
    background: transparent;
}

:root[data-mode="dark"] .load-more-btn:hover:not(:disabled) {
    color: var(--fg-300, #ccc);
    background: var(--bg-800, rgba(255,255,255,0.04));
}

/* Responsive */
@media (max-width: 640px) {
    .chapter-index {
        padding: 0.5rem 0.25rem;
    }

    .index-controls {
        padding: 0;
        margin-bottom: 0.5rem;
    }

    .back-link {
        padding: 0.35rem 0.5rem;
        font-size: 0.75rem;
    }

    .back-link span {
        display: none;
    }

    .icon-btn {
        padding: 0.35rem 0.5rem;
        font-size: 0.8125rem;
    }

    /* Hide tooltip on mobile */
    .order-btn::after {
        display: none;
    }

    .chapter-list {
        padding: 0;
    }

    .chapter-index-group::before {
        font-size: 0.625rem;
        padding: 0.4rem 0.375rem 0.3rem;
    }

    .chapter-group-name {
        font-size: 0.6875rem;
        padding: 0.2rem 0.375rem;
    }

    .chapter-link {
        padding: 0.375rem 0.375rem;
        gap: 0.4rem;
    }

    .price-badge {
        min-width: 18px;
        height: 18px;
        font-size: 0.5625rem;
    }

    .chapter-title {
        font-size: 0.75rem;
    }

    .chapter-subtitle {
        font-size: 0.625rem;
    }

    .load-more-btn {
        padding: 0.275rem 0.75rem;
        font-size: 0.625rem;
    }
}