/* ========================================
   Subject Pages - Additional Styles
   ======================================== */

/* Subject Header */
.subject-header {
    padding: var(--spacing-lg) 0;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: var(--spacing-md);
    transition: color var(--transition-fast);
}

.back-link:hover {
    color: var(--text-primary);
}

.subject-title-block {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-xs);
}

.subject-badge {
    display: inline-block;
    padding: 0.35rem 0.75rem;
    font-size: 0.8rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    color: white;
}

.subject-badge.cs {
    background: var(--cs-color);
}

.subject-badge.math {
    background: var(--math-color);
}

.subject-badge.physics {
    background: var(--physics-color);
}

.subject-badge.business {
    background: var(--business-color);
}

.subject-page-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.subject-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Subject Content */
.subject-content {
    flex: 1;
}

/* Paper Section */
.paper-section {
    margin-bottom: var(--spacing-xl);
}

.paper-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.paper-badge {
    display: inline-block;
    padding: 0.25rem 0.6rem;
    font-size: 0.75rem;
    font-weight: 600;
    background: var(--accent-primary);
    color: white;
    border-radius: var(--radius-sm);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.paper-info {
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: var(--spacing-md);
}

/* Chapters Grid */
.chapters-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

/* Chapter Card */
.chapter-card {
    display: flex;
    gap: var(--spacing-md);
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(0, 0, 0, 0.04);
    transition: box-shadow var(--transition-normal);
}

.chapter-card:hover {
    box-shadow: var(--shadow-md);
}

.chapter-card.featured {
    border-left: 3px solid var(--accent-primary);
}

.chapter-number {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 48px;
    height: 48px;
    background: var(--bg-primary);
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    flex-shrink: 0;
}

.chapter-info {
    flex: 1;
}

.chapter-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
}

.chapter-tag {
    display: inline-block;
    padding: 0.15rem 0.5rem;
    font-size: 0.7rem;
    font-weight: 500;
    background: rgba(108, 92, 231, 0.1);
    color: var(--accent-primary);
    border-radius: 4px;
    margin-bottom: var(--spacing-xs);
}

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

.topic-list li {
    position: relative;
    padding-left: var(--spacing-md);
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.7;
}

.topic-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.65em;
    width: 4px;
    height: 4px;
    background: var(--text-muted);
    border-radius: 50%;
}

/* Resource Links */
.resource-links {
    margin-top: var(--spacing-md);
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    padding-top: var(--spacing-sm);
    border-top: 1px solid rgba(0, 0, 0, 0.05);
}

.resource-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 0.5rem 0.85rem;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--bg-primary);
    border: 1px solid rgba(0, 0, 0, 0.05);
    border-radius: var(--radius-sm);
    text-decoration: none;
    transition: all var(--transition-fast);
    flex: 1;
    min-width: 120px;
    justify-content: center;
}

.resource-btn:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.resource-btn svg {
    width: 16px;
    height: 16px;
    color: var(--text-muted);
    transition: color var(--transition-fast);
}

.resource-btn.notes:hover {
    border-color: #0984e3;
}

.resource-btn.video:hover {
    border-color: #d63031;
}

.resource-btn.flashcards:hover {
    border-color: #6c5ce7;
}

.resource-btn.topicals:hover {
    border-color: #00b894;
}

.resource-btn.notes:hover svg {
    color: #0984e3;
}

.resource-btn.video:hover svg {
    color: #d63031;
}

.resource-btn.flashcards:hover svg {
    color: #6c5ce7;
}

.resource-btn.topicals:hover svg {
    color: #00b894;
}

/* Responsive */
@media (max-width: 600px) {
    .subject-page-title {
        font-size: 1.5rem;
    }

    .chapter-card {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .chapter-number {
        width: 40px;
        height: 40px;
        font-size: 0.9rem;
    }

    .resource-links {
        display: grid;
        grid-template-columns: 1fr 1fr;
    }

    .resource-btn {
        min-width: auto;
    }
}

/* Notes Dropdown */
.notes-dropdown {
    position: relative;
    display: inline-flex;
    flex: 1;
    min-width: 120px;
}

.notes-dropdown .dropdown-toggle {
    cursor: pointer;
    width: 100%;
}

.notes-dropdown .dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-card);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    z-index: 100;
    display: none;
    flex-direction: column;
    margin-top: 4px;
    overflow: hidden;
}

.notes-dropdown.active .dropdown-menu {
    display: flex;
}

.notes-dropdown .dropdown-menu a {
    padding: 0.6rem 0.85rem;
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.notes-dropdown .dropdown-menu a:last-child {
    border-bottom: none;
}

.notes-dropdown .dropdown-menu a:hover {
    background: var(--bg-primary);
    color: #0984e3;
}