/*
 * Topics Page Styling
 * Modern, responsive design for topic listing and browsing
 */

/* ============================================
   Page Header
   ============================================ */

.topics-header {
    background: linear-gradient(135deg, #f0f4ff 0%, #e8f0fe 100%);
    padding: 0;
    margin: 0;
}

.topics-heading {
    font-size: var(--text-section);
    font-weight: 700;
    color: var(--neutral-900);
    margin-bottom: 0.5rem;
}

.topics-subtitle {
    font-size: var(--text-lg);
    color: var(--neutral-600);
    margin: 0;
}

/* ============================================
   Category Filters
   ============================================ */

.topics-filters {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    flex-wrap: wrap;
}

.filter-label {
    font-weight: 600;
    color: var(--neutral-700);
    padding-top: 0.5rem;
    white-space: nowrap;
}

.filter-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.filter-chip {
    padding: 0.5rem 1.25rem;
    border-radius: 2rem;
    font-size: 0.9375rem;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    background: white;
}

.filter-chip:hover {
    background: var(--primary-light);
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.15);
}

.filter-chip.active {
    background: var(--primary-color);
    color: white;
}

.filter-chip.active:hover {
    background: #5a67d8;
}

/* ============================================
   Search Box
   ============================================ */

.topics-search {
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.search-wrapper {
    position: relative;
    display: flex;
    gap: 0.5rem;
}

.search-icon-left {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--neutral-400);
    pointer-events: none;
    z-index: 1;
}

.search-input {
    flex: 1;
    padding: 0.875rem 1rem 0.875rem 3rem;
    border: 2px solid #e5e7eb;
    border-radius: 0.75rem;
    font-size: 1rem;
    transition: all 0.2s;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-input::placeholder {
    color: var(--neutral-400);
}

.search-button {
    padding: 0.875rem 1.5rem;
    border-radius: 0.75rem;
    font-weight: 600;
    white-space: nowrap;
}

.search-hint {
    margin-top: 0.5rem;
    font-size: 0.875rem;
    color: var(--neutral-500);
    text-align: center;
}

/* ============================================
   Topics Grid
   ============================================ */

.topics-grid {
    display: grid;
    grid-template-columns: repeat(1, 1fr);
    gap: 2rem;
}

@media (min-width: 640px) {
    .topics-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .topics-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 2rem;
    }
}

@media (min-width: 1280px) {
    .topics-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* ============================================
   Pagination
   ============================================ */

.topics-pagination .pagination {
    margin-top: 2rem;
}

.topics-pagination .page-link {
    border-radius: 0.5rem;
    margin: 0 0.25rem;
    padding: 0.5rem 0.875rem;
    color: var(--primary-color);
    border: 2px solid transparent;
    transition: all 0.2s;
}

.topics-pagination .page-link:hover {
    background: var(--primary-light);
    border-color: var(--primary-color);
}

.topics-pagination .page-item.active .page-link {
    background: var(--primary-color);
    border-color: var(--primary-color);
}

.topics-pagination .page-item.disabled .page-link {
    opacity: 0.5;
}

/* ============================================
   Empty State
   ============================================ */

.topics-empty {
    text-align: center;
    padding: 5rem 2rem;
}

.empty-icon {
    margin-bottom: 1.5rem;
    color: var(--neutral-300);
}

.empty-title {
    font-size: var(--text-2xl);
    font-weight: 600;
    color: var(--neutral-600);
    margin-bottom: 0.75rem;
}

.empty-description {
    font-size: var(--text-lg);
    color: var(--neutral-500);
    margin: 0;
}

/* ============================================
   Responsive Adjustments
   ============================================ */

@media (max-width: 767px) {
    .topics-header {
        padding: 2rem 0 1.5rem;
    }

    .topics-heading {
        font-size: var(--text-2xl);
    }

    .topics-subtitle {
        font-size: var(--text-base);
    }

    .filter-chips {
        width: 100%;
    }

    .search-button span {
        display: none;
    }

    .search-button {
        padding-left: 1rem;
        padding-right: 1rem;
    }
}