:root {
    /* Brand Colors */
    --brand-red: #dc2626;
    --brand-red-dark: #b91c1c;
    --brand-red-light: #ef4444;
    
    /* Neutral Colors */
    --color-dark: #1f2937;
    --color-gray: #6b7280;
    --color-light-gray: #f3f4f6;
    --color-white: #ffffff;
    --color-border: #e5e7eb;
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 200ms ease-in-out;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-primary);
    color: var(--color-dark);
    background-color: var(--color-white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}


/* ========================================
   2. HERO SECTION
   ======================================== */
.trending-hero {
    background: linear-gradient(135deg, var(--brand-red) 0%, var(--brand-red-dark) 100%);
    color: var(--color-white);
    padding: var(--spacing-xl) var(--spacing-md);
    text-align: center;
}

.hero-title {
    font-size: 1.75rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1rem;
    opacity: 0.95;
    font-weight: 400;
    margin: 0;
}

/* Tablet & Up */
@media (min-width: 768px) {
    .trending-hero {
        padding: 3rem var(--spacing-lg);
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.125rem;
    }
}

/* ========================================
   3. FILTERS SECTION
   ======================================== */
.filters-section {
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-lg) var(--spacing-md);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.filters-wrapper {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.filter-group {
    width: 100%;
}

/* Time Filter Buttons */
.filter-buttons {
    display: flex;
    gap: var(--spacing-sm);
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.filter-buttons::-webkit-scrollbar {
    display: none;
}

.filter-btn {
    flex-shrink: 0;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-lg);
    background-color: var(--color-light-gray);
    color: var(--color-dark);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 600;
    transition: all var(--transition-base);
    white-space: nowrap;
    border: 2px solid transparent;
}

.filter-btn:hover {
    background-color: var(--color-border);
    transform: translateY(-1px);
}

.filter-btn.active {
    background-color: var(--brand-red);
    color: var(--color-white);
    border-color: var(--brand-red-dark);
}

/* Category Select */
.filter-select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
    background-color: var(--color-white);
    cursor: pointer;
    transition: border-color var(--transition-base);
}

.filter-select:focus {
    outline: none;
    border-color: var(--brand-red);
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.1);
}

/* Search Form */
.search-form {
    display: flex;
    gap: var(--spacing-sm);
    width: 100%;
}

.search-input {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    transition: border-color var(--transition-base);
}

.search-input:focus {
    outline: none;
    border-color: var(--brand-red);
    box-shadow: 0 0 0 3px rgba(220, 38, 38, 0.1);
}

.btn-search {
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--brand-red);
    color: var(--color-white);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1.125rem;
    cursor: pointer;
    transition: background-color var(--transition-base);
}

.btn-search:hover {
    background-color: var(--brand-red-dark);
}

/* Tablet & Up */
@media (min-width: 768px) {
    .filters-wrapper {
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
    }
    
    .filter-group {
        width: auto;
        flex: 1;
    }
    
    .filter-group:last-child {
        max-width: 300px;
    }
}

/* ========================================
   4. RESULTS INFO
   ======================================== */
.results-info {
    padding: var(--spacing-md);
    background-color: var(--color-light-gray);
}

.results-count {
    margin: 0;
    font-size: 0.875rem;
    color: var(--color-gray);
    font-weight: 500;
}

/* ========================================
   5. TRENDING CARDS
   ======================================== */
.trending-grid {
    padding: var(--spacing-lg) var(--spacing-md);
}

.trending-card {
    background-color: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.trending-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
    border-color: var(--brand-red-light);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.topic-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--color-light-gray);
    color: var(--color-dark);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge-free {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    background-color: var(--brand-red);
    color: var(--color-white);
    border-radius: var(--radius-sm);
    font-size: 0.625rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: var(--spacing-sm);
    color: var(--color-dark);
}

.card-summary {
    font-size: 0.875rem;
    color: var(--color-gray);
    line-height: 1.5;
    margin-bottom: var(--spacing-md);
    flex-grow: 1;
}

.card-meta {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.meta-item {
    font-size: 0.75rem;
    color: var(--color-gray);
    font-weight: 500;
}

.card-stats {
    display: flex;
    gap: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.stat-item {
    font-size: 0.75rem;
    color: var(--color-gray);
    font-weight: 500;
}

.card-footer {
    margin-top: auto;
}

.btn-primary-card {
    display: block;
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--brand-red);
    color: var(--color-white);
    text-align: center;
    text-decoration: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.875rem;
    transition: all var(--transition-base);
}

.btn-primary-card:hover {
    background-color: var(--brand-red-dark);
    transform: translateX(4px);
    color: var(--color-white);
}

/* ========================================
   6. NO RESULTS
   ======================================== */
.no-results {
    text-align: center;
    padding: 3rem var(--spacing-md);
}

.no-results p {
    font-size: 1.125rem;
    color: var(--color-gray);
    margin-bottom: var(--spacing-lg);
}

.no-results .btn-primary {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-xl);
    background-color: var(--brand-red);
    color: var(--color-white);
    text-decoration: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    transition: background-color var(--transition-base);
}

.no-results .btn-primary:hover {
    background-color: var(--brand-red-dark);
}

/* ========================================
   7. PAGINATION
   ======================================== */
.pagination-section {
    padding: var(--spacing-xl) var(--spacing-md);
}

.pagination {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.page-item {
    list-style: none;
}

.page-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-dark);
    text-decoration: none;
    font-weight: 500;
    transition: all var(--transition-base);
}

.page-link:hover {
    background-color: var(--color-light-gray);
    border-color: var(--brand-red);
    color: var(--brand-red);
}

.page-item.active .page-link {
    background-color: var(--brand-red);
    color: var(--color-white);
    border-color: var(--brand-red);
}

/* ========================================
   8. PERFORMANCE OPTIMIZATIONS
   ======================================== */

/* Reduce animations on mobile for better performance */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* GPU acceleration for transforms */
.trending-card,
.filter-btn,
.btn-primary-card {
    will-change: transform;
}

/* ========================================
   9. DARK MODE SUPPORT (Optional)
   ======================================== */
@media (prefers-color-scheme: dark) {
    :root {
        --color-dark: #f3f4f6;
        --color-gray: #9ca3af;
        --color-light-gray: #1f2937;
        --color-white: #111827;
        --color-border: #374151;
    }
    
    body {
        background-color: #0f172a;
    }
    
    .trending-card {
        background-color: #1e293b;
    }
}