/* ===================================
   CSS Variables & Reset
   =================================== */
:root {
    /* Color Palette */
    --primary-color: #2c5f8d;
    --primary-dark: #1a3f5f;
    --primary-light: #4a7ba7;
    --secondary-color: #e8722e;
    --secondary-dark: #c85d1f;
    
    --accent-color: #5eb3d6;
    --success-color: #2ecc71;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    
    --text-dark: #2c3e50;
    --text-medium: #546e7a;
    --text-light: #7f8c8d;
    
    --bg-white: #ffffff;
    --bg-light: #f8f9fa;
    --bg-gray: #ecf0f1;
    --bg-dark: #34495e;
    
    --border-color: #dfe6e9;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-heading: 'Georgia', serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Layout */
    --container-width: 1200px;
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-white);
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===================================
   Typography
   =================================== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    line-height: 1.3;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: var(--spacing-sm);
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

/* ===================================
   Header
   =================================== */
.main-header {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-color) 100%);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo h1 {
    color: var(--bg-white);
    font-size: 1.8rem;
    font-weight: 700;
    margin: 0;
    letter-spacing: 1px;
}

.logo span {
    color: var(--accent-color);
    font-size: 0.9rem;
    font-weight: 400;
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.main-nav a {
    color: var(--bg-white);
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.main-nav a:hover,
.main-nav a.active {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--accent-color);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: transparent;
    border: none;
    cursor: pointer;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--bg-white);
    transition: var(--transition);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    position: relative;
    background: linear-gradient(135deg, #1a3f5f 0%, #2c5f8d 50%, #4a7ba7 100%);
    color: var(--bg-white);
    padding: var(--spacing-xl) 0;
    min-height: 500px;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><circle cx="50" cy="50" r="2" fill="rgba(255,255,255,0.1)"/></svg>');
    opacity: 0.3;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to bottom, transparent 0%, rgba(0,0,0,0.2) 100%);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero h2 {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.hero-subtitle {
    font-size: 1.2rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.95;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    margin: var(--spacing-lg) 0;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-color);
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    text-decoration: none;
}

.btn-primary {
    background-color: var(--secondary-color);
    color: var(--bg-white);
}

.btn-primary:hover {
    background-color: var(--secondary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-link {
    background: transparent;
    color: var(--primary-color);
    padding: var(--spacing-xs);
    font-size: 0.9rem;
}

.btn-link:hover {
    text-decoration: underline;
}

/* ===================================
   Quick Search Section
   =================================== */
.quick-search {
    background-color: var(--bg-white);
    padding: var(--spacing-lg) 0;
    box-shadow: var(--shadow-sm);
}

.search-box h3 {
    text-align: center;
    color: var(--text-dark);
    margin-bottom: var(--spacing-md);
}

.search-form {
    max-width: 600px;
    margin: 0 auto;
}

.search-input-wrapper {
    display: flex;
    gap: 0;
    box-shadow: var(--shadow-md);
    border-radius: var(--border-radius);
    overflow: hidden;
}

#searchInput {
    flex: 1;
    padding: var(--spacing-md);
    border: 2px solid var(--border-color);
    border-right: none;
    font-size: 1rem;
    outline: none;
}

#searchInput:focus {
    border-color: var(--primary-color);
}

.search-btn {
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--primary-color);
    color: var(--bg-white);
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

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

/* ===================================
   Main Content
   =================================== */
.main-content {
    padding: var(--spacing-xl) 0;
}

.intro-section {
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-lg);
    background-color: var(--bg-light);
    border-radius: var(--border-radius);
}

.intro-content h2 {
    color: var(--primary-color);
}

.feature-list {
    list-style: none;
    padding-left: 0;
    margin-top: var(--spacing-md);
}

.feature-list li {
    padding: var(--spacing-xs) 0 var(--spacing-xs) var(--spacing-lg);
    position: relative;
}

.feature-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

/* ===================================
   Practices Section
   =================================== */
.practices-section {
    margin-bottom: var(--spacing-xl);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-header h2 {
    color: var(--primary-color);
}

.section-header p {
    color: var(--text-medium);
}

.content-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: var(--spacing-lg);
}

/* ===================================
   Filters Sidebar
   =================================== */
.filters-sidebar {
    background-color: var(--bg-light);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    height: fit-content;
    position: sticky;
    top: 100px;
}

.filter-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--border-color);
}

.filter-header h3 {
    margin: 0;
    color: var(--primary-color);
}

.filter-group {
    margin-bottom: var(--spacing-md);
}

.filter-group h4 {
    font-size: 1rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-dark);
    font-family: var(--font-primary);
}

.checkbox-label {
    display: flex;
    align-items: center;
    padding: var(--spacing-xs) 0;
    cursor: pointer;
    transition: var(--transition);
}

.checkbox-label:hover {
    color: var(--primary-color);
}

.checkbox-label input[type="checkbox"] {
    margin-right: var(--spacing-xs);
    cursor: pointer;
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color);
}

/* ===================================
   Results Area
   =================================== */
.results-area {
    flex: 1;
}

.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: var(--bg-light);
    border-radius: var(--border-radius);
}

.results-count {
    font-weight: 600;
    color: var(--text-dark);
}

.results-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

#sortSelect {
    padding: var(--spacing-xs) var(--spacing-sm);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: var(--bg-white);
    cursor: pointer;
    outline: none;
}

#sortSelect:focus {
    border-color: var(--primary-color);
}

.active-filters {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.filter-tag {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: var(--primary-color);
    color: var(--bg-white);
    border-radius: 20px;
    font-size: 0.9rem;
}

.filter-tag button {
    background: transparent;
    border: none;
    color: var(--bg-white);
    cursor: pointer;
    font-size: 1.2rem;
    line-height: 1;
}

/* ===================================
   Programs Grid
   =================================== */
.programs-grid {
    display: grid;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.program-card {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    transition: var(--transition);
    cursor: pointer;
}

.program-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.program-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-sm);
}

.program-title {
    flex: 1;
}

.program-title h3 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
    font-size: 1.3rem;
}

.program-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    font-size: 0.9rem;
    color: var(--text-medium);
}

.program-meta span {
    display: flex;
    align-items: center;
    gap: 4px;
}

.program-description {
    color: var(--text-dark);
    margin-bottom: var(--spacing-sm);
}

.program-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.tag {
    padding: 4px var(--spacing-sm);
    background-color: var(--bg-gray);
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--text-dark);
}

.tag.intervention-prevention { background-color: #e3f2fd; color: #1976d2; }
.tag.intervention-cessation { background-color: #f3e5f5; color: #7b1fa2; }
.tag.intervention-secondhand { background-color: #e8f5e9; color: #388e3c; }
.tag.intervention-policy { background-color: #fff3e0; color: #f57c00; }

.evidence-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px var(--spacing-sm);
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: 600;
}

.evidence-high {
    background-color: #d4edda;
    color: #155724;
}

.evidence-moderate {
    background-color: #fff3cd;
    color: #856404;
}

.evidence-emerging {
    background-color: #cce5ff;
    color: #004085;
}

.program-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: var(--spacing-sm);
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--border-color);
}

.program-link {
    color: var(--primary-color);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.program-link:hover {
    color: var(--secondary-color);
}

/* ===================================
   Pagination
   =================================== */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-lg);
}

.page-btn,
.page-number {
    padding: var(--spacing-xs) var(--spacing-sm);
    border: 1px solid var(--border-color);
    background-color: var(--bg-white);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

.page-btn:hover:not(:disabled),
.page-number:hover {
    background-color: var(--primary-color);
    color: var(--bg-white);
    border-color: var(--primary-color);
}

.page-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.page-number.active {
    background-color: var(--primary-color);
    color: var(--bg-white);
    border-color: var(--primary-color);
}

.page-numbers {
    display: flex;
    gap: var(--spacing-xs);
}

/* ===================================
   Resources Section
   =================================== */
.resources-section {
    margin-bottom: var(--spacing-xl);
}

.resources-section h2 {
    text-align: center;
    color: var(--primary-color);
    margin-bottom: var(--spacing-lg);
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.resource-card {
    background-color: var(--bg-light);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    text-align: center;
    transition: var(--transition);
}

.resource-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.resource-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.resource-card h3 {
    color: var(--primary-color);
    margin-bottom: var(--spacing-sm);
}

.resource-link {
    display: inline-block;
    margin-top: var(--spacing-sm);
    color: var(--secondary-color);
    font-weight: 600;
}

.resource-link:hover {
    color: var(--secondary-dark);
}

/* ===================================
   Updates Section
   =================================== */
.updates-section {
    margin-bottom: var(--spacing-xl);
}

.updates-section h2 {
    text-align: center;
    color: var(--primary-color);
    margin-bottom: var(--spacing-lg);
}

.updates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.update-card {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    transition: var(--transition);
}

.update-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.update-date {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-xs);
}

.update-card h3 {
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-bottom: var(--spacing-sm);
}

.update-link {
    color: var(--secondary-color);
    font-weight: 600;
}

/* ===================================
   Footer
   =================================== */
.main-footer {
    background-color: var(--bg-dark);
    color: var(--bg-light);
    padding: var(--spacing-xl) 0 var(--spacing-md);
    margin-top: var(--spacing-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-section h4 {
    color: var(--accent-color);
    margin-bottom: var(--spacing-sm);
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: var(--spacing-xs);
}

.footer-section a {
    color: var(--bg-light);
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    margin-bottom: var(--spacing-xs);
    font-size: 0.9rem;
}

.disclaimer {
    font-size: 0.85rem;
    color: var(--text-light);
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 968px) {
    .content-layout {
        grid-template-columns: 1fr;
    }
    
    .filters-sidebar {
        position: static;
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--spacing-md);
    }
}

@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: flex;
    }
    
    .main-nav ul {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--primary-dark);
        flex-direction: column;
        padding: var(--spacing-md);
        box-shadow: var(--shadow-lg);
    }
    
    .main-nav ul.active {
        display: flex;
    }
    
    .results-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    
    .resources-grid,
    .updates-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.2rem; }
    
    .hero h2 {
        font-size: 1.5rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .stat-number {
        font-size: 2rem;
    }
}

/* ===================================
   Loading State
   =================================== */
.loading {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-medium);
}

.loading::after {
    content: '';
    display: inline-block;
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===================================
   Accessibility
   =================================== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

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