/* Tutorial Archive Stylesheet */
:root {
    --primary-color: #2563eb;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-card: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --border-color: #e2e8f0;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --border-color: #475569;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header */
.header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.search-box {
    position: relative;
}

.search-box input {
    padding: 0.5rem 1rem 0.5rem 2.5rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 0.9rem;
    width: 250px;
}

.search-box .search-icon {
    position: absolute;
    left: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.filter-select, .theme-toggle {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    background: var(--bg-primary);
    color: var(--text-primary);
    cursor: pointer;
}

.theme-toggle {
    background: var(--primary-color);
    color: white;
    border: none;
}

/* Main Content */
.main {
    padding: 2rem 0;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.stats-bar {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 2rem;
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
}

.stat {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.stat-number {
    font-weight: 600;
    color: var(--primary-color);
}

/* Date Cards */
.date-grid {
    display: grid;
    gap: 1.5rem;
}

.date-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

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

.date-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
}

.date-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.date-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.favorites-count {
    color: var(--accent-color);
}

/* Section Headers */
.section {
    margin-bottom: 1.5rem;
}

.section-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* Tutorial Cards */
.tutorial-grid {
    display: grid;
    gap: 1.5rem;
    grid-template-columns: 1fr; /* Mobile: single column */
}

/* Desktop: Multi-column layout */
@media (min-width: 768px) {
    .tutorial-grid {
        grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
        gap: 1.5rem;
    }
}

/* Large screens: Max 3 columns for readability */
@media (min-width: 1200px) {
    .tutorial-grid {
        grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
        max-width: 1400px;
    }
}

.tutorial-card, .news-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 1rem;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    height: 100%; /* Equal height cards */
}

.tutorial-card:hover, .news-card:hover {
    border-color: var(--primary-color);
    background: var(--bg-card);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.tutorial-card:hover, .news-card:hover {
    border-color: var(--primary-color);
    background: var(--bg-card);
}

.tutorial-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.75rem;
}

.tutorial-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.tutorial-meta {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.difficulty-badge {
    padding: 0.125rem 0.5rem;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
}

.difficulty-beginner { background: #dcfce7; color: #166534; }
.difficulty-intermediate { background: #fef3c7; color: #92400e; }
.difficulty-advanced { background: #fecaca; color: #991b1b; }

.time-badge {
    padding: 0.125rem 0.5rem;
    background: var(--primary-color);
    color: white;
    border-radius: 0.25rem;
    font-size: 0.75rem;
}

.tutorial-description {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    line-height: 1.5;
    flex-grow: 1; /* Takes available space */
}

.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem;
    margin-bottom: 0.75rem;
}

.tech-tag {
    padding: 0.125rem 0.5rem;
    background: var(--border-color);
    color: var(--text-secondary);
    border-radius: 0.25rem;
    font-size: 0.75rem;
}

.tutorial-actions {
    display: flex;
    gap: 0.5rem;
    margin-top: auto; /* Push actions to bottom of card */
}

.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 0.375rem;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    transition: all 0.2s ease;
}

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

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn:hover {
    transform: translateY(-1px);
}

/* News Cards */
.news-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.5rem;
}

.news-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

.news-source {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.news-insight {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    line-height: 1.5;
    flex-grow: 1; /* Takes available space */
}

/* Navigation */
.navigation {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.nav-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
}

.nav-link:hover {
    background: #1d4ed8;
    transform: translateY(-1px);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 0 0.75rem;
    }
    
    .header-content {
        flex-direction: column;
        align-items: stretch;
    }
    
    .controls {
        justify-content: center;
    }
    
    .search-box input {
        width: 100%;
    }
    
    .stats-bar {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .date-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .tutorial-header {
        flex-direction: column;
        gap: 0.5rem;
    }
}

/* Loading States */
.loading {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    border-top-color: var(--primary-color);
    animation: spin 1s ease-in-out infinite;
}

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