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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #8b5cf6;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --dark: #1f2937;
    --light: #f9fafb;
    --border: #e5e7eb;
    --text: #374151;
    --text-light: #6b7280;
    --shadow: rgba(0, 0, 0, 0.1);
    --shadow-lg: rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px var(--shadow-lg);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    padding: 60px 40px;
    text-align: center;
}

.header-content h1 {
    font-size: 3.5rem;
    margin-bottom: 10px;
    font-weight: 800;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 20px;
}

blockquote {
    font-style: italic;
    opacity: 0.85;
    font-size: 1.1rem;
    margin-top: 20px;
    padding: 15px;
    border-left: 4px solid rgba(255, 255, 255, 0.3);
    background: rgba(255, 255, 255, 0.1);
    border-radius: 5px;
    display: inline-block;
}

.controls {
    padding: 30px 40px;
    background: var(--light);
    border-bottom: 2px solid var(--border);
}

.search-bar {
    position: relative;
    margin-bottom: 20px;
}

.search-bar input {
    width: 100%;
    padding: 16px 50px 16px 20px;
    font-size: 1.1rem;
    border: 2px solid var(--border);
    border-radius: 12px;
    outline: none;
    transition: all 0.3s ease;
}

.search-bar input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.clear-btn {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--text-light);
    color: white;
    border: none;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    display: none;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.clear-btn:hover {
    background: var(--danger);
    transform: translateY(-50%) scale(1.1);
}

.clear-btn.show {
    display: flex;
}

.action-buttons {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
}

.action-buttons button {
    flex: 1;
    padding: 14px 24px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.surprise-btn {
    background: linear-gradient(135deg, var(--warning) 0%, #f97316 100%);
    color: white;
}

.surprise-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(245, 158, 11, 0.3);
}

.show-all-btn {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    color: white;
}

.show-all-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(16, 185, 129, 0.3);
}

.filter-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    min-height: 40px;
}

.chip {
    padding: 8px 16px;
    background: white;
    border: 2px solid var(--primary);
    color: var(--primary);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.chip:hover {
    background: var(--primary);
    color: white;
    transform: scale(1.05);
}

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

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    padding: 30px 40px;
    background: white;
}

.stat-card {
    text-align: center;
    padding: 20px;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border-radius: 12px;
    border: 2px solid #bae6fd;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 5px;
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.categories {
    padding: 40px;
}

.category {
    margin-bottom: 40px;
    opacity: 0;
    animation: fadeIn 0.5s forwards;
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

.category-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 3px solid var(--primary);
    cursor: pointer;
    transition: all 0.3s ease;
}

.category-header:hover {
    transform: translateX(10px);
}

.category-icon {
    font-size: 2rem;
}

.category-title {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--dark);
    flex: 1;
}

.category-count {
    background: var(--primary);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}

.category-toggle {
    font-size: 1.5rem;
    color: var(--text-light);
    transition: transform 0.3s ease;
}

.category-toggle.collapsed {
    transform: rotate(-90deg);
}

.tutorials {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.tutorial-card {
    background: white;
    border: 2px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.tutorial-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--primary);
    transform: scaleY(0);
    transition: transform 0.3s ease;
}

.tutorial-card:hover::before {
    transform: scaleY(1);
}

.tutorial-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px var(--shadow);
    border-color: var(--primary);
}

.tutorial-card.highlight {
    animation: pulse 1.5s ease-in-out;
    border-color: var(--warning);
    background: linear-gradient(135deg, #fff7ed 0%, #ffedd5 100%);
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

.tutorial-language {
    display: inline-block;
    background: var(--primary);
    color: white;
    padding: 4px 12px;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.tutorial-title {
    font-size: 1.1rem;
    color: var(--dark);
    margin-bottom: 10px;
    line-height: 1.4;
}

.tutorial-link {
    color: var(--primary);
    text-decoration: none;
    font-size: 0.9rem;
    display: inline-flex;
    align-items: center;
    gap: 5px;
    margin-top: 10px;
}

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

.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    animation: fadeIn 0.3s;
}

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 40px;
    border-radius: 20px;
    max-width: 600px;
    position: relative;
    animation: slideIn 0.3s;
}

@keyframes slideIn {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close-modal {
    position: absolute;
    right: 20px;
    top: 20px;
    font-size: 2rem;
    font-weight: bold;
    color: var(--text-light);
    cursor: pointer;
    transition: color 0.3s ease;
}

.close-modal:hover {
    color: var(--danger);
}

.modal h2 {
    color: var(--primary);
    margin-bottom: 20px;
    font-size: 2rem;
}

.modal p {
    margin-bottom: 15px;
    line-height: 1.8;
}

.modal a {
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
}

.modal a:hover {
    text-decoration: underline;
}

footer {
    text-align: center;
    padding: 20px;
    color: white;
    margin-top: 20px;
}

footer a {
    color: white;
    text-decoration: underline;
}

.empty-state {
    text-align: center;
    padding: 60px 40px;
    color: var(--text-light);
}

.empty-state-icon {
    font-size: 4rem;
    margin-bottom: 20px;
}

.empty-state-text {
    font-size: 1.5rem;
    font-weight: 600;
}

/* Responsive */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .header-content h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .controls, .stats, .categories {
        padding: 20px;
    }

    .tutorials {
        grid-template-columns: 1fr;
    }

    .action-buttons {
        flex-direction: column;
    }

    .stat-number {
        font-size: 2rem;
    }
}