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

:root {
    --primary: #500000;
    --primary-light: #8B3A3A;
    --secondary: #2B0000;
    --background: #F8F8F8;
    --white: #FFFFFF;
    --gray: #757575;
    --gray-light: #F0F0F0;
    --success: #2E7D32;
    --warning: #E65100;
    --danger: #C62828;
    --gold: #FFD700;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, sans-serif;
    background: var(--background);
    color: var(--secondary);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navbar */
.navbar {
    background: var(--white);
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.nav-links a {
    color: var(--secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary);
}

.nav-links button {
    background: var(--primary);
    color: var(--white);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 3rem 0;
}

.hero h1 {
    font-size: 2.5rem;
    color: var(--secondary);
    margin-bottom: 0.5rem;
}

.hero p {
    color: var(--gray);
    font-size: 1.1rem;
}

/* Sections */
.tutorials-section {
    margin: 3rem 0;
}

.section-header {
    margin-bottom: 1.5rem;
}

.section-header h2 {
    font-size: 1.8rem;
    color: var(--secondary);
    font-weight: 800;
}

.subtitle {
    color: var(--gray);
    font-size: 0.9rem;
}

/* Tutorial Grid */
.tutorials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.tutorial-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
}

.tutorial-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.tutorial-thumbnail {
    width: 100%;
    height: 160px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.play-icon {
    width: 60px;
    height: 60px;
    background: rgba(255,255,255,0.85);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}

.trending-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    background: var(--gold);
    color: var(--secondary);
    padding: 4px 8px;
    border-radius: 8px;
    font-size: 0.75rem;
    font-weight: bold;
}

.tutorial-info {
    padding: 1rem;
}

.tutorial-title {
    font-size: 1.1rem;
    font-weight: bold;
    color: var(--secondary);
    margin-bottom: 0.25rem;
}

.tutorial-artist {
    color: var(--gray);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
}

.tutorial-stats {
    display: flex;
    gap: 1rem;
    font-size: 0.85rem;
}

.stat {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    color: var(--gray);
}

/* Tutorial List */
.tutorials-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.tutorial-list-item {
    background: var(--white);
    padding: 1rem;
    border-radius: 12px;
    display: flex;
    gap: 1rem;
    cursor: pointer;
    transition: transform 0.3s;
}

.tutorial-list-item:hover {
    transform: translateX(4px);
}

.list-thumbnail {
    width: 90px;
    height: 90px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 12px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.list-info {
    flex: 1;
}

.difficulty-badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: bold;
    padding: 2px 8px;
    border-radius: 4px;
    margin-top: 0.5rem;
}

.difficulty-beginner { color: var(--success); }
.difficulty-intermediate { color: var(--warning); }
.difficulty-advanced { color: var(--danger); }

/* Auth Forms */
.auth-container {
    min-height: calc(100vh - 80px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.auth-box {
    background: var(--white);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
}

.auth-box h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--secondary);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--secondary);
}

.form-group input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--gray-light);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
}

.btn {
    width: 100%;
    padding: 0.875rem;
    background: var(--primary);
    color: var(--white);
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s;
}

.btn:hover {
    background: var(--secondary);
}

.auth-link {
    text-align: center;
    margin-top: 1.5rem;
    color: var(--gray);
}

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

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }

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

    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }
}

.error {
    color: var(--danger);
    font-size: 0.875rem;
    margin-top: 0.5rem;
}

.loading {
    text-align: center;
    padding: 2rem;
    color: var(--gray);
}