:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --dark-bg: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --success-color: #22c55e;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
}

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

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

/* Header */
.header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav {
    display: flex;
    gap: 2rem;
    align-items: center;
}

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

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-name {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.btn-logout {
    background: var(--error-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 500;
    transition: opacity 0.3s;
}

.btn-logout:hover {
    opacity: 0.8;
}

/* Container */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
}

/* Login Page */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 2rem;
}

.login-box {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 3rem;
    width: 100%;
    max-width: 400px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.login-title {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 2rem;
}

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

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.form-input {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--dark-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    color: var(--text-primary);
    font-size: 1rem;
    transition: border-color 0.3s;
}

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

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    width: 100%;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

/* Alert */
.alert {
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    font-weight: 500;
}

.alert-error {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--error-color);
    color: var(--error-color);
}

.alert-success {
    background: rgba(34, 197, 94, 0.1);
    border: 1px solid var(--success-color);
    color: var(--success-color);
}

/* Search Bar */
.search-bar {
    margin-bottom: 2rem;
}

.search-input {
    width: 100%;
    max-width: 500px;
    padding: 0.75rem 1rem;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    color: var(--text-primary);
    font-size: 1rem;
}

/* Grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.75rem;
    overflow: hidden;
    transition: all 0.3s;
    cursor: pointer;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    border-color: var(--primary-color);
}

.card-image {
    width: 100%;
    height: 300px;
    object-fit: cover;
    background: var(--dark-bg);
}

.card-content {
    padding: 1rem;
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.card-category {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* Loading */
.loading {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.spinner {
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

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

/* Hidden */
.hidden {
    display: none !important;
}

/* Responsive */
@media (max-width: 768px) {
    .nav {
        gap: 1rem;
    }

    .grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 1rem;
    }

    .card-image {
        height: 225px;
    }

    .header-content {
        padding: 0 1rem;
    }

    .container {
        padding: 1rem;
    }
}

/* Tabs */
.tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.tab {
    padding: 1rem 1.5rem;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-weight: 600;
    cursor: pointer;
    position: relative;
    transition: color 0.3s;
}

.tab:hover {
    color: var(--text-primary);
}

.tab.active {
    color: var(--primary-color);
}

.tab.active::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    z-index: 2000;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    max-width: 800px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 700;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.5rem;
    transition: all 0.3s;
}

.modal-close:hover {
    background: var(--dark-bg);
    color: var(--text-primary);
}

.modal-body {
    padding: 1.5rem;
}

.video-player {
    width: 100%;
    aspect-ratio: 16/9;
    background: #000;
    border-radius: 0.5rem;
}