/* ========== Reset & Base ========== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #252525;
    --text-primary: #f0f0f0;
    --text-secondary: #a0a0a0;
    --accent: #6c63ff;
    --accent-hover: #5a52e0;
    --error: #ff4d4d;
    --success: #4caf50;
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
    --radius: 12px;
    --transition: 0.2s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

.hidden {
    display: none !important;
}

/* ========== Layout ========== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 24px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ========== Header ========== */
.header {
    padding: 32px 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
    border-bottom: 1px solid var(--bg-tertiary);
    margin-bottom: 32px;
}

.header-title {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.header-subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.view-controls {
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.icon-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    border: 1px solid var(--bg-tertiary);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.icon-btn:hover {
    border-color: var(--accent);
    color: var(--text-primary);
}
.icon-btn.active {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

.back-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--bg-secondary);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.9rem;
    cursor: pointer;
    transition: background var(--transition), border-color var(--transition);
}

.back-btn:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent);
}

.back-icon {
    font-size: 1.1rem;
}

/* ========== Video Grid ========== */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    padding-bottom: 48px;
}

.video-card {
    background: var(--bg-secondary);
    border-radius: var(--radius);
    overflow: hidden;
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition);
    box-shadow: var(--shadow);
}

.video-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.6);
}

.card-cover {
    position: relative;
    aspect-ratio: 16 / 9;
    overflow: hidden;
    background: var(--bg-tertiary);
}

.card-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition);
}

.video-card:hover .card-cover img {
    transform: scale(1.05);
}

.card-cover-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-secondary));
    color: var(--text-secondary);
}

.card-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition);
}

.video-card:hover .card-overlay {
    opacity: 1;
}

.play-icon {
    width: 56px;
    height: 56px;
    background: var(--accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    color: white;
    padding-left: 4px;
    box-shadow: 0 4px 16px rgba(108, 99, 255, 0.4);
}

.card-info {
    padding: 16px;
}

.card-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 4px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

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

/* ========== Video List ========== */
.video-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding-bottom: 48px;
}

.list-item {
    display: flex;
    align-items: center;
    gap: 16px;
    background: var(--bg-secondary);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius);
    padding: 12px;
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.list-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
    border-color: var(--accent);
}

.list-thumb {
    width: 180px;
    flex-shrink: 0;
    aspect-ratio: 16 / 9;
    border-radius: 10px;
    overflow: hidden;
    background: var(--bg-tertiary);
    position: relative;
}
.list-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.list-thumb-placeholder {
    display: none;
    align-items: center;
    justify-content: center;
    position: absolute;
    inset: 0;
    font-size: 2rem;
    background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-secondary));
    color: var(--text-secondary);
}

.list-info {
    flex: 1;
    min-width: 0;
}
.list-title {
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: 6px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.list-meta {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.list-action {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--accent);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 16px rgba(108, 99, 255, 0.35);
}
.play-icon-sm {
    padding-left: 2px;
    font-size: 0.9rem;
}

@media (max-width: 640px) {
    .list-thumb {
        width: 110px;
    }
    .list-action {
        display: none;
    }
}

/* ========== Loading ========== */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 80px 24px;
    gap: 16px;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--bg-tertiary);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

.loading-text {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ========== Error State ========== */
.error {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 80px 24px;
    gap: 12px;
    text-align: center;
}

.error-icon {
    font-size: 3rem;
}

.error-title {
    font-size: 1.25rem;
    font-weight: 600;
}

.error-message {
    color: var(--text-secondary);
    max-width: 480px;
}

.retry-btn {
    margin-top: 12px;
    padding: 10px 24px;
    background: var(--accent);
    border: none;
    border-radius: var(--radius);
    color: white;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--transition);
}

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

/* ========== Empty State ========== */
.empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 80px 24px;
    gap: 12px;
}

.empty-icon {
    font-size: 3rem;
}

.empty-text {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* ========== Player Page ========== */
.player-page {
    padding-top: 0;
}

.player-main {
    flex: 1;
    display: flex;
    align-items: flex-start;
    justify-content: center;
}

.player-wrapper {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    position: relative;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    aspect-ratio: 16 / 9;
}

.video-player {
    width: 100%;
    height: 100%;
    outline: none;
    background: black;
}

.player-loading,
.player-error {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    background: var(--bg-secondary);
}

.player-loading .loading-spinner {
    width: 48px;
    height: 48px;
    border-width: 4px;
}

.player-error {
    text-align: center;
    padding: 24px;
}

/* ========== Footer ========== */
.footer {
    margin-top: auto;
    padding: 24px 0;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
    border-top: 1px solid var(--bg-tertiary);
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
    .video-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
        gap: 16px;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }

    .header {
        padding: 24px 0 16px;
    }

    .header-title {
        font-size: 1.4rem;
    }

    .video-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 12px;
    }

    .back-btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .video-grid {
        grid-template-columns: 1fr;
    }
}