:root {
    color-scheme: light;
    font-family: Inter, system-ui, sans-serif;
    background: #f3f5f9;
    color: #1f2937;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
}

.app-shell {
    display: grid;
    grid-template-columns: 280px 1fr;
    min-height: 100vh;
}

.sidebar {
    background: #111827;
    color: #f9fafb;
    padding: 20px 16px 24px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    transition: width 0.25s ease, transform 0.25s ease;
}

.sidebar.collapsed {
    width: 72px;
}

.sidebar-header {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.sidebar-title {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
}

#seriesSelect {
    width: 100%;
    padding: 6px 10px;
    background: #1f2937;
    color: #f9fafb;
    border: 1px solid rgba(255, 255, 255, .15);
    border-radius: 6px;
    font-size: 0.85rem;
    cursor: pointer;
    appearance: auto;
}

.sidebar-header h1 {
    margin: 0;
    font-size: 1.1rem;
}

.sidebar-header p {
    margin: 4px 0 0;
    font-size: 0.9rem;
    color: #9ca3af;
}

.sidebar-toggle {
    border: 1px solid rgba(255, 255, 255, .15);
    background: transparent;
    color: inherit;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    cursor: pointer;
}

.video-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
    overflow-y: auto;
    padding-right: 4px;
}

.video-item {
    display: block;
    border-radius: 14px;
    padding: 14px 16px;
    background: rgba(255, 255, 255, .05);
    color: inherit;
    text-decoration: none;
    transition: background 0.2s ease, transform 0.2s ease;
}

.video-item:hover,
.video-item.active {
    background: rgba(255, 255, 255, .16);
    transform: translateX(2px);
}

.video-item span {
    display: block;
    font-size: 0.95rem;
}

.video-item small {
    color: #9ca3af;
    margin-top: 4px;
    display: block;
    font-size: 0.78rem;
}

.content {
    padding: 28px 28px 36px;
}

.player-panel {
    max-width: 1080px;
    margin: 0 auto;
}

.player-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 18px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.eyebrow {
    margin: 0 0 6px;
    color: #6b7280;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    font-size: 0.72rem;
}

.player-header h2 {
    margin: 0;
    font-size: clamp(1.5rem, 2vw, 2rem);
}

.player-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.speed-label {
    font-size: 0.95rem;
}

#speedSelect,
.fullscreen-button {
    border: 1px solid #d1d5db;
    background: white;
    color: #111827;
    padding: 10px 14px;
    border-radius: 12px;
    font-size: 0.95rem;
}

.fullscreen-button {
    cursor: pointer;
}

.video-container {
    background: #000;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 18px 48px rgba(15, 23, 42, .08);
}

video {
    width: 100%;
    height: auto;
    display: block;
    background: black;
}

.video-description {
    margin-top: 18px;
    padding: 18px 22px;
    background: #ffffff;
    border-radius: 18px;
    border: 1px solid #e5e7eb;
    color: #374151;
}

@media (max-width: 900px) {
    .app-shell {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: sticky;
        top: 0;
        z-index: 10;
        width: 100%;
        border-bottom: 1px solid rgba(255, 255, 255, .08);
    }

    .sidebar.collapsed {
        width: 100%;
    }

    .content {
        padding: 18px 18px 28px;
    }
}