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

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --bg-tertiary: #eeeeee;
    --text-primary: #000000;
    --text-secondary: #666666;
    --border-color: #dddddd;
    --hover-bg: #e8e8e8;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
}

body.dark-theme {
    --bg-primary: #000000;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #2a2a2a;
    --text-primary: #ffffff;
    --text-secondary: #999999;
    --border-color: #333333;
    --hover-bg: #2a2a2a;
    --shadow: 0 2px 8px rgba(255, 255, 255, 0.1);
    --shadow-lg: 0 4px 16px rgba(255, 255, 255, 0.15);
}

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

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    overflow: hidden;
}

.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    height: 60px;
    position: sticky;
    top: 0;
    z-index: 100;

    .header-left {
        display: flex;
        align-items: center;
        gap: 16px;
        flex: 0 0 240px;
    }

    .header-center {
        flex: 1;
        display: flex;
        justify-content: center;
        max-width: 600px;
        margin: 0 20px;
    }

    .header-right {
        flex: 0 0 240px;
        display: flex;
        justify-content: flex-end;
    }
}

.menu-btn,
.settings-btn {
    background: transparent;
    border: none;
    font-size: 24px;
    cursor: pointer;
    padding: 8px;
    border-radius: 4px;
    transition: background 0.2s;

    &:hover {
        background: var(--hover-bg);
    }
}

.logo {
    font-size: 20px;
    font-weight: 600;
    letter-spacing: -0.5px;
}

.search-bar {
    display: flex;
    width: 100%;
    max-width: 600px;
    border: 1px solid var(--border-color);
    border-radius: 24px;
    overflow: hidden;
    background: var(--bg-secondary);

    input {
        flex: 1;
        border: none;
        padding: 10px 16px;
        font-size: 14px;
        background: transparent;
        color: var(--text-primary);
        outline: none;

        &::placeholder {
            color: var(--text-secondary);
        }
    }

    button {
        background: transparent;
        border: none;
        padding: 0 16px;
        cursor: pointer;
        font-size: 18px;
        transition: background 0.2s;

        &:hover {
            background: var(--hover-bg);
        }
    }
}

.sidebar {
    position: fixed;
    left: 0;
    top: 60px;
    width: 240px;
    height: calc(100vh - 60px);
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    transition: transform 0.3s;
    z-index: 50;

    &.hidden {
        transform: translateX(-100%);
    }
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    padding: 12px 8px;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 12px 16px;
    background: transparent;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    color: var(--text-primary);
    transition: background 0.2s;
    text-align: left;

    .nav-icon {
        font-size: 20px;
    }

    &:hover {
        background: var(--hover-bg);
    }

    &.active {
        background: var(--bg-tertiary);
        font-weight: 600;
    }
}

.main-content {
    margin-left: 240px;
    padding: 20px;
    height: calc(100vh - 60px);
    overflow-y: auto;
    transition: margin-left 0.3s;

    &.full-width {
        margin-left: 0;
    }
}

.page {
    &.hidden {
        display: none;
    }
}

.page-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;

    h2 {
        font-size: 24px;
        font-weight: 600;
    }
}

.region-select {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 14px;
    cursor: pointer;
    outline: none;

    &:hover {
        background: var(--hover-bg);
    }
}

.loading {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
    font-size: 16px;

    &.hidden {
        display: none;
    }
}

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;

    &.compact {
        gap: 12px;
    }

    &.cols-2 { grid-template-columns: repeat(2, 1fr); }
    &.cols-3 { grid-template-columns: repeat(3, 1fr); }
    &.cols-4 { grid-template-columns: repeat(4, 1fr); }
    &.cols-5 { grid-template-columns: repeat(5, 1fr); }
    &.cols-6 { grid-template-columns: repeat(6, 1fr); }
}

.video-card {
    cursor: pointer;
    border-radius: 8px;
    overflow: hidden;
    transition: transform 0.2s, box-shadow 0.2s;

    &:hover {
        transform: translateY(-4px);
        box-shadow: var(--shadow-lg);
    }

    .thumbnail-container {
        position: relative;
        width: 100%;
        padding-bottom: 56.25%;
        background: var(--bg-tertiary);
        overflow: hidden;

        img {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .duration {
            position: absolute;
            bottom: 8px;
            right: 8px;
            background: rgba(0, 0, 0, 0.8);
            color: white;
            padding: 2px 6px;
            border-radius: 4px;
            font-size: 12px;
            font-weight: 600;
        }
    }

    .video-info {
        padding: 12px;

        .video-title {
            font-size: 14px;
            font-weight: 600;
            margin-bottom: 8px;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
            line-height: 1.4;
        }

        .video-channel {
            font-size: 13px;
            color: var(--text-secondary);
            margin-bottom: 4px;
        }

        .video-stats {
            font-size: 12px;
            color: var(--text-secondary);
            display: flex;
            gap: 8px;
        }
    }
}

.watch-container {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 24px;
    margin-bottom: 32px;

    @media (max-width: 1200px) {
        grid-template-columns: 1fr;
    }
}

.video-player-container {
    #videoPlayer {
        width: 100%;
        aspect-ratio: 16 / 9;
        background: #000;
        border-radius: 8px;
    }

    .video-info {
        margin-top: 16px;

        h2 {
            font-size: 20px;
            font-weight: 600;
            margin-bottom: 12px;
        }

        .video-meta {
            display: flex;
            align-items: center;
            gap: 16px;
            margin-bottom: 16px;
            flex-wrap: wrap;
            color: var(--text-secondary);
            font-size: 14px;

            .video-stats {
                display: flex;
                gap: 16px;
                margin-left: auto;

                span {
                    display: flex;
                    align-items: center;
                    gap: 4px;
                }
            }
        }

        .channel-info {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 16px 0;
            border-top: 1px solid var(--border-color);
            border-bottom: 1px solid var(--border-color);

            img {
                width: 48px;
                height: 48px;
                border-radius: 50%;
                background: var(--bg-tertiary);
            }

            .channel-details {
                h3 {
                    font-size: 16px;
                    font-weight: 600;
                    margin-bottom: 2px;
                }

                span {
                    font-size: 13px;
                    color: var(--text-secondary);
                }
            }
        }

        .video-description {
            margin-top: 16px;
            padding: 12px;
            background: var(--bg-secondary);
            border-radius: 8px;
            font-size: 14px;
            line-height: 1.6;
            white-space: pre-wrap;
            max-height: 200px;
            overflow-y: auto;
        }
    }
}

.video-sidebar {
    .quality-selector {
        margin-bottom: 20px;
        padding: 12px;
        background: var(--bg-secondary);
        border-radius: 8px;

        label {
            display: block;
            font-size: 13px;
            font-weight: 600;
            margin-bottom: 8px;
        }

        select {
            width: 100%;
            padding: 8px;
            border: 1px solid var(--border-color);
            border-radius: 4px;
            background: var(--bg-primary);
            color: var(--text-primary);
            font-size: 14px;
            cursor: pointer;
        }
    }

    .related-videos {
        h3 {
            font-size: 16px;
            font-weight: 600;
            margin-bottom: 12px;
        }

        .related-video {
            display: flex;
            gap: 12px;
            margin-bottom: 12px;
            cursor: pointer;
            padding: 8px;
            border-radius: 8px;
            transition: background 0.2s;

            &:hover {
                background: var(--hover-bg);
            }

            .related-thumbnail {
                width: 160px;
                height: 90px;
                border-radius: 4px;
                background: var(--bg-tertiary);
                object-fit: cover;
                flex-shrink: 0;
            }

            .related-info {
                flex: 1;
                min-width: 0;

                .related-title {
                    font-size: 13px;
                    font-weight: 600;
                    margin-bottom: 6px;
                    display: -webkit-box;
                    -webkit-line-clamp: 2;
                    -webkit-box-orient: vertical;
                    overflow: hidden;
                    line-height: 1.3;
                }

                .related-channel {
                    font-size: 12px;
                    color: var(--text-secondary);
                    margin-bottom: 2px;
                }

                .related-stats {
                    font-size: 11px;
                    color: var(--text-secondary);
                }
            }
        }
    }
}

.comments-section {
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);

    h3 {
        font-size: 18px;
        font-weight: 600;
        margin-bottom: 20px;
    }
}

.comment {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
    padding: 12px;
    border-radius: 8px;
    background: var(--bg-secondary);

    .comment-avatar {
        width: 40px;
        height: 40px;
        border-radius: 50%;
        background: var(--bg-tertiary);
        flex-shrink: 0;
    }

    .comment-content {
        flex: 1;

        .comment-author {
            font-size: 13px;
            font-weight: 600;
            margin-bottom: 4px;
            display: flex;
            align-items: center;
            gap: 8px;

            .comment-time {
                font-size: 12px;
                font-weight: 400;
                color: var(--text-secondary);
            }
        }

        .comment-text {
            font-size: 14px;
            line-height: 1.5;
            margin-bottom: 8px;
            white-space: pre-wrap;
        }

        .comment-likes {
            font-size: 12px;
            color: var(--text-secondary);
        }
    }
}

.load-more-btn {
    display: block;
    margin: 20px auto;
    padding: 12px 24px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;

    &:hover {
        background: var(--hover-bg);
    }

    &.hidden {
        display: none;
    }
}

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;

    &.hidden {
        display: none;
    }

    .modal-content {
        background: var(--bg-primary);
        border-radius: 8px;
        width: 100%;
        max-width: 700px;
        max-height: 90vh;
        display: flex;
        flex-direction: column;
        box-shadow: var(--shadow-lg);
    }

    .modal-header {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);

        h2 {
            font-size: 20px;
            font-weight: 600;
        }

        .close-btn {
            background: transparent;
            border: none;
            font-size: 24px;
            cursor: pointer;
            padding: 4px;
            border-radius: 4px;
            transition: background 0.2s;

            &:hover {
                background: var(--hover-bg);
            }
        }
    }

    .modal-body {
        flex: 1;
        overflow-y: auto;
        padding: 20px;
    }

    .modal-footer {
        padding: 20px;
        border-top: 1px solid var(--border-color);
        display: flex;
        justify-content: flex-end;
        gap: 12px;
    }
}

.settings-group {
    margin-bottom: 32px;

    &:last-child {
        margin-bottom: 0;
    }

    h3 {
        font-size: 16px;
        font-weight: 600;
        margin-bottom: 16px;
        padding-bottom: 8px;
        border-bottom: 1px solid var(--border-color);
    }
}

.setting-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
    gap: 16px;

    label {
        font-size: 14px;
        flex: 1;
    }

    select,
    input[type="text"],
    input[type="number"] {
        padding: 8px 12px;
        border: 1px solid var(--border-color);
        border-radius: 4px;
        background: var(--bg-secondary);
        color: var(--text-primary);
        font-size: 14px;
        min-width: 150px;
    }

    &.checkbox {
        label {
            cursor: pointer;
            user-select: none;
        }

        input[type="checkbox"] {
            width: 18px;
            height: 18px;
            cursor: pointer;
        }
    }

    .refresh-btn {
        padding: 8px 12px;
        background: var(--bg-secondary);
        border: 1px solid var(--border-color);
        border-radius: 4px;
        color: var(--text-primary);
        font-size: 13px;
        cursor: pointer;
        transition: background 0.2s;

        &:hover {
            background: var(--hover-bg);
        }
    }

    .status-indicator {
        padding: 6px 12px;
        border-radius: 4px;
        font-size: 13px;
        background: var(--bg-secondary);
        color: var(--text-secondary);

        &.online {
            background: #e8f5e9;
            color: #2e7d32;
        }

        &.offline {
            background: #ffebee;
            color: #c62828;
        }
    }
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;

    &:hover {
        opacity: 0.8;
    }

    &.btn-primary {
        background: var(--text-primary);
        color: var(--bg-primary);
    }

    &.btn-secondary {
        background: var(--bg-secondary);
        color: var(--text-primary);
        border: 1px solid var(--border-color);
    }
}

.toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    padding: 12px 24px;
    background: var(--text-primary);
    color: var(--bg-primary);
    border-radius: 24px;
    font-size: 14px;
    box-shadow: var(--shadow-lg);
    z-index: 2000;
    animation: slideUp 0.3s ease;

    &.hidden {
        display: none;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}

.hidden {
    display: none !important;
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);

        &.show {
            transform: translateX(0);
        }
    }

    .main-content {
        margin-left: 0;
    }

    .watch-container {
        grid-template-columns: 1fr;
    }

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