:root {
    /* YouTube Signature Dark Palette */
    --bg-base: #0f0f0f;
    --bg-surface: #212121;
    --bg-surface-hover: #272727;
    --hover-overlay: #383838;
    --hover-overlay-subtle: #2a2a2a;
    --text-primary: #f1f1f1;
    --text-secondary: #aaaaaa;
    --text-muted: #717171;
    --accent-main: #ff0000;
    --accent-gradient: linear-gradient(135deg, #ff0000 0%, #cc0000 100%);
    --border-color: #303030;
    --border-hover: #484848;
    --border-focus: #555555;
    --glass-bg: rgba(33, 33, 33, 0.85);
    --glass-border: rgba(255, 255, 255, 0.08);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-pill: 24px;
    --transition: 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.35);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);

    --card-glow-color: rgba(255, 255, 255, 0.04);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', system-ui, sans-serif;
}

html {
    scroll-behavior: smooth;
}

body {
    background: var(--bg-base);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* Smooth Transitions for Color Themes */
body, header, .sidebar-panel, .card, .custom-dropdown-trigger, .modal-content, .comment-item, .sidebar-channel-item, .sidebar-suggestion-item {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-base);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-surface-hover);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}