styles.css

        /* --- CSS Variables --- */
        :root {
            /* Font Families */
            --font-family-sans: 'Inter', sans-serif;
            --font-family-mono: 'Fira Code', monospace;
            --font-family-base: var(--font-family-sans);

            /* Transitions */
            --transition-speed: 0.2s;
            --transition-timing: cubic-bezier(0.25, 0.46, 0.45, 0.94); /* Smooth ease-out-quad */
            --transition-timing-spring: cubic-bezier(0.34, 1.56, 0.64, 1); /* Subtle overshoot/spring for bounces */
            --transition-fast: 0.15s;

            /* Radii */
            --border-radius-sm: 4px;
            --border-radius-md: 6px;
            /* Slightly smaller */
            --border-radius-lg: 10px;
            /* Slightly smaller */

            /* Sidebar */
            --sidebar-min-width: 255px;
            --sidebar-max-width: 500px;
            --sidebar-default-width: 255px;
            --sidebar-resize-handle-width: 5px;

            /* Shadows (More Pronounced for Depth) */
            --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05), 0 1px 1px rgba(0, 0, 0, 0.05);
            --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.08);
            --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.12), 0 2px 4px rgba(0, 0, 0, 0.08);
            --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.15), 0 5px 10px rgba(0, 0, 0, 0.1);
            --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.2), 0 10px 20px rgba(0, 0, 0, 0.15);

            /* Z-Indexes */
            --z-sticky: 10;
            --z-dropdown: 50;
            /* Example */
            --z-modal: 100;
            --z-toast: 1000;
            /* For notifications */


            /* --- Light Theme --- */
            --primary-color: #D32F2F;
            --primary-color-dark: #B71C1C;
            --primary-color-light: #FFEBEE;
            /* Keep this light for contrast */
            --background-color: #ffffff;
            /* Pure white */
            --surface-color: #fdfdfd;
            /* Slightly off-white */
            --surface-color-alt: #f5f5f5;
            /* Lighter grey */
            --text-color: #1a1a1a;
            /* Darker text */
            --text-color-muted: #555555;
            /* Adjusted grey */
            --text-color-subtle: #888888;
            /* Lighter subtle grey */
            --border-color: #e0e0e0;
            --border-color-second: #e0e0e0;
            /* Lighter border */
            --border-color-light: #ebebeb;
            --hover-bg-color: #f0f0f0;
            /* Subtle hover */
            --focus-ring-color: rgba(211, 47, 47, 0.2);
            /* Slightly softer focus */
            --icon-color: #444444;
            --icon-color-hover: var(--text-color);
            --toast-bg: #333333;
            --toast-text: #f8f9fa;
            --resizer-color: var(--border-color);
            --resizer-hover-color: var(--primary-color);
            /* Add Primary RGB for potential use */
            --primary-color-rgb: 211, 47, 47;
        }

        html[data-theme="dark"] {
            --primary-color: #E57373;
            /* Keep red vibrant */
            --primary-color-dark: #bb6262;
            /* Lighter red for hover/active */
            --primary-color-light: rgba(229, 115, 115, 0.1);
            /* Subtle highlight */
            --background-color: #131316;
            /* Much darker background */
            --surface-color: #131316;
            /* Darker surface */
            --surface-color-alt: #2a2a2a;
            /* Slightly lighter dark */
            --text-color: #e1e1e1;
            /* Slightly less bright white */
            --text-color-muted: #a0a0a0;
            /* Lighter muted */
            --text-color-subtle: #707070;
            /* Darker subtle */
            --border-color: transparent;
            /* Changed to transparent */
            --border-color-light: #282828;
            /* Second Color */
            --border-color-second: #333333;
            /* Button Color */
            --button-color: #18181b;
            /* Subtle inner border */
            --hover-bg-color: #2c2c2c;
            /* Darker hover */
            --focus-ring-color: rgba(229, 115, 115, 0.3);
            /* Keep focus visible */
            --icon-color: #a0a0a0;
            --icon-color-hover: var(--text-color);
            --toast-bg: #e1e1e1;
            /* Light toast on dark bg */
            --toast-text: #1a1a1a;
            --resizer-color: var(--border-color);
            --resizer-hover-color: var(--primary-color);
            /* Add Primary RGB for potential use */
            --primary-color-rgb: 229, 115, 115;
            --video-card-background: #18181b;
        }


        /* --- Base & Reset --- */
        *,
        *::before,
        *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        html {
            font-size: 16px;
            scroll-behavior: smooth;
            height: 100%;
        }

        body {
            background-color: var(--background-color);
            color: var(--text-color);
            font-family: var(--font-family-base);
            line-height: 1.6;
            transition: background-color var(--transition-speed) var(--transition-timing), color var(--transition-speed) var(--transition-timing);
            overscroll-behavior-y: contain;
            height: 100%;
            min-height: 100%;
            opacity: 0;
            animation: fadeIn 0.5s var(--transition-timing) forwards; /* Use new timing */
            padding-top: env(safe-area-inset-top, 0px);
            padding-bottom: env(safe-area-inset-bottom, 0px);
            padding-left: env(safe-area-inset-left, 0px);
            padding-right: env(safe-area-inset-right, 0px);
        }

        /* Disable animation for iOS PWA */
        html.ios-pwa body {
            opacity: 1 !important;
            animation: none !important;
        }

        /* Apple-like fade-in animation */
        @keyframes fadeIn {
            from { opacity: 0; margin-top: 10px; }
            to { opacity: 1; margin-top: 0; }
        }

        img,
        svg {
            display: block;
            max-width: 100%;
        }

        button,
        input {
            font-family: inherit;
            font-size: inherit;
        }

        *:focus-visible {
            /* Consistent focus outline */
            outline: 2px solid var(--focus-ring-color);
            outline-offset: 2px;
            box-shadow: 0 0 0 4px var(--focus-ring-color);
            border-radius: var(--border-radius-sm);
        }

        *:focus {
            outline: none;
        }

        /* Remove default focus for non-keyboard */

        /* --- Layout --- */
        .container {
            display: flex;
            height: 100%;
            overflow: hidden;
        }

        /* --- Sidebar --- */
        .sidebar {
            width: var(--sidebar-default-width);
            min-width: var(--sidebar-min-width);
            max-width: var(--sidebar-max-width);
            border-right: 1px solid var(--border-color-light);
            display: flex;
            flex-direction: column;
            flex-shrink: 0;
            transition: background-color var(--transition-speed) var(--transition-timing), border-color var(--transition-speed) var(--transition-timing);
            position: relative;
            will-change: background-color, border-color;
        }

        /* Sidebar Resizer */
        .sidebar-resizer {
            position: absolute;
            top: 0;
            right: -3px;
            width: var(--sidebar-resize-handle-width);
            height: 100%;
            background-color: transparent;
            cursor: col-resize;
            z-index: var(--z-dropdown);
        }

        .sidebar-resizer:hover::after,
        .sidebar-resizer.resizing::after {
            content: "";
            position: absolute;
            top: 0;
            left: 0px; /* Adjust to expand from center */
            width: 5px; /* Make it wider on hover/active */
            height: 100%;
            background-color: var(--resizer-hover-color);
            opacity: 1; /* Make it fully opaque */
            transition: background-color var(--transition-speed) var(--transition-timing), width var(--transition-speed) var(--transition-timing), opacity var(--transition-speed) var(--transition-timing), left var(--transition-speed) var(--transition-timing);
            border-radius: 2px; /* Slight roundness */
        }

        .sidebar-resizer::after {
            content: "";
            position: absolute;
            top: 0;
            left: 1px;
            width: 3px;
            height: 100%;
            background-color: var(--resizer-color);
            opacity: 0.3;
            transition: background-color var(--transition-speed) var(--transition-timing), width var(--transition-speed) var(--transition-timing), opacity var(--transition-speed) var(--transition-timing), left var(--transition-speed) var(--transition-timing);
            border-radius: 2px;
        }

        .sidebar-content {
            /* Scrollable area */
            padding: 15px; /* Adjusted padding */
            overflow-y: auto;
            flex-grow: 1;
            border: 1px solid var(--border-color-light); /* Added border */
            border-radius: var(--border-radius-lg); /* Added border-radius */
            margin: 10px 10px 5px 10px; /* Added margin (Top, Sides, Bottom) */
            background-color: var(--surface-color); /* Ensure background color */
            transition: background-color var(--transition-speed) var(--transition-timing), border-color var(--transition-speed) var(--transition-timing), padding var(--transition-speed) var(--transition-timing), margin var(--transition-speed) var(--transition-timing); /* Added transition */
        }

        .sidebar-footer {
            padding: 15px; /* Adjusted padding */
            /* border-top: 1px solid var(--border-color-light); */ /* Removed original border-top */
            flex-shrink: 0;
            background-color: var(--background-color);
            transition: background-color var(--transition-speed) var(--transition-timing), border-color var(--transition-speed) var(--transition-timing), padding var(--transition-speed) var(--transition-timing), margin var(--transition-speed) var(--transition-timing); /* Added transition */
            border: 1px solid var(--border-color-light); /* Added border */
            border-radius: var(--border-radius-lg); /* Added border-radius */
            margin: 5px 10px 10px 10px; /* Added margin (Top, Sides, Bottom) */
        }

        .sidebar-header {
             /* Keep default or remove if not needed */
             /* Add horizontal padding to align with margined content/footer */
        }

        .sidebar h2 {
            font-weight: 700;
            font-size: 1.2rem;
            color: var(--text-color);
            display: flex;
            align-items: center;
            gap: 8px;
            margin-bottom: 16px;
            margin-top: -4px;
            transition: color var(--transition-speed) var(--transition-timing);
        }

        .sidebar h2 svg {
            width: 30px;
            height: 30px;
            color: var(--primary-color);
        }

        /* Form Styles */
        .form-section {
            margin-bottom: 20px;
        }

        .form-section label {
            display: block;
            font-weight: 500;
            margin-bottom: 6px;
            font-size: 0.875rem;
            color: var(--text-color-muted);
        }

        input[type="text"],
        input[type="url"],
        input[type="search"] {
            width: 100%;
            padding: 8px 12px;
            border: 1px solid var(--border-color);
            border-radius: var(--border-radius-md);
            font-size: 0.9rem;
            background-color: var(--button-color);
            color: var(--text-color);
            transition: border-color var(--transition-speed) var(--transition-timing), box-shadow var(--transition-speed) var(--transition-timing), background-color var(--transition-speed) var(--transition-timing), color var(--transition-speed) var(--transition-timing);
        }

        input[type="text"]:focus,
        input[type="url"]:focus,
        input[type="search"]:focus {
            border-color: var(--primary-color);
            background-color: var(--surface-color);
            box-shadow: 0 0 0 3px var(--focus-ring-color);
            /* Keep focus ring */
        }

        input::placeholder {
            color: var(--text-color-subtle);
        }

        input[type="search"] {
            padding-left: 30px;
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%236c757d' viewBox='0 0 16 16'%3E%3Cpath d='M11.742 10.344a6.5 6.5 0 1 0-1.397 1.398h-.001c.03.04.062.078.098.115l3.85 3.85a1 1 0 0 0 1.415-1.414l-3.85-3.85a1.007 1.007 0 0 0-.115-.1zM12 6.5a5.5 5.5 0 1 1-11 0 5.5 5.5 0 0 1 11 0z'/%3E%3C/svg%3E");
            background-repeat: no-repeat;
            background-position: 10px center;
            background-size: 14px 14px;
        }

        html[data-theme="dark"] input[type="search"] {
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' fill='%23b0b3b8' viewBox='0 0 16 16'%3E%3Cpath d='M11.742 10.344a6.5 6.5 0 1 0-1.397 1.398h-.001c.03.04.062.078.098.115l3.85 3.85a1 1 0 0 0 1.415-1.414l-3.85-3.85a1.007 1.007 0 0 0-.115-.1zM12 6.5a5.5 5.5 0 1 1-11 0 5.5 5.5 0 0 1 11 0z'/%3E%3C/svg%3E");
        }

        /* Button Styles */
        button {
            background-color: #d75f5f;
            color: white;
            border: none;
            padding: 8px 16px;
            border-radius: var(--border-radius-md);
            cursor: pointer;
            font-size: 0.9rem;
            font-weight: 600;
            transition: background-color var(--transition-speed) var(--transition-timing),
                        transform var(--transition-speed) var(--transition-timing-spring), /* Use spring for transform */
                        box-shadow var(--transition-speed) var(--transition-timing-spring), /* Use spring for shadow */
                        opacity var(--transition-speed) var(--transition-timing);
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 6px;
            box-shadow: var(--shadow-xs);
            line-height: 1.4;
            /* Prevent text jump on loading */
            will-change: transform, background-color, box-shadow; /* Hint to the browser for better performance */
        }

        button:not(:disabled):hover {
            transform: translateY(-2px) scale(1.02) translateZ(0); /* Add translateZ(0) for GPU acceleration */
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
            background-color: #bb6262;
        }

        button:not(:disabled):active {
            transform: translateY(0px) translateZ(0); /* Ensure consistency and make it "press" in */
            box-shadow: var(--shadow-xs);
        }

        button:disabled {
            background-color: var(--surface-color-alt);
            color: var(--text-color-subtle);
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
            opacity: 0.7;
        }

        button.is-loading {
            pointer-events: none;
        }

        /* Loading spinner inside button */
        .spinner {
            width: 1em;
            height: 1em;
            border: 2px solid currentColor;
            border-right-color: transparent;
            border-radius: 50%;
            animation: spin 0.6s linear infinite;
            margin-left: -2px;
            /* Adjust alignment */
        }

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

        button.secondary {
            font-size: 0.8rem;
            background-color: var(--surface-color);
            color: var(--text-color-muted);
            border: 1px solid var(--border-color-second);
            padding: 6px 10px;
            font-weight: 500;
            box-shadow: none;
        }

        button.secondary:not(:disabled):hover {
            background-color: var(--hover-bg-color);
            color: var(--text-color);
            transform: none;
            box-shadow: none;
        }

        button.icon-button {
            background: none;
            color: var(--icon-color);
            padding: 6px;
            font-size: 1.1rem;
            /* Icon size */
            line-height: 1;
            border-radius: 50%;
            box-shadow: none;
        }

        button.icon-button:not(:disabled):hover {
            background-color: var(--hover-bg-color);
            color: var(--icon-color-hover);
            transform: none;
            box-shadow: none;
        }

        button.icon-button svg {
            width: 1.1em;
            height: 1.1em;
        }

        /* Playlist List */
        .playlist-list {
            list-style: none;
            margin-top: 16px;
        }

        .playlist-item {
            padding: 8px 12px;
            margin-bottom: 4px;
            border-radius: var(--border-radius-md);
            cursor: pointer;
            display: flex;
            justify-content: space-between;
            align-items: center;
            transition: transform 0.3s var(--transition-timing), opacity 0.3s var(--transition-timing), background-color 0.2s var(--transition-timing), border-color 0.2s var(--transition-timing), box-shadow 0.2s var(--transition-timing); /* Add shadow transition */
            position: relative;
            font-size: 0.9rem;
            border: 1px solid transparent;
            will-change: transform, background-color, box-shadow;
        }

        .playlist-item:hover {
            background-color: var(--hover-bg-color);
            box-shadow: var(--shadow-xs); /* Slight shadow */
        }

        .playlist-item.active {
            background-color: var(--primary-color-light);
            color: var(--primary-color-dark);
            font-weight: 600;
            border-color: var(--primary-color-light);
        }

        html[data-theme="dark"] .playlist-item.active {
            color: var(--primary-color);
            border-color: rgba(var(--primary-color-rgb), 0.3);
        }

        .playlist-item.dragging {
            opacity: 0.4;
            cursor: grabbing;
            background: var(--surface-color-alt);
            box-shadow: var(--shadow-md);
            border-color: var(--border-color);
            will-change: transform, opacity;
        }

        /* Playlist drag-over style (similar to video card drag-over) */
        .playlist-item.drag-over {
            outline: 2px dashed var(--primary-color);
            outline-offset: -2px;
            background-color: var(--primary-color-light); /* Use a more active background */
            transform: scale(1.01); /* Subtle "target" scale */
            transition: all var(--transition-fast) ease-in-out; /* Quick transition for drag feedback */
        }

        .playlist-name {
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            margin-right: 8px;
            flex-grow: 1;
            /* pointer-events: none; */ /* Removed to allow clicking name to select */
        }

        .playlist-count {
            font-size: 0.8rem;
            color: var(--text-color-subtle);
            margin-left: 4px;
            font-weight: 400;
            flex-shrink: 0;
            pointer-events: none;
        }

        .playlist-item.active .playlist-count {
            color: var(--primary-color);
        }

        html[data-theme="dark"] .playlist-item.active .playlist-count {
            color: var(--primary-color);
        }

        .playlist-item .controls {
            display: flex;
            gap: 2px;
            opacity: 0;
            transition: opacity var(--transition-speed) var(--transition-timing);
            flex-shrink: 0;
            margin-left: 8px;
            align-items: center; /* Align controls vertically */
        }

        .playlist-item:hover .controls,
        .playlist-item.active .controls,
        .playlist-item .controls:focus-within {
            /* Show on focus too */
            opacity: 1;
        }

        .playlist-item .controls button,
        .playlist-item .controls .playlist-drag-handle { /* Include drag handle */
            /* Make control buttons smaller */
            padding: 4px;
            font-size: 0.9rem;
            line-height: 1;
            min-width: auto;
            background-color: transparent;
            color: var(--text-color-muted);
            box-shadow: none;
        }

        .playlist-item .controls button:hover,
        .playlist-item .controls .playlist-drag-handle:hover { /* Include drag handle */
            background-color: var(--surface-color-alt);
            color: var(--text-color);
        }

        html[data-theme="dark"] .playlist-item .controls button:hover,
        html[data-theme="dark"] .playlist-item .controls .playlist-drag-handle:hover {
            background-color: var(--background-color);
        }

        .playlist-item .controls button svg,
        .playlist-item .controls .playlist-drag-handle svg { /* Include drag handle */
            width: 0.9em;
            height: 0.9em;
        }

        .playlist-drag-handle {
            cursor: grab; /* Use grab cursor for the handle */
        }
        .playlist-drag-handle:active {
            cursor: grabbing; /* Use grabbing cursor while dragging */
            color: var(--text-color); /* Change color while active */
        }


        /* --- Main Content --- */
        .main-content {
            flex: 1;
            padding: 10px 25px;
            overflow-y: auto;
            transition: background-color var(--transition-speed) var(--transition-timing);
            border: 1px solid var(--border-color-light);
            border-radius: var(--border-radius-lg);
            margin: 10px 10px 10px 10px;
            will-change: background-color;
        }

        .main-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 24px;
            flex-wrap: wrap;
            gap: 16px;
            padding-bottom: 16px;
            border-bottom: 1px solid var(--border-color-light);
            transition: all var(--transition-speed) var(--transition-timing);
            opacity: 0;
            animation: fadeIn var(--transition-speed) var(--transition-timing) 0.1s forwards; /* Use new timing */
        }

        #currentPlaylistTitle {
            font-weight: 700;
            font-size: 1.5rem;
            /* Slightly smaller */
            color: var(--text-color);
            min-height: 1.5rem;
            flex-grow: 1;
            transition: color var(--transition-speed) var(--transition-timing);
        }

        .playlist-actions {
            /* Combined controls */
            display: flex;
            align-items: center;
            gap: 12px;
            flex-shrink: 0;
        }

        .control-group {
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .control-group label,
        .control-group span {
            font-size: 0.875rem;
            font-weight: 500;
            color: var(--text-color-muted);
            cursor: pointer;
        }

        /* Autoplay Toggle Switch (No change needed, uses vars) */
        .switch {
            position: relative;
            display: inline-block;
            width: 34px;
            height: 20px;
        }

        .switch input {
            opacity: 0;
            width: 0;
            height: 0;
        }

        .slider {
            position: absolute;
            cursor: pointer;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background-color: var(--surface-color-alt);
            transition: .4s;
            border-radius: 20px;
        }

        .slider:before {
            position: absolute;
            content: "";
            height: 14px;
            width: 14px;
            left: 3px;
            bottom: 3px;
            background-color: var(--surface-color);
            transition: .4s;
            border-radius: 50%;
            box-shadow: var(--shadow-xs);
        }

        input:checked+.slider {
            background-color: var(--primary-color);
        }

        input:checked+.slider:before {
            transform: translateX(14px);
        }

        html[data-theme="dark"] .slider:before {
            background-color: var(--text-color-muted);
        }

        html[data-theme="dark"] input:checked+.slider:before {
            background-color: var(--surface-color);
        }


        /* Add Video Form */
        .video-form {
            background-color: var(--surface-color);
            padding: 10px 20px;
            border-radius: var(--border-radius-lg);
            box-shadow: var(--shadow-sm);
            margin-bottom: 20px;
            border: 1px solid var(--border-color-light);
            transition: background-color var(--transition-speed) var(--transition-timing), border-color var(--transition-speed) var(--transition-timing), box-shadow var(--transition-speed) var(--transition-timing);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .video-form label {
            margin-bottom: 0;
            flex-shrink: 0;
        }

        .video-form input[type="url"] {
            flex-grow: 1;
            margin-bottom: 0;
        }

        .video-form button {
            flex-shrink: 0;
        }


        /* Player Wrapper */
        .player-wrapper {
            margin-top: 24px;
            margin-bottom: 24px;
            border-radius: var(--border-radius-lg);
            overflow: hidden;
            box-shadow: var(--shadow-md);
            position: relative;
            z-index: var(--z-sticky);
            border: 1px solid var(--border-color-light);
            transition: border-color var(--transition-speed) var(--transition-timing), box-shadow var(--transition-speed) var(--transition-timing);
            background-color: #000;
            /* Black background behind player */
        }

        .close-player-btn {
            position: absolute;
            top: 5px;
            right: 5px;
            z-index: calc(var(--z-sticky) + 1);
            background-color: rgba(0, 0, 0, 0.5);
            color: white;
            border: none;
            border-radius: 50%;
            width: 28px;
            height: 28px;
            padding: 0;
            display: flex;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            opacity: 0.7;
            transition: opacity 0.2s ease, background-color 0.2s ease;
            transform: translateY(0);
        }

        .close-player-btn:hover {
            opacity: 1;
            background-color: rgba(0, 0, 0, 0.7);
        }

        .close-player-btn svg {
            width: 16px;
            /* Adjust size as needed */
            height: 16px;
        }

        /* Player Container */
        .player-container {
            position: relative;
            padding-bottom: 56.25%;
            height: 0;
            overflow: hidden;
            transition: opacity var(--transition-speed) ease-in-out, height var(--transition-speed) ease-in-out;
            will-change: opacity, height;
        }

        /* Style to hide the video when audio-only is active */
        body.audio-only-active .player-container {
            height: 0 !important;
            padding-bottom: 0 !important;
            overflow: hidden;
            opacity: 0;
        }

        /* Keep the wrapper visible but maybe add an indicator? */
        body.audio-only-active .player-wrapper {
            min-height: auto;
            padding: 5px 40px 5px 15px;
            background-color: var(--surface-color-alt);
            box-shadow: var(--shadow-sm);
            display: block;
            position: sticky;
        }

        /* New styles for audio-only info */
        .audio-only-info {
            display: none;
            align-items: center;
            gap: 6px;
            font-size: 0.85rem;
            color: var(--text-color-muted);
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }

        .audio-only-info .audio-title {
            font-weight: 600;
            color: var(--text-color);
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }

        body.audio-only-active .audio-only-info {
            display: flex;
        }
        /* End new styles */

        /* Audio-only mode close button */
        body.audio-only-active .close-player-btn {
            top: 50%;
            right: 8px;
            transform: translateY(-50%); /* Center vertically using transform */
            background-color: transparent;
            color: var(--icon-color);
            /* Add these to prevent layout shift on hover */
            margin: 0;
            transition: opacity 0.2s ease, background-color 0.2s ease, color 0.2s ease;
        }

        body.audio-only-active .close-player-btn:hover {
            background-color: var(--hover-bg-color);
            color: var(--icon-color-hover);
            /* Maintain position on hover */
            transform: translateY(-50%);
        }

        #player {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            border: none;
        }

        /* Video Grid */
        .video-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
            /* Smaller min */
            gap: 16px;
            margin-top: 24px;
            transition: all 0.3s ease;
            will-change: transform, opacity;
        }

        .video-card {
            background-color: var(--video-card-background);
            border-radius: var(--border-radius-md);
            overflow: hidden;
            box-shadow: var(--shadow-xs);
            cursor: pointer;
            transition: transform 0.3s var(--transition-timing-spring), opacity 0.3s var(--transition-timing), box-shadow 0.3s var(--transition-timing); /* Use spring for transform, smooth for others */
            display: flex;
            flex-direction: column;
            position: relative;
            border: 1px solid transparent;
            /* Placeholder for hover/drag */
            will-change: transform, opacity, box-shadow;
        }

        .video-card:hover {
            transform: translateY(-5px) scale(1.02) translateZ(0);
            opacity: 0.98; /* Slightly less opaque */
            box-shadow: var(--shadow-md); /* More pronounced shadow on hover */
            will-change: transform, opacity, box-shadow;
        }

        /* Drag & Drop Styles */
        .video-card.dragging {
            opacity: 0.4;
            box-shadow: var(--shadow-lg);
            transform: scale(0.98);
            cursor: grabbing;
            /* border-color: var(--primary-color); */ /* Removed border */
            background: var(--surface-color-alt);
            will-change: transform, opacity;
        }

        /* Style for the active/playing video card */
        .video-card.playing {
            border-color: var(--primary-color);
            box-shadow: var(--shadow-md);
            background-color: var(--primary-color-light);
            /* Keep the transparent border placeholder for consistency */
            border-width: 1px;
            border-style: solid;
        }

        html[data-theme="dark"] .video-card.playing {
            background-color: rgba(var(--primary-color-rgb), 0.15);
            border-color: var(--primary-color-dark);
        }

        /* Remove ::before/::after and inset box-shadow styles */
        /*
        .video-card::before,
        .video-card::after { ... }
        .video-card::before { ... }
        .video-card::after { ... }
        .video-card.drag-over-top::before,
        .video-card.drag-over-bottom::after { ... }
        .video-card.drag-over-top { ... }
        .video-card.drag-over-bottom { ... }
        */

        /* Restore the original drag-over outline style */
        .video-card.drag-over {
            box-shadow: var(--shadow-md); /* Keep hover shadow */
            /* Use border or outline for drop indicator */
            outline: 2px dashed var(--primary-color);
            outline-offset: -2px; /* Inside the card */
            transform: scale(1.01); /* Subtle "target" scale */
            background-color: var(--primary-color-light); /* Use a more active background */
            transition: all var(--transition-fast) ease-in-out; /* Quick transition for drag feedback */
        }
        html[data-theme="dark"] .video-card.drag-over {
            background-color: rgba(var(--primary-color-rgb), 0.2);
        }


        /* Optional: Add space indicator between cards (Removed as we use ::before/::after now) */
        /* .drop-indicator { ... } */


        .thumbnail-wrapper {
            position: relative;
            padding-bottom: 56.25%;
            height: 0;
            overflow: hidden;
            background-color: var(--surface-color-alt);
            transition: background-color var(--transition-speed) var(--transition-timing);
        }

        .thumbnail {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            object-fit: cover;
            display: block;
            transition: transform 0.3s ease-out;
        }

        .video-card:hover .thumbnail {
            transform: scale(1.03);
        }

        .video-info {
            padding: 10px 12px;
            flex-grow: 1;
            display: flex;
            justify-content: space-between;
            align-items: flex-start;
            gap: 8px;
        }

        .video-info h4 {
            font-size: 0.85rem;
            font-weight: 600;
            margin: 0;
            line-height: 1.4;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
            text-overflow: ellipsis;
            flex-grow: 1;
            transition: color var(--transition-speed) var(--transition-timing);
        }

        .video-controls {
            display: flex;
            gap: 0;
            opacity: 0;
            flex-shrink: 0;
            transition: opacity var(--transition-speed) var(--transition-timing);
            align-items: center;
        }

        .video-card:hover .video-controls,
        .video-card .video-controls:focus-within {
            opacity: 1;
        }

        .video-controls button,
        .video-controls .drag-handle {
            padding: 4px;
            font-size: 1rem;
            line-height: 1;
            background: none;
            color: var(--text-color-muted);
            box-shadow: none;
            border-radius: 50%;
        }

        .video-controls button:hover,
        .video-controls .drag-handle:hover {
            color: var(--text-color);
            background-color: var(--hover-bg-color);
            transform: none;
        }

        .drag-handle {
            cursor: grab;
            font-size: 1.1rem;
            padding: 4px;
        }

        .drag-handle:active {
            cursor: grabbing;
            color: var(--text-color);
        }

        .video-controls button svg,
        .drag-handle svg {
            width: 1em;
            height: 1em;
        }

        /* Placeholder Message */
        .placeholder-message {
            text-align: center;
            color: var(--text-color-muted);
            margin-top: 40px;
            font-size: 1rem;
            padding: 30px 20px;
            background-color: var(--surface-color);
            border-radius: var(--border-radius-lg);
            box-shadow: var(--shadow-sm);
            border: 1px dashed var(--border-color);
            transition: background-color var(--transition-speed) var(--transition-timing), color var(--transition-speed) var(--transition-timing), border-color var(--transition-speed) var(--transition-timing), box-shadow var(--transition-speed) var(--transition-timing);
        }

        /* Settings Area in Sidebar Footer */
        .sidebar-settings {
            display: flex;
            flex-direction: column;
            gap: 12px;
        }

        .settings-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            gap: 10px;
        }

        .settings-group {
            display: flex;
            align-items: center;
            gap: 6px;
        }

        .settings-group label {
            font-size: 0.8rem;
            color: var(--text-color-muted);
            font-weight: 500;
            margin-bottom: 0;
        }

        .settings-group button.font-btn {
            /* Specific font button style */
            padding: 4px 8px;
            font-size: 0.75rem;
            min-width: 35px;
            font-weight: 500;
            border: 1px solid var(--border-color);
            background-color: var(--surface-color);
            color: var(--text-color-muted);
            box-shadow: none;
        }

        .settings-group button.font-btn.active {
            background-color: var(--primary-color);
            color: white;
            border-color: var(--primary-color);
        }

        .settings-group button.font-btn:not(.active):hover {
            background-color: var(--hover-bg-color);
            color: var(--text-color);
            border-color: var(--border-color-light);
        }

        .settings-group button.icon-button svg {
            width: 1em;
            height: 1em;
        }

        /* Ensure size */

        /* Toast Notifications */
        .toast-container {
            position: fixed;
            bottom: 20px;
            right: 20px;
            z-index: 9999;
            display: flex;
            flex-direction: column;
            gap: 10px;
            align-items: flex-end;
        }

        .toast {
            background-color: var(--toast-bg);
            color: var(--toast-text);
            padding: 12px 18px;
            border-radius: var(--border-radius-md);
            box-shadow: var(--shadow-lg);
            font-size: 0.9rem;
            opacity: 0;
            transform: translateY(10px);
            transition: opacity 0.3s ease, transform 0.3s ease;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .toast.show {
            opacity: 1;
            transform: translateY(0);
        }

        .toast.error {
            background-color: var(--primary-color-dark);
            color: white;
        }

        .toast.success {
            background-color: #28a745;
            color: white;
        }

        /* Example success color */
        .toast svg {
            width: 1.1em;
            height: 1.1em;
            flex-shrink: 0;
        }

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

        .visually-hidden {
            /* For accessibility, hide visually but keep for screen readers */
            position: absolute;
            width: 1px;
            height: 1px;
            padding: 0;
            margin: -1px;
            overflow: hidden;
            clip: rect(0, 0, 0, 0);
            white-space: nowrap;
            border: 0;
        }

        /* Hide scrollbars but maintain functionality */
        .sidebar-content,
        .main-content,
        .playlist-list,
        *::-webkit-scrollbar {
            /* Hide scrollbar for Chrome, Safari and Opera */
            scrollbar-width: none;
            /* Firefox */
            -ms-overflow-style: none;
            /* IE and Edge */
        }

        /* Hide WebKit scrollbar */
        .sidebar-content::-webkit-scrollbar,
        .main-content::-webkit-scrollbar,
        .playlist-list::-webkit-scrollbar,
        *::-webkit-scrollbar {
            display: none;
            width: 0;
            height: 0;
        }

        /* --- Mobile Responsiveness --- */
        @media (max-width: 768px) {
            .container {
                flex-direction: column;
                /* Stack sidebar and main content */
                height: auto;
                /* Allow content to determine height */
                overflow: visible;
                /* Prevent container from cutting off content */
            }

            .sidebar {
                width: 100% !important;
                /* Override inline style from resizer */
                max-width: none;
                /* Remove max width */
                height: auto;
                /* Adjust height based on content */
                border-right: none;
                border-bottom: 1px solid var(--border-color-light);
                /* Add border below */
                min-height: 200px;
                /* Give it some minimum height */
                position: relative;
                /* Ensure it stays in flow */
                flex-shrink: 1;
                /* Allow sidebar to shrink if needed, though unlikely now */
                order: 2;
                /* Display after main content */
            }

            .sidebar-resizer {
                display: none;
                /* Hide resizer on mobile */
            }

            .sidebar-content {
                /* Adjust padding slightly */
                padding: 12px; /* Adjusted mobile padding */
                /* Limit height to prevent excessive scrolling */
                overflow-y: auto;
                /* Ensure it's scrollable if content overflows */
                margin: 10px 10px 20px 10px; /* Keep margin */
            }

            /* Add this rule to hide the main sidebar title on mobile */
            .sidebar-header h2 {
                display: none;
            }

            /* Adjust header padding on mobile */
             .sidebar-header {
                 padding: 0 10px; /* Keep horizontal padding */ 
             }

            .sidebar-footer {
                padding: 12px 16px; /* Restore original mobile padding */
                margin: 0; /* Remove margin added previously */
                border: none; /* Remove border added previously */
                border-top: 1px solid var(--border-color-light); /* Restore original border-top */
                border-radius: 0; /* Remove border-radius */
                /* Transition property will inherit from the base rule */
            }

            .main-content {
                padding: 16px;
                /* Reduce padding */
                overflow-y: visible;
                /* Allow content to scroll with the body */
                order: 1;
                /* Display before sidebar */
            }

            .main-header {
                flex-direction: column;
                /* Stack title and actions */
                align-items: flex-start;
                gap: 12px;
                padding-bottom: 12px;
            }

            #currentPlaylistTitle {
                font-size: 1.3rem;
                /* Slightly smaller title */
            }

            .playlist-actions {
                gap: 10px;
                /* Reduce gap */
                flex-wrap: wrap;
                /* Allow actions to wrap */
                width: 100%;
                /* Take full width */
                justify-content: space-between;
                /* Space out elements */
            }

            /* Hide the audio only control group on mobile */
            #audioOnlyControlGroup {
                display: none;
            }

            .video-form {
                flex-direction: column;
                /* Stack form elements */
                align-items: stretch;
                /* Stretch elements to full width */
                padding: 12px 16px;
                gap: 10px;
            }

            .video-form input[type="url"] {
                margin-bottom: 0;
                /* Remove bottom margin */
            }

            /* Add this rule to prevent mobile zoom on input focus */
            input[type="text"],
            input[type="url"],
            input[type="search"] {
                font-size: 16px;
                /* Prevent auto-zoom on iOS */
            }

            .player-wrapper {
                position: sticky;
                top: calc(10px + env(safe-area-inset-top, 0px)); /* Adjust top position for safe area */
                margin-top: 16px;
                margin-bottom: 16px;
                /* Keep other styles like border-radius, overflow */
                z-index: var(--z-sticky);
            }

            .video-grid {
                /* Adjust grid for smaller screens */
                grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
                gap: 12px;
                margin-top: 16px;
            }

            .video-card:hover {
                /* Disable hover transform on touch devices where hover is sticky */
                transform: none;
                box-shadow: var(--shadow-xs);
                /* Revert to base shadow */
                border-color: transparent;
            }

            .video-card .video-controls,
            .playlist-item .controls {
                /* Make controls always visible on touch for easier access */
                opacity: 1;
            }

            /* Hide playlist drag handle on mobile */
            .playlist-drag-handle {
                display: none;
            }


            .video-controls .drag-handle {

                /* Hide drag handle on mobile */
            }

            .video-info {
                padding: 8px 10px;
                /* Adjust padding */
            }

            .video-info h4 {
                font-size: 0.8rem;
                /* Slightly smaller */
            }

            .settings-row {
                /* Allow settings rows to wrap if needed */
                flex-wrap: wrap;
            }

            .toast-container {
                bottom: 20px;
                left: 50%;
                transform: translateX(-50%);
                right: auto;
                max-width: calc(100% - 40px);
                width: 100%;
                align-items: center;
            }

            .toast {
                width: 100%;
                max-width: 400px;
            }

            /* Increase touch target size for icon buttons */
            button.icon-button,
            .playlist-item .controls button,
            .video-controls button,
            .settings-group button.icon-button {
                padding: 8px;
                /* Increase padding for easier tapping */
            }

            .settings-group button.font-btn {
                padding: 6px 10px;
                /* Slightly larger font buttons */
            }

            /* --- Mobile Tap Feedback --- */
            .playlist-item:active {
                background-color: var(--primary-color-light); /* More direct feedback */
                transform: translateY(0); /* Press back down */
                transition: background-color 0.05s ease-out, transform 0.05s ease-out;
            }

            .video-card:active {
                transform: scale(0.98);
                /* Slight shrink effect */
                background-color: var(--hover-bg-color);
                transition: background-color 0.05s ease-out, transform 0.05s ease-out;
            }

            /* --- End Mobile Tap Feedback --- */

            /* Hide the new audio-only info text on mobile as well if desired */
            .audio-only-info {
                /* display: none; */ /* Uncomment if you want to hide it on mobile */
            }
            body.audio-only-active .player-wrapper {
                padding: 5px 40px 5px 10px; /* Adjust mobile padding */
                padding-top: calc(5px + env(safe-area-inset-top, 0px)); /* Adjust top padding for safe area */
            }

            .playlist-item:hover {
                background-color: inherit; /* Disables the hover effect on mobile */
            }
        }

        /* Further adjustments for very small screens */
        @media (max-width: 480px) {
            .sidebar-content {
                padding: 12px;
            }

            .main-content {
                padding: 12px;
            }

            .video-grid {
                /* Maybe force single column */
                grid-template-columns: 1fr;
                gap: 10px;
            }

            .video-info h4 {
                -webkit-line-clamp: 3;
                /* Allow slightly more title text */
            }

            .playlist-actions {
                /* Stack controls vertically if needed */
                /* flex-direction: column;
       align-items: flex-start; */
            }
        }

        /* Pagination */
        .pagination-controls {
            display: flex;
            justify-content: center;
            align-items: center;
            gap: 15px;
            margin-top: 24px;
            padding: 10px 0;
            background-color: var(--surface-color);
            border-radius: var(--border-radius-md);
            box-shadow: var(--shadow-xs);
            border: 1px solid var(--border-color-light);
            transition: background-color var(--transition-speed) var(--transition-timing), border-color var(--transition-speed) var(--transition-timing), box-shadow var(--transition-speed) var(--transition-timing);
            padding-bottom: calc(10px + env(safe-area-inset-bottom, 0px)); /* Adjust padding for safe area */
        }

        .pagination-controls button {
            /* Use secondary style as base */
            background-color: var(--surface-color-alt);
            color: var(--text-color-muted);
            padding: 6px 12px;
            font-size: 0.85rem;
            font-weight: 500;
            box-shadow: none;
            min-width: 80px;
            /* Ensure consistent button width */
        }

        .pagination-controls button:not(:disabled):hover {
            background-color: var(--hover-bg-color);
            color: var(--text-color);
            transform: none;
            box-shadow: none;
        }

        .pagination-controls button:disabled {
            background-color: transparent;
            color: var(--text-color-subtle);
            opacity: 0.6;
            cursor: not-allowed;
            border: 1px solid var(--border-color-light);
        }

        .page-info {
            font-size: 0.85rem;
            color: var(--text-color-muted);
            font-weight: 500;
            min-width: 80px;
            /* Approx width */
            text-align: center;
        }

        @keyframes slideIn {
            from { transform: translateY(20px); opacity: 0; }
            to { transform: translateY(0); opacity: 1; }
        }

        /* Smooth transitions for theme changes */
        html[data-theme="dark"],
        html[data-theme="light"] {
            transition: background-color 0.5s var(--transition-timing), color 0.5s var(--transition-timing);
            will-change: background-color, color;
        }

        @keyframes scaleUp {
            0% {
                transform: scale(0.9);
                opacity: 0;
            }
            100% {
                transform: scale(1);
                opacity: 1;
            }
        }

        .playlist-item.added {
            animation: scaleUp 0.3s var(--transition-timing-spring) forwards; /* Apply spring timing */
            will-change: transform, opacity;
        }

        .video-card.added {
            animation: scaleUp 0.3s var(--transition-timing-spring) forwards; /* Apply spring timing */
            will-change: transform, opacity;
        }

        /* Promote resizer to GPU layer */
        .sidebar-resizer:hover::after {
            transform: translate3d(0, 0, 0);
            will-change: transform;
        }

        .header {
            padding-top: env(safe-area-inset-top, 0px);
        }
        .footer {
            padding-bottom: env(safe-area-inset-bottom, 0px);
        }