body {
            font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            background-color: var(--bg);
            color: var(--text);
            margin: 0;
            display: flex;
            height: 100vh;
            overflow: hidden;
            user-select: none;
        }

        /* Sidebar container */
        .sidebar {
            width: 260px;
            background-color: var(--bg);
            border-right: 1px solid var(--border);
            display: flex;
            flex-direction: column;
            padding: 20px;
            z-index: 200;
            box-shadow: 2px 0 10px rgba(0,0,0,0.5);
        }

        h2 { 
            margin-top: 0; 
            font-size: 1.1rem; 
            font-weight: 700;
            letter-spacing: -0.025em;
        }
        p.desc { font-size: 0.8rem;  color: var(--muted); margin-bottom: 20px; line-height: 1.4; }

        .component-list {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 8px;
            margin-bottom: 20px;
        }

        button.comp-btn {
            background: var(--bg);
            border: 1px solid var(--border);
            color: var(--text);
            padding: 8px;
            border-radius: 6px;
            cursor: pointer;
            transition: all 0.2s;
            font-size: 0.75rem;
            font-weight: 600;
        }
        button.comp-btn:hover { 
            border-color: var(--accent-color); 
            background: var(--tag-bg);
            color: var(--text);
        }

        .truth-table-panel {
            flex-grow: 1;
            overflow-y: auto;
            border-top: 1px solid #27272a;
            padding-top: 15px;
        }
        
        .truth-table-panel h3 {
            font-size: 0.85rem;
            color: var(--text);
            margin-top: 0;
            margin-bottom: 10px;
        }

        table {
            width: 100%;
            border-collapse: collapse;
            font-size: 0.75rem;
            text-align: center;
        }
        th, td { border: 1px solid var(--border); padding: 6px; }
        th { background: var(--tag-bg); color: var(--accent-color); font-weight: 600; }
        tr.active-row { background: rgba(34, 197, 94, 0.15); }

        /* Workspace sandbox area */
        .workspace {
            flex-grow: 1;
            position: relative;
            background-size: 20px 20px;
            overflow: hidden;
            background-color: var(--bg);
            background-image: radial-gradient(var(--border) 1px, transparent 1px);
            }

        /* Gates/Nodes */
        .gate {
            position: absolute;
            background: var(--bg);
            border: 1.5px solid var(--border);
            border-radius: 8px;
            padding: 5px 10px;
            min-width: 75px;
            text-align: center;
            box-shadow: 0 4px 12px rgba(0,0,0,0.5);
            cursor: grab;
            z-index: 10;
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 42px;
            box-sizing: border-box;
            transition: border-color 0.15s, box-shadow 0.15s;
        }
        .gate:active { cursor: grabbing; }
        .gate.selected {
            border-color: var(--accent-color) !important;
            box-shadow: 0 0 8px rgba(0, 210, 255, 0.4);
        }
        .gate-title { 
            font-size: 0.75rem;
            font-weight: 700; 
            pointer-events: none; 
            margin: 0 auto;
            color: var(--text);
        }

        /* Terminals (Connection Nodes) */
        .terminal {
            width: 10px;
            height: 10px;
            background: #52525b;
            border-radius: 50%;
            cursor: crosshair;
            transition: all 0.2s;
            position: relative;
            border: 1px solid var(--bg-color);
        }
        .terminal:hover { transform: scale(1.3); background: var(--bg); }
        .terminal.output { margin-right: -15px; }
        .terminal.input { margin-left: -15px; }
        
        /* Active signal wire simulation glows */
        .terminal.on { background: var(--wire-on) !important; box-shadow: 0 0 6px var(--wire-on); }
        
        /* Switch and Bulb styles */
        .gate.switch { border-color: #3f3f46; }
        .gate.bulb { border-color: #3f3f46; }
        .gate.bulb.on { 
            border-color: #eab308 !important; 
            box-shadow: 0 0 12px rgba(234, 179, 8, 0.4); 
            background: rgba(234, 179, 8, 0.1);
        }
        .gate.bulb.on .gate-title { color: #facc15; }

        /* SVG Wire Overlay layer */
        svg {
            position: absolute;
            top: 0; left: 0;
            width: 100%; height: 100%;
            pointer-events: none;
            z-index: 5;
        }
        path {
            fill: none;
            stroke-width: 3;
            stroke-linecap: round;
            transition: stroke 0.1s;
            pointer-events: stroke;
            cursor: pointer;
        }

        /* Toolbar overlay */
        .toolbar {
            position: absolute;
            top: 15px;
            right: 150px;
            display: flex;
            gap: 8px;
            z-index: 20;
        }
        .action-btn {
            background: var(--bg);
            padding: 6px 12px; 
            border-radius: 6px; 
            cursor: pointer;
            font-size: 0.75rem;
            font-weight: 600;
            transition: all 0.15s;
            color: var(--text);
            border: 1px solid var(--border);
        }
        .action-btn:hover { 
            background: var(--tag-bg);
            color: var(--text);
        }
        .action-btn.delete { 
            background: #7f1d1d; 
            border-color: #991b1b; 
            color: #fca5a5;
        }
        .action-btn.delete:hover {
            background: #991b1b;
            color: #fff;
        }

        footer {
            margin-top: 60px;
            padding: 30px 20px;
            text-align: center;
            border-radius: 12px 12px 0 0;
        }

        footer a {
            color: var(--text);
            text-decoration: none;
            font-weight: 900;
            border: 2px solid var(--border);
            padding: 8px 16px;
            display: inline-block;
            transition: all 0.2s ease;
        }

        footer a:hover {
            background: var(--text);
            color: var(--bg);
        }