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

:root {
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --bg-palette: #2d2d44;
    --bg-canvas: #0f3460;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --accent-blue: #4a90e2;
    --accent-green: #50c878;
    --accent-purple: #9b59b6;
    --accent-red: #e74c3c;
    --grid-dot: rgba(255, 255, 255, 0.1);
    --border-color: #3a3a5c;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    overflow: hidden;
    height: 100vh;
}

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

/* Header */
.app-header {
    padding: 20px 30px;
    background: var(--bg-secondary);
    border-bottom: 2px solid var(--border-color);
}

.app-header h1 {
    font-size: 2.5em;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.app-header p {
    font-size: 1em;
    color: var(--text-secondary);
}

/* Main Content */
.main-content {
    display: flex;
    flex: 1;
    overflow: hidden;
}

/* Component Palette */
.component-palette {
    width: 280px;
    background: var(--bg-palette);
    padding: 20px;
    overflow-y: auto;
    border-right: 2px solid var(--border-color);
}

.component-palette h2 {
    font-size: 1.3em;
    margin-bottom: 5px;
    color: var(--text-primary);
}

.palette-instruction {
    font-size: 0.9em;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.palette-section {
    margin-bottom: 25px;
}

.palette-section h3 {
    font-size: 1em;
    color: var(--text-secondary);
    margin-bottom: 12px;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 1px;
}

.component-item {
    display: flex;
    align-items: center;
    padding: 12px;
    margin-bottom: 8px;
    background: var(--bg-secondary);
    border-radius: 8px;
    cursor: grab;
    transition: all 0.2s;
    border: 2px solid transparent;
}

.component-item:hover {
    background: var(--bg-primary);
    border-color: var(--accent-purple);
    transform: translateX(5px);
}

.component-item:active {
    cursor: grabbing;
}

.component-item.dragging {
    opacity: 0.5;
}

.component-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    margin-right: 12px;
    font-weight: bold;
    font-size: 0.9em;
}

.input-icon {
    background: var(--accent-blue);
}

.output-icon {
    background: var(--accent-green);
}

.gate-icon {
    background: var(--accent-purple);
}

.component-info {
    flex: 1;
}

.component-name {
    font-weight: 600;
    margin-bottom: 4px;
}

.component-desc {
    font-size: 0.85em;
    color: var(--text-secondary);
}

.quick-actions {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.action-list {
    list-style: none;
    font-size: 0.9em;
    color: var(--text-secondary);
}

.action-list li {
    padding: 6px 0;
    padding-left: 20px;
    position: relative;
}

.action-list li:before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--accent-purple);
}

/* Canvas Container */
.canvas-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    position: relative;
    background: var(--bg-primary);
}

.canvas-controls-top {
    display: flex;
    gap: 10px;
    padding: 15px 20px;
    background: var(--bg-secondary);
    border-bottom: 2px solid var(--border-color);
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.95em;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
}

.btn-simulate {
    background: var(--accent-green);
    color: white;
}

.btn-simulate.active {
    box-shadow: 0 0 10px rgba(80, 200, 120, 0.5);
}

.sim-indicator {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: white;
    display: inline-block;
}

.btn-simulate.active .sim-indicator {
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.btn-delete {
    background: var(--accent-red);
    color: white;
}

.btn-clear, .btn-export {
    background: var(--bg-palette);
    color: var(--text-primary);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
}

/* Canvas */
.canvas {
    flex: 1;
    position: relative;
    background: var(--bg-canvas);
    background-image: 
        radial-gradient(circle, var(--grid-dot) 1px, transparent 1px);
    background-size: 20px 20px;
    overflow: hidden;
    cursor: crosshair;
}

.connection-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.connection-line {
    stroke: var(--accent-green);
    stroke-width: 2;
    fill: none;
    pointer-events: stroke;
}

/* Circuit Components */
.circuit-component {
    position: absolute;
    cursor: move;
    z-index: 10;
    user-select: none;
}

.circuit-component.selected {
    outline: 2px solid var(--accent-green);
    outline-offset: 2px;
}

.component-box {
    background: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 15px;
    min-width: 100px;
    text-align: center;
    transition: all 0.2s;
}

.component-box:hover {
    border-color: var(--accent-purple);
    box-shadow: 0 4px 12px rgba(155, 89, 182, 0.3);
}

.component-box.input {
    background: var(--accent-blue);
}

.component-box.output {
    background: var(--accent-green);
}

.component-box.gate {
    background: var(--accent-purple);
}

.component-title {
    font-weight: 600;
    margin-bottom: 8px;
    font-size: 0.9em;
}

.component-value {
    font-size: 1.2em;
    font-weight: bold;
    margin: 8px 0;
    min-height: 24px;
}

.input-control {
    width: 60px;
    padding: 5px;
    text-align: center;
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 4px;
    color: white;
    font-weight: bold;
    cursor: pointer;
    margin: 5px auto;
    display: block;
}

.input-control:hover {
    background: rgba(255, 255, 255, 0.3);
}

/* Connection Points */
.connection-point {
    position: absolute;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--accent-green);
    border: 2px solid white;
    cursor: pointer;
    z-index: 20;
    transition: all 0.2s;
}

.connection-point:hover {
    transform: scale(1.3);
    box-shadow: 0 0 8px var(--accent-green);
}

.connection-point.input {
    background: var(--accent-blue);
}

.connection-point.output {
    background: var(--accent-green);
}

/* Canvas Controls Bottom */
.canvas-controls-bottom {
    position: absolute;
    bottom: 20px;
    left: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    z-index: 100;
}

.btn-icon {
    width: 40px;
    height: 40px;
    border: none;
    border-radius: 6px;
    background: var(--bg-palette);
    color: var(--text-primary);
    cursor: pointer;
    font-size: 1.2em;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    border: 1px solid var(--border-color);
}

.btn-icon:hover {
    background: var(--bg-secondary);
    transform: scale(1.1);
}

/* Scrollbar Styling */
.component-palette::-webkit-scrollbar {
    width: 8px;
}

.component-palette::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

.component-palette::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

.component-palette::-webkit-scrollbar-thumb:hover {
    background: var(--accent-purple);
}