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

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --success-color: #4CAF50;
    --warning-color: #ff9800;
    --danger-color: #f44336;
    --bg-color: #f5f7fa;
    --card-bg: #ffffff;
    --text-primary: #2d3748;
    --text-secondary: #718096;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, var(--bg-color) 0%, #e0e7ff 100%);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
.header {
    text-align: center;
    padding: 30px 20px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border-radius: 15px;
    margin-bottom: 30px;
    box-shadow: var(--shadow-lg);
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.header p {
    font-size: 1.1rem;
    opacity: 0.95;
}

/* Navigation Tabs */
.nav-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
    justify-content: center;
}

.nav-tab {
    padding: 12px 24px;
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.nav-tab:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.nav-tab.active {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border-color: var(--primary-color);
}

/* Main Content */
.main-content {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: 30px;
    margin-bottom: 30px;
}

/* Control Panel */
.control-panel {
    background: var(--card-bg);
    padding: 25px;
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
    height: fit-content;
    position: sticky;
    top: 20px;
}

.algorithm-selector {
    margin-bottom: 25px;
}

.algorithm-selector label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
}

.select-input {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background: white;
    cursor: pointer;
    transition: border-color 0.3s;
}

.select-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.controls {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.input-group {
    display: flex;
    flex-direction: column;
}

.input-group label {
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
}

.text-input {
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.text-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.button-group {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.btn {
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    background: var(--bg-color);
    color: var(--text-primary);
    border: 2px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--border-color);
    transform: translateY(-2px);
}

.speed-control {
    display: flex;
    align-items: center;
    gap: 10px;
}

.speed-control label {
    font-weight: 600;
    min-width: 60px;
}

.slider {
    flex: 1;
    height: 6px;
    border-radius: 3px;
    background: var(--border-color);
    outline: none;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
}

.slider::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
}

/* Visualization Area */
.visualization-area {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.canvas-container {
    background: var(--card-bg);
    padding: 30px;
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
    min-height: 500px;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    gap: 4px;
    flex-wrap: wrap;
}

/* Array Bar Styles */
.array-bar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border-radius: 4px 4px 0 0;
    transition: all 0.3s ease;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    color: white;
    font-weight: 600;
    font-size: 0.9rem;
    padding: 5px;
    min-width: 40px;
    box-shadow: var(--shadow);
}

.array-bar.comparing {
    background: var(--warning-color);
    transform: scale(1.1);
}

.array-bar.swapping {
    background: var(--danger-color);
    transform: scale(1.1);
}

.array-bar.sorted {
    background: var(--success-color);
}

.array-bar.pivot {
    background: var(--accent-color);
    transform: scale(1.15);
}

/* Info Panel */
.info-panel {
    background: var(--card-bg);
    padding: 25px;
    border-radius: 15px;
    box-shadow: var(--shadow-lg);
}

.info-panel h3 {
    margin-bottom: 15px;
    color: var(--text-primary);
    font-size: 1.3rem;
}

.algorithm-info {
    background: var(--bg-color);
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    line-height: 1.8;
}

.algorithm-info p {
    color: var(--text-secondary);
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
}

.stat-item {
    background: var(--bg-color);
    padding: 15px;
    border-radius: 8px;
    text-align: center;
}

.stat-label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

/* Footer */
.footer {
    text-align: center;
    padding: 20px;
    color: var(--text-secondary);
    background: var(--card-bg);
    border-radius: 15px;
    box-shadow: var(--shadow);
}

/* Linked List Styles */
.linked-list-container {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 10px;
    padding: 30px;
}

.list-node {
    display: flex;
    align-items: center;
    background: var(--card-bg);
    border: 3px solid var(--primary-color);
    border-radius: 10px;
    padding: 15px 20px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.list-node.active {
    background: var(--warning-color);
    color: white;
    transform: scale(1.1);
}

.list-node-value {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.list-node.active .list-node-value {
    color: white;
}

.arrow {
    font-size: 2rem;
    color: var(--primary-color);
    font-weight: bold;
}

/* Tree Styles */
.tree-container {
    display: flex;
    justify-content: center;
    padding: 30px;
    overflow-x: auto;
}

.tree-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 10px;
}

.tree-node-circle {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 1.1rem;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 3px solid white;
}

.tree-node-circle.visited {
    background: var(--success-color);
}

.tree-node-circle.current {
    background: var(--warning-color);
    transform: scale(1.2);
    box-shadow: var(--shadow-lg);
}

.tree-children {
    display: flex;
    gap: 20px;
    margin-top: 20px;
}

/* Graph Styles */
.graph-container {
    padding: 30px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 500px;
}

.graph-svg {
    width: 100%;
    height: 500px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    background: var(--card-bg);
}

.graph-node {
    fill: var(--primary-color);
    stroke: white;
    stroke-width: 3;
    cursor: pointer;
    transition: all 0.3s ease;
}

.graph-node.visited {
    fill: var(--success-color);
}

.graph-node.current {
    fill: var(--warning-color);
    r: 25;
}

.graph-edge {
    stroke: var(--text-secondary);
    stroke-width: 2;
    fill: none;
}

.graph-edge.visited {
    stroke: var(--success-color);
    stroke-width: 3;
}

.graph-label {
    font-size: 14px;
    font-weight: 700;
    fill: white;
    text-anchor: middle;
    dominant-baseline: central;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }

    .control-panel {
        position: static;
    }
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 2rem;
    }

    .nav-tabs {
        gap: 5px;
    }

    .nav-tab {
        padding: 10px 15px;
        font-size: 0.9rem;
    }

    .canvas-container {
        padding: 15px;
        min-height: 400px;
    }

    .array-bar {
        min-width: 30px;
        font-size: 0.8rem;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.canvas-container > * {
    animation: fadeIn 0.5s ease;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
}

.array-bar.comparing,
.array-bar.swapping {
    animation: pulse 0.5s ease infinite;
}