:root {
    --primary-bg: #0f172a;
    --secondary-bg: #1e293b;
    --accent-primary: #3b82f6;
    --accent-secondary: #10b981;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --border-color: #334155;
    --comparing-color: #fbbf24;
    --swapping-color: #ef4444;
    --sorted-color: #10b981;
    --unsorted-color: #64748b;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--primary-bg);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 32px 24px;
}

header {
    text-align: center;
    margin-bottom: 48px;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.author {
    font-size: 1rem;
    color: var(--text-secondary);
    font-weight: 400;
}

.controls {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 32px;
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    align-items: center;
    justify-content: space-between;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.control-group label {
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.control-group select,
.control-group input[type="range"] {
    background: var(--primary-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 8px 12px;
    color: var(--text-primary);
    font-size: 0.875rem;
    transition: all 0.2s ease;
}

.control-group select:focus,
.control-group input[type="range"]:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.buttons {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

button {
    padding: 10px 20px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

#start-btn {
    background: var(--accent-primary);
    color: white;
    border-color: var(--accent-primary);
}

#start-btn:hover:not(:disabled) {
    background: #2563eb;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

#pause-btn {
    background: var(--comparing-color);
    color: #1f2937;
    border-color: var(--comparing-color);
}

#pause-btn:hover:not(:disabled) {
    background: #f59e0b;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(251, 191, 36, 0.3);
}

#reset-btn {
    background: var(--swapping-color);
    color: white;
    border-color: var(--swapping-color);
}

#reset-btn:hover {
    background: #dc2626;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3);
}

#generate-btn {
    background: var(--accent-secondary);
    color: white;
    border-color: var(--accent-secondary);
}

#generate-btn:hover {
    background: #059669;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.visualization-container {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 32px;
    margin-bottom: 32px;
    overflow: hidden;
}

.array-container {
    display: flex;
    align-items: flex-end;
    justify-content: center;
    height: 400px;
    gap: 1px;
    padding: 16px;
}

.bar {
    background: var(--unsorted-color);
    border-radius: 2px 2px 0 0;
    transition: all 0.15s ease;
    position: relative;
    min-width: 6px;
    flex: 1;
}

.bar.comparing {
    background: var(--comparing-color);
    transform: scaleY(1.02);
}

.bar.swapping {
    background: var(--swapping-color);
    animation: swap 0.4s ease;
}

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

@keyframes swap {
    0% { transform: translateX(0) scale(1.05); }
    50% { transform: translateX(var(--swap-distance)) scale(1.05); }
    100% { transform: translateX(0) scale(1); }
}

.info {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 32px;
}

.algorithm-info {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
}

.algorithm-info h3 {
    color: var(--accent-primary);
    margin-bottom: 16px;
    font-size: 1.25rem;
    font-weight: 600;
}

.algorithm-description {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 16px;
}

.complexity-info {
    background: var(--primary-bg);
    border-radius: 8px;
    padding: 16px;
    border-left: 4px solid var(--accent-primary);
}

.complexity-info h4 {
    color: var(--text-primary);
    margin-bottom: 8px;
    font-size: 1rem;
    font-weight: 600;
}

.complexity-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: 4px;
    font-size: 0.875rem;
}

.complexity-label {
    color: var(--text-secondary);
}

.complexity-value {
    color: var(--accent-secondary);
    font-weight: 500;
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
}

.stat {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    text-align: center;
}

.stat h4 {
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat p {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

@media (max-width: 768px) {
    .controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .buttons {
        justify-content: center;
    }
    
    .stats {
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .array-container {
        height: 300px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 16px;
    }
    
    .controls {
        padding: 20px;
        gap: 16px;
    }
    
    .visualization-container {
        padding: 20px;
    }
    
    .buttons {
        flex-direction: column;
    }
    
    button {
        width: 100%;
    }
}