:root {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --accent-color: #e74c3c;
    --comparing-color: #f39c12;
    --sorted-color: #9b59b6;
    --background-color: #f5f7fa;
    --text-color: #333;
    --card-background: #ffffff;
    --border-radius: 8px;
    --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

h1 {
    color: var(--primary-color);
    margin-bottom: 10px;
}

main {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    padding: 20px;
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    align-items: center;
    justify-content: center;
}

.btn {
    padding: 10px 20px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s;
}

.btn:hover {
    background-color: #2980b9;
}

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

input[type="range"], input[type="number"] {
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

.visualization-area {
    padding: 20px;
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    min-height: 300px;
    display: flex;
    align-items: flex-end;
    justify-content: center;
}

.array-container {
    display: flex;
    align-items: flex-end;
    gap: 5px;
    width: 100%;
    height: 250px;
    overflow-x: auto;
    padding-bottom: 20px;
    justify-content: flex-start;
    min-width: min-content;
}

.array-bar {
    background-color: var(--primary-color);
    border-radius: 3px 3px 0 0;
    transition: height 0.3s, background-color 0.3s;
    position: relative;
    width: 30px;
    min-width: 30px;
}

.array-bar::after {
    content: attr(data-value);
    position: absolute;
    bottom: -25px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 12px;
}

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

.array-bar.swapping {
    background-color: var(--accent-color);
}

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

.explanation {
    padding: 20px;
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

h2, h3 {
    margin-bottom: 15px;
    color: var(--primary-color);
}

#stepExplanation {
    margin-bottom: 20px;
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
}

.memory-visualization {
    padding: 15px;
    background-color: #f8f9fa;
    border-radius: var(--border-radius);
}

#memoryState {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 10px;
}

.memory-cell {
    width: 30px;
    height: 30px;
    border: 1px solid #ddd;
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
}

.memory-cell.active {
    border-color: var(--accent-color);
    background-color: rgba(231, 76, 60, 0.1);
}

footer {
    text-align: center;
    margin-top: 30px;
    padding: 20px;
    color: #7f8c8d;
    font-size: 14px;
}

@media (max-width: 768px) {
    .controls {
        flex-direction: column;
        align-items: stretch;
    }

    .speed-control, .array-control {
        justify-content: space-between;
    }

    .array-bar::after {
        display: none;
    }
}