:root {
    --bg-color: #f9fafb; /* gray-50 */
    --text-color: #111827; /* gray-900 */
    --accent-primary: #4f46e5; /* indigo-600 */
    --accent-secondary: #db2777; /* pink-600 */
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(229, 231, 235, 0.5); /* gray-200 */
    --font-main: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    padding: 4rem 0;
    position: relative;
}

h1 {
    font-size: 3.5rem;
    background: linear-gradient(to right, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1rem;
    line-height: 1.2;
}

h2 {
    font-size: 2rem;
    margin-top: 3rem;
    color: var(--accent-primary);
}

.subtitle {
    font-size: 1.5rem;
    color: #64748b; /* slate-500 */
    font-weight: 300;
}

.card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 1rem;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    transition: transform 0.2s;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

.simulation-container {
    background: #1e293b; /* slate-800 - keep dark for contrast with canvas */
    border-radius: 0.5rem;
    overflow: hidden;
    margin: 1.5rem 0;
    position: relative;
    border: 1px solid #334155;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 1rem;
}

canvas {
    max-width: 100%;
    background: #0f172a; /* slate-900 */
    border-radius: 4px;
}

.controls {
    margin-top: 1rem;
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
    justify-content: center;
}

button {
    background: var(--accent-primary);
    color: #ffffff;
    border: none;
    padding: 0.5rem 1.5rem;
    border-radius: 2rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 1rem;
    box-shadow: 0 4px 6px -1px rgba(79, 70, 229, 0.3);
}

button:hover {
    background: #4338ca; /* indigo-700 */
    transform: scale(1.05);
}

button.secondary {
    background: transparent;
    border: 2px solid var(--accent-secondary);
    color: var(--accent-secondary);
    box-shadow: none;
}

button.secondary:hover {
    background: var(--accent-secondary);
    color: white;
}

.analogy-box {
    border-left: 4px solid var(--accent-secondary);
    padding-left: 1.5rem;
    margin: 1.5rem 0;
    font-style: italic;
    color: #475569; /* slate-600 */
    background: rgba(219, 39, 119, 0.05);
    padding: 1rem;
    border-radius: 0 0.5rem 0.5rem 0;
}

.math-block {
    font-family: 'Fira Code', monospace;
    background: #1e293b; /* Keep dark for code/math */
    color: #e2e8f0;
    padding: 1rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    margin: 1rem 0;
    border: 1px solid var(--glass-border);
    box-shadow: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);
}

.highlight {
    color: var(--accent-primary);
    font-weight: bold;
}

footer {
    text-align: center;
    padding: 4rem 0;
    color: #64748b;
    font-size: 0.9rem;
}

/* Range Slider Styling */
input[type=range] {
    -webkit-appearance: none;
    appearance: none;
    width: 200px;
    background: transparent;
}

input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    height: 16px;
    width: 16px;
    border-radius: 50%;
    background: var(--accent-secondary);
    cursor: pointer;
    margin-top: -6px;
}

input[type=range]::-webkit-slider-runnable-track {
    width: 100%;
    height: 4px;
    cursor: pointer;
    background: #334155;
    border-radius: 2px;
}

@media (max-width: 600px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; margin-top: 2rem; }
    .subtitle { font-size: 1.1rem; }
    .container { padding: 1rem; }
    header { padding: 2rem 0; }
    
    .card { padding: 1.5rem; }
    
    .controls {
        flex-direction: column;
        width: 100%;
    }
    
    button { width: 100%; }
    
    input[type=range] { width: 100%; }
}

@media (min-width: 768px) {
    html {
        font-size: 80%;
    }
}