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

:root {
    /* Color Palette */
    --bg-primary: #0a0e17;
    --bg-secondary: #131824;
    --bg-tertiary: #1a2030;
    --accent-blue: #00d4ff;
    --accent-copper: #ff8c42;
    --accent-purple: #a855f7;
    --text-primary: #e8edf4;
    --text-secondary: #9ca3af;
    --glass-bg: rgba(26, 32, 48, 0.6);
    --glass-border: rgba(255, 255, 255, 0.1);
    --success: #10b981;
    --warning: #f59e0b;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Border Radius */
    --radius-sm: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
}

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #0a0e17 0%, #1a1f35 100%);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

.container {
    max-width: 1800px;
    margin: 0 auto;
    padding: var(--spacing-lg);
}

/* Header */
header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-xl) var(--spacing-lg);
    background: var(--glass-bg);
    backdrop-filter: blur(15px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4),
        inset 0 0 32px rgba(0, 212, 255, 0.05);
}

h1 {
    font-size: 2.8rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--accent-blue) 0%, #00a3ff 50%, var(--accent-purple) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-md);
    text-shadow: 0 10px 20px rgba(0, 212, 255, 0.1);
}

.header-metadata {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.15rem;
    font-weight: 400;
    letter-spacing: 0.01em;
}

.author-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 1rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: 2rem;
    margin-top: var(--spacing-xs);
}

.author-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-secondary);
    opacity: 0.7;
}

.author-name {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-blue);
    letter-spacing: 0.02em;
}

/* Main Content Layout */
.main-content {
    display: grid;
    grid-template-columns: 320px 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

/* Control Panel */
.control-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    height: fit-content;
    position: sticky;
    top: var(--spacing-lg);
}

.panel-section {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--glass-border);
}

.panel-section:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.panel-section h2 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--accent-blue);
}

.control-group {
    margin-bottom: var(--spacing-md);
}

.control-group:last-child {
    margin-bottom: 0;
}

.control-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
}

/* Toggle Switch */
.toggle-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-sm);
}

.toggle-switch {
    position: relative;
    width: 50px;
    height: 26px;
}

.toggle-switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.toggle-slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: 26px;
    transition: all 0.3s ease;
}

.toggle-slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: var(--text-secondary);
    border-radius: 50%;
    transition: all 0.3s ease;
}

.toggle-switch input:checked+.toggle-slider {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    border-color: var(--accent-blue);
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.4);
}

.toggle-switch input:checked+.toggle-slider:before {
    transform: translateX(24px);
    background-color: white;
}

.toggle-status {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    min-width: 40px;
}

.toggle-switch input:checked~.toggle-status {
    color: var(--accent-blue);
}

/* Range Sliders */
input[type="range"] {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: var(--bg-tertiary);
    outline: none;
    -webkit-appearance: none;
    margin: var(--spacing-xs) 0;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    cursor: pointer;
    box-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
    transition: all 0.2s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.8);
}

input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    cursor: pointer;
    border: none;
    box-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
    transition: all 0.2s ease;
}

input[type="range"]::-moz-range-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.8);
}

.value-display {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    color: var(--accent-blue);
    font-weight: 500;
}

/* Checkboxes */
.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    cursor: pointer;
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
    transition: background 0.2s ease;
}

.checkbox-label:hover {
    background: rgba(255, 255, 255, 0.05);
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--accent-blue);
}

.checkbox-label span {
    font-size: 0.9rem;
    color: var(--text-primary);
}

/* Buttons */
.button-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.control-btn {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
}

.control-btn:hover {
    background: var(--bg-secondary);
    border-color: var(--accent-blue);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 212, 255, 0.2);
}

.control-btn.primary {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    border: none;
    color: white;
    font-weight: 600;
}

.control-btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 212, 255, 0.4);
}

/* Info Panel */
.info-panel {
    background: rgba(0, 212, 255, 0.05);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    padding-bottom: var(--spacing-md) !important;
    min-height: 200px;
}

.info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.info-item:last-child {
    margin-bottom: 0;
}

.info-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.info-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-blue);
}

/* Canvas Container */
.canvas-container {
    position: relative;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    min-height: 700px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#simulationCanvas {
    display: block;
    width: 100%;
    height: 100%;
}

.canvas-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
}

.physics-note {
    position: absolute;
    top: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--radius-md);
    border: 1px solid var(--accent-blue);
    color: var(--accent-blue);
    font-size: 0.9rem;
    font-weight: 500;
    box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.7;
    }
}

/* Footer Info Section */
.info-section {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.info-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--accent-copper);
}

.info-card ul {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.info-card li {
    padding: var(--spacing-sm);
    background: rgba(255, 140, 66, 0.05);
    border-left: 3px solid var(--accent-copper);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    line-height: 1.6;
}

.info-card li strong {
    color: var(--accent-copper);
    font-weight: 600;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .main-content {
        grid-template-columns: 1fr;
    }

    .control-panel {
        position: static;
    }

    .info-card ul {
        grid-template-columns: 1fr;
    }
}

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

    .container {
        padding: var(--spacing-md);
    }

    .canvas-container {
        min-height: 500px;
    }
}