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

:root {
    --bg-primary: #0a0a1a;
    --bg-secondary: #12122a;
    --bg-card: rgba(25, 25, 50, 0.8);
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-success: #10b981;
    --accent-warning: #f59e0b;
    --accent-danger: #ef4444;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: rgba(99, 102, 241, 0.3);
    --glow-primary: rgba(99, 102, 241, 0.4);
    --glow-secondary: rgba(139, 92, 246, 0.3);
}

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Background Animation */
.bg-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background:
        radial-gradient(ellipse at 20% 20%, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(139, 92, 246, 0.1) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(16, 185, 129, 0.05) 0%, transparent 70%);
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 30px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    backdrop-filter: blur(10px);
}

.header-title {
    display: flex;
    align-items: center;
    gap: 15px;
}

.header-title .icon {
    width: 45px;
    height: 45px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    box-shadow: 0 4px 15px var(--glow-primary);
}

.header-title h1 {
    font-size: 1.5rem;
    font-weight: 600;
    background: linear-gradient(135deg, var(--text-primary), var(--accent-primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-title p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.header-actions {
    display: flex;
    gap: 10px;
}

/* Main Layout */
.main-container {
    display: grid;
    grid-template-columns: 280px 1fr 320px;
    gap: 20px;
    padding: 20px;
    max-width: 1600px;
    margin: 0 auto;
    min-height: calc(100vh - 80px);
}

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    backdrop-filter: blur(10px);
    overflow: hidden;
}

.card-header {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.05));
    padding: 15px 20px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.card-header .icon {
    font-size: 1.2rem;
}

.card-header h3 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
}

.card-body {
    padding: 20px;
}

/* Left Panel - Controls */
.left-panel {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

/* Control Groups */
.control-group {
    margin-bottom: 20px;
}

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

.control-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.control-label span {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.control-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    color: var(--accent-primary);
    background: rgba(99, 102, 241, 0.1);
    padding: 2px 8px;
    border-radius: 4px;
}

/* Custom Slider */
input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--text-primary);
    border: 3px solid var(--accent-primary);
    cursor: pointer;
    box-shadow: 0 2px 10px var(--glow-primary);
    transition: transform 0.2s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 20px;
    border: none;
    border-radius: 10px;
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: white;
    box-shadow: 0 4px 15px var(--glow-primary);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--glow-primary);
}

.btn-secondary {
    background: rgba(99, 102, 241, 0.1);
    color: var(--accent-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: rgba(99, 102, 241, 0.2);
}

.btn-success {
    background: linear-gradient(135deg, var(--accent-success), #059669);
    color: white;
}

.btn-warning {
    background: linear-gradient(135deg, var(--accent-warning), #d97706);
    color: white;
}

.btn-danger {
    background: linear-gradient(135deg, var(--accent-danger), #dc2626);
    color: white;
}

.btn-group {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.btn-group .btn {
    flex: 1;
    min-width: 80px;
}

/* Simulation Canvas Area */
.simulation-area {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.canvas-container {
    position: relative;
    background: rgba(0, 0, 0, 0.5);
    border-radius: 16px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

#theCanvas {
    display: block;
    width: 100%;
    height: auto;
}

.canvas-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    padding: 15px 20px;
    background: linear-gradient(rgba(0, 0, 0, 0.8), transparent);
}

.percentage-display {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.1rem;
    font-weight: 600;
    padding: 8px 15px;
    border-radius: 8px;
    backdrop-filter: blur(10px);
}

.percentage-left {
    background: rgba(239, 68, 68, 0.2);
    color: #fca5a5;
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.percentage-right {
    background: rgba(16, 185, 129, 0.2);
    color: #6ee7b7;
    border: 1px solid rgba(16, 185, 129, 0.3);
}

/* Playback Controls */
.playback-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    padding: 15px;
    background: var(--bg-card);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.playback-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    transition: all 0.3s ease;
}

.playback-btn.play-pause {
    width: 60px;
    height: 60px;
    font-size: 1.5rem;
}

.speed-control {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-left: 20px;
    padding-left: 20px;
    border-left: 1px solid var(--border-color);
}

.speed-control span {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.speed-control input[type="range"] {
    width: 100px;
}

/* Display Options */
.display-options {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.display-option {
    flex: 1;
    min-width: 100px;
}

.display-option input[type="radio"],
.display-option input[type="checkbox"] {
    display: none;
}

.display-option label {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 15px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.85rem;
}

.display-option input[type="radio"]:checked+label,
.display-option input[type="checkbox"]:checked+label {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-color: var(--accent-primary);
}

.display-option label:hover {
    background: rgba(99, 102, 241, 0.2);
}

/* Right Panel */
.right-panel {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

/* Preset Scenarios */
.preset-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.preset-btn {
    padding: 12px;
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.preset-btn:hover {
    background: rgba(99, 102, 241, 0.2);
    transform: translateY(-2px);
}

.preset-btn.active {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-color: var(--accent-primary);
}

.preset-btn .title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.preset-btn .desc {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* Physics Data Display */
.data-grid {
    display: grid;
    gap: 12px;
}

.data-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 15px;
    background: rgba(99, 102, 241, 0.05);
    border-radius: 8px;
    border: 1px solid rgba(99, 102, 241, 0.1);
}

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

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

/* Formula Display */
.formula-box {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 10px;
    padding: 15px;
    text-align: center;
    border: 1px solid rgba(99, 102, 241, 0.2);
}

.formula-box .formula {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    color: var(--accent-warning);
    margin-bottom: 8px;
}

.formula-box .description {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Observations */
.observation-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.observation-list li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px 12px;
    background: rgba(16, 185, 129, 0.05);
    border-radius: 8px;
    border-left: 3px solid var(--accent-success);
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.observation-list li .icon {
    color: var(--accent-success);
    flex-shrink: 0;
}

/* Tooltips */
.tooltip-trigger {
    position: relative;
    cursor: help;
}

.tooltip-trigger .tooltip {
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 10px 15px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    white-space: nowrap;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 100;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.tooltip-trigger:hover .tooltip {
    opacity: 1;
    visibility: visible;
    bottom: calc(100% + 10px);
}

/* Help Button */
.help-btn {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: rgba(99, 102, 241, 0.2);
    border: 1px solid var(--border-color);
    color: var(--accent-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.help-btn:hover {
    background: var(--accent-primary);
    color: white;
}

/* Status Indicator */
.status-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 15px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.status-indicator.running {
    background: rgba(16, 185, 129, 0.2);
    color: var(--accent-success);
}

.status-indicator.paused {
    background: rgba(245, 158, 11, 0.2);
    color: var(--accent-warning);
}

.status-indicator .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: currentColor;
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.5;
    }
}

/* Learning Tips */
.learning-tip {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.05));
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 15px;
    margin-top: 10px;
}

.learning-tip .tip-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 10px;
    color: var(--accent-warning);
    font-weight: 600;
    font-size: 0.9rem;
}

.learning-tip .tip-content {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Responsive Design */
@media (max-width: 1400px) {
    .main-container {
        grid-template-columns: 260px 1fr 280px;
    }
}

@media (max-width: 1200px) {
    .main-container {
        grid-template-columns: 1fr;
    }

    .left-panel,
    .right-panel {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 15px;
    }
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--accent-primary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-secondary);
}