/* ========================================
   Double Pendulum Visualization Styles
   ======================================== */

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

:root {
    --bg-primary: #0f1419;
    --bg-secondary: #1a1f2e;
    --bg-tertiary: #252b3d;
    --text-primary: #e8eaf0;
    --text-secondary: #a0a8b8;
    --accent-blue: #4fc3f7;
    --accent-red: #f06292;
    --accent-green: #81c784;
    --accent-orange: #ffb74d;
    --accent-purple: #ba68c8;
    --border-color: #2d3748;
    --shadow-color: rgba(0, 0, 0, 0.3);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.double-pendulum-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: 12px;
    box-shadow: 0 4px 12px var(--shadow-color);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Main Layout */
.viz-layout {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 20px;
    margin-bottom: 20px;
}

@media (max-width: 1024px) {
    .viz-layout {
        grid-template-columns: 1fr;
    }
}

/* Canvas Area */
.canvas-area {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.canvas-wrapper {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 4px 12px var(--shadow-color);
}

.canvas-wrapper.small {
    padding: 10px;
}

#pendulumCanvas {
    width: 100%;
    height: 500px;
    display: block;
    background: radial-gradient(circle at center, #1a2332 0%, #0f1419 100%);
    border-radius: 8px;
}

#phaseCanvas {
    width: 100%;
    height: 300px;
    display: block;
    background: var(--bg-tertiary);
    border-radius: 8px;
}

/* Stats Panel */
.stats-panel {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    background: var(--bg-secondary);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 12px var(--shadow-color);
}

.stat-group {
    background: var(--bg-tertiary);
    padding: 15px;
    border-radius: 8px;
    border-left: 3px solid var(--accent-blue);
}

.stat-group h4 {
    margin-bottom: 10px;
    color: var(--accent-blue);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    padding: 5px 0;
    font-size: 0.85rem;
    border-bottom: 1px solid var(--border-color);
}

.stat-row:last-child {
    border-bottom: none;
}

.stat-row span:first-child {
    color: var(--text-secondary);
}

.stat-row span:last-child {
    font-family: 'Courier New', monospace;
    font-weight: 600;
    color: var(--text-primary);
}

/* Controls Panel */
.controls-panel {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 4px 12px var(--shadow-color);
}

/* Tabs */
.viz-tabs {
    display: flex;
    gap: 5px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.tab-btn {
    flex: 1;
    min-width: 80px;
    padding: 10px 15px;
    background: var(--bg-tertiary);
    border: none;
    border-radius: 6px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
}

.tab-btn:hover {
    background: var(--bg-primary);
    color: var(--text-primary);
}

.tab-btn.active {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    color: white;
    font-weight: 600;
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Controls */
.tab-content h3 {
    margin-bottom: 15px;
    color: var(--accent-blue);
    font-size: 1.2rem;
}

.control-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    margin-bottom: 20px;
}

.btn {
    padding: 12px 20px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 600;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-green), #66bb6a);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(129, 199, 132, 0.4);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--bg-primary);
    transform: translateY(-2px);
}

.btn-accent {
    background: linear-gradient(135deg, var(--accent-orange), #ff9800);
    color: white;
    width: 100%;
}

.btn-accent:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(255, 183, 77, 0.4);
}

.btn-small {
    padding: 8px 12px;
    font-size: 0.85rem;
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-small:hover {
    background: var(--accent-blue);
    color: white;
}

.preset-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}

/* Control Groups */
.control-group {
    margin-bottom: 20px;
    padding: 15px;
    background: var(--bg-tertiary);
    border-radius: 8px;
}

.control-group h4 {
    margin-bottom: 10px;
    color: var(--accent-blue);
    font-size: 1rem;
}

.control-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
    line-height: 1.4;
}

.control-group label {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
    font-size: 0.9rem;
}

.control-group input[type="range"] {
    flex: 1;
    height: 6px;
    border-radius: 3px;
    background: var(--bg-primary);
    outline: none;
    -webkit-appearance: none;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-blue);
    cursor: pointer;
    transition: all 0.2s ease;
}

.control-group input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 0 8px var(--accent-blue);
}

.control-group input[type="range"]::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-blue);
    cursor: pointer;
    border: none;
}

.control-group span {
    min-width: 50px;
    text-align: right;
    font-family: 'Courier New', monospace;
    font-weight: 600;
    color: var(--accent-blue);
}

.control-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.control-group select {
    flex: 1;
    padding: 8px 12px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    color: var(--text-primary);
    cursor: pointer;
    outline: none;
}

.control-group select:hover {
    border-color: var(--accent-blue);
}

/* Parameter Groups */
.parameter-group {
    margin-bottom: 20px;
}

.parameter-group h4 {
    margin-bottom: 15px;
    color: var(--accent-purple);
    font-size: 1rem;
}

/* Theory Content */
.theory-content {
    max-height: 500px;
    overflow-y: auto;
    padding-right: 10px;
}

.theory-content::-webkit-scrollbar {
    width: 8px;
}

.theory-content::-webkit-scrollbar-track {
    background: var(--bg-primary);
    border-radius: 4px;
}

.theory-content::-webkit-scrollbar-thumb {
    background: var(--accent-blue);
    border-radius: 4px;
}

.theory-content h4 {
    margin-top: 20px;
    margin-bottom: 10px;
    color: var(--accent-blue);
    font-size: 1rem;
}

.theory-content p {
    margin-bottom: 10px;
    font-size: 0.9rem;
    line-height: 1.5;
    color: var(--text-secondary);
}

.formula {
    background: var(--bg-primary);
    padding: 15px;
    margin: 10px 0;
    border-radius: 6px;
    font-family: 'Courier New', monospace;
    font-size: 1.1rem;
    text-align: center;
    color: var(--accent-orange);
    border-left: 3px solid var(--accent-orange);
}

.formula-box {
    background: var(--bg-primary);
    padding: 15px;
    margin: 10px 0;
    border-radius: 6px;
    font-size: 0.85rem;
    border-left: 3px solid var(--accent-purple);
}

.formula-box p {
    font-family: 'Courier New', monospace;
    color: var(--text-primary);
    margin-bottom: 10px;
    line-height: 1.4;
}

.theory-list {
    list-style: none;
    padding-left: 0;
}

.theory-list li {
    padding: 8px 0;
    padding-left: 20px;
    position: relative;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.theory-list li:before {
    content: "▸";
    position: absolute;
    left: 0;
    color: var(--accent-blue);
    font-weight: bold;
}

/* Responsive Design */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.8rem;
    }

    .subtitle {
        font-size: 0.95rem;
    }

    #pendulumCanvas {
        height: 350px;
    }

    .stats-panel {
        grid-template-columns: 1fr;
    }

    .control-buttons {
        grid-template-columns: 1fr;
    }

    .preset-buttons {
        grid-template-columns: 1fr;
    }

    .viz-tabs {
        flex-direction: column;
    }

    .tab-btn {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .double-pendulum-container {
        padding: 10px;
    }

    header {
        padding: 15px;
    }

    .canvas-wrapper,
    .controls-panel {
        padding: 15px;
    }

    .theory-content {
        max-height: 400px;
    }
}