:root {
    --primary-color: #2563eb;
    --secondary-color: #3b82f6;
    --accent-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-color: #f1f5f9;
    --border-color: #334155;
    --success-color: #22c55e;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 1.1rem;
    color: #94a3b8;
    max-width: 800px;
    margin: 0 auto;
}

main {
    display: grid;
    gap: 2rem;
}

section {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

h2 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}

h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.theory-section {
    border-left: 4px solid var(--primary-color);
}

.formula-box {
    background: #0f172a;
    padding: 1.5rem;
    border-radius: 8px;
    margin: 1.5rem 0;
    text-align: center;
}

.formula {
    font-family: 'Times New Roman', serif;
    font-size: 1.4rem;
    color: var(--accent-color);
    margin-top: 1rem;
    font-style: italic;
}

.visualization-section {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.canvas-container {
    position: relative;
    background: #0f172a;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

#pendulumCanvas {
    width: 100%;
    height: 500px;
    display: block;
}

.overlay-info {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(15, 23, 42, 0.9);
    padding: 1rem;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    backdrop-filter: blur(10px);
}

.info-item {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    font-size: 0.9rem;
}

.info-item span:first-child {
    color: #94a3b8;
}

.info-item span:last-child {
    color: var(--accent-color);
    font-weight: bold;
    font-family: monospace;
}

.analysis-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.phase-heatmap,
.spectrum {
    background: #0f172a;
    padding: 1rem;
    border-radius: 8px;
}

#phaseHeatmap,
#spectrumCanvas {
    width: 100%;
    height: 250px;
    display: block;
}

.controls-section {
    border-left: 4px solid var(--accent-color);
}

.control-group {
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.control-group label {
    min-width: 200px;
    font-weight: 500;
}

.control-group input[type="range"] {
    flex: 1;
    min-width: 200px;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border-color);
    border-radius: 3px;
    outline: none;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    transition: background 0.3s;
}

.control-group input[type="range"]::-webkit-slider-thumb:hover {
    background: var(--secondary-color);
}

.control-group input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    transition: background 0.3s;
}

.control-group input[type="range"]::-moz-range-thumb:hover {
    background: var(--secondary-color);
}

.control-group span {
    min-width: 60px;
    text-align: right;
    font-family: monospace;
    font-size: 1.1rem;
    color: var(--accent-color);
}

.button-group {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 2rem;
}

button {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    background: var(--primary-color);
    color: white;
}

button:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

button:active {
    transform: translateY(0);
}

#pauseBtn {
    background: var(--warning-color);
}

#pauseBtn:hover {
    background: #d97706;
}

#resetBtn {
    background: var(--danger-color);
}

#resetBtn:hover {
    background: #dc2626;
}

.observation-section {
    border-left: 4px solid var(--success-color);
}

.observation-section ul {
    list-style: none;
    padding: 0;
}

.observation-section li {
    padding: 0.75rem 0;
    padding-left: 2rem;
    position: relative;
    border-bottom: 1px solid var(--border-color);
}

.observation-section li:last-child {
    border-bottom: none;
}

.observation-section li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-weight: bold;
}

.params-section {
    border-left: 4px solid var(--warning-color);
}

#paramsDisplay {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.param-card {
    background: #0f172a;
    padding: 1rem;
    border-radius: 8px;
    border-left: 3px solid var(--primary-color);
}

.param-card .param-label {
    color: #94a3b8;
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.param-card .param-value {
    color: var(--accent-color);
    font-family: monospace;
    font-size: 1.1rem;
}

footer {
    text-align: center;
    margin-top: 3rem;
    padding: 2rem;
    color: #94a3b8;
    font-size: 0.9rem;
}

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

@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    h1 {
        font-size: 1.8rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    h2 {
        font-size: 1.4rem;
    }

    #pendulumCanvas {
        height: 350px;
    }

    .control-group {
        flex-direction: column;
        align-items: flex-start;
    }

    .control-group label {
        min-width: auto;
    }

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

    .button-group {
        flex-direction: column;
    }

    button {
        width: 100%;
    }
}

@media (max-width: 480px) {
    #pendulumCanvas {
        height: 250px;
    }

    #phaseHeatmap,
    #spectrumCanvas {
        height: 200px;
    }
}