:root {
    /* Light mode colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #1a1a1a;
    --text-secondary: #6c757d;
    --border-color: #dee2e6;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --accent-primary: #4f46e5;
    --accent-hover: #4338ca;
    --accent-light: #eef2ff;
    --chart-bg: #ffffff;
    --control-bg: #ffffff;
    --input-bg: #f8f9fa;
    --slider-track: #e9ecef;
    --slider-thumb: #4f46e5;
}

[data-theme="dark"] {
    /* Dark mode colors */
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
    --accent-primary: #6366f1;
    --accent-hover: #818cf8;
    --accent-light: #1e1b4b;
    --chart-bg: #1e293b;
    --control-bg: #1e293b;
    --input-bg: #334155;
    --slider-track: #475569;
    --slider-thumb: #818cf8;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-secondary);
    min-height: 100vh;
    color: var(--text-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

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

.header {
    position: relative;
    text-align: center;
    margin-bottom: 30px;
    padding: 20px 0;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--text-primary);
}

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

.theme-toggle {
    position: absolute;
    top: 50%;
    right: 0;
    transform: translateY(-50%);
    background: var(--control-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    font-size: 0.9rem;
    color: var(--text-primary);
    transition: all 0.2s ease;
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    z-index: 10;
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    transform: translateY(-50%) translateY(-1px);
    box-shadow: var(--shadow-md);
}

.theme-toggle .icon {
    font-size: 1.2rem;
    flex-shrink: 0;
    width: 1.2rem;
    text-align: center;
    display: inline-block;
}

.theme-toggle .theme-text {
    max-width: 0;
    margin-left: 0;
    opacity: 0;
    overflow: hidden;
    white-space: nowrap;
    transition: all 0.2s ease;
}

.theme-toggle:hover .theme-text {
    max-width: 60px;
    margin-left: 6px;
    opacity: 1;
}

.main-content {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: 30px;
    align-items: start;
}

.controls-panel {
    background: var(--control-bg);
    border-radius: 16px;
    padding: 25px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

.chart-container {
    background: var(--chart-bg);
    border-radius: 16px;
    padding: 30px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.control-group {
    margin-bottom: 25px;
}

.control-group h3 {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--text-primary);
    font-weight: 600;
}

.control-row {
    display: flex;
    align-items: center;
    margin-bottom: 12px;
}

.control-row input[type="range"] {
    margin-left: auto;
    margin-right: 8px;
    flex-shrink: 0;
}

.control-row select {
    margin-left: 12px;
}

label {
    font-size: 0.9rem;
    color: var(--text-primary);
    font-weight: 500;
}

input[type="range"] {
    width: 105px;
    height: 6px;
    border-radius: 3px;
    background: var(--slider-track);
    outline: none;
    -webkit-appearance: none;
    transition: background 0.3s ease;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--slider-thumb);
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    transition: all 0.2s ease;
}

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

input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--slider-thumb);
    cursor: pointer;
    border: none;
    box-shadow: var(--shadow-sm);
    transition: all 0.2s ease;
}

input[type="range"]::-moz-range-thumb:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

.value-display {
    background: var(--input-bg);
    padding: 4px 8px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-family: 'Monaco', 'Courier New', monospace;
    color: var(--text-primary);
    min-width: 70px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

select {
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    padding: 8px 12px;
    font-size: 0.9rem;
    outline: none;
    cursor: pointer;
    width: 100%;
    transition: all 0.2s ease;
}

select:hover {
    border-color: var(--accent-primary);
}

select:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-light);
}

select option {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.simulation-controls {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

button {
    flex: 1;
    padding: 12px;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.9rem;
}

.btn-primary {
    background: var(--accent-primary);
    color: white;
    border: 1px solid var(--accent-primary);
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--input-bg);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

#chart {
    width: 100%;
    height: 500px;
    border-radius: 12px;
    background: var(--chart-bg);
    transition: background 0.3s ease;
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 15px;
    padding: 10px;
    background: var(--input-bg);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent-primary);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        opacity: 1;
    }

    50% {
        opacity: 0.5;
    }

    100% {
        opacity: 1;
    }
}

.chart-title {
    color: var(--text-primary);
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 20px;
    text-align: center;
    transition: color 0.3s ease;
}

#statusText {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .controls-panel {
        order: 2;
    }

    .chart-container {
        order: 1;
    }

    .header {
        padding: 20px 0;
        display: flex;
        flex-direction: column;
        align-items: center;
        gap: 20px;
    }

    .theme-toggle {
        position: static;
        transform: none;
    }

    .theme-toggle:hover {
        transform: translateY(-1px);
    }
}