:root {
    /* Modern City Theme */
    --app-bg: #f5f7fa;
    --sidebar-bg: rgba(255, 255, 255, 0.9);
    --glass-border: rgba(0, 122, 255, 0.15);
    --text-primary: #1d1d1f;
    --text-secondary: #86868b;

    --accent-blue: #007aff;
    --accent-green: #34c759;
    --accent-orange: #ff9500;
    --accent-gray: #8e8e93;

    --lane-bike: #34c759;
    --lane-car: #007aff;
    --lane-shared: #ff9500;
    --lane-potential: #d1d1d6;

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.12);

    --font-family: "Outfit", "Noto Serif SC", sans-serif;
    --font-title: "Ma Shan Zheng", cursive;
    --font-tech: "Rajdhani", sans-serif;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--app-bg);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    background-image: radial-gradient(#e1e5ea 1px, transparent 1px);
    background-size: 20px 20px;
}

.app-container {
    width: 90vw;
    height: 85vh;
    max-width: 1400px;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px) saturate(120%);
    -webkit-backdrop-filter: blur(20px) saturate(120%);
    border-radius: 24px;
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow-lg);
    display: flex;
    overflow: hidden;
}

.sidebar {
    width: 360px;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--glass-border);
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    gap: 1.2rem;
    flex-shrink: 0;
    overflow-y: auto;
    z-index: 20;
}

.sidebar-header {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.window-controls {
    display: flex;
    gap: 8px;
    margin-bottom: 0.5rem;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dot.red {
    background: #ff5f56;
}

.dot.yellow {
    background: #ffbd2e;
}

.dot.green {
    background: #27c93f;
}

h1 {
    font-family: var(--font-title);
    font-size: 2rem;
    font-weight: 400;
    color: var(--text-primary);
    letter-spacing: 0.05em;
}

.subtitle {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-style: italic;
    margin-top: -5px;
    font-family: var(--font-tech);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.highlight {
    color: var(--accent-blue);
}

.controls-wrapper {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    flex-grow: 1;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.view-buttons {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.apple-btn {
    display: inline-flex;
    align-items: center;
    justify-content: flex-start;
    padding: 12px 16px;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 1px solid rgba(0, 0, 0, 0.05);
    font-family: var(--font-family);
    gap: 10px;
    background: white;
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
}

.apple-btn:hover {
    background: #f5f5f7;
    transform: translateX(2px);
}

.apple-btn.active {
    background: var(--accent-blue);
    color: white;
    border-color: var(--accent-blue);
    box-shadow: var(--shadow-md);
}

.apple-btn.active .icon {
    filter: brightness(0) invert(1);
}

.info-panel {
    background: white;
    padding: 12px;
    border-radius: 12px;
    font-size: 0.9rem;
    color: var(--text-primary);
    border: 1px solid rgba(0, 0, 0, 0.05);
    box-shadow: var(--shadow-sm);
}

#statusText {
    font-weight: 600;
    color: var(--accent-blue);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.stat-item {
    display: flex;
    flex-direction: column;
    padding: 8px;
    background: #f5f7fa;
    border-radius: 8px;
}

.stat-label {
    font-size: 0.7rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.stat-value {
    font-size: 1.1rem;
    font-weight: 700;
    font-family: var(--font-tech);
}

.stat-value.green {
    color: var(--accent-green);
}

.stat-value.blue {
    color: var(--accent-blue);
}

.stat-value.orange {
    color: var(--accent-orange);
}

.stat-value.gray {
    color: var(--accent-gray);
}

.suggestion-box {
    background: linear-gradient(135deg, #f0f9ff, #e6f7ff);
    padding: 12px;
    border-radius: 12px;
    border: 1px solid rgba(0, 122, 255, 0.1);
    min-height: 80px;
    display: flex;
    align-items: center;
}

.suggestion-content {
    font-size: 0.85rem;
    line-height: 1.4;
    color: var(--text-primary);
}

.info-box {
    background: linear-gradient(135deg, rgba(52, 199, 89, 0.1), rgba(0, 122, 255, 0.1));
    padding: 1rem;
    border-radius: 12px;
    border: 1px solid rgba(52, 199, 89, 0.2);
}

.info-box h3 {
    font-size: 0.9rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-family: var(--font-family);
}

.info-box p {
    font-size: 0.75rem;
    line-height: 1.4;
    color: var(--text-secondary);
    margin-bottom: 0.4rem;
}

.visualizer-stage {
    flex-grow: 1;
    padding: 2rem;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #f2f2f7;
    position: relative;
}

.glass-pane {
    width: 100%;
    height: 100%;
    background: white;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    border: 1px solid white;
    position: relative;
    overflow: hidden;
}

.grid-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
        linear-gradient(rgba(0, 0, 0, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 0, 0, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
}

.graph-title {
    position: absolute;
    top: 1rem;
    left: 1rem;
    background: rgba(255, 255, 255, 0.95);
    padding: 1rem 1.5rem;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    z-index: 10;
    pointer-events: none;
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.graph-title h2 {
    font-family: var(--font-family);
    font-size: 1.4rem;
    color: var(--text-primary);
    margin: 0;
}

.graph-title p {
    font-family: var(--font-tech);
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin: 4px 0 0 0;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.legend {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: rgba(255, 255, 255, 0.95);
    padding: 0.75rem 1rem;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    box-shadow: var(--shadow-sm);
    z-index: 10;
    pointer-events: none;
    border: 1px solid rgba(0, 0, 0, 0.05);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-primary);
}

.legend-line {
    width: 24px;
    height: 4px;
    border-radius: 2px;
}

.legend-line.bike {
    background: var(--lane-bike);
}

.legend-line.car {
    background: var(--lane-car);
}

.legend-line.shared {
    background: repeating-linear-gradient(45deg,
            var(--lane-bike),
            var(--lane-bike) 4px,
            var(--lane-car) 4px,
            var(--lane-car) 8px);
}

.legend-line.potential {
    background: transparent;
    border-top: 2px dashed var(--lane-potential);
    height: 0;
}

/* Graph Elements */
.edge-line {
    stroke-width: 4px;
    stroke-linecap: round;
    transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    opacity: 0.1;
    /* Default faded */
}

.edge-line.bike {
    stroke: var(--lane-bike);
    opacity: 1;
}

.edge-line.car {
    stroke: var(--lane-car);
    opacity: 1;
}

.edge-line.shared {
    stroke: var(--lane-shared);
    opacity: 1;
    stroke-dasharray: 8, 4;
}

.edge-line.potential {
    stroke: var(--lane-potential);
    stroke-width: 2px;
    stroke-dasharray: 4, 4;
    opacity: 0.5;
}

/* View Specific States */
.view-intersection .edge-line:not(.shared) {
    opacity: 0.05;
}

.view-intersection .edge-line.shared {
    stroke-width: 6px;
    filter: drop-shadow(0 0 4px var(--lane-shared));
}

.view-diff-bike .edge-line:not(.bike) {
    opacity: 0.05;
}

.view-diff-bike .edge-line.bike {
    stroke-width: 6px;
    filter: drop-shadow(0 0 4px var(--lane-bike));
}

.view-diff-car .edge-line:not(.car) {
    opacity: 0.05;
}

.view-diff-car .edge-line.car {
    stroke-width: 6px;
    filter: drop-shadow(0 0 4px var(--lane-car));
}

.view-complement .edge-line:not(.potential) {
    opacity: 0.05;
}

.view-complement .edge-line.potential {
    opacity: 1;
    stroke-width: 3px;
    animation: dash 1s linear infinite;
}

@keyframes dash {
    to {
        stroke-dashoffset: -8;
    }
}

.node-circle {
    fill: white;
    stroke: #d1d1d6;
    stroke-width: 2px;
    transition: all 0.3s ease;
}

.node-circle:hover {
    stroke: var(--accent-blue);
    transform: scale(1.2);
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: rgba(0, 0, 0, 0.02);
}

::-webkit-scrollbar-thumb {
    background: #c1c1c1;
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: #a8a8a8;
}