body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f9ff;
    color: #333;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 0;
    padding: 20px;
}

.container {
    background: white;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    max-width: 800px;
    width: 100%;
    text-align: center;
}

h1 {
    color: #1e3a8a;
    margin-bottom: 20px;
}

.canvas-container {
    margin: 0 auto;
    max-width: 600px;
}

svg {
    width: 100%;
    height: auto;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    background-color: #fff;
}

.controls {
    margin-top: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    padding: 15px;
    background-color: #f8fafc;
    border-radius: 8px;
}

/* Removed .control-items and previous #status-display styles */

#status-display {
    font-weight: bold;
    color: #1e3a8a;
    margin-bottom: 15px;
    padding: 8px 12px;
    background: white;
    border-radius: 4px;
    border-left: 4px solid #2563eb;
}

.info-panel {
    margin-top: 20px;
    text-align: left;
    padding: 15px;
    background-color: #f1f5f9;
    border-radius: 8px;
}

.info-panel ul {
    list-style: none;
    padding: 0;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.info-panel li {
    background: white;
    padding: 8px 12px;
    border-radius: 4px;
    border-left: 4px solid #cbd5e1;
}

.info-panel span {
    font-weight: bold;
    color: #0f172a;
}

/* SVG Animation Classes (can be used for CSS-based transitions if needed) */
.chamber {
    transition: d 0.2s ease-in-out;
}

.leaflet-left, .leaflet-right {
    transition: transform 0.1s ease-in-out;
    /* Origins defined per valve below */
}

/* AV Valves (Tricuspid, Mitral) - Hinge at top corners */
#valve-tricuspid .leaflet-left, #valve-mitral .leaflet-left { transform-origin: -25px 0px; }
#valve-tricuspid .leaflet-right, #valve-mitral .leaflet-right { transform-origin: 25px 0px; }

/* SL Valves (Pulmonary, Aortic) - Hinge at bottom corners */
#valve-pulmonary .leaflet-left, #valve-aortic .leaflet-left { transform-origin: -20px 0px; }
#valve-pulmonary .leaflet-right, #valve-aortic .leaflet-right { transform-origin: 20px 0px; }