body {
    font-family: 'Inter', sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}
.tooltip {
    position: absolute;
    text-align: center;
    padding: 8px 12px;
    font-size: 14px;
    background: #2d3748; /* gray-800 */
    color: white;
    border-radius: 8px;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.2s;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}
.axis-label {
    font-size: 14px;
    font-weight: 600;
    fill: #4a5568; /* gray-600 */
}
.quadrant-label {
    font-size: 16px;
    font-weight: 700;
    fill: #a0aec0; /* gray-400 */
}
.highlight-label {
    font-size: 12px;
    fill: #2d3748; /* gray-800 */
    font-weight: 600;
}
.tick line {
    stroke: #e2e8f0; /* gray-200 */
}
.tick text {
    fill: #718096; /* gray-500 */
}
.domain {
    stroke: #cbd5e0; /* gray-300 */
}