.venn-label {
    font-size: 16px;
    font-weight: 600;
    text-shadow: 0 1px 2px rgba(255, 255, 255, 0.8);
}

.venn-label.population {
    fill: #2e7d32;
}

.venn-label.positive {
    fill: #f57c00;
}

.venn-label.diseased {
    fill: #c62828;
}

.venn-line {
    stroke: #333333;
    stroke-width: 1.5px;
    stroke-opacity: 0.7;
}

.venntooltip {
    position: absolute;
    text-align: center;
    min-width: 128px;
    padding: 8px 12px;
    background: rgba(50, 50, 50, 0.9);
    color: #fff;
    border-radius: 4px;
    pointer-events: none;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
    font-size: 14px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.venn-circle {
    transition: fill-opacity 0.3s ease, stroke-width 0.3s ease;
}

.venn-path {
    transition: fill-opacity 0.3s ease, stroke-width 0.3s ease;
    cursor: pointer;
}