.custom-tooltip {
    position: absolute;
    background: rgba(0, 0, 0, 0.9);
    color: #fff;
    padding: 8px 10px;
    border-radius: 6px;
    font-size: 0.85em;
    display: none;
    z-index: 9999;
    max-width: 90%;          /* maximale Breite */
    white-space: normal;        /* Text umbrechen */
    line-height: 1.3;
    box-shadow: 0 2px 6px rgba(0,0,0,0.25);
}

/* Optional: kleines Dreieck oberhalb */
.custom-tooltip::before {
    content: "";
    position: absolute;
    top: -20px;
    left: 50%;
    transform: translateX(-50%);
    border-width: 10px;
    border-style: solid;
    border-color: transparent transparent rgba(0,0,0,0.9) transparent;
}