.mmm-plan-day-list {
    min-height: 80px; /* oder 100px, wie du willst */
    padding: 0.5em;
    background: color-mix(in srgb, var(--mmm-primary) 4%, transparent);
    border-radius: var(--ast-border-radius);
}
.mmm-plan-day-list.drop-target {
    background: color-mix(in srgb, var(--mmm-primary) 12%, transparent);
}