.a-mention-popup {
    position: fixed;
    display: flex;
    flex-direction: column;
    min-width: 180px;
    max-width: 320px;
    max-height: 220px;
    overflow-y: auto;
    background-color: white;
    border: 1px solid #ccc;
    border-radius: 3px;
    box-shadow: 0 6px 12px rgb(0 0 0 / 18%);
    z-index: 1000;
    box-sizing: border-box;
}

.a-mention-item {
    display: flex;
    align-items: center;
    min-height: 28px;
    padding: 4px 12px;
    font-size: 14px;
    cursor: pointer;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.a-mention-item:hover,
.a-mention-item-selected {
    background-color: #2196f3;
    color: white;
}

.a-mention-empty {
    padding: 6px 12px;
    font-size: 14px;
    color: #888888;
}

.a-mention-highlight {
    background-color: #2196f32b;
    color: #0b5394;
    font-weight: bold;
    padding: 1px 4px;
    border-radius: 3px;
    white-space: nowrap;
}