.ac_dropdown {
    position: absolute;
    background: white;
    border: 1px solid #ccc;
    display: none;
    z-index: 9999;
    max-height: 200px;
    overflow-y: auto;
}

.ac_item {
    padding: 8px;
    cursor: pointer;
    border-bottom: 1px solid #eee;
}

.ac_item:hover {
    background: #f0f0f0;
}