.dropdown {
    position: relative;
    font-size: 14px;
    color: #333;
    z-index:1;
}
.dropdown .dropdown-list {
    padding: 12px;
    background: #fff;
    position: absolute !important;
    position: initial;
    top: 30px;
    left: 2px;
    right: 2px;
    box-shadow: 0 1px 2px 1px rgba(0, 0, 0, 0.15);
    transform-origin: 50% 0;
    transform: scale(1, 0);
    transition: transform .15s ease-in-out .15s;
    max-height: 66vh;
    overflow-y: scroll;
}
.dropdown .dropdown-option {
    display: block;
    padding: 8px 12px;
    opacity: 0;
    transition: opacity .15s ease-in-out;
}
.dropdown .dropdown-label {
    display: block;
    height: 30px;
    background: #fff;
    border: 1px solid #ccc;
    padding: 6px 12px;
    line-height: 1;
    cursor: pointer;
}
.dropdown .dropdown-label:before {
    content: '▼';
    float: right;
}
.dropdown.on .dropdown-list {
    transform: scale(1, 1);
    transition-delay: 0s;
}
.dropdown.on .dropdown-list .dropdown-option {
    opacity: 1;
    transition-delay: .2s;
}
.dropdown.on .dropdown-label:before {
    content: '▲';
}
.dropdown [type="checkbox"] {
    position: relative;
    top: -1px;
    margin-right: 4px;
}