.mdl-dropdown {
    position: absolute;
    display: flex;
    z-index: 9999;
    opacity: 0;
    margin: 0;
    padding: 5px 0;
    border-radius: 2px;
    background: #fff;
    transition: opacity 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    box-sizing: border-box;
    box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.14), 0 3px 1px -2px rgba(0, 0, 0, 0.2), 0 1px 5px 0 rgba(0, 0, 0, 0.12);
}
.mdl-dropdown *, .mdl-dropdown *:before, .mdl-dropdown *:after {
    box-sizing: inherit;
}