.blocker {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    z-index: 1;
    padding: 20px;
    box-sizing: border-box;
    background-color: rgb(0, 0, 0);
    background-color: rgba(0, 0, 0, 0.75);
    text-align: center;
}

.blocker:before {
    content: "";
    display: inline-block;
    height: 100%;
    vertical-align: middle;
    margin-right: -0.05em;
}

.blocker.behind {
    background-color: transparent;
}

.modal {
    display: none;
    vertical-align: middle;
    position: relative;
    z-index: 2;
    box-sizing: border-box;
    background: #fff;
    -webkit-box-shadow: 0 0 10px #000;
    -moz-box-shadow: 0 0 10px #000;
    -o-box-shadow: 0 0 10px #000;
    -ms-box-shadow: 0 0 10px #000;
    box-shadow: 0 0 10px #000;
    text-align: left;
}

@-webkit-keyframes sk-stretchdelay {
    0%, 40%, 100% {
        -webkit-transform: scaleY(0.5)
    }
    20% {
        -webkit-transform: scaleY(1.0)
    }
}

@keyframes sk-stretchdelay {
    0%, 40%, 100% {
        transform: scaleY(0.5);
        -webkit-transform: scaleY(0.5);
    }
    20% {
        transform: scaleY(1.0);
        -webkit-transform: scaleY(1.0);
    }
}