html,
body {
    height: 100%;
}

.container {
    height: 100%;
    width: 100%;
    background-size: cover;
    background-repeat: no-repeat;
}
.container-box {
    display: inline-block;
    padding: 10px;
    background: rgba(255, 255, 255, 0.8);
    border: 1px solid #fff;
    position: fixed;
    top: 55%;
    left: 0;
}

.modal-content {
    background: rgba(255, 255, 255, 0.7);
}

.rotated {
    -moz-transform: rotate(-90deg);
    -ms-transform: rotate(-90deg);
    -o-transform: rotate(-90deg);
    -webkit-transform: rotate(-90deg);
    transform-origin: top left;
}