html,
body {
    width: 100%;
    height: 100%;
}


/* .container {
    position: relative;
    width: 100%;
    height: 100%;
    background-color: #333;
} */

.btn {
    position: absolute;
    top: 0;
    width: 90px;
    /* height: 100%; */
    padding-left: 30px;
}

.btn a {
    text-align: center;
    display: inline-block;
    text-decoration: none;
    margin-top: 50px;
    color: #fff;
    width: 85px;
    height: 30px;
    line-height: 30px;
    background-color: #008c8c;
    border-radius: 10px;
}