style.css

body {
    background-color: #303030;
    font: 14px normal Arial, Helvetica, sans-serif;
    z-index: -4;
    color: #ffffff;
}

a {
    color: #ffffff;
}

a:hover {
    transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out, border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
    color: #808080;
}

input {
    border: 1px solid #ffffff;
    border-radius: 3px;
    padding: 5px;
    margin: 5px;
    width: 50%;
    color: #ffffff;
    background-color: #303030;
}

.okbtn {
    background-color: #00a700;
    border: 1px solid #00a700;
    border-radius: 3px;
    padding: 5px;
    margin: 5px;
    width: 150px;
    color: #ffffff;
}

.full-center {
    margin: 0;
    position: relative;
    top: 50%;
    left: 50%;
    text-align: center;
    -ms-transform: translate(-50%, 0%);
    transform: translate(-50%, 0%);
    width: 400px;
}