body {
    margin: 0;
    padding: 0;
    font-family: "Microsoft YaHei UI", Arial;
    font-size: 16px;
    background: blue;
    color: #fff;
    -webkit-animation: bg 4s linear infinite alternate;
    -o-animation: bg 14s linear infinite alternate;
    animation: bg 14s linear infinite alternate;
}

@keyframes bg {
    from {
        background: red;
    }
    to {
        background: blue;
    }
}

.sign {
    width: 270px;
    height: 300px;
    margin: 0 auto;
    padding: 20px;
    position: absolute;
    top: 50%;
    left: 50%;
    -webkit-transform: translate3D(-50%, -48%, 0);
    -moz-transform: translate3D(-50%, -48%, 0);
    -ms-transform: translate3D(-50%, -48%, 0);
    -o-transform: translate3D(-50%, -48%, 0);
    transform: translate3D(-50%, -48%, 0);
    background-color: rgba(255, 255, 255, .3);
    -webkit-box-shadow: 0 0 160px rgba(255, 255, 255, .5);
    -moz-box-shadow: 0 0 160px rgba(255, 255, 255, .5);
    box-shadow: 0 0 160px rgba(255, 255, 255, .5);
    -webkit-transition: all .7s;
    -moz-transition: all .7s;
    -ms-transition: all .7s;
    -o-transition: all .7s;
    transition: all .7s;
}

.sign:hover {
    -webkit-transform: translate3D(-50%, -50%, 0);
    -moz-transform: translate3D(-50%, -50%, 0);
    -ms-transform: translate3D(-50%, -50%, 0);
    -o-transform: translate3D(-50%, -50%, 0);
    transform: translate3D(-50%, -50%, 0);
    -webkit-box-shadow: 0 0 160px rgba(0, 0, 0, .5);
    -moz-box-shadow: 0 0 160px rgba(0, 0, 0, .5);
    box-shadow: 0 0 160px rgba(0, 0, 0, .5);
}

h1 {
    line-height: 1em;
    text-align: center;
    font-weight:bolder;
    font-size: 32px;
}

i {
    font-style: normal;
    font-size: 0.8em;
}

.sign form {
    width: 100%;
    height: 280px;
}

.sign h2{
    font-size: 24px;
    font-weight: bold;
 }

.sign span {
    font-size: 16px;
}

.sign input {
    width: 250px;
    padding: 2px 6px;
    border: 0;
    border-bottom: 1px solid rgba(255, 255, 255, .5);
    background-color: rgba(0, 0, 0, 0);
    outline: none;
    color: #fff;
    line-height: 20px;
    font-size: 15px;
    -webkit-transition: font-size .4s;
    -moz-transition: font-size .4s;
    -ms-transition: font-size .4s;
    -o-transition: font-size .4s;
    transition: font-size .4s;
}

input::-webkit-input-placeholder {
    color: #bbb;
}

input:-moz-placeholder {
    color: #bbb;
}

input::-moz-placeholder {
    color: #bbb;
}

input:-ms-input-placeholder {
    color: #bbb;
}

input:hover {
    border-bottom-color: rgba(255, 255, 255, 1);
}

input:focus {
    border-bottom-color: rgba(255, 255, 255, 1);
    font-size: 17px;
}

#status,#status1,#status2 {
    font-size: 14px !important;
    line-height: 1em;
    text-align: right;
    color: #eee;
    margin: 6px 6px 6px 0;
}

input[type="button"] {
    width: 60px !important;
    font-size: 16px !important;
    margin: 0 36px 0 36px;
}

input[type="button"]:hover {
    text-shadow: 0 0 2px white;
}

.sign h6 {
    text-align: center;
}

.hint {
    color: yellow !important;
}