body {
    margin: 0;
    padding: 0;
    background: -webkit-radial-gradient(top, circle cover, #fbfff7 0%, #6eade8 80%)
}

a {
    text-decoration: none;
}

.box {
    display: -webkit-flex;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.container {
    display: flex;
    background:#fff;
    width: 450px;
    height: 600px;
    overflow: auto;
    box-shadow: 2px 1px 6px #CC9999;
    flex-direction: column;
    position: absolute;
}

@keyframes fadeIn {
    0% {
        opacity: 0;
        left: 910px;
    }

    20% {
        opacity: 0.2;
        left: 728px;
    }

    40% {
        opacity: 0.4;
        left: 546px;
    }

    60% {
        opacity: 0.6;
        left: 364px;
    }

    80% {
        opacity: 0.8;
        left: 182px;
    }

    100% {
        opacity: 1;
        left: 0;
    }
}

.fadeIn {
    animation: fadeIn .3s linear forwards;
}

@keyframes fadeOut {
    0% {
        opacity: 1;
        left: 0;
    }

    20% {
        opacity: 0.8;
        left: 182px;
    }

    40% {
        opacity: 0.6;
        left: 364px;
    }

    60% {
        opacity: 0.4;
        left: 546px;
    }

    80% {
        opacity: 0.2;
        left: 728px;
    }

    100% {
        opacity: 0;
        left: 910px;
    }
}

.fadeOut {
    animation: fadeOut .3s linear forwards;
}

.register_container {
    opacity: 0;
    right: 0;
    top: 0;
    left: 910px;
    bottom: 0;
    margin: auto;
}

.login_container {
    opacity: 1;
    right: 0;
    top: 0;
    left: 0;
    bottom: 0;
    margin: auto;
}

.form {
    height: 90%;
    display: flex;
    flex-direction: column;
}

.form h2 {
    flex: 1;
    align-self: center;
    font-size: 40px;
    line-height: 80px;
    color: #0084FF
}

.form .cont {
    flex: 5;
    align-self: center;
    display: flex;
    width: 100%;
    flex-direction: column;
}

.form .cont label {
    position: relative;
    align-self: center;
    width: 60%;
    height: 20%;
    margin-bottom: 20px;
    display: flex;
    flex-direction: row;
}

@keyframes scaleFont {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(.9);
        bottom: 40%;
    }
    100% {
        transform: scale(.8);
        bottom: 60%;
    }
}

.form .cont label span {
    position: absolute;
    font-size: 20px;
    display: inline;
    bottom: 8%;
    animation: scaleFont 0.3s ease;
    animation-fill-mode: forwards; /* 保存动画最后状态 */
}

.form .input {
    border: none;
    border-bottom: 1px solid #e6e6e6;
    outline: none;
    width: 100%;
    align-self: flex-end;
    height: 30px;
    font-size: 20px;
}

.form .line {
    width: 0;
    position: absolute;
    background-color: blue;
    height: 2px;
    margin: 0 auto;
    bottom: 0;
    left: 0;
    right: 0;
    transition: width .3s linear;
}

.form .btn {
    border: none;
    width: 100%;
    height: 80%;
    background: #0084FF;
    color: #fff;
    font-size: 25px;
    border-radius: 11px;
    align-self: flex-end;
}

.form .btn:hover {
    background-color: #005eb6;
    cursor: pointer;
}

.tab {
    height: 12%;
    width: 100%;
    border-top: 1px solid #EBEBEB;
    background: #f6f6f6;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 20px;
}