* {
    margin: 0;
}
html,
body {
    height: 100%;
}

.box {
    background-size: cover;
    margin: 0 auto;
    position: relative;
    width: 100%;
    height: 100%;
}

.login-box {
    width: 100%;
    max-width: 500px;
    height: 400px;
    position: absolute;
    top: 50%;

    margin-top: -200px;
    /*设置负值，为要定位子盒子的一半高度*/

}

@media screen and (min-width:500px) {

    .login-box {
        left: 50%;
        /*设置负值，为要定位子盒子的一半宽度*/
        margin-left: -250px;
    }

}

@media screen and (max-width:500px) {

    .box {
        background-size: cover;
        margin: 0 auto;
        position: relative;
        width: 100%;
        height: 100%;
    }

    .form-group {
        margin-top: 20px !important;
    }

    .link p {
        height: 10px !important;
        font-size: 10px !important;
        margin-top: 30px;
    }

    .title {
        height: 10px !important;
    }
}

#username .form-control {
    background: none !important;
}

.form-control:focus {
    border-color: none !important;
    outline: 0;
    box-shadow: none !important;
}

.form {
    width: 100%;
    max-width: 500px;
    height: 275px;
    margin: 25px auto 0px auto;
    padding-top: 15px;
}

.login-content {
    height: 360px;
    width: 100%;
    max-width: 500px;
    background: url(../style/img_frame.png) no-repeat;
    background-size: 100% 100%;
    float: left;
}

.form-control,
.input-group {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 30px;
}

.form-group {
    margin-bottom: 0px !important;
}

.login-title {
    padding: 20px 10px;
    background-color: rgba(0, 0, 0, .6);
}

.login-title h1 {
    margin-top: 10px !important;
}

.login-title small {
    color: #fff;
}

.input-group .form-control {
    width: 55%;
}

.input-group input {
    border: none;
    background: #191513;
}

.link p {
    line-height: 20px;
    margin-top: 15px;
}
.btns:active {
    background: url(../style/btn_register.png) no-repeat;
}

.btn {
    display: flex;
    justify-content: center;
    align-items: center;
}

.btns {
    line-height: 32px;
    width: 107px;
    height: 32px;
    color: #fed873;
    text-align: center;
    /* margin-top: ; */
    background: url(../style/btn_register.png) no-repeat;
}

.title {
    display: block;
    text-align: center;
    height: 5px;
    color: red !important;
    font-size: 14px;
}

input::-webkit-input-placeholder {
    color: #51493c !important;
}
.user_hint {
    margin-left: 3px;
    width: 10px;
    display: block;
}
.password_hint {
    margin-left: 3px;
    width: 10px;
    display: block;
}
.confirm_hint {
    margin-left: 3px;
    width: 10px;
    display: block;
    margin-right: 32px;
}
.question_hint {
    margin-left: 3px;
    width: 10px;
    display: block;
    margin-right: 32px;
}
.anwser_hint {
    margin-left: 3px;
    width: 10px;
    display: block;
    margin-right: 32px;
}