body {
    background: url('./body_bg.jpg') repeat center top;
    background-size: cover;
}

.wrap {
    padding: 80px 0;
}
.form-group{
    
}
.form-control{
    height:54px;
}
.login_t{
    color:#fff;
}
.login_bd{
    float:unset;
    margin:0 auto;
    padding:100px 200px 0 200px;
    width:740px;
    height:476px;
    background: url('./login_bg.png') no-repeat center;
}

#input_username{
    border:none;
    border-bottom:1px solid #7d7d7d;
    padding-left:30px;
    background:url(./name.png) no-repeat left center;
}
#input_password{
    border:none;
    border-bottom:1px solid #7d7d7d;
    padding-left:30px;
    background:url(./pass.png) no-repeat left center;
}
#input_captcha{
    border:none;
    border-bottom:1px solid #7d7d7d;
    padding-left:30px;
    background:url(./code.png) no-repeat left center;
}
#button_sub{
    margin:40px auto 0;
    padding:0;
    width:300px;
    height:45px;
    line-height:45px;
    font-size:18px;
    border-radius:25px;
    border:none;
    background: -webkit-linear-gradient(left, #de00ff , #5a00ff); /* Safari 5.1 - 6.0 */
    background: -o-linear-gradient(right, #de00ff, #5a00ff); /* Opera 11.1 - 12.0 */
    background: -moz-linear-gradient(right, #de00ff, #5a00ff); /* Firefox 3.6 - 15 */
    background: linear-gradient(to right, #de00ff , #5a00ff); /* 标准的语法 */
}