html{
    background: linear-gradient(-45deg, #333333, #666666, #444444, #555555);
    background-size: 400% 400%;
    animation: gradient 15s ease infinite;
    height: 100vh;
}

@keyframes gradient {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

body{
    background: none;
}

.hide{
    display: none;
}

.form_login{
    margin: calc(50vh - 150px) auto;
    max-width: 300px;
    position: relative;
}

.form_login input{
    display: block;
    appearance: none;
    outline: 0;
    background: rgb(0,0,0,0.1);
    border: 1px solid #666666;
    color:#dddddd;
    border-radius: 5px;
    padding: 6px 15px;
    width: 100%;
    transition: .2s;
}

.form_login input:hover{
    background: rgb(0,0,0,0.2);
    color: #eeeeee;
}

.form_login label{
    color: #ffffff;
    font-size: 0.8em;
    opacity: 0.5;
}

.form_login > .title_block{
    position: absolute;
    width: calc(100% - 20px);
    top:-80px;
}

.form_login > .title_block > h2 > img{
    width: 30px;
}

.form_login > .title_block > h2{
    color:#888888;
    margin-top: 10px;
    font-weight: 700;
}

.btn .btn_spin_right{
    position: absolute;
    margin-left: 5px;
    margin-top: 5px;
}

.alert_error{
    position: absolute;
    bottom: -95px;
    width: 100%;
    left:0;
    font-size: 0.8em;
}

.btn_back{
    display: block;
    text-align: center;
    color: #eeeeee;
    margin-top: 20px;
    text-decoration: none;
}

.btn_back:hover{
    color: #ffffff;
}