@import url('https://fonts.googleapis.com/css?family=Montserrat:600|Noto+Sans|Open+Sans:400,700&display=swap');

* {
    margin: 0;
    padding: 0;
    border-radius: 5px;
    box-sizing: border-box;
    
}

body {
    height: 100vh;
    display: flex;
    align-items: center;
    text-align: center;
    font-family: sans-serif;
    justify-content: center;
    background: url(bg.jpg);
    background-size: cover;
    background-position: center;
    background-color: blue;
}

.container {
    position: relative;
    width: 400px;
    background: white;
    padding: 60px 40px;
}

header {
    font-size: 40px;
    margin-bottom: 60px;
    font-family: 'Montserrat', sans-serif;
}

.input-field, form .button {
    margin: 25px 0;
    position: relative;
    height: 50px;
    width: 100%;
}

    .input-field input {
        height: 100%;
        width: 100%;
        border: 1px solid silver;
        padding-left: 15px;
        outline: none;
        font-size: 19px;
        transition: .4s;
    }

input:focus {
    border: 1px solid #1DA1F2;
}

.input-field label, span.show {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
}

.input-field label {
    left: 15px;
    pointer-events: none;
    color: grey;
    font-size: 18px;
    transition: .4s;
}

span.show {
    right: 20px;
    color: #111;
    font-size: 14px;
    font-weight: bold;
    cursor: pointer;
    user-select: none;
    visibility: hidden;
    font-family: 'Open Sans', sans-serif;
}

input:valid ~ span.show {
    visibility: visible;
}

input:focus ~ label,
input:valid ~ label {
    transform: translateY(-33px);
    background: white;
    font-size: 16px;
    color: #1DA1F2;
}

form .button {
    margin-top: 30px;
    overflow: hidden;
    z-index: 111;
}

.button .inner {
    position: absolute;
    height: 100%;
    width: 300%;
    left: -100%;
    z-index: -1;
    transition: all .4s;
    background: -webkit-linear-gradient(right,#00dbde,#fc00ff,#00dbde,#fc00ff);
}

.button:hover .inner {
    left: 0;
}

.button button {
    width: 100%;
    height: 100%;
    border: none;
    background: none;
    outline: none;
    color: white;
    font-size: 20px;
    cursor: pointer;
    font-family: 'Montserrat', sans-serif;
}

.container .auth {
    margin: 35px 0 20px 0;
    font-size: 19px;
    color: grey;
}

.links {
    display: flex;
    cursor: pointer;
}

.facebook, .google {
    height: 40px;
    width: 100%;
    border: 1px solid silver;
    border-radius: 3px;
    margin: 0 10px;
    transition: .4s;
}

    .facebook:hover {
        border: 1px solid #4267B2;
    }

    .google:hover {
        border: 1px solid #dd4b39;
    }

    .facebook i, .facebook span {
        color: #4267B2;
    }

    .google i, .google span {
        color: #dd4b39;
    }

.links i {
    font-size: 23px;
    line-height: 40px;
    margin-left: -90px;
}

.links span {
    position: absolute;
    font-size: 17px;
    font-weight: bold;
    padding-left: 8px;
    font-family: 'Open Sans', sans-serif;
}

.signup {
    margin-top: 50px;
    font-family: 'Noto Sans', sans-serif;
}

    .signup a {
        color: #3498db;
        text-decoration: none;
    }

        .signup a:hover {
            text-decoration: underline;
        }