signup.css

body{
    margin:0;
    padding: 0;
    font-family: montserrat;
    background: linear-gradient(120deg,#2980b9,#8e44ad);
    height:100vh;
    overflow: hidden;
}

.center{
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    width: 400px;
    background: white;
    border-radius: 10px;
}

.center h1{
    text-align: center;
    padding: 0 0 20px 0;
    border-bottom: 1px solid silver;
}

.center form{
    padding:0 40px;
    box-sizing: border-box;
}

form .txt_field{
    position: relative;
    border-bottom: 2px solid #adadad;
    margin: 30px 0;
}
.txt_field input{
    width:100%;
    padding: 0 5px;
    height: 40px;
    font-size:16px;
    border:none;
    background: none;
    outline:none;
}

.txt_field label{
    position: absolute;
    top:50%;
    left:5px;
    color:#adadad;
    transform: translateY(-50%);
    font-size: 16px;
    pointer-events: none;
}

.txt_field span::before{
    content:'';
    position: absolute;
    top:40px;
    left:0;
    width:100%;
    height:2px;
    background:#2691d9 ;
}

.txt_field input:focus ~ label,
.txt_field input:valid ~ label{
    top: -5px;
    color: #2691d9;
}

.txt_field input:focus ~  span::before,
.txt_field input:valid ~  span::before{
    width:100%;
}

.pass:hover{
    text-decoration: underline;
    color:rgb(243, 24, 42);
}

input[type="submit"]{
    width:100%;
    height: 50px;
    border: 2px solid;
    background: #2691d9;
    border-radius: 25px;
    font-size: 18px;
    cursor: pointer;
    outline:none;
}
input[type="submit"]:hover{
    border-color: #2691d9;
    color:white;
    transition:.5s; 
}

.login_link{
    margin:30px 0;
    text-align: center;
    font-size: 16px;
    color:#666666;
}
.login_link a{
    color:#2691d9;
    text-decoration: none;
}
.login_link a:hover{
    color:#2691d9;
    text-decoration: underline;
}

.center form .error-msg{
    margin:10px 0;
    background: crimson;
    display: block;
    color:#fff;
    border-radius: 5px;
    font-size:25px;
    text-align: center;
    padding:10px;
}