html {
            height: 100%;
        }

        body {
            margin: 0;
            padding: 0;
            font-family: sans-serif;
            background: linear-gradient(#141e30, #243b55);
        }

        .login-box {
            position: absolute;
            top: 50%;
            left: 50%;
            width: 400px;
            padding: 40px;
            transform: translate(-50%, -50%);
            background: rgba(0, 0, 0, .5);
            box-sizing: border-box;
            box-shadow: 0 15px 25px rgba(0, 0, 0, .6);
            border-radius: 10px;
        }

        .login-box h2 {
            margin: 0 0 5px;
            padding: 0;
            color: #fff;
            text-align: center;
        }
        .login-box h4 {
            margin: 0 0 30px;
            padding: 0;
            color: #fff;
            text-align: center;
        }

        .login-box .user-box {
            position: relative;
        }

        .login-box .user-box input {
            width: 100%;
            padding: 10px 0;
            font-size: 16px;
            color: #fff;
            margin-bottom: 30px;
            border: none;
            border-bottom: 1px solid #fff;
            outline: none;
            background: transparent;
            
            
        }

        .login-box .user-box label {
            position: absolute;
            top: 0;
            left: 0;
            padding: 10px 0;
            font-size: 16px;
            color: #fff;
            pointer-events: none;
            transition: .5s;
            -webkit-transition: .5s;
            -moz-transition: .5s;
            -ms-transition: .5s;
            -o-transition: .5s;
}
input:-webkit-autofill,
input:-webkit-autofill:hover, 
input:-webkit-autofill:focus, 
input:-webkit-autofill:active{
    -webkit-background-clip: text;
    -webkit-text-fill-color: #ffffff;
    transition: background-color 5000s ease-in-out 0s;
    border-radius: 7px;
    -webkit-border-radius: 7px;
    -moz-border-radius: 7px;
    -ms-border-radius: 7px;
    -o-border-radius: 7px;
    -webkit-transition: background-color 5000s ease-in-out 0s;
    -moz-transition: background-color 5000s ease-in-out 0s;
    -ms-transition: background-color 5000s ease-in-out 0s;
    -o-transition: background-color 5000s ease-in-out 0s;
}
        .login-box .user-box input:focus~label,
        .login-box .user-box input:valid~label {
            top: -32px;
            left: 0;
            color: #03e9f4;
            font-size: 13px;
        }

        .login-box form button {
            position: relative;
            display: inline-block;
            padding: 10px 20px;
            color: #03e9f4;
            font-size: 16px;
            text-decoration: none;
            
            overflow: hidden;
            transition: .5s;
            margin-top: 20px;
            letter-spacing: 1px
        }

        .login-box button:hover {
            background: #03e9f4;
            color: #fff;
            border-radius: 5px;
            box-shadow: 0 0 5px #03e9f4,
                0 0 25px #03e9f4,
                0 0 50px #03e9f4,
                0 0 100px #03e9f4;
        }

        .login-box button span {
            position: absolute;
            display: block;
        }

        .login-box button span:nth-child(1) {
            top: 0;
            left: -100%;
            width: 100%;
            height: 2px;
            background: linear-gradient(90deg, transparent, #03e9f4);
            animation: btn-anim1 1s linear infinite;
        }

        @keyframes btn-anim1 {
            0% {
                left: -100%;
            }

            50%,
            100% {
                left: 100%;
            }
        }

        .login-box button span:nth-child(2) {
            top: -100%;
            right: 0;
            width: 2px;
            height: 100%;
            background: linear-gradient(180deg, transparent, #03e9f4);
            animation: btn-anim2 1s linear infinite;
            animation-delay: .25s
        }

        @keyframes btn-anim2 {
            0% {
                top: -100%;
            }

            50%,
            100% {
                top: 100%;
            }
        }

        .login-box button span:nth-child(3) {
            bottom: 0;
            right: -100%;
            width: 100%;
            height: 2px;
            background: linear-gradient(270deg, transparent, #03e9f4);
            animation: btn-anim3 1s linear infinite;
            animation-delay: .5s
        }

        @keyframes btn-anim3 {
            0% {
                right: -100%;
            }

            50%,
            100% {
                right: 100%;
            }
        }

        .login-box button span:nth-child(4) {
            bottom: -100%;
            left: 0;
            width: 2px;
            height: 100%;
            background: linear-gradient(360deg, transparent, #03e9f4);
            animation: btn-anim4 1s linear infinite;
            animation-delay: .75s
        }

        @keyframes btn-anim4 {
            0% {
                bottom: -100%;
            }

            50%,
            100% {
                bottom: 100%;
            }
        }