login.css

html,
body {
    height: 100%;
}

@media screen and (max-width: 768px) {
  nav {
    display: flex;
    flex-direction: row;
    font-size: 10px;
  }
}

body {
    margin: 0;
    top:50%;
    background-color: #FFFFFF;
    overflow: hidden;
}

nav {
    position: relative;
    top: 5%;
    right: 0;
    left: 0;
    width: 319px;
    display: table;
    margin: 0 auto;
    transform: translateY(-50%);
}

nav a {
    position: relative;
    width: 33.333%;
    display: table-cell;
    text-align: center;
    color: #949494;
    text-decoration: none;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    font-weight: bold;
    padding: 10px 20px;
    transition: 0.2s ease color;
}

nav a:before,
nav a:after {
    content: "";
    position: absolute;
    border-radius: 50%;
    transform: scale(0);
    transition: 0.2s ease transform;
}

nav a:before {
    top: 0;
    left: 10px;
    width: 6px;
    height: 6px;
}

nav a:after {
    top: 5px;
    left: 18px;
    width: 4px;
    height: 4px;
}

nav a:nth-child(1):before {
    background-color: yellow;
}

nav a:nth-child(1):after {
    background-color: red;
}

nav a:nth-child(2):before {
    background-color: #00e2ff;
}

nav a:nth-child(2):after {
    background-color: #89ff00;
}

nav a:nth-child(3):before {
    background-color: purple;
}

nav a:nth-child(3):after {
    background-color: palevioletred;
}

nav a:nth-child(4):before {
  background-color: darkgreen;
}


nav a:nth-child(4):after {
  background-color: lightgreen;
}


nav a:nth-child(5):before {
  background-color: darkblue;
}


nav a:nth-child(5):after {
  background-color: lightblue;
}

#indicator {
position: absolute;
left: 5%;
bottom: 0;
width: 30px;
height: 3px;
/* background-color: #fff; */
border-radius: 5px;
transition: 0.2s ease left;
}

nav a:hover {
    /* color: #fff; */
}

nav a:hover:before,
nav a:hover:after {
    transform: scale(1);
}

nav a:nth-child(1):hover ~ #indicator {
    background: linear-gradient(130deg, yellow, red);
}

nav a:nth-child(2):hover ~ #indicator {
    left: 28%;
    background: linear-gradient(130deg, #00e2ff, #89ff00);
}

nav a:nth-child(3):hover ~ #indicator {
    left: 49%;
    background: linear-gradient(130deg, purple, palevioletred);
}

nav a:nth-child(4):hover ~ #indicator {
  left: 70%;
  background: linear-gradient(130deg, green, yellow);
}

nav a:nth-child(5):hover ~ #indicator {
  left: 89%;
  background: linear-gradient(130deg, darkblue, lightblue);
}


@import url("https://fonts.googleapis.com/css2?family=Noto+Sans:wght@700&family=Poppins:wght@400;500;600&display=swap");
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Poppins", sans-serif;
}
body {
    background: white;
    height: 100vh;
}
.center {
    position: relative;
    top: 50%;
    left: 50%;
    transform: translate(-49%, -70%);
    max-width: 420px;
    width: 100%;
    background: rgba(180, 180, 180, 0.2);
    border-radius: 50px;
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.05);
}
.center h1 {
    text-align: center;
    padding: 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;
    transition: 0.5s;
}
.txt_field span::before {
    content: "";
    position: absolute;
    top: 40px;
    left: 0;
    width: 0%;
    height: 2px;
    background: #2691d9;
    transition: 0.5s;
}
.txt_field input:focus ~ label,
.txt_field input:valid ~ label {
    top: -10px;
    color: #2691d9;
}
.txt_field input:focus ~ span::before,
.txt_field input:valid ~ span::before {
    width: 100%;
}

input[type="submit"] {
    position: relative;
    width: 80%;
    top: -12px;
    left: 35px;
    height: 50px;
    background: #2691d9;
    border-radius: 50px;
    font-size: 18px;
    color: #e9f4fb;
    font-weight: 700;
    cursor: pointer;
    outline: none;
    transition: 0.5s;
    border: none;
}
input[type="submit"]:hover {
    border-color: #2691d9;
}