style.css

:root {
  --dark-color: #212121;
  --bg-color:#1A2238;
}

body {
  font-family: system-ui;
  text-align: center;
  color: #FFF;
  margin-top: 40px;
  font-size: 1.5em;
  background-color : var(--bg-color);
}

h4 {
  font-weight: normal;
  margin-bottom: 5px;
}
h1 {
  font-weight: normal;
  margin-top: 0;
  margin-bottom: 40px;
  font-size: 2em;
}

img {
  border-radius: 150%;
  height: 120px;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
}
main * {
  margin-bottom: 12px;
}

input {
  text-align: center;
  font-size: large;
  outline: none;
  border: none;
  border-radius: 20px;
  border-bottom: 2px solid #F4DB7D;
  text-transform: capitalize;
  background-color: #1A2238;
  color: #6492f6;
}
::placeholder { /* Chrome, Firefox, Opera, Safari 10.1+ */
  color: #9DAAF2;
  opacity: 1; /* Firefox */
}

:-ms-input-placeholder { /* Internet Explorer 10-11 */
  color: #9DAAF2;
}

::-ms-input-placeholder { /* Microsoft Edge */
  color: #9DAAF2;
}
/* for styling the autocomplete style */
input:-webkit-autofill,
input:-webkit-autofill:hover,
input:-webkit-autofill:focus,
input:-webkit-autofill:active {
  transition: background-color 5000s ease-in-out 0s;
  -webkit-text-fill-color: var(--dark-color) !important;
}

button {
  background: #9DAAF2;
  color: #1A2238;
  border: none;
  font-size: 0.8em;
  padding: 5px 15px;
  margin: 20px;
  border-radius: 5px;
  cursor: pointer;
}
a {
  color: #6492f6;
}

/* dark mode css */
@media (prefers-color-scheme: dark) {
  /* body {
    background: var(--dark-color);
    color: #fff;
  }
  input,
  input:active {
    background: var(--dark-color);
    border-color: #fff;
    color: #fff;
  } */

  /* for styling the autocomplete style */
  input:-webkit-autofill,
  input:-webkit-autofill:hover,
  input:-webkit-autofill:focus,
  input:-webkit-autofill:active {
    transition: background-color 5000s ease-in-out 0s;
    -webkit-text-fill-color: #fff !important;
  }
}