html {
  font-size: 62.5%;
}
*,
*::before,
*:after {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
}

.login-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  width: 100%;
  background-color: steelblue;
}

.login-form {
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 320px;
  padding: 2rem 1rem;
  margin: 5px;
  border-radius: 5px;
  color: #fff;
  background-color: rgba(0, 0, 0, 0.3);
}
.login-form .heading {
  text-align: center;
}
.input-group {
  position: relative;
}
.form-control {
  background-color: transparent;
  width: 100%;
  font-size: 1.6rem;
  margin-top: 3rem;
  border: 0;
  color: #fff;
  border-bottom: 2px solid #fff;
  padding: 0.5rem 0;
}

.form-control:focus {
  outline: transparent;
  border-color: lightblue;
}

.input-group label {
  position: absolute;
  top: 3rem;
  left: 0;
  font-size: 1.6rem;
}

.input-group label span {
  display: inline-block;
  font-size: 1.8rem;
  cursor: text;
}

.input-group input:focus + label span,
.input-group input:valid + label span {
  color: lightblue;
  transform: translateY(-2.5rem);
}

.login-form .help {
  margin-top: 1.5rem;
  font-size: 1.3rem;
}
.login-form .help .link {
  text-decoration: none;
  color: lightblue;
}
.login-form .help .link:hover {
  color: #fff;
}

.btn {
  margin-top: 3rem;
  background-color: steelblue;
  color: #fff;
  padding: 0.5rem 0;
  font-size: 1.6rem;
  border: 0;
  cursor: pointer;
  border-radius: 5px;
  letter-spacing: 0.1rem;
}
.btn:active {
  transform: scale(0.98);
}