index.css

body {
  margin: 0;
  padding: 0;
}
.header {
  background-color: dodgerblue;
  text-align: center;
  padding: 14px 0px;
  box-shadow: 2px 2px 2px rgba(0, 0, 0, 0.4);
  color: white;
  margin-bottom: 140px;
}
.header span {
  padding: 2px 10px;
  border-radius: 50%;
  background-color: lightgray;
  color: black;
}
h2 {
  font-weight: 500;
}
.container {
  width: 80%;
  margin: auto;
}
.row {
  display: flex;
  justify-content: center;
  margin-top: 20px;
  margin-bottom: 50px;
}
.row .card {
  box-shadow: 2px 2px 6px rgba(0, 0, 0, 0.3);
  padding: 10px;
  border-radius: 3px;
  width: 50%;
  margin: auto;
}
.card h2 {
  text-align: center;
  font-size: 25px;
  margin: 0px;
  margin-top: 5px;
  margin-bottom: 25px;
}
.row form {
  width: 100%;
  margin: auto;
}
.row input {
  width: 75%;
}
.row input[type="submit"] {
  width: 23%;
  padding: 5px 4px;
  border: none;
  background-color: dodgerblue;
  color: white;
  border-radius: 3px;
}
.row input[type="checkbox"] {
  width: auto;
}
footer {
  width: 52%;
  margin: auto;
  font-size: 14.5px;
}

@media screen and (max-width: 768px) {
  .header {
    padding: 10px 0px;
    margin-bottom: 140px;
  }
  .card {
    width: 100% !important;
  }
  footer {
    width: 100%;
    margin: auto;
    font-size: 14.5px;
  }
  .row label {
    font-size: 15px;
  }
}