style.css

@import url('https://fonts.googleapis.com/css2?family=Archivo:wght@300&display=swap');

* {
  padding: 0;
  margin: 0;
}

body {
  background-color: #f7cf3c;
  font-family: 'Archivo', sans-serif;
  color: #313131;
}

form {
  background-color: #f7f7f7;
  border-style: solid;
  border-width: 10px;
  border-color: #313131;
  display: flex;
  flex-direction: column;
  margin: 30vh auto;
  width: 30vw;
  padding: 20px;
}

h1 {
  margin-bottom: 20px;
}

label {
  color: #00548e;
  font-size: 15pt;
  margin-bottom: 3px;
}

input {
  border-width: 3px;
  border-style: solid;
  border-color: #00548e;
  border-radius: 4px;
  width: 90%;
  height: 30px;
  margin-bottom: 30px;
}

button {
  background-color: #00548e;
  color: #fff;
  font-size: 15pt;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  outline: none;
  width: 30%;
  margin: 0 auto;
  padding: 10px 15px;
}

@media (max-width: 700px) {
  form {
    background-color: #f7f7f7;
    border-style: solid;
    border-width: 10px;
    border-color: #313131;
    display: flex;
    flex-direction: column;
    margin: 20vh auto;
    width: 70vw;
    padding: 20px;
  }
  button {
    background-color: #00548e;
    color: #fff;
    font-size: 15pt;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    outline: none;
    width: 50%;
    margin: 0 auto;
    padding: 10px 15px;
  }
}