style.css

html, body {
  height: 100%;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: 70px;
  padding-bottom: 40px;
  background-color: #f5f5f5;
}

.daftar-buku{
  width: 100%;
  max-width: 500px;
  padding: 15px;
  margin: auto;
}

.validasi-form {
  width: 100%;
  max-width: 1000px;
  padding: 15px;
  margin: 2rem auto;
}