style.scss

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    background: #333;
}
main {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    .centered {
        background: #aaa;
      padding: 20px;
      width: 100%;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
        Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
      max-width: 400px;
      box-shadow: 0 0 15px rgba(0, 0, 0, 0.164);
      h1 {
        text-align: center;
        margin-bottom: 20px;
        font-size: 25px;
        a {
          text-decoration: none;
        }
      }
      label {
        width: 100%;
        display: block;
        margin-bottom: 20px;
        input {
          width: 100%;
          height: 40px;
          border: solid 1px;
          outline: none;
          padding: 5px;
          font-size: 18px;
          margin-top: 2px;
        }
      }
      .centered-submit {
        width: 100%;
        height: 35px;
        border: solid 1px;
        cursor: pointer;
      }
      button {
        font-weight: bold;
      }
    }
  }