header,
  main,
  footer {
    box-sizing: border-box;
    width: 1100px;
    margin: 0 auto;
  }
  :global(a) {
    text-decoration: none;
  }
  main {
  flex: 1;
  }
  h1 {
    margin-left: 0.5em;
    color: white;
  }
  h1 a {
    color: white;
    text-decoration: none;
  }
  h1 a:hover {
    color: #cbcbcb;
  }
  h1:hover {
    color: #cbcbcb;
  }
  header {
    background-color: rgb(37, 37, 37);
    left: 0;
    right: 0;
    bottom: 0;
    padding: 2em 2em 0.5em;
    margin: 0 auto;
    width: 100%;
  }
  .main-container p{
    text-align: center;
    }
input{
    width: 30%;
    margin: 0 auto;
    padding: 0.5em;
    font-size: medium;
}
input:invalid {
background-color: lightpink;
}
.nyuryoku{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 70vh;
}
#checkButton{
    display: flex;
    flex-direction: row;
    display: block;
    width: 120px;
    text-align: center;
    margin-top: 1em;
    padding: 0.5em 1em;
    background-color: rgb(37, 37, 37);
    color: white;
    cursor: pointer;
}
  footer {
    background-color: rgb(37, 37, 37);
    color: white;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 1em 2em 0.5em;
    margin: 0 auto;
    width: 100%;
  }