body {
  background-color: white;
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
}
@media screen and (max-width: 1000px) {
  .wrapper header .logo {
    color: darkorange;
    margin-right: 20px;
    font-size: 30px;
  }
  .wrapper header nav li {
    display: inline-block;
    margin-left: 10px;
    margin-right: 20px;
    border-bottom: 1px solid black;
    padding-bottom: 1px;
    font-size: 30px;
  }
  .wrapper header {
    top: 0; /* 追記 */
    left: 0; /* 追記 */
    background-color: whitesmoke;
    position: fixed;
    width: 100%;
    height: 90px;
  }
}
@media screen and (min-width:1001px) {
  .wrapper header .logo {
    color: darkorange;
    margin-right: 20px;
  }
  
  .wrapper header nav li {
    display: inline-block;
    margin-left: 10px;
    margin-right: 20px;
    border-bottom: 1px solid black;
    padding-bottom: 1px;
  }
  .wrapper header {
    top: 0; /* 追記 */
    left: 0; /* 追記 */
    background-color: whitesmoke;
    position: fixed;
    width: 100%;
  }
}

.wrapper header nav a {
  text-decoration: none;
  color: #000000;
}

.wrapper header nav a:hover {
  color: blue;
}

.wrapper header nav a:active {
  background-color: lightgray;
}
.wrapper footer {
  flex-direction: column;
  display: flex;
  margin-top: auto;
  text-align: center;
  position: sticky;
  bottom: 0;
}

.wrapper main {
  text-align: center;
  margin-top: 100px;
}
@media screen and (max-width: 1000px) {
  .wrapper main #underline{
    width: 350px;
    margin-top: 40px;
    margin-left: auto;
    margin-right:auto;
    border-bottom: solid 2px gray;
    padding-bottom: 2px;
    font-size: 35px;
  }
  .wrapper main #longunderline{
    width: 500px;
    margin-top: 40px;
    margin-left: auto;
    margin-right:auto;
    border-bottom: solid 2px gray;
    padding-bottom: 2px;
    font-size: 35px;
  }
  .wrapper main p{
    font-size: 22px;
  }
}
@media screen and (min-width:1001px) {
  .wrapper main #underline{
    width: 350px;
    margin-top: 40px;
    margin-left: auto;
    margin-right:auto;
    border-bottom: solid 2px gray;
    padding-bottom: 2px;
    font-size: 25px;
  }
  .wrapper main #longunderline{
    width: 500px;
    margin-top: 40px;
    margin-left: auto;
    margin-right:auto;
    border-bottom: solid 2px gray;
    padding-bottom: 2px;
    font-size: 25px;
  }
  .wrapper main p{
    font-size: 20px;
  }
}