@import url("https://fonts.googleapis.com/css2?family=DotGothic16&display=swap");
* {
  font-family: DotGothic16;
  letter-spacing: 0.15em;
  font-size: 15px; }

#center {
  height: 100vh;
  max-width: 100%;
  display: flex;
  align-items: center;
  justify-content: center; }

.bga {
  height: 100vh;
  width: 100%;
  visibility: hidden;
  position: fixed;
  z-index: -1; }

#box {
  width: 500px;
  padding: 50px 0px 30px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background-color: #66CCFF; }

.menu {
  text-decoration: none;
  list-style-type: none;
  display: flex;
  justify-content: center; }

.item {
  padding: 25px;
  text-align: center; }

a {
  text-decoration: none;
  color: black; }
a:hover{
  color: #fff;
}
#introduction{
  padding: 10px;
  text-align: center;
  font-size: .8em;
  color: #fff;
}
#digital, #analog {
  width: 60px; }

#audio {
  width: 50px; }

#undefined {
  width: 66px; }