body{
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
header{
  height: 150px;
  text-align: center;
  border: 1px solid;
  font-size: 40px;
  line-height: 150px;
  background-color: #cce5ff;
}
span{
  border-image: url("cat-line.PNG") 15 round;
  border-style:solid;
  border-width:10px;
}
h1{
  text-align: center;
}
div{
  display: flex;
  flex: 1;
  background-color: #d6ffff;
}
main{
  flex: 1;
  border: 1px solid;
}
nav{
  width: 200px;
  border: 1px solid;
}
footer{
  height: 100px;
  border: 1px solid;
  background-color: #d6ffff;
  margin-left: 1;
}

.center{
    text-align: center;
}
.now{
  text-decoration: underline;
}
.back1{
  background-image: url(kusa.png);
}
.maruwaku{
  border: 3px solid navy;
  border-top-right-radius: 2em;
  border-bottom-left-radius: 2em;
  background: #cce5ff;
  box-shadow: #2f4f4f 2px 2px 3px;
  padding: 1ex
}
.maruwaku:hover{
  transition: 3s;
  transform: rotate(30deg);
}