header{
  background-color:steelblue;  
  padding-bottom:5px;
  padding:5px;
}

h1{
  float:left;
  color:white;
  margin-right:20px;
  margin-left:20px;
}

li{
  margin-top:15px;
  text-decoration:none;
  display:inline-block;
  font-size:150%;
  width:90px;
}
.mainmenu{
  margin-left:20px;
  margin:5px;
}
.nagai{
  width:auto;
  margin-left:20px;
  margin:5px;
}
a{
  color:white;
  text-decoration:none;
}

h2{
  font-size:150%;
  text-align:center;
}

h3{
  font-size:200%;
  margin-left:200px;
  color:white;
}
h4{
  margin:20px;
  margin-bottom:30px;
  
}
.kotae{
  color:white;
  background-color:steelblue;
  padding:15px;
  padding-left:25px;
  padding-right:25px;
  text-decoration:none;
  border:none;
  box-shadow:none;
  border-radius:10px;
}
.kotae:hover{
 opacity:0.8;
}