html{
  background-image: url("../images/works_bg01.png");
}

body{
  background-color:burlywood;
  max-width: 800px;
  margin: 10px auto auto auto;
  padding: 0 20px 20px 20px;
  border: 7px solid black;
}

a{
  color:darkred;
}

h1{
  text-align: center;
  margin: 20px;
}

table, table th, table td {
  margin-left: auto;
  margin-right: auto;
  border: 1px solid black;
}

.right{
  text-align: right;
}

.center{
  text-align: center;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.hitokoto{
  margin: 10px;
}

.date{
  text-align: right;
  font-style: italic;
}

.formula{
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.back{
  margin-top: 30px;
  text-align: left;
}

.txt{
  margin: 30px 15px 40px 15px;
}

.txt_w{
  margin: 30px 15px 40px 15px;
}

.txt_w li{
  margin: 15px 0px 5px 0px;
}

.full_img{
  width: 100%;
}