console 命令行工具 X clear

console

<h1>Hello!</h1>
<h1 id="demo">Hello!</h1>

h1{
  padding:50px 0;
  width:100px;
  height:50px;
  border: 2px solid write;
  text-align: center;
}

#demo{
  transform:rotateY(90deg);
}