If you don't know, please read this.
The source code for Editor.html:
"
  
    
    
HTML CSS JS Editor
    
      

    
    
  

  
    
    
    
    
    

    
    
Hedgesoft HTML CSS JS Editor is a free source HTML CSS JS Editor website that you can create a web, if you want to save, please press enter. Credits to me. Created by me and all codes by VS Code.
  
  "
The code for style.css:
"h4 {
    color: rgb(255, 255, 255);
    font-family: Arial, Consolas
    text-align: center;
}
textarea {
  width: 50%;
  float: top;
  min-height: 250px;
  overflow: scroll;
  margin: auto;
  display: inline-block;
  background: #f4f4f9;
  outline: none;
  font-family: Consolas;
  font-size: 17px;
}

iframe {
  bottom: 0;
  position: relative;
  width: 100%;
  height: 35em;
}"
The code for app.js:
"function compile() {
  var html = document.getElementById("html");
  var css = document.getElementById("css");
  var js = document.getElementById("js");
  var code = document.getElementById("code").contentWindow.document;

  document.body.onkeyup = function() {
    code.open();
    code.writeln(
      html.value +
        "" +
        ""
    );
    code.close();
  };
}

compile();"
The end