JSFiddle - React, Tailwind, and code Playground

HTML

Wie heißt der Kaiser von 
<input type="text" id="input_answer" value="" onChange="checkInput(this)" />
<DIV id="answer"></DIV>

CSS

.wrong {
    display: block;
    color: red;
}
.correct {
    display: block;
    color: green;
}

JavaScript

function checkInput(el){
    var target = document.getElementById("answer");
   if(el.value.toLowerCase() == "china"){
        target.innerText = "KORREKT";
        target.setAttribute("class","correct");
   }else{
        target.innerText = "FALSCH";
        target.setAttribute("class","wrong");
   }
}