JSFiddle - React, Tailwind, and code Playground

HTML

Wie heißt der Kaiser von 
<input type="text" id="input_answer" value="" />
<input type="button" value="Prüfen" onClick="checkInput('input_answer','china')"/>
<DIV id="correct" class="correct">KORREKT</DIV>
<DIV id="wrong" class="wrong">FALSCH</DIV>

CSS

.wrong {
    display: none;
    color: red;
}
.correct {
    display: none;
    color: green;
}

JavaScript

function checkInput(elInput,strAnswer){
    var elcorrect = document.getElementById('correct');
    var elwrong = document.getElementById('wrong');
    var elInput = document.getElementById(elInput);
    
   if(elInput.value.toLowerCase() == strAnswer.toLowerCase()){
        elcorrect.style.display = "block";
        elwrong.style.display = "none";
   }else{
        elwrong.style.display = "block";
        elcorrect.style.display = "none";
   }
}