Widget:Teste

<style>

 /* Estilizando a calculadora */
 #calc {
   width: 220px;
   border: 2px solid #444;
   padding: 10px;
   border-radius: 8px;
   background-color: #f9f9f9;
   margin: 10px auto;
   font-family: Arial, sans-serif;
 }
 #display {
   width: 100%;
   height: 40px;
   font-size: 18px;
   text-align: right;
   margin-bottom: 10px;
   padding: 5px;
   border: 1px solid #ccc;
   border-radius: 4px;
 }
 .buttons {
   display: flex;
   flex-wrap: wrap;
   justify-content: space-between;
 }
 .buttons button {
   width: 48px;
   height: 48px;
   font-size: 16px;
   margin-bottom: 5px;
   cursor: pointer;
   border: 1px solid #888;
   border-radius: 4px;
   background-color: #eee;
   transition: background-color 0.2s ease;
 }
 .buttons button:hover {
   background-color: #ddd;
 }
 /* Botão de limpar ocupa toda a linha */
 .clear-btn {
   width: 100%;
   background-color: #f66;
   color: #fff;
 }
 .clear-btn:hover {
   background-color: #e55;
 }

</style>

 <input type="text" id="display" disabled />

   <button onclick="appendToDisplay('7')">7</button>
   <button onclick="appendToDisplay('8')">8</button>
   <button onclick="appendToDisplay('9')">9</button>
   <button onclick="appendToDisplay('/')">÷</button>
   <button onclick="appendToDisplay('4')">4</button>
   <button onclick="appendToDisplay('5')">5</button>
   <button onclick="appendToDisplay('6')">6</button>
   <button onclick="appendToDisplay('*')">×</button>
   <button onclick="appendToDisplay('1')">1</button>
   <button onclick="appendToDisplay('2')">2</button>
   <button onclick="appendToDisplay('3')">3</button>
   <button onclick="appendToDisplay('-')">−</button>
   <button onclick="appendToDisplay('0')">0</button>
   <button onclick="appendToDisplay('.')">.</button>
   <button onclick="computeResult()">=</button>
   <button onclick="appendToDisplay('+')">+</button>
   <button class="clear-btn" onclick="clearDisplay()">C</button>

<script>

 // Adiciona o valor clicado ao display
 function appendToDisplay(val) {
   document.getElementById('display').value += val;
 }

 // Calcula o resultado usando eval() e trata possíveis erros
 function computeResult() {
   let display = document.getElementById('display');
   try {
     // Usamos eval() para realizar o cálculo
     let result = eval(display.value);
     display.value = result;
   } catch (e) {
     display.value = "Erro";
   }
 }

 // Limpa o display
 function clearDisplay() {
   document.getElementById('display').value = ;
 }

</script>