Vue Js Textbox allow only capital letter

<!DOCTYPE html>
<html>
<head>
  <script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
</head>
<body>
  <div id="app">
    <h3>Vue Js Textbox allow ony capital letter</h3>
    <input type="text" v-model="inputValue" @input="handleInput" />
    <div v-if="!isInputValid" class="error-message">Only capital letters are allowed.</div>
  </div>
  <script>
    const app = Vue.createApp({
      data() {
        return {
          inputValue: "",
          isInputValid: true
        };
      },
      methods: {
        handleInput() {
          // Check if the input consists of only capital letters
          this.isInputValid = /^[A-Z]*$/.test(this.inputValue);
          // Remove any non-capital letters from the input
          this.inputValue = this.inputValue.replace(/[^A-Z]/g, "");
        }
      }
    });
    app.mount('#app');
  </script>
  <style>
      #app {
      width: 400px;
      margin: 0 auto;
      box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.12), 0 2px 4px 0 rgba(0, 0, 0, 0.24);
      text-align: center;
      padding: 20px;
      height: 100%;
    }

.error-message {
      color: red;
      font-size: 14px;
      margin-top: 5px;
    }

input[type="text"] {
      padding: 10px;
      font-size: 16px;
      border: 1px solid #ccc;
      border-radius: 4px;
      outline-color: blue;
      /* Change the color as desired */
    }
  </style>
</body>
</html>