<!DOCTYPE html>
<html lang="ja">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>年齢判定プログラム</title>
<style>
body {
font-family: sans-serif;
padding: 20px;
}
.container {
max-width: 400px;
margin: 0 auto;
}
.form-group {
margin-bottom: 15px;
}
label {
display: block;
margin-bottom: 5px;
font-weight: bold;
}
input {
width: 100%;
padding: 8px;
font-size: 16px;
border: 2px solid #ddd;
border-radius: 4px;
}
button {
padding: 10px 20px;
font-size: 16px;
cursor: pointer;
background-color: #4CAF50;
color: white;
border: none;
border-radius: 4px;
margin-top: 10px;
}
button:hover {
background-color: #45a049;
}
#result {
margin-top: 20px;
padding: 15px;
border-radius: 4px;
font-size: 18px;
font-weight: bold;
}
.adult {
background-color: #d4edda;
color: #155724;
}
.minor {
background-color: #fff3cd;
color: #856404;
}
</style>
</head>
<body>
<div class="container">
<h1>年齢判定プログラム</h1>
<div class="form-group">
<label for="age">年齢を入力してください:</label>
<input type="number" id="age" min="0" max="150" value="18">
</div>
<button id="checkButton">判定する</button>
<div id="result"></div>
</div>
<script>
const ageInput = document.querySelector("#age");
const checkButton = document.querySelector("#checkButton");
const result = document.querySelector("#result");
checkButton.addEventListener("click", () => {
const age = Number(ageInput.value);
if (age >= 20) {
result.textContent = "成人です";
result.className = "adult";
} else {
result.textContent = "未成年です";
result.className = "minor";
}
});
</script>
</body>
</html>
