body {
    font-family: Arial, sans-serif;
    background: #eef2f5;
}

.aqi-container {
    width: 360px;
    margin: 100px auto;
    padding: 20px;
    background: #fff;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 0 12px rgba(0,0,0,0.15);
}

button {
    padding: 10px 18px;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

#result {
    margin-top: 15px;
    font-size: 16px;
    font-weight: bold;
}