start.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>start</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <div class="container">
        <form action="https://duckduckgo.com/" method="get">
            <input type="text" name="q" id="search">
        </form>
    </div>

    <script>
            const searchInput = document.getElementById('search');

            searchInput.focus();
        
            document.addEventListener('click', function() {
                searchInput.focus();
            });
                
            window.addEventListener('beforeunload', function(event) {
                if (search) {
                    search.value = '';
                }
            });
    </script>
</body>
</html>