<!DOCTYPE html>
<html lang="en">
<head>
    <title>404 - Page Not Found</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <style>
        body {
            margin: 0;
            padding: 0;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
            background: #F8FAFC;
            color: #1E293B;
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 100vh;
            text-align: center;
        }
        h1 { font-size: 4rem; font-weight: 700; margin: 0; color: #2563EB; }
        p { font-size: 1.2rem; color: #4B5563; margin: 16px 0 32px; }
        a {
            display: inline-block;
            padding: 12px 28px;
            background: #2563EB;
            color: #fff;
            text-decoration: none;
            border-radius: 8px;
            font-weight: 600;
            transition: background 0.2s;
        }
        a:hover { background: #1D4ED8; }
        a:focus-visible { outline: 2px solid #2563EB; outline-offset: 2px; }
    </style>
</head>
<body>
    <main>
        <h1>404</h1>
        <p>This page doesn't exist.</p>
        <a href="/">Back to home</a>
    </main>
</body>
</html>
