body { margin: 0; font-family: -apple-system, "Segoe UI", Roboto, Arial, sans-serif; color: #14213d; background: #f7f9fc; }
main { max-width: 720px; margin: 0 auto; padding: 48px 20px; }
[data-testid="hello-title"] { font-size: 2rem; }
[data-testid="hello-date"] { margin: 10px 0; }
[data-testid="fetch-hello"] { margin-top: 20px; cursor: pointer; }