*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: sans-serif; display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 100vh; background: #fff; color: #111; }
h1 { font-size: 2rem; margin-bottom: 0.5rem; }