* { box-sizing: border-box; margin: 0; padding: 0; } body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: #ffffff; color: #1a1a1a; } #app { display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 100vh; padding: 1rem; } h1 { font-size: 2rem; }