:root{font-family:Arial,sans-serif;line-height:1.5;font-weight:400;color:#111;background:#f5f5f5}*{box-sizing:border-box}html,body,#root{margin:0;min-height:100%}body{min-width:320px}.page{max-width:900px;margin:0 auto;padding:24px}.card{background:#fff;border:1px solid #ddd;border-radius:10px;padding:16px}