/* common.css */
* { margin:0; padding:0; box-sizing:border-box; }
body { font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif; background:#f9f9f9; color:#333; line-height:1.5; padding:20px; }
h1 { font-size:2rem; margin-bottom:1rem; color:#222; }