body { font-family: Arial, sans-serif; margin:0; padding:0; }
header { display:flex; justify-content:space-between; align-items:center; background:green; color:white; padding:10px; }
button { margin:5px; padding:8px; border:none; border-radius:5px; background:darkgreen; color:white; }
.product { border:1px solid #ccc; margin:5px; padding:5px; border-radius:5px; }