box-sizing: content-box vs border-box?

content-box (mặc định): width/height chỉ tính content, padding+border cộng thêm. border-box: width/height bao gồm content+padding+border. border-box dễ quản lý hơn, nên dùng * { box-sizing: border-box }.

content-box (default): width/height applies only to content; padding and border are added on top. border-box: width/height includes content + padding + border. border-box is easier to manage — use * { box-sizing: border-box }.