Cấu trúc css

body: font-family, font-size, margin, line-height, padding
a, h1, h2, h3,...
#containter
#menu
#content
#header,
chia cột

/*==Style cho menu===*/

#menu ul {

  background: #1F568B;

  list-style-type: none;

  text-align: center;

}

Lựa chọn 1




#menu li {

  color: #f1f1f1;

  display: inline-block;

  width: 120px;

  height: 40px;

  line-height: 40px;

  margin-left: -5px;

}




https://thachpham.com/web-development/html-css/thuc-hanh-tao-layout-css-don-gian.html
http://tuhocphp.com/tao-menu-ngang-don-gian-bang-css-va-html/