Organize CSS

/* table of contents
1. global styles
2. typography
3. layout
4. components
   4.1. buttons
   4.2. ....
*/

/* ============
   1. global styles
   ============*/
body
/* ============
   2. typography
   ============*/
h1, h2, a....
/* ============
   3. layout
   ============*/
header, section, footer....
/* ============
   4. components
   ============*/

   /* 4.1. buttons */
button....
.....