CSS

[zencitta]

box-sizing: border-box; Specify that <div> elements should have padding and border included in the element's total width and height:

[zencitta]

Both em and rem are flexible, scalable units which are translated by the browser into pixel values, depending on the font size settings in your design.

[zencitta]

• em is relative to the font-size of its parent element.
• rem are always relative to the font-size of the element.
• A point is a physical measurement equal to 1/72 of an inch.

rem idea is good, but in practice is not very nice. cause when scale up/down the font may get too big/small. A proposed practice is too use rem for module, but rm for element within module.

[zencitta]

• A normal line-height setting is 1.5, which means 1.5 * font-size
• The most important point to note when using letter-spacing is that the value specified does not change the default, it is added to the default spacing the browser applies (based on the font metrics). It is animatable with _CSS Transitions_.

[zencitta]

word-break:break-all break a word into multiple lines if a single word is too long