The defaultapp.css
The themes/defaultapp.css file contains some global CSS rules and classes commonly used in web applications.
Box sizing set to border-box
The following rule is applied to facilitate CSS layout.
* {
box-sizing: border-box;
}
Margin, padding and height of <html> and <body> tags
Margin and padding are set to 0 to avoid user-agent styling. For example, most of browsers set margins on <body>.
To facilitate layout of pages that fill the whole available height, height: 100% is set on <html> and <body> tags.
html, body {
height: 100%;
margin: 0;
padding: 0;
}
The width100 and height100 utility classes
These classes are just shortcuts for setting width/height to 100%.
class="width100 height100"
is equivalent to
style="width: 100%; height: 100%"