body background
Background background-color: border-box default
Canvas canvas
An area
Background-color canvas background canvas features :( viewport or greater)
The minimum width of the viewport width
The minimum height of the viewport height
html elements Background:
Background color of the canvas covering the body element (recommended)
If html element has a background color, body frame covering normal background color box, otherwise, body covered with canvas canvas background color set the background image (summarized relatively html element)
BACKGROUND FIG percentage relative to the width of the viewport window.innerWidth
FIG percentage of the height of the background relative height html elements (page height)
The percentage of the lateral position of background, a preset value, the relative viewport
Percentage longitudinal position of the background, a preset value, the relative height of html (web height)
Examples: html {padding: 10px;} body {width: 1200px; border: 4px dashed red; background: url ( '../ img / 201801.png') no-repeat; background-size: 50% 50%; / / background map viewport width * width = 50%; background height height = html height * 50%; background-position: right 10px bottom 10px; // viewport relative to the right 10px, edge opposite the html 10px}