problem scenario: the recently developed Vue project found that the network is too poor, causing the first screen of the page to go blank for nearly 3 seconds. You want to optimize the first screen rendering problem. Optimization scheme: 1 reduce co...
what is the default for css if you do not specify line-height? Is it equal to font-size? Sometimes it feels like setting it manually to be the same as font-size is not the same as letting him not set it by default. ...
question 1: the combined class selector selects the node behind it, so how do you choose the previous one? <a href="https: segmentfault.com" class="p1">This is a paragraph.1< a> <a href="https: segmen...
encounters a problem with first-child
multiple layers are nested with each other, and then use the p:first-child selector, which cannot be selected correctly. Code: <body> 111 222 333 < body> use p:first-child {color:red;} at this time,...