Why the margin-left fails in the two different resolutions in the above picture
That’s not invalid, that’s overwritten. Look at the above img:nth-child(3)
img:nth-child(3)
is covered because you wrote the @media query @media can set different styles for different screen sizesIn the second picture, the effective margin-left:40
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
That’s not invalid, that’s overwritten. Look at the above
img:nth-child(3)is covered because you wrote the @media query
@media can set different styles for different screen sizes
In the second picture, the effective margin-left:40