How to remove the image border, I have been searching for hours

The reason why – from my observation is – your code is:

border: none;

Try the following:

border: 0px !important;

The reason why your styling doesn’t work is because your style.css comes before and is overwritten by the violet.css stylesheet.

Hope this helps.

what about custom css? which is come first?

Custom CSS should load later – and you should not be modifying theme files anyway – as your changes will be lost when the theme is updated.

Using !important is not good coding practice, so that’s really not an ideal solution.

Try this:

.post img, .type-page img,
ul.products li.product img {
   border: none;
}

All custom stuff should be loaded last. The !important is perfectly fine to use if you need something quick. For production though, do as the previous poster wrote.