CSS Parsing errors

Question

I am using CSS Lint to detect errors and warnings in a specific css. CSS Lint detects 3 errors:

in below piece of css code:

a.btn,
:not(li.menu_icon a.btn),
.k-button.btn,
input[type=submit].btn, 
input[type=button].btn, 
button[type=submit].btn:not(.gridAddBtn), 
button[type=button].btn:not(.gridAddBtn), 
a[name=butonWorkFlow].btn {
    background-image: none;
    min-width: 90px;
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
}

...but I do not know how to correct it. I have basic knowledge about css.

Answer 1

CSS Lint is no longer being updated, so does not recognize the updated :not() syntax. Use an up-to-date linter, such as stylelint, which will pass your CSS.

Answer 2

:not(selector) is part of CSS3. Might be you are using lower version.