index.css

/**
    htmlintred
    HTML css linter
**/

/* Inline styles */
*[style],

/* Faulty or Missing Link Targets */
a:not([href]),
a[href="#"],
a[href=""],
a[href*="javascript:void(0)"],
a:not([target="_blank"]),
a:not([target="_self"]),
a:not([target="_parent"]),
a:not([target="_top"]),

/* Unaccessible Images */
img:not([alt]),
img[alt=""],
img[src=""],

/* Missing Document Language */
html:not([lang]),
html[lang=""],

/* Incorrect Character Set */
meta[charset]:not([charset="UTF-8"]),
meta[charset="UTF-8"]:not(:first-child),

/* Unaccessible Viewport Attributes */
meta[name="viewport"][content*="user-scalable=no"],
meta[name="viewport"][content*="maximum-scale"],
meta[name="viewport"][content*="minimum-scale"],

/* Unlabelled Form Elements */
input:not([id]),
select:not([id]),
textarea:not([id]),
label:not([for]),
input:not([name]),
select:not([name]),
textarea:not([name]),
form:not([name]):not([id]),

/* Empty Interactive Elements */
button:empty,
a:empty,

/* Unnecessary or Deprecated Attributes */
script[type="text/javascript"],
link[rel="stylesheet"][type="text/css"],

/* Invalid roles */
div[role="nav"]
{
    border: 2px solid red;
}