属性选择器

/* <a> elements with a title attribute */
a[title] {
  color: purple;
}

/* <a> elements with an href matching "https://example.org" */
a[href="https://example.org"] {
  color: green;
}

/* <a> elements with an href containing "example" */
a[href*="example"] {
  font-size: 2em;
}

/* <a> elements with an href ending ".org" */
a[href$=".org"] {
  font-style: italic;
}

a {
  color: blue;
}

/* Internal links, beginning with "#" */
a[href^="#"] {
  background-color: gold;
}

/* Links with "example" anywhere in the URL */
a[href*="example"] {
  background-color: silver;
}

/* Links with "insensitive" anywhere in the URL,
   regardless of capitalization */
a[href*="insensitive" i] {
  color: cyan;
}

/* Links that end in ".org" */
a[href$=".org"] {
  color: red;
}

<ul>
  <li><a href="#internal">Internal link</a></li>
  <li><a href="http://example.com">Example link</a></li>
  <li><a href="#InSensitive">Insensitive internal link</a></li>
  <li><a href="http://example.org">Example org link</a></li>
</ul>

/* All divs with a `lang` attribute are bold. */
div[lang] {
  font-weight: bold;
}

/* All divs in US English are blue. */
div[lang~="en-us"] {
  color: blue;
}

/* All divs in Portuguese are green. */
div[lang="pt"] {
  color: green;
}

/* All divs in Chinese are red, whether
   simplified (zh-CN) or traditional (zh-TW). */
div[lang|="zh"] {
  color: red;
}

/* All divs with a Traditional Chinese
   `data-lang` are purple. */
/* Note: You could also use hyphenated attributes
   without double quotes */ 
div[data-lang="zh-TW"] {
  color: purple;
}

<div lang="en-us en-gb en-au en-nz">Hello World!</div>
<div lang="pt">Olá Mundo!</div>
<div lang="zh-CN">世界您好！</div>
<div lang="zh-TW">世界您好！</div>
<div data-lang="zh-TW">世界您好！</div>