:read-only

 :read-only CSS 伪类 表示元素不可被用户编辑的状态（如锁定的文本输入框）。

/* Selects any <input> element that is read-only */
/* Supported in Firefox with a prefix */
input:-moz-read-only {
  background-color: #ccc;
}

/* Supported in Blink/WebKit/Edge without a prefix */
input:read-only {
  background-color: #ccc;
}

:read-only

<input type="text" value="Type whatever you want here.">
<input type="text" value="This is a read-only field." readonly>
<p>This is a normal paragraph.</p>
<p contenteditable="true">You can edit this paragraph!</p>

input { min-width: 25em; }
input:-moz-read-only { background: cyan; }
input:read-only { background: cyan; }

p:-moz-read-only { background: lightgray; }
p:read-only { background: lightgray; }
p[contenteditable="true"] { color: blue; }

• :read-write
• HTML contenteditable attribute