display: table-column-group;
<h1>CSS Default Value For <kbd>(colgroup)</kbd></h1>
<p>By default, "colgroup" element is displayed like this:</p>
<col span="2" style="background-color:violet">
<col style="background-color:yellow">
<h2>Default CSS Properties</h2>
display: table-column-group;
var h=document.querySelector("h1");h.style.padding="30px",h.style.background="#333",h.style.color="#fff",h.style.boxShadow="0 0 3px 0 #aaa",h.style.borderTopLeftRadius="5px",h.style.borderTopRightRadius="5px";var k=document.querySelectorAll("h1 kbd");k.forEach(function(e){e.style.color="#0f0"});var c=document.querySelector(".content");c.style.cssText="background:#f8f9fa;box-shadow:0 0 3px 0 #aaa;border-bottom-left-radius:5px;border-bottom-right-radius:5px;padding:20px 30px;margin-top:-22px";var p=document.querySelector(".default");p.style.cssText="background:#fefefe;box-shadow:inset 0 0 3px 0 #aaa;border-left:5px solid #333;padding:10px";