When designing a web page, I found characters like '✔' cannot appear at all in Firefox when they can in Chrome.
Example CSS code corresponding an input which type is 'check':
#todo-list li .toggle:after {
content: '✔';
/* 40 + a couple of pixels visual adjustment */
line-height: 43px;
font-size: 20px;
color: #d9d9d9;
text-shadow: 0 -1px 0 #bfbfbf;
}
It works in Chrome just perfectly. Sorry I don't have enough credits to post images. But when in Firefox, the character just doesn't come out, but display as a regular checkbox. I HAVE set my charset as 'utf-8' in the html file.