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How can I toggle or hide CSS pseudo-elements on event (e.g., click)?

Background
I have an HTML div which contains a ‘tooltip’-like feature (i.e., a text box pops up when a certain element is clicked or hovered over); this tooltip has decorative pseudo-elements to make it look like a ‘speech bubble,’ added in css as :before and :after .
I have a JS script, which is intended to show and hide the tooltip and decoration, in response to click events (i.e., toggle them between ‘show’ and ‘hide’ states).
Problem
I can’t get the decorative pseudo-elements to hide when the tooltip is hidden; as pseudo-elements, they are not part of the DOM and so I can’t use normal selectors to manipulate them.
When the tooltip is hidden on click, the decorative pseudo-elements persist, which is not a usable result.
I can’t do away with the decorative elements, they are part of the work specification.
Approach tried so far
Based on this question, my thought was to add an empty span with its own class, to which I’d prepend and append these pseudo-elements. Then, add or remove the class on click based on whether it exists already, or not.
I have also tried setting the class to which the pseudo-elements are pre/appended to display:none on click, but this also seems not to work
However, I cannot convince the pseudo-elements to hide on click.
I’ve included a screenshot of what these remnant pseudo-elements look like in the live environment.
Note: I tried to work up a running simulation for the purpose of this question, but I wasn’t able to and the original css file is massive; the code included below is for reference only.
All guidance is much appreciated!
const barContainer = document.querySelector(".bar-container");
const decorationElement = document.querySelector("#decoration");
document.addEventListener('click', function(event) {
console.log('click event listener triggered');
if (event.target.closest('.link') || event.target.classList.contains('link')) {
if (barContainer.classList.contains('open')) {
barContainer.classList.remove('open')
decorationElement.classList.remove('decoration')
document.querySelector('.tooltip-container').setAttribute('style', 'display:none');
} else {
barContainer.classList.add('open')
decorationElement.classList.add('decoration')
document.querySelector('.tooltip-container').setAttribute('style', 'display:block');
}
} else {
barContainer.classList.remove('open')
decorationElement.classList.remove('decoration')
document.querySelector('.tooltip-container').setAttribute('style', 'display:none');
}
});
.foo-container {
height: auto;
position: relative;
}
.bar-container {
height: auto;
position: relative;
text-align: center;
}
.bar-container:hover .tooltip-container,
.tooltip-container:hover,
.bar-container.open .tooltip-container {
position: absolute;
display: block;
text-align: left;
background-color: #ffffff;
box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
bottom: 50px;
right: 5%;
border-radius: 4%;
font-weight: 300;
max-width: 90%;
font-size: 14px;
padding: 20px 0;
}
/*the below two rule sets create the rotated 'decoration' */
.bar-container:hover .tooltip-container:before,
.tooltip-container:hover:before,
.bar-container.open .tooltip-container:before,
.foo-container .bar-container:hover .decoration:before {
content: "";
width: 65px;
height: 35px;
position: absolute;
overflow: hidden;
transform: rotate(-180deg);
z-index: 10;
bottom: 0;
left: 170px;
background-color: white;
}
.foo-container .bar-container.open .decoration:before,
.foo-container .bar-container:hover .decoration:before {
content: "";
position: absolute;
width: 30px;
height: 30px;
background: #fff;
transform: rotate(45deg);
left: 30px;
box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
z-index: 2;
top: -42px;
}
/* end 'deocration' */
<div class="foo-container">
<div class="bar-container">
<p>text <span class='link'>the-link<span id='decoration' class='decoration'></span></span>
</p>
<div class='tooltip-container'>
<p>lorem </p>
</div>
</div>
</div>
Screenshot of the undesirable 'persistent pseudo-elements' behavior -->

HTML & CSS Tooltip Keeping On Screen

I need help keeping my CSS tooltip on screen for my website. It unfortunately is too big for the website near the edge of the screen and also is WAY too big for any mobile device and doesn't position correctly (probably because I plan to add very large descriptions in each tooltip). I would like to just use CSS but would be willing to use JS as I'm starting to think that may be the only way to do it correctly, but I'm having a lot of trouble figuring out how to make it work.
I basically had copied over the code from another website with many tweaks if it helps you understand my code better: https://www.w3schools.com/css/css_tooltip.asp
The only results I could find online were about centering the tooltip on the screen which strangely didn't work and code using SCSS which I'm not experienced with and would prefer not to use.
Here is my partial HTML and CSS code:
body {
overflow-x: hidden;
overflow-y: scroll;
}
.ref {
position: relative;
display: inline-block;
border-bottom: 1px dotted black;
}
.ref .versekjv {
visibility: hidden;
width: 250px;
background-color: black;
color: #fff;
text-align: left;
padding: 5px;
border-radius: 6px;
z-index: 98;
position: absolute;
top: 100%;
left: 50%;
margin-left: -125px;
flex-direction: column;
}
.ref .versekjv::after {
content: " ";
position: absolute;
bottom: 100%;
left: 50%;
margin-left: -5px;
border-width: 5px;
border-style: solid;
border-color: transparent transparent black transparent;
}
.ref:hover .versekjv {
visibility: visible;
}
.redletters {
color:red;
}
#media screen and (max-width:1000px){
.ref .versekjv {
font-size: 1rem;
max-width: 20rem;
position: fixed;
bottom: auto; top: 13%;
left: 78%;
text-align: left;
transform: translate(-50%);
transform: translateX(-50%);
white-space: normal;
z-index: 98;
}
.ref .versekjv::after {
border-color: transparent;
}
}
<li class="box"><a>
<div class="innerbox">Reference</div>
<div class="innerbox"><u class="ref">Reference<span class="versekjv"><b>Bible Book</b><p><i>#</i> Verse Text</p></span></u></div>
<div class="innerbox"><u class="ref">Reference<span class="versekjv"><b>Bible Book</b><p><i>#</i> Verse Text</p></span></u>; <u class="ref">Reference<span class="versekjv"><b>Bible Book</b><p><i>Verse Num.</i> Verse Text</p></span></u></div>
</a></li>
Thank you so much for your help!

First, you need to get the DOM object of your tooltip,
let tooltip = document.querySelector(".ref .versekjv")
Then, you can use the js method "getBoundingClientRect", which gives you an object that has top, right, left and bottom fields which give you the distances of your element from top, right, left and bottom of the viewport. If your element is fully visible inside the element, all four fields would be positive numbers, otherwise it means it's partly invisible, for example a left field of "-10" means about 10px of length of your elements is beyond the left edge of the viewport.
What you can do is that you always check the top, left, ... distances of your element, and if they are negative numbers, manually change them and thus position your element correctly, which could be achieved like this:
tooltip.style.left = 20

Hide the "resizing" handle in a resizable div?

There are a few other questions which are similar, but none works or seems in the right area. I'm trying to make a table's columns' widths resizable. My table is a normal HTML table, except that it has the Bootstrap 4 class table (maybe they could have thought of a different name...!).
My css looks like this:
.resizable-div {
resize: horizontal;
overflow: auto;
margin: 0px;
padding: 0px;
border: 1px solid black;
display:block;
min-width: 100px;
min-height: 30px;
}
The relevant bit of JS where I add the cell to the table row with a resizable div inside it, and text inside that, is like this:
row.appendChild(cell);
const resizableTdDiv = document.createElement( 'div' );
resizableTdDiv.classList.add( 'resizable-div');
cell.appendChild( resizableTdDiv );
const cellTextNode = document.createTextNode(isHeader ? fieldName : value);
resizableTdDiv.appendChild(cellTextNode);
The result works fine: resizable columns. Hurrah. There is only one fly in the ointment:
I can get rid of the borders, of course. I just want to lose those pesky handler triangles in the bottom right corners... all of them!
I realise users have to be given an idea that they are able to resize the columns... but I'd be perfectly happy to do that some other way if I could replace those triangle icons with 100% transparent ones (for example).
Edit
Here's a JSFiddle! Amazingly easy to do!

You can do this in WebKit based browsers currently with the ::-webkit-resizer pseudo element.
div{
overflow:auto;
resize:both;
width:50%;
}
div:nth-of-type(2)::-webkit-resizer{
background:transparent;
}
<div>
Not Hidden
</div>
<div>
Hidden
</div>

WebKit provides a pseudo-element for this ::-webkit-resizer and you can hide those triangles by applying display: none, -webkit-appearance: none, or background: transparent.
For Firefox or anything without WebKit an alternative / workaround would be to position a custom handle over top of each resizable div. This may require some different markup though.
.wrapper {
position: relative;
display: inline-block;
}
.resizable-div {
position: relative;
resize: both;
overflow: auto;
margin: 0px;
padding: 0px;
border: 1px solid black;
display:block;
min-width: 100px;
min-height: 30px;
}
.handle {
position: absolute;
bottom: 0;
right: 0;
width: 20px;
height: 20px;
background: black;
pointer-events: none;
}
/* ::-webkit-resizer {
background: transparent;
} */
<div class="wrapper">
<div class="resizable-div"></div>
<div class="handle"></div>
</div>

Modal inside translated div does not occupy the whole screen [duplicate]

I have a situation where, in normal CSS circumstances, a fixed div would be positioned exactly where it is specified (top:0px, left:0px).
This does not seem to be respected if I have a parent that has a translate3d transform. Am I not seeing something? I have tried other webkit-transform like style and transform origin options but had no luck.
I have attached a JSFiddle with an example where I would have expected the yellow box be at the top corner of the page rather than inside of the container element.
You can find below a simplified version of the fiddle:
#outer {
position:relative;
-webkit-transform:translate3d(0px, 20px , 0px);
height: 300px;
border: 1px solid #5511FF;
padding: 10px;
background: rgba(100,180,250, .8);
width: 80%;
}
#middle{
position:relative;
border: 1px dotted #445511;
height: 300px;
padding: 5px;
background: rgba(250,10,255, .6);
}
#inner {
position: fixed;
top: 0px;
box-shadow: 3px 3px 3px #333;
height: 20px;
left: 0px;
background: rgba(200,180,80, .8);
margin: 5px;
padding: 5px;
}
<div id="container">
Blue: Outer, <br>
Purple: Middle<br>
Yellow: Inner<br>
<div id="outer">
<div id="middle">
<div id="inner">
Inner block
</div>
</div>
</div>
</div>
How can I make translate3d work with fixed-positioned children?

This is because the transform creates a new local coordinate system, as per W3C spec:
In the HTML namespace, any value other than none for the transform results in the creation of both a stacking context and a containing block. The object acts as a containing block for fixed positioned descendants.
This means that fixed positioning becomes fixed to the transformed element, rather than the viewport.
There's not currently a work-around that I'm aware of.
It is also documented on Eric Meyer's article: Un-fixing Fixed Elements with CSS Transforms.

As Bradoergo suggested, just get the window scrollTop and add it to the absolute position top like:
function fix_scroll() {
var s = $(window).scrollTop();
var fixedTitle = $('#fixedContainer');
fixedTitle.css('position','absolute');
fixedTitle.css('top',s + 'px');
}fix_scroll();
$(window).on('scroll',fix_scroll);
This worked for me anyway.

I had a flickering on my fixed top nav when items in the page were using transform, the following applied to my top nav resolved the jumping/flickering issue:
#fixedTopNav {
position: fixed;
top: 0;
transform: translateZ(0);
-webkit-transform: translateZ(0);
}
Thanks to this answer on SO

In Firefox and Safari you can use position: sticky; instead of position: fixed; but it will not work in other browsers. For that you need javascript.

In my opinion, the best method to deal with this is to apply the same translate, but break children that need to be fixed out of their parent (translated) element; and then apply the translate to a div inside the position: fixed wrapper.
The results look something like this (in your case):
<div style='position:relative; border: 1px solid #5511FF;
-webkit-transform:translate3d(0px, 20px , 0px);
height: 100px; width: 200px;'>
</div>
<div style='position: fixed; top: 0px;
box-shadow: 3px 3px 3px #333;
height: 20px; left: 0px;'>
<div style='-webkit-transform:translate3d(0px, 20px, 0px);'>
Inner block
</div>
</div>
JSFiddle: https://jsfiddle.net/hju4nws1/
While this may not be ideal for some use cases, typically if you're fixing a div you probably could care less about what element is its parent/where it falls in the inheritance tree in your DOM, and seems to solve most of the headache - while still allowing both translate and position: fixed to live in (relative) harmony.

I ran across the same problem. The only difference is that my element with 'position: fixed' had its 'top' and 'left' style properties set from JS. So I was able to apply a fix:
var oRect = oElement.getBoundingClientRect();
oRect object will contain real (relative to view port) top and left coordinates. So you can adjust your actual oElement.style.top and oElement.style.left properties.

I have an off canvas sidebar that uses -webkit-transform: translate3d. This was preventing me from placing a fixed footer on the page. I resolved the issue by targeting a class on the html page that is added to the tag on initialization of the sidebar and then writing a css :not qualifier to state "-webkit-transform: none;" to the html tag when that class is not present on the html tag. Hope this helps someone out there with this same issue!

Try to apply opposite transform to the child element:
<div style='position:relative; border: 1px solid #5511FF;
-webkit-transform:translate3d(0px, 20px , 0px);
height: 100px; width: 200px;'>
<div style='position: fixed; top: 0px;
-webkit-transform:translate3d(-100%, 0px , 0px);
box-shadow: 3px 3px 3px #333;
height: 20px; left: 0px;'>
Inner block
</div>
</div>

Add a dynamic class while the element transforms.$('#elementId').addClass('transformed').
Then go on to declare in css,
.translat3d(#x, #y, #z) {
-webkit-transform: translate3d(#X, #y, #z);
transform: translate3d(#x, #y, #z);
//All other subsidaries as -moz-transform, -o-transform and -ms-transform
}
then
#elementId {
-webkit-transform: none;
transform: none;
}
then
.transformed {
#elementId {
.translate3d(0px, 20px, 0px);
}
}
Now position: fixed when provided with a top and z-index property values on a child element just work fine and stay fixed until the parent element transforms. When the transformation is reverted the child element pops as fixed again. This should easen the situation if you are actually using a navigation sidebar that toggles open and closes upon a click, and you have a tab-set which should stay sticky as you scroll down the page.

One way to deal with this is to apply the same transform to the fixed element:
<br>
<div style='position:relative; border: 1px solid #5511FF;
-webkit-transform:translate3d(0px, 20px , 0px);
height: 100px; width: 200px;'>
<div style='position: fixed; top: 0px;
-webkit-transform:translate3d(0px, 20px , 0px);
box-shadow: 3px 3px 3px #333;
height: 20px; left: 0px;'>
Inner block
</div>
</div>

How to add HTML tags inside Title attribue [duplicate]

Example:
Link
How do I change the presentation of the "title" attribute in the browser?. By default, it just has yellow background and small font. I would like to make it bigger and change the background color.
Is there a CSS way to style the title attribute?

It seems that there is in fact a pure CSS solution, requiring only the css attr expression, generated content and attribute selectors (which suggests that it works as far back as IE8):
https://jsfiddle.net/z42r2vv0/2/
a {
position: relative;
display: inline-block;
margin-top: 20px;
}
a[title]:hover::after {
content: attr(title);
position: absolute;
top: -100%;
left: 0;
}
<a href="http://www.google.com/" title="Hello world!">
Hover over me
</a>
update w/ input from #ViROscar: please note that it's not necessary to use any specific attribute, although I've used the "title" attribute in the example above; actually my recommendation would be to use the "alt" attribute, as there is some chance that the content will be accessible to users unable to benefit from CSS.
update again I'm not changing the code because the "title" attribute has basically come to mean the "tooltip" attribute, and it's probably not a good idea to hide important text inside a field only accessible on hover, but if you're interested in making this text accessible the "aria-label" attribute seems like the best place for it: https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Techniques/Using_the_aria-label_attribute

You can't style an actual title attribute
How the text in the title attribute is displayed is defined by the browser and varies from browser to browser. It's not possible for a webpage to apply any style to the tooltip that the browser displays based on the title attribute.
However, you can create something very similar using other attributes.
You can make a pseudo-tooltip with CSS and a custom attribute (e.g. data-title)
For this, I'd use a data-title attribute. data-* attributes are a method to store custom data in DOM elements/HTML. There are multiple ways of accessing them. Importantly, they can be selected by CSS.
Given that you can use CSS to select elements with data-title attributes, you can then use CSS to create :after (or :before) content that contains the value of the attribute using attr().
Styled tooltip Examples
Bigger and with a different background color (per question's request):
[data-title]:hover:after {
opacity: 1;
transition: all 0.1s ease 0.5s;
visibility: visible;
}
[data-title]:after {
content: attr(data-title);
background-color: #00FF00;
color: #111;
font-size: 150%;
position: absolute;
padding: 1px 5px 2px 5px;
bottom: -1.6em;
left: 100%;
white-space: nowrap;
box-shadow: 1px 1px 3px #222222;
opacity: 0;
border: 1px solid #111111;
z-index: 99999;
visibility: hidden;
}
[data-title] {
position: relative;
}
Link with styled tooltip (bigger and with a different background color, as requested in the question)<br/>
Link with normal tooltip
More elaborate styling (adapted from this blog post):
[data-title]:hover:after {
opacity: 1;
transition: all 0.1s ease 0.5s;
visibility: visible;
}
[data-title]:after {
content: attr(data-title);
position: absolute;
bottom: -1.6em;
left: 100%;
padding: 4px 4px 4px 8px;
color: #222;
white-space: nowrap;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
border-radius: 5px;
-moz-box-shadow: 0px 0px 4px #222;
-webkit-box-shadow: 0px 0px 4px #222;
box-shadow: 0px 0px 4px #222;
background-image: -moz-linear-gradient(top, #f8f8f8, #cccccc);
background-image: -webkit-gradient(linear,left top,left bottom,color-stop(0, #f8f8f8),color-stop(1, #cccccc));
background-image: -webkit-linear-gradient(top, #f8f8f8, #cccccc);
background-image: -moz-linear-gradient(top, #f8f8f8, #cccccc);
background-image: -ms-linear-gradient(top, #f8f8f8, #cccccc);
background-image: -o-linear-gradient(top, #f8f8f8, #cccccc);
opacity: 0;
z-index: 99999;
visibility: hidden;
}
[data-title] {
position: relative;
}
Link with styled tooltip<br/>
Link with normal tooltip
Known issues
Unlike a real title tooltip, the tooltip produced by the above CSS is not, necessarily, guaranteed to be visible on the page (i.e. it might be outside the visible area). On the other hand, it is guaranteed to be within the current window, which is not the case for an actual tooltip.
In addition, the pseudo-tooltip is positioned relative to the element that has the pseudo-tooltip rather than relative to where the mouse is on that element. You may want to fine-tune where the pseudo-tooltip is displayed. Having it appear in a known location relative to the element can be a benefit or a drawback, depending on the situation.
You can't use :before or :after on elements which are not containers
There's a good explanation in this answer to "Can I use a :before or :after pseudo-element on an input field?"
Effectively, this means that you can't use this method directly on elements like <input type="text"/>, <textarea/>, <img>, etc. The easy solution is to wrap the element that's not a container in a <span> or <div> and have the pseudo-tooltip on the container.
Examples of using a pseudo-tooltip on a <span> wrapping a non-container element:
[data-title]:hover:after {
opacity: 1;
transition: all 0.1s ease 0.5s;
visibility: visible;
}
[data-title]:after {
content: attr(data-title);
background-color: #00FF00;
color: #111;
font-size: 150%;
position: absolute;
padding: 1px 5px 2px 5px;
bottom: -1.6em;
left: 100%;
white-space: nowrap;
box-shadow: 1px 1px 3px #222222;
opacity: 0;
border: 1px solid #111111;
z-index: 99999;
visibility: hidden;
}
[data-title] {
position: relative;
}
.pseudo-tooltip-wrapper {
/*This causes the wrapping element to be the same size as what it contains.*/
display: inline-block;
}
Text input with a pseudo-tooltip:<br/>
<span class="pseudo-tooltip-wrapper" data-title="input type="text""><input type='text'></span><br/><br/><br/>
Textarea with a pseudo-tooltip:<br/>
<span class="pseudo-tooltip-wrapper" data-title="this is a textarea"><textarea data-title="this is a textarea"></textarea></span><br/>
From the code on the blog post linked above (which I first saw in an answer here that plagiarized it), it appeared obvious to me to use a data-* attribute instead of the title attribute. Doing so was also suggested in a comment by snostorm on that (now deleted) answer.

Here is an example of how to do it:
a.tip {
border-bottom: 1px dashed;
text-decoration: none
}
a.tip:hover {
cursor: help;
position: relative
}
a.tip span {
display: none
}
a.tip:hover span {
border: #c0c0c0 1px dotted;
padding: 5px 20px 5px 5px;
display: block;
z-index: 100;
background: url(../images/status-info.png) #f0f0f0 no-repeat 100% 5%;
left: 0px;
margin: 10px;
width: 250px;
position: absolute;
top: 10px;
text-decoration: none
}
Link<span>This is the CSS tooltip showing up when you mouse over the link</span>

CSS can't change the tooltip appearance. It is browser/OS-dependent. If you want something different you'll have to use Javascript to generate markup when you hover over the element instead of the default tooltip.

I have found the answer here: http://www.webdesignerdepot.com/2012/11/how-to-create-a-simple-css3-tooltip/
my own code goes like this, I have changed the attribute name, if you maintain the title name for the attribute you end up having two popups for the same text, another change is that my text on hovering displays underneath the exposed text.
.tags {
display: inline;
position: relative;
}
.tags:hover:after {
background: #333;
background: rgba(0, 0, 0, .8);
border-radius: 5px;
bottom: -34px;
color: #fff;
content: attr(data-gloss);
left: 20%;
padding: 5px 15px;
position: absolute;
z-index: 98;
width: 350px;
}
.tags:hover:before {
border: solid;
border-color: #333 transparent;
border-width: 0 6px 6px 6px;
bottom: -4px;
content: "";
left: 50%;
position: absolute;
z-index: 99;
}
<a class="tags" data-gloss="Text shown on hovering">Exposed text</a>

I thought i'd post my 20 lines JavaScript solution here. It is not perfect, but may be useful for some depending on what you need from your tooltips.
When to use it
Automatically styles the tooltip for all HTML elements with a TITLE attribute defined (this includes elements dynamically added to the document in the future)
No Javascript/HTML changes or hacks required for every tooltip (just the TITLE attribute, semantically clear)
Very light (adds about 300 bytes gzipped and minified)
You want only a very basic styleable tooltip
When NOT to use
Requires jQuery, so do not use if you don't use jQuery
Bad support for nested elements that both have tooltips
You need more than one tooltip on the screen at the same time
You need the tooltip to disappear after some time
The code
// Use a closure to keep vars out of global scope
(function () {
var ID = "tooltip", CLS_ON = "tooltip_ON", FOLLOW = true,
DATA = "_tooltip", OFFSET_X = 20, OFFSET_Y = 10,
showAt = function (e) {
var ntop = e.pageY + OFFSET_Y, nleft = e.pageX + OFFSET_X;
$("#" + ID).html($(e.target).data(DATA)).css({
position: "absolute", top: ntop, left: nleft
}).show();
};
$(document).on("mouseenter", "*[title]", function (e) {
$(this).data(DATA, $(this).attr("title"));
$(this).removeAttr("title").addClass(CLS_ON);
$("<div id='" + ID + "' />").appendTo("body");
showAt(e);
});
$(document).on("mouseleave", "." + CLS_ON, function (e) {
$(this).attr("title", $(this).data(DATA)).removeClass(CLS_ON);
$("#" + ID).remove();
});
if (FOLLOW) { $(document).on("mousemove", "." + CLS_ON, showAt); }
}());
Paste it anywhere, it should work even when you run this code before the DOM is ready (it just won't show your tooltips until DOM is ready).
Customize
You can change the var declarations on the second line to customize it a bit.
var ID = "tooltip"; // The ID of the styleable tooltip
var CLS_ON = "tooltip_ON"; // Does not matter, make it somewhat unique
var FOLLOW = true; // TRUE to enable mouse following, FALSE to have static tooltips
var DATA = "_tooltip"; // Does not matter, make it somewhat unique
var OFFSET_X = 20, OFFSET_Y = 10; // Tooltip's distance to the cursor
Style
You can now style your tooltips using the following CSS:
#tooltip {
background: #fff;
border: 1px solid red;
padding: 3px 10px;
}

A jsfiddle for custom tooltip pattern is Here
It is based on CSS Positioning and pseduo class selectors
Check MDN docs for cross-browser support of pseudo classes
<!-- HTML -->
<p>
<a href="http://www.google.com/" class="tooltip">
I am a
<span> (This website rocks) </span></a> a developer.
</p>
/*CSS*/
a.tooltip {
position: relative;
}
a.tooltip span {
display: none;
}
a.tooltip:hover span, a.tooltip:focus span {
display:block;
position:absolute;
top:1em;
left:1.5em;
padding: 0.2em 0.6em;
border:1px solid #996633;
background-color:#FFFF66;
color:#000;
}

Native tooltip cannot be styled.
That being said, you can use some library that would show styles floating layers when element is being hovered (instead of the native tooltips, and suppress them) requiring little or no code modifications...

You cannot style the default browser tooltip. But you can use javascript to create your own custom HTML tooltips.

a[title="My site"] {
color: red;
}
This also works with any attribute you want to add for instance:
HTML
<div class="my_class" anything="whatever">My Stuff</div>
CSS
.my_class[anything="whatever"] {
color: red;
}
See it work at: http://jsfiddle.net/vpYWE/1/