How to replicate the CSS design of a website

Problem

I have a existing parent website and I have to design a new website with similar theme and css styles.

I do not have access to the code of the parent website in which I can look into the styling.

Is there a way I can extract or replicate the css style of the website and use it for the new one. I just need to get the same theme going in the new website as well.

I came across that I could use some adobe tools for the same.

Can anyone give a brief idea of how this can be done or is there a generic procedure to be followed in replicating the style.

Problem courtesy of: Dark Matter

Solution

Replicate given design using your own, most appropriate appropriate markup and CSS rules—and have some sort of QA process that will help you find obvious inconsistencies with appearance and interaction.

Why I don't think you want to copy HTML and CSS from the parent site:

The parent website can change its style later in an unpredictable way. You will have to duplicate these changes. Since you mentioned you don't have the access to the codebase, you can't just diff their changes and apply them to your codebase.

Therefore I'd say it's best to ignore the original HTML and CSS, and just follow your eye and have a QA that will carefully test your work for consistency with the original.

(I had to do a similar thing once, and I think it usually isn't required to follow parent website pixel-perfect—just consistent enough to facilitate painless navigation for the end user.

In cases where pixel-perfect consistency is required it makes more sense to build the additional website off the same codebase as original. You weren't given that possibility, so I doubt that perfection will be requested from you.)

Solution courtesy of: Tony

Discussion

The css is probably minified. This question shows ways to unminify it so you can read it.

Browsers such as Firefox and Chrome have a built in Code Inspector tool that will show you which styles are applied to each item. Just right-click on a page element (for example, a paragraph or heading), and select "Inspect Element" from the menu that appears. A toolbar will appear at the bottom of your window. Use the arrow on the toolbar to select different elements to examine. Usually the left side of that tool shows the HTML for that element and the right-side shows the CSS styles applied and the line of the css they come from. You can get a similar tool in IE by pressing the F12 key.

If you have a text editor that allows regular expressions in the search (Dreamweaver has this if you have the Creative Suite) use this search term with the "regular expression" box checked: #[a-z|0-9]{3,6}. This will find all of the hexadecimal values for the colors you need. It says to find the pound sign followed by either three or six letters or numbers, which will mostly be hexadecimal values (e.g. #333 or #333333 for dark grey). It may also bring up some IDs and you can ignore those and keep searching. You'll also want to search for rgba because colors may be listed that way. Using this in conjunction with the browser's code inspector will help you figure out the colors that are used on different elements. Some things may have background images, so you'll need to use the code inspector to figure that out. The code inspector will also show you how much padding you'll need, widths, etc.

Discussion courtesy of: PixelGraph

I think Your trying to shoot fly with cannon. All javascript/css/html code is at Your hand when viewing sources. No advanced tools are needed.

For better look on minified files You may try developers tools provided by modern browsers like chrome and firefox.

You may also just use beautification tools for css and html like http://www.codebeautifier.com to get nice, indented document.

Just google html or css beautification and find the one that fit Your needs in best way. Most of them are free online tools.

Discussion courtesy of: Jarema

This recipe can be found in it's original form on Stack Over Flow.