CSS CSS
The language that decides how a web page looks, kept in its own file so one change can restyle every page at once.
Also known as Cascading Style Sheets stylesheet web page styling
Definition
CSS is the language that decides how a web page looks. Colours, fonts, spacing, the width of a column, what moves when the mouse passes over it. The words and pictures come from HTML. CSS is the layer that makes them look like your business rather than a plain document.
The idea behind it is simple, and it is the reason CSS exists. The styling lives in its own file, apart from the text. One line in that file sets the colour of every button on every page. Change it once and the whole site changes with it.
That is the theory. In practice it is the question worth asking a supplier before you buy anything. If we change our brand colour next year, how many places does someone have to edit? On a site built carefully the answer is one. On a site assembled in a hurry the colour is written in four hundred places, and the rebrand becomes a small project. Both sites look identical on launch day. The difference only shows up later.
CSS is also what lets one website fit a phone, a tablet and a desk screen. The same page rearranges itself. If someone offers you a separate mobile site, that is an old way of working and it doubles what you have to keep updated. The same layer handles Arabic too. A proper stylesheet flips the whole page from right to left without a second website being built, which is how Linkysoft ships bilingual sites.
It is easy to underrate CSS because it looks like decoration. It is not. It decides whether text stays readable on a phone in sunlight, whether a button is big enough for a thumb, and how fast the page appears. A heavy stylesheet full of rules nobody uses slows every page on the site. When Linkysoft takes over a website design and build we usually delete more rules than we write, and the same discipline applies inside a web application, where hundreds of admin screens should share one set of styles instead of each carrying its own. The words on those screens still come from HTML.
Questions about CSS
What is the difference between HTML and CSS?
Do I need CSS to have a mobile-friendly site?
Can I change my site's colours myself?
Can CSS slow a website down?
Still not sure how this applies to your project?
Tell us what you are building and we will answer in plain language.