How to detect device and swap the CSS file ? Last Updated : 23 Jul, 2025 Comments Improve Suggest changes Like Article Like Report When creating a webpage, the most important thing is the user experience with the frontend, especially the designing part or CSS. For a smooth experience, a frontend developer needs to make the webpage responsive. As "one size doesn't fit all", a single design will not work on all devices. That's why the "media query" was introduced. Media queries are very helpful when it comes to styling specific parts of the website on the basis of the screen width, height, bits/pixel, and many more.But sometimes writing media queries can be confusing if a lot of them are to be written or if we have to completely change the styling of the webpage for different devices. So, we can use different CSS files for different screen sizes. This can be done by adding media query in the <link rel="stylesheet" href="style.css"> section in the HTML file. Media query can be added to the linking section of CSS like this, given below <link rel="stylesheet" media="media query properties" href="stylesheet.css"> Media type that can be used all (default)Used for all media type devicesprint Used for printersscreenUsed for computer screens, tablets, smart-phones etc.speechUsed for screen readers that "reads" the page out loud Some commonly used media feature for making webpage responsive max-widthSets a maximum width till which CSS properties will be followedmin-widthSets a minimum width till which CSS properties will be followedorientationCan be set to portrait/landscape Note: All features of media query can be used while linking CSS to the HTML. HTML <!-- Filenmae:index.html --> <!DOCTYPE HTML> <html lang="en" dir="ltr"> <head> <title>GFG</title> <!-- main css --> <link rel="stylesheet" href="master.css"> <!-- CSS with media query --> <link rel="stylesheet" media="screen and (max-width: 360px)" href="small-screen.css"> <link rel="stylesheet" media="screen and (min-width: 360px) and (max-width: 550px)" href="large-screen.css"> </head> <body> GeeksForGeeks </body> </html> CSS Files: 1. master.css file CSS /* Filename: master.css */ body { display: flex; align-items: center; font-family: sans-serif; } 2. small-screen.css file CSS // small-screen.css body { color: rgb(29, 176, 5); background-color: white; } 3. large-screen.css file CSS /* Filename:large-screen.css */ body { color: rgb(67, 164, 55); background-color: black; } Output: When the width of the screen is less than 360pxWhen the width of the screen is more than 360px and less than 550pxWhen the width of the screen is larger than 550px Comment More infoAdvertise with us Next Article CSS Introduction A ankitzm Follow Improve Article Tags : Web Technologies CSS CSS-Questions Similar Reads CSS Tutorial CSS stands for Cascading Style Sheets. It is a stylesheet language used to style and enhance website presentation. CSS is one of the three main components of a webpage, along with HTML and JavaScript.HTML adds Structure to a web page.JavaScript adds logic to it and CSS makes it visually appealing or 7 min read CSS Introduction CSS (Cascading Style Sheets) is a language designed to simplify the process of making web pages presentable.It allows you to apply styles to HTML documents by prescribing colors, fonts, spacing, and positioning.The main advantages are the separation of content (in HTML) and styling (in CSS) and the 4 min read CSS Syntax CSS is written as a rule set, which consists of a selector and a declaration block. The basic syntax of CSS is as follows:The selector is a targeted HTML element or elements to which we have to apply styling.The Declaration Block or " { } " is a block in which we write our CSS.HTML<html> <h 2 min read CSS Selectors CSS Selectors are used to target HTML elements on your pages, allowing you to apply styles based on their ID, class, type attributes, and more. There are mainly 5 types of selectors.Basic CSS Selectors: These are used to target elements by tag, .class, or # ID for fundamental styling needs.Combinato 7 min read CSS Comments CSS comments are used to add notes or explanations to your code, helping you and others understand it better. They start with /* and end with */ and can be used for both single-line and multi-line comments. Note: Comments are ignored by browsers, so they won’t affect how your webpage looks or works. 2 min read CSS Colors CSS colors are used to set the color of different parts of a webpage, like text, background, and borders. This helps make the page look more attractive and easier to read. You can define colors using names, hex codes, RGB values, and more.You can try different formats of colors here- #content-iframe 5 min read CSS Borders Borders in CSS are used to create a visible outline around an element. They can be customized in terms ofWidth: The thickness of the border.Style: The appearance of the border (solid, dashed, dotted, etc.).Color: The color of the border.You can try different types of borders here- #custom-iframe{ he 5 min read CSS Margins CSS margins are used to create space around an element, separating it from neighboring elements and the edges of the webpage. They control the layout by adjusting the distance between elements, providing better organization and readability.Syntax:body { margin: value;}HTML<html> <head> 4 min read CSS Height and Width Height and Width in CSS are used to set the height and width of boxes. Their values can be set using length, percentage, or auto.Width and HeightThe width and height properties in CSS are used to define the dimensions of an element. The values can be set in various units, such as pixels (px), centim 4 min read CSS Outline CSS outline is a property used to draw a line around an element's border. It does not affect the layout, unlike borders. It's often used to highlight elements, providing a visual emphasis without altering the dimensions of the element.Syntaxselector{ outline: outline-width outline-type outline-color 4 min read Like