Introduction

Building web pages is a challenge. Not only do you need to craft these pages with HTML, CSS, and JavaScript to perform the tasks you set out, but you also need to ensure they are accessible to most users. Additionally, you need to ensure the pages render nicely regardless of whether the device is a PC, tablet, or mobile device, which means you need to consider aspects like screen size; the orientation of the device; that is, landscape or portrait; and pixel density.

There are many different techniques to ensure your web pages look good on many devices, but it all starts with having a strategy, a vision for what the experience will be for the user depending on what device is used. Once you have that vision set, you can start to implement it.

Some choices you will need to make are how many columns should be listed, if your content is presented as columns. How should other things behave, like padding and margins? Should the content be centered or left-aligned? Should...