Responsive Design
Design approach where layout, images and typography adapt automatically to the screen size of the device in use.
Also known as: Adaptive layout, Mobile first design
Responsive design makes sure that a website, landing page or email stays readable on every device without zooming or sideways scrolling. Instead of fixed pixel widths, layouts use relative sizes, breakpoints and flexible images. This produces a consistent user experience from the smartphone up to a large monitor.
Technical foundations
At the core, responsive layouts use media queries, flexible grids and images with different resolutions per device class. A mobile first approach starts with the smallest screen and grows the layout upwards step by step. Font sizes, spacing and tap targets are chosen so they remain usable with a finger.
What can go wrong day to day
Common problems include tap targets that are too small, truncated text in tables, oversized images on mobile viewports or buttons that end up below the fold. Emails suffer when the HTML is optimised for desktop and becomes unreadable on phones. Regular testing on real devices or solid emulators is mandatory, because every mailbox and browser renders slightly differently.
Practical relevance in JD Mail
JD Mail templates are built to behave responsively across common mail clients and to scale correctly on mobile devices. This matters because most recipients open mail on a phone first and badly readable layouts immediately push open and click rates down. Anyone adding custom modules should check them in the preview beforehand so font sizes and images render cleanly on the move.