You design the visual appearance of the product.
Ensure that the most important information can be identified at first glance. Use a simple structure, clear hierarchies and keep in mind the reading order. Ensure that the page remains comprehensible even when zoomed to 200%.
Testing: Use the zoom function in your browser or on your phone.
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The contrast between text and background must be at least 4.5:1. For the interface and other non-text elements that are important to understanding, a minimum contrast of 3:1 applies. Take particular care with background images, avoid them whenever possible.
Testing: Colour Contrast Analyser
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Ensure that all touch targets have a size of at least 44 x 44 pixels. Also, use sufficiently sized and clearly legible fonts without serifs. As a rule of thumb, a size of at least 16 pixels is recommended.
Testing: Measure using the relevant developer tools.
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Structure the keyboard focus so that it is obvious where the user is in each situation. As an example, go to sbb.ch and press the Tab button several times.
Testing: Take away the mouse or connect an external keyboard to your phone.
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