How to specify the background color of a PWA

Key takeaways:

1. Progressive Web Applications (PWAs) provide an app-like experience within web browsers, offering cross-platform functionality, efficiency, and offline capabilities.

2. PWAs can be customized for appearance and user experience using HTML and CSS, where the background color and other design elements are controlled by CSS selectors.

3. The background-color property in CSS is crucial for defining the overall look of a PWA. Specificity of selectors determines which styles are applied to different elements, influencing user interface consistency and aesthetics.

A progressive web application (PWA) is a type of web application that operates within a web browser but offers users an experience similar to using a mobile app. PWAs are engineered for efficiency and boast the ability to function seamlessly across various platforms, including offline environments. These applications not only consume minimal internet data but also stand out for their cross-platform adaptability and responsive designs, making them indispensable in the realm of contemporary technology.

A simple PWA

Let's consider a practical example of a progressive web application (PWA) designed with a user interface similar to shopping apps. This PWA incorporates three tabs visibly displayed on the screen, each dedicated to presenting a scrollable list of items. This design mimics the functionality commonly found in PWAs and shopping applications, allowing users to conveniently browse through various products or content within the app.

Code explanation

The code supplied above executes a fundamental progressive web application (PWA) that grants users the capability to browse multiple lists across three separate tabs. Now, let's delve into two significant files that pertain to the topic we're about to explore.

The index.html file

1. Line 9: We establish a link tag that points to another file named inline.css within the project directory. This file serves as the stylesheet responsible for customizing the appearance of our PWA.

2. Line 30–44: Enclosed within <script></script> tags, you'll find JavaScript code responsible for enabling user interaction. In this context, it manages an event triggered when a button is pressed, resulting in the display of an alert.

The inline.css file

1. Lines 10–18: The html selector serves as a high-level directive that permits us to modify the styling of various elements within the HTML structure. Here, we specify properties such as the overall background color, font, and font size.

2. Line 140: The align-items property is used to horizontally align elements, in this case, a button.

3. Line 141: Similarly, the justify-content property is employed to vertically align the button.

In the realm of PWAs, the choice of colors and styling is crucial for enhancing the overall user experience. This not only aids accessibility but also contributes toward improved user engagement and interaction. We achieve the desired visual aesthetics for our PWA through the application of Cascading Style Sheets (CSS), which allows us to format and control the visual presentation of the HTML content within our PWA.

Specificity of selectors

Within the provided CSS file, you'll notice that various selectors define background or color properties. Altering these property values for different selectors will result in distinct elements changing their colors. For instance, modifying the background value on line 91 will impact the color of the header. Similarly, the footer has its color variable, which can be fine-tuned in line 142.

To make adjustments to the background color of this progressive web application (PWA), you can edit the background-color property in line 12.

Test your understanding

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Conclusion

In PWAs, defining the background color and other visual elements is crucial for enhancing user experience. CSS selectors, particularly those with higher specificity, control various elements of the design. By understanding and tweaking these properties, developers can craft engaging and accessible interfaces, improving user interaction and overall satisfaction with the application.