Some tips and advice for writing effective styles in CSS

CSS (Cascading Style Sheets) is a language used to describe the appearance style of HTML (Hypertext Markup Language) documents. CSS plays a vital role in web design. It defines the color, font, spacing, layout and other characteristics of web pages. If you want to become a good web developer, you must master the basic concepts and usage of CSS.

Here are some tips and advice on how to write effective styles in CSS.

1. Use meaningful selectors

Selectors are a way of selecting HTML elements to which styles should be applied. When writing CSS styles, you should use meaningful selectors to ensure that your style is clear and maintainable. For example, if you want to select all buttons with class "btn", you can write the following selector:

.btn {
color: #fff;
background-color: #007bff;
border-color: #007bff;
}

This will apply the style to all buttons with the class name "btn". Because selectors are so specific and meaningful, other developers or designers can easily understand and modify the style.

2. Use concise CSS

CSS should always be kept concise to make it easy to understand and maintain. Use abbreviated attributes (such as background) to simplify styling. For example, the following two style definitions achieve the same effect:

.background-image {
background-color: #fff;
background-image: url('example.jpg');
background-position: center center;
background-size: cover;
background-repeat: no-repeat;
}

.background-image {
background: # fff url('example.jpg') center center/cover no-repeat;
}

Abbreviated attributes not only save writing time, but also make the code easier to read and maintain.

3. Use variables and constants

When writing complex CSS, using variables and constants can make the code clearer and easier to maintain. You can use a CSS preprocessor such as Sass or Less to define and use variables and constants, or you can use CSS custom properties to define variables. For example, the following code defines a variable named --primary-color and applies it to the background color and text color:

:root {
--primary-color: #007bff;
}

.button {
background-color: var(--primary-color);
color: var(--primary-color);
}

By using variables and constants, you can easily change colors and other properties that apply throughout your web application.

4. Use EM and REM units first

When defining font size in CSS, EM and REM units should be used instead of pixels. This is because EM and REM units scale relative to the size of the parent or root element, which creates more flexible and scalable styles. For example:

body {
font-size: 16px;
}

h1 {
font-size: 2em; / 32px /
}

p {
font-size: 0.875em; / 14px /
}

In the above example, the title and paragraph Font size is scaled based on the size of the parent or root element, not a specific pixel value.

5. Use Flexbox or Grid layout

Flexbox and Grid are currently the most popular CSS layout technologies, and they make positioning and aligning content easier. Horizontal and vertical layouts can be easily defined using Flexbox, while Grid can be used for more complex grid layouts.

For example, the following code uses Flexbox to top align content and distribute them horizontally:

.container {
display: flex;
justify-content: space-between;
align-items: center;
}

.container > div {
margin: 0 10px;
}

.container > div:first -child {
margin-left: 0;
}

.container > div:last-child {
margin-right: 0;
}

In the above code, Flexbox specifies how the container should lay out the content and sets the margins of the child elements to ensure proper spacing.

Summary:

Through the above techniques and some small summaries of experience, you can help you write CSS styles more effectively and save them for easier use during subsequent maintenance: Use meaningful selectors, abbreviate styles to make them cleaner, use variables and constants to change property values, prefer EM and REM units over pixels, use Flexbox or Grid layout to lay out content more easily. Master these tips and you can write CSS styles faster and easier.

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