How to implement a flexible grid using CSS Positions layout

How to use CSS Positions layout to implement elastic grid

CSS Positions layout is a commonly used method in web page layout. It can achieve the effect of elastic grid, so that Web page elements are displayed adaptively on different devices. In this article, we will introduce how to use CSS Positions layout to implement elastic grid, and provide specific code examples.

1. Understand CSS Positions layout

Before starting to implement it, you first need to understand the concepts and characteristics of CSS Positions layout. CSS Positions layout refers to controlling the position and size of elements by using the position attribute and top, bottom, left, right and other attributes in CSS. There are four commonly used values ​​for the position attribute: static, relative, absolute and fixed. When implementing elastic grids, we usually use relative or absolute values.

1. relative: relative positioning, the element is positioned relative to its normal position. Change the position of the element by setting the top, bottom, left, and right attributes.
2. Absolute: Absolute positioning, the element is positioned relative to its nearest positioned parent element. If there is no positioned parent element, it is positioned relative to the body.

2. Code example to implement elastic grid

The following is a code example to implement elastic grid using CSS Positions layout:

HTML code:

<div class="container">
  <div class="item">Item 1</div>
  <div class="item">Item 2</div>
  <div class="item">Item 3</div>
  <div class="item">Item 4</div>
</div>

CSS code:

.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-evenly;
  align-items: center;
  height: 400px;
}

.item {
  width: 200px;
  height: 200px;
  background-color: #f2f2f2;
  margin-bottom: 20px;
  position: relative;
}

.item:nth-child(2n) {
  position: absolute;
  top: 0;
  right: 0;
}

.item:nth-child(2n+1) {
  position: absolute;
  bottom: 0;
  left: 0;
}

In the above code, we first create a container containing four child elements and use display: flex; to arrange the child elements horizontally. Then use flex-wrap: wrap; and justify-content: space-evenly; to achieve flexible layout and horizontal center alignment. Then, set the style of each child element to a width of 200px, a height of 200px, a background color of #f2f2f2, a bottom margin of 20px, and position: relative;.

By setting the style of .item:nth-child(2n) to position: absolute;, top: 0;, right: 0;, and the style of .item:nth-child(2n 1) to position : absolute;, bottom: 0;, left: 0;, we can position the child elements to achieve the effect of elastic grid.

Through the above CSS Positions layout and referring to the above code example, we can easily implement a flexible grid that can adapt to the display effects of different devices.

Summary:

Using CSS Positions layout can achieve the effect of elastic grid, allowing web page elements to be displayed adaptively on different devices. When implementing elastic grids, we usually use relative or absolute values, combined with top, bottom, left, right and other attributes to control the position and size of elements. I hope this article can help you understand and use CSS Positions layout to implement elastic grid.

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