CSS flexible layout property optimization tips: align-items and flex-grow

CSS flexible layout attribute optimization skills: align-items and flex-grow

In front-end development, use flexible layout (Flexbox) to implement the adaptive layout of web pages has become a common technology choice. Flexible layout controls the distribution and arrangement of elements in a container through a series of CSS properties and values. Among these properties, align-items and flex-grow are two very important properties, which can help us achieve a more flexible and elegant layout effect.

1. align-items property

align-items is a CSS property used to arrange items in the flexible box. It determines the alignment of the items on the cross axis. Common attribute values ​​include: flex-start, flex-end, center, baseline, and stretch.

1.1 flex-start: Items will be aligned at the starting position of the cross axis.

1.2 flex-end: Items will be aligned at the end of the cross axis.

1.3 center: The items are centered on the cross axis.

1.4 baseline: Items will be aligned to the baseline.

1.5 stretch: Default value, the item will be stretched to fit the height of the container.

Appropriate use of the align-items attribute can make the alignment of items in the flexible container more flexible.

For example, we can use align-items: center; in a horizontal navigation bar to center the elements of the navigation bar vertically, as shown in the following code:

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

.navbar__logo {
  margin-left: 20px;
}

.navbar__menu {
  margin-right: 20px;
}

.navbar__item {
  margin-left: 10px;
}

In this example, the navigation bar container uses flexible layout, and the elements of the navigation bar are aligned vertically in the center by setting the align-items: center; attribute. In this way, the elements of the navigation bar can be arranged in a centered manner under different screen sizes, improving the flexibility of the layout effect.

2. flex-grow property

flex-grow is a CSS property used to specify the enlargement ratio of an item in the remaining space. By default, items have a flex-grow value of 0, which means they do not occupy the remaining space. When set to a non-zero value, the item takes up proportionately more space.

Normally, you can set the flex-grow property of several sub-elements in a container to the same value to achieve an even distribution of the remaining space.

For example, in a picture wall layout, we can set the flex-grow value of each picture item to 1, that is, each element will occupy the remaining space in the same proportion, as shown in the following code:

.image-wall {
  display: flex;
  justify-content: flex-start;
}

.image-item {
  flex-grow: 1;
}

.image-item img {
  width: 100%;
  height: auto;
}

In this example, the container of the picture wall uses flexible layout, and by setting the flex-grow value of each picture item to 1, the effect of evenly allocating the remaining space to each picture item is achieved. In this way, no matter how the container width of the picture wall changes, each picture item can be enlarged or reduced according to the same proportion, which facilitates the implementation of responsive layout.

Summary:

By properly using the align-items and flex-grow properties, we can achieve a more flexible and elegant layout effect in elastic layout. The align-items property helps us control the alignment of items on the cross axis, while the flex-grow property helps us achieve an even distribution of items in the remaining space. In actual projects, we can flexibly use these attributes to optimize our code according to specific layout requirements.

The above is an introduction to align-items and flex-grow in CSS flexible layout attribute optimization techniques. I hope it can be helpful and guiding for you to understand and use flexible layout.

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