** component is a basic container that is used as the root node of the page structure or is used to group the content.
> **NOTE**
>
> This component is supported since API version 4. Updates will be marked with a superscript to indicate their earliest API version.
## Child Components
Supported
## Attributes
| Name| Type| Default Value| Mandatory| Description|
| -------- | -------- | -------- | -------- | -------- |
| id | string | - | No| Unique ID of the component.|
| style | string | - | No| Style declaration of the component.|
| class | string | - | No| Style class of the component, which is used to refer to a style table.|
| ref | string | - | No| Reference information of child elements, which is registered with the parent component on **$refs**.|
## Events
| Name| Parameter| Description|
| -------- | -------- | -------- |
| click | - | Triggered when the component is clicked.|
| longpress | - | Triggered when the component is long pressed.|
| swipe
5+ | [SwipeEvent](js-lite-common-events.md) | Triggered when a user quickly swipes on the component.|
## Styles
| Name| Type| Default Value| Mandatory| Description|
| -------- | -------- | -------- | -------- | -------- |
| flex-direction | string | row | No| Main axis direction of the flex container, which defines how items are placed in the container. Available values are as follows:
- **column**: Items are placed vertically from top to bottom.
- **row**: Items are placed horizontally from left to right.|
| flex-wrap | string | nowrap | No| Whether items in the flex container are displayed in a single line or multiple lines. The value cannot be dynamically updated. Available values are as follows:
- **nowrap**: Flex items are displayed in a single line.
- **wrap**: Flex items are displayed in multiple lines.|
| justify-content | string | flex-start | No| How items are aligned along the main axis of the flex container. Available values are as follows:
- **flex-start**: Items are packed toward the start edge of the container along the main axis.
- **flex-end**: Items are packed toward the end edge of the container along the main axis.
- **center**: Items are packed toward the center of the container along the main axis.
- **space-between**: Items are positioned with space between the rows.
- **space-around**: Items are positioned with space before, between, and after the rows.|
| align-items | string | stretch
5+flex-start
1-4 | No| How items are aligned along the cross axis in a flex container. Available values are as follows:
- **stretch**: Items are stretched to the same height or width as the container along the cross axis.
5+- **flex-start**: Items are packed toward the start edge of the cross axis.
- **flex-end**: Items are packed toward the end edge of the cross axis.
- **center**: Items are packed toward the center of the cross axis.|
| display | string | flex | No| Type of the view box of the item. The value cannot be dynamically updated. Available values are as follows:
- **flex**: flexible layout
- **none**: not rendered|
| width | <length> \| <percentage>
5+ | - | No| Component width.
If this attribute is not set, the default value **0** is used.|
| height | <length> \| <percentage>
5+ | - | No| Component height.
If this attribute is not set, the default value **0** is used. |
| padding | <length> | 0 | No| Shorthand attribute to set the padding for all sides.
The attribute can have one to four values:
- If you set only one value, it specifies the padding for all the four sides.
- If you set two values, the first value specifies the top and bottom padding, and the second value specifies the left and right padding.
- If you set three values, the first value specifies the top padding, the second value specifies the left and right padding, and the third value specifies the bottom padding.
- If you set four values, they respectively specify the padding for top, right, bottom, and left sides (in clockwise order).|
| padding-[left\|top\|right\|bottom] | <length> | 0 | No| Left, top, right, and bottom padding.|
| margin | <length> \| <percentage>
5+ | 0 | No| Shorthand attribute to set the margin for all sides. The attribute can have one to four values:
- If you set only one value, it specifies the margin for all the four sides.
- If you set two values, the first value specifies the top and bottom margins, and the second value specifies the left and right margins.
- If you set three values, the first value specifies the top margin, the second value specifies the left and right margins, and the third value specifies the bottom margin.
- If you set four values, they respectively specify the margin for top, right, bottom, and left sides (in clockwise order).|
| margin-[left\|top\|right\|bottom] | <length> \| <percentage>
5+ | 0 | No| Left, top, right, and bottom margins.|
| border-width | <length> | 0 | No| Shorthand attribute to set the margin for all sides.|
| border-color | <color> | black | No| Shorthand attribute to set the color for all borders.|
| border-radius | <length> | - | No| Radius of round-corner borders.|
| background-color | <color> | - | No| Background color.|
| opacity
5+ | number | 1 | No| Opacity of an element. The value ranges from **0** to **1**. The value **1** means opaque, and **0** means completely transparent.|
| [left\|top] | <length> \| <percentage>
6+ | - | No| Edge of the element.
- **left**: left edge position of the element. This attribute defines the offset between the left edge of the margin area of a positioned element and left edge of its containing block.
- **top**: top edge position of the element. This attribute defines the offset between the top edge of a positioned element and that of a block included in the element. |
## Example
1. Flex style
```html
```
```css
/* xxx.css */
.container {
flex-direction: column;
justify-content: center;
align-items: center;
width: 454px;
height: 454px;
}
.flex-box {
justify-content: space-around;
align-items: center;
width: 400px;
height: 140px;
background-color: #ffffff;
}
.flex-item {
width: 120px;
height: 120px;
border-radius: 16px;
}
.color-primary {
background-color: #007dff;
}
.color-warning {
background-color: #ff7500;
}
.color-success {
background-color: #41ba41;
}
```

2. Flex wrap style
```html
```
```css
/* xxx.css */
.container {
flex-direction: column;
justify-content: center;
align-items: center;
width: 454px;
height: 454px;
}
.flex-box {
justify-content: space-around;
align-items: center;
flex-wrap: wrap;
width: 300px;
height: 250px;
background-color: #ffffff;
}
.flex-item {
width: 120px;
height: 120px;
border-radius: 16px;
}
.color-primary {
background-color: #007dff;
}
.color-warning {
background-color: #ff7500;
}
.color-success {
background-color: #41ba41;
}
```
