<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
<title>3.4 flex布局--项目的属性</title>
<link rel="stylesheet" href="css/flex.css">
<style>
/*1、display 属性*/
.box {
display: flex;
/*width: 100%;*/
}
.box-1 {
display: inline-flex;
}
/*2、flex-direction 属性*/
.box-2-1 {
flex-direction: row;
}
.box-2-2 {
flex-direction: row-reverse;
}
.box-2-3 {
flex-direction: column;
}
.box-2-4 {
flex-direction: column-reverse;
}
/*3、flex-wrap 属性*/
.box-3-1 {
flex-direction: row;
flex-wrap: nowrap;
}
.box-3-2 {
flex-direction: row;
flex-wrap: wrap
}
.box-3-3 {
flex-direction: row;
flex-wrap: wrap-reverse;
}
/*4、flex-flow 属性*/
.box-4 {
flex-flow: row nowrap;
flex-flow: row wrap;
flex-flow: row wrap-reverse;
}
/*5、justify-content 属性*/
.box-5-1 {
justify-content: flex-start;
}
.box-5-2 {
justify-content: flex-end;
}
.box-5-3 {
justify-content: center;
}
.box-5-4 {
justify-content: space-between;
}
.box-5-5 {
justify-content: space-around;
}
/*6、align-items 属性*/
.box-6-1 {
align-items: flex-start;
}
.box-6-2 {
align-items: flex-end;
}
.box-6-3 {
align-items: center;
}
.box-6-4 {
align-items: baseline;
}
.box-6-4 .box-item{
font-size: 88px;
line-height: initial;
text-decoration: underline;
}
.box-6-4 .item-tall{
font-size: 122px;
line-height: initial;
}
.box-6-5 {
align-items: stretch;
}
.box-6-5 .box-item {
height: auto;
}
/*7、align-content 属性*/
.box-7-1 {
flex-wrap: wrap;
align-content: flex-start;
}
.box-7-2 {
flex-wrap: wrap;
align-content: flex-end;
}
.box-7-3 {
flex-wrap: wrap;
align-content: center;
}
.box-7-4 {
flex-wrap: wrap;
align-content: space-between
}
.box-7-5 {
flex-wrap: wrap;
align-content: space-around;
}
.box-7-6 {
flex-wrap: wrap;
align-content: stretch;
}
.box-7-6 .box-item {
height: auto;
}
</style>
<style>
/*1、order属性*/
.box-8 .order {
order: -1;
}
.box-item div {
font-size: 14px;
position: relative;
top: -150px;
}
/*2、flex-grow 属性*/
.box-9-1 .box-item {
flex-grow: 1;
}
.box-9-1 .grow-2 {
flex-grow: 2;
}
.box-9-2 .grow {
flex-grow: 1;
}
/*3、flex-shrink 属性*/
.box-10 .box-item {
flex-shrink: 1;
}
.box-10 .shrink{
flex-shrink: 0;
}
/*4、flex-basis 属性*/
.box-11 .box-item {
/*width: 200px;*/
flex-basis: 400px;
}
/*5、flex 属性*/
.box-12 .box-item {
flex: 1;
/*flex: 1 1 auto;
flex: auto;*/
}
/*6、align-self 属性*/
.box-13 {
align-items: center;
height: 400px;
}
.box-13 .start {
align-self: flex-start;
}
.box-13 .end {
align-self: flex-end;
}
</style>
</head>
<body>
<h1>Flex 布局</h1>
<p>
<a href="#flex1">1. 什么是 flex 布局</a><br>
<a href="#flex2">2. 基本概念</a><br>
<a href="#flex3">3. 容器的属性</a><br>
<a href="#flex4">4. 项目的属性</a><br>
<a href="#flex5">5. 实例</a>
</p>
<!-- 一、什么是 flex 布局 -->
<div>
<h2 id="flex1">一、什么是 flex 布局</h2>
<p>Flex 是 Flexible Box 的缩写,意为"灵活的盒子"或"弹性的盒子",所以 flex 布局一般也叫作"弹性布局"</p>
</div>
<!-- 二、基本概念 -->
<div>
<h2 id="flex2">二、基本概念</h2>
<p>
1. 什么是 flex 容器(flex container)?<br>
采用 flex 布局的元素,称为 flex 容器<br>
.box {
display: flex | inline-flex;
}
</p>
<p>
2. 什么是 flex 项目(flex item)?<br>
flex 容器的所有子元素自动成为容器成员,称为 flex 项目
</p>
<img src="img/3.3-1.png" alt="flex" style="width: 100%;">
<p>项目默认沿主轴排列</p>
</div>
<!-- 三、容器的属性 -->
<div>
<h2 id="flex3">三、容器的属性</h2>
<p>
<a href="#flex3-1">1. display</a><br>
<a href="#flex3-2">2. flex-direction</a><br>
<a href="#flex3-3">3. flex-wrap</a><br>
<a href="#flex3-4">4. flex-flow</a><br>
<a href="#flex3-5">5. justify-content</a><br>
<a href="#flex3-6">6. align-items</a><br>
<a href="#flex3-7">7. align-content</a>
</p>
<h3 id="flex3-1">1、display 属性</h3>
<p>display 属性决定是否使用flex布局</p>
<p>
.box {
display: flex | inline-flex;
}
</p>
<p>flex:将对象作为弹性伸缩盒显示</p>
<div class="box">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<p>inline-flex:将对象作为内联块级弹性伸缩盒显示</p>
<div class="box box-1">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<h3 id="flex3-2">2、flex-direction 属性</h3>
<p>flex-direction 属性决定主轴的方向(即项目的排列方向)</p>
<p>
.box {
flex-direction: row | row-reverse | column | column-reverse;
}
</p>
<p>row(默认值):主轴为水平方向,起点在左端</p>
<div class="box box-2-1">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<p>row-reverse:主轴为水平方向,起点在右端</p>
<div class="box box-2-2">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<p>column:主轴为垂直方向,起点在上沿</p>
<div class="box box-2-3">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<p>column-reverse:主轴为垂直方向,起点在下沿</p>
<div class="box box-2-4">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<h3 id="flex3-3">3、flex-wrap 属性</h3>
<p>
默认情况下,项目都排在一条线(又称"轴线")上<br>
flex-wrap 属性定义,如果一条轴线排不下,如何换行
</p>
<p>
.box{
flex-wrap: nowrap | wrap | wrap-reverse;
}
</p>
<p>nowrap(默认):不换行</p>
<div class="box box-3-1">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
</div>
<p>wrap:换行,第一行在上方</p>
<div class="box box-3-2">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
</div>
<p>wrap-reverse:换行,第一行在下方</p>
<div class="box box-3-3">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
</div>
<h3 id="flex3-4">4、flex-flow</h3>
<p>flex-flow 属性是 flex-direction 属性和 flex-wrap 属性的简写形式,默认值为 row nowrap</p>
<p>
.box {
flex-flow: <flex-direction> || <flex-wrap>;
}
</p>
<div class="box box-4">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
</div>
<h3 id="flex3-5">5、justify-content 属性</h3>
<p>justify-content 属性定义了项目在主轴上的对齐方式</p>
<p>
.box {
justify-content: flex-start | flex-end | center | space-between | space-around;
}
</p>
<p>flex-start(默认值):左对齐</p>
<div class="box box-5-1">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<p>flex-end:右对齐</p>
<div class="box box-5-2">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<p>center: 居中</p>
<div class="box box-5-3">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<p>space-between:两端对齐,项目之间的间隔都相等</p>
<div class="box box-5-4">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<p>space-around:每个项目两侧的间隔相等。所以,项目之间的间隔比项目与边框的间隔大一倍</p>
<div class="box box-5-5">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
</div>
<h3 id="flex3-6">6、align-items 属性</h3>
<p>align-items 属性定义项目在交叉轴上如何对齐</p>
<p>
.box {
align-items: flex-start | flex-end | center | baseline | stretch;
}
</p>
<p>flex-start:交叉轴的起点对齐</p>
<div class="box box-6-1">
<div class="box-item">1</div>
<div class="box-item item-tall">2</div>
<div class="box-item">3</div>
<div class="box-item item-tall">4</div>
</div>
<p>flex-end:交叉轴的终点对齐</p>
<div class="box box-6-2">
<div class="box-item">1</div>
<div class="box-item item-tall">2</div>
<div class="box-item">3</div>
<div class="box-item item-tall">4</div>
</div>
<p>center:交叉轴的中点对齐</p>
<div class="box box-6-3">
<div class="box-item">1</div>
<div class="box-item item-tall">2</div>
<div class="box-item">3</div>
<div class="box-item item-tall">4</div>
</div>
<p>baseline: 项目的第一行文字的基线对齐</p>
<div class="box box-6-4">
<div class="box-item">1</div>
<div class="box-item item-tall">2</div>
<div class="box-item">3</div>
<div class="box-item item-tall">4</div>
</div>
<p>stretch(默认值):如果项目未设置高度或设为auto,将占满整个容器的高度</p>
<div class="box box-6-5">
<div class="box-item">1</div>
<div class="box-item item-tall">2</div>
<div class="box-item">3</div>
<div class="box-item item-tall">4</div>
</div>
<h3 id="flex3-7">7、align-content 属性</h3>
<p>
align-content 属性定义了多根轴线(多行)在交叉轴上的对齐方式<br>
如果项目只有一根轴线(一行),该属性不起作用
</p>
<p>
.box {
align-content: flex-start | flex-end | center | space-between | space-around | stretch;
}
</p>
<p>flex-start:交叉轴的起点对齐</p>
<div class="box box-tall box-7-1">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
<div class="box-item">8</div>
<div class="box-item">9</div>
</div>
<p>flex-end:与交叉轴的终点对齐</p>
<div class="box box-tall box-7-2">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
<div class="box-item">8</div>
<div class="box-item">9</div>
</div>
<p>center:与交叉轴的中点对齐</p>
<div class="box box-tall box-7-3">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
<div class="box-item">8</div>
<div class="box-item">9</div>
</div>
<p>space-between:与交叉轴两端对齐,轴线之间的间隔平均分布</p>
<div class="box box-tall box-7-4">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
<div class="box-item">8</div>
<div class="box-item">9</div>
</div>
<p>
space-around:每根轴线两侧的间隔都相等<br>
所以,轴线之间的间隔比轴线与边框的间隔大一倍
</p>
<div class="box box-tall box-7-5">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
<div class="box-item">8</div>
<div class="box-item">9</div>
</div>
<p>stretch(默认值):轴线占满整个交叉轴</p>
<div class="box box-tall box-7-6">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
<div class="box-item">7</div>
<div class="box-item">8</div>
<div class="box-item">9</div>
</div>
</div>
<!-- 四、项目的属性 -->
<div>
<h2 id="flex4">四、项目的属性</h2>
<p>
<a href="#flex4-1">1. order</a><br>
<a href="#flex4-2">2. flex-grow</a><br>
<a href="#flex4-3">3. flex-shrink</a><br>
<a href="#flex4-4">4. flex-basis</a><br>
<a href="#flex4-5">5. flex</a><br>
<a href="#flex4-6">6. align-self</a>
</p>
<h3 id="flex4-1">1、order 属性</h3>
<p>
order 属性定义项目的排列顺序<br>
数值越小,排列越靠前,默认为0
</p>
<p>
.item {
order: <integer>;
}
</p>
<div class="box box-8">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item order">4 <div>(order:-1)</div></div>
</div>
<h3 id="flex4-2">2、flex-grow 属性</h3>
<p>flex-grow 属性定义项目的放大比例,默认为0,即如果存在剩余空间,也不放大</p>
<p>
如果所有项目的 flex-grow 属性都为1,则它们将等分剩余空间(如果有的话)<br>
如果一个项目的 flex-grow 属性为2,其他项目都为1,则前者占据的剩余空间将比其他项多一倍
</p>
<p>
.item {
flex-grow: <number>; /* default 0 */
}
</p>
<div class="box box-9-1">
<div class="box-item">1 <div>flex-grow: 1</div></div>
<div class="box-item grow-2">2 <div>flex-grow: 2</div></div>
<div class="box-item">3 <div>flex-grow: 1</div></div>
</div>
<p>
如果有的项目有 flex-grow 属性,有的项目有 width 属性,<br>
有 flex-grow 属性的项目将等分剩余空间
</p>
<div class="box box-9-2">
<div class="box-item grow">1 <div>flex-grow: 1</div></div>
<div class="box-item">2 <div>width: 200px</div></div>
<div class="box-item grow">3 <div>flex-grow: 1</div></div>
</div>
<h3 id="flex4-3">3、flex-shrink 属性</h3>
<p>flex-shrink 属性定义了项目的缩小比例,默认为1,即如果空间不足,该项目将缩小</p>
<p>
如果所有项目的 flex-shrink 属性都为1,当空间不足时,都将等比例缩小<br>
如果一个项目的 flex-shrink 属性为0,其他项目都为1,则空间不足时,前者不缩小<br>负值对该属性无效。
</p>
<p>
.item {
flex-shrink: <number>; /* default 1 */
}
</p>
<div class="box box-10">
<div class="box-item shrink">1 <div>flex-shrink: 0</div></div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
</div>
<h3 id="flex4-4">4、flex-basis 属性</h3>
<p>
flex-basis 属性定义了在分配多余空间之前,项目占据的主轴空间(main size)<br>
浏览器根据这个属性,计算主轴是否有多余空间<br>
它的默认值为auto,即项目的本来大小
</p>
<p>
.item {
flex-basis: <length>; | auto; /* default auto */
}
</p>
<div class="box box-11">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
</div>
<h3 id="flex4-5">5、flex 属性</h3>
<p>
flex 属性是 flex-grow, flex-shrink 和 flex-basis 的简写,默认值为0 1 auto<br>
后两个属性可选
</p>
<p>该属性有两个快捷值:auto (1 1 auto) 和 none (0 0 auto)</p>
<p>
.item {
flex: none | [ <flex-grow> <flex-shrink>? || <flex-basis> ]
}
</p>
<div class="box box-12">
<div class="box-item">1</div>
<div class="box-item">2</div>
<div class="box-item">3</div>
<div class="box-item">4</div>
<div class="box-item">5</div>
<div class="box-item">6</div>
</div>
<h3 id="flex4-6">6、align-self 属性</h3>
<p>
align-self 属性允许单个项目有与其他项目不一样的对齐方式,可覆盖align-items属性<br>
默认值为auto,表示继承父元素的align-items属性,如果没有父元素,则等同于stretch
</p>
<p>
.item {
align-self: auto | flex-start | flex-end | center | baseline | stretch;
}
</p>
<div class="box box-13">
<div class="box-item start">1</div>
<div class="box-item">2</div>
<div class="box-item end">3<div>flex-end</div></div>
<div class="box-item">4</div>
</div>
</div>
</body>
</html>
// ======== css/flex.css
body {
padding: 20px;
margin: 0 auto;
background-color: #E2E2E2;
max-width: 1024px;
color: #595B66;
font-family: 'Microsoft Yahei', sans-serif;
}
h1,h2,h3,h4 {
color: #797979;
padding: 5px 0;
}
h1, h2 {
border-bottom: 2px solid #797979;
}
h1 {
text-align: center;
}
p {
font-size: 20px;
background: #797979;
padding: 10px;
border-radius: 5px;
color: white;
line-height: 2;
}
p a {
font-size: 20px;
color: white;
}
p a:hover {
color: red;
}
a {
color: #FFD200;
text-decoration: none;
}
.box {
background-color: white;
margin: 0 0 55px;
}
.box-tall {
height: 800px;
}
.box-item {
width: 200px;
height: 200px;
line-height: 200px;
vertical-align: middle;
margin: 5px;
background-color: #ffd200;
font-size: 100px;
color: white;
text-align: center;
}
.item-tall {
height: 400px;
line-height: 400px;
}
一、什么是 flex 布局
Flex 是 Flexible Box 的缩写,意为”灵活的盒子”或”弹性的盒子”,所以 flex 布局一般也叫作”弹性布局”
二、基本概念
1. 什么是 flex 容器(flex container)?
采用 flex 布局的元素,称为 flex 容器
.box { display: flex | inline-flex; }
2. 什么是 flex 项目(flex item)?
flex 容器的所有子元素自动成为容器成员,称为 flex 项目
项目默认沿主轴排列
三、容器的属性
1. display
2. flex-direction
3. flex-wrap
4. flex-flow
5. justify-content
6. align-items
7. align-content
1、display 属性
display 属性决定是否使用flex布局
.box { display: flex | inline-flex; }
flex:将对象作为弹性伸缩盒显示1234
inline-flex:将对象作为内联块级弹性伸缩盒显示1234
2、flex-direction 属性
flex-direction 属性决定主轴的方向(即项目的排列方向)
.box { flex-direction: row | row-reverse | column | column-reverse; }
row(默认值):主轴为水平方向,起点在左端1234
row-reverse:主轴为水平方向,起点在右端1234
column:主轴为垂直方向,起点在上沿1234
column-reverse:主轴为垂直方向,起点在下沿1234
3、flex-wrap 属性
默认情况下,项目都排在一条线(又称”轴线”)上
flex-wrap 属性定义,如果一条轴线排不下,如何换行
.box{ flex-wrap: nowrap | wrap | wrap-reverse; }
nowrap(默认):不换行1234567
wrap:换行,第一行在上方1234567
wrap-reverse:换行,第一行在下方1234567
4、flex-flow
flex-flow 属性是 flex-direction 属性和 flex-wrap 属性的简写形式,默认值为 row nowrap
.box { flex-flow: <flex-direction> || <flex-wrap>; }1234567
5、justify-content 属性
justify-content 属性定义了项目在主轴上的对齐方式
.box { justify-content: flex-start | flex-end | center | space-between | space-around; }
flex-start(默认值):左对齐1234
flex-end:右对齐1234
center: 居中1234
space-between:两端对齐,项目之间的间隔都相等1234
space-around:每个项目两侧的间隔相等。所以,项目之间的间隔比项目与边框的间隔大一倍1234
6、align-items 属性
align-items 属性定义项目在交叉轴上如何对齐
.box { align-items: flex-start | flex-end | center | baseline | stretch; }
flex-start:交叉轴的起点对齐1234
flex-end:交叉轴的终点对齐1234
center:交叉轴的中点对齐1234
baseline: 项目的第一行文字的基线对齐1234
stretch(默认值):如果项目未设置高度或设为auto,将占满整个容器的高度1234
7、align-content 属性
align-content 属性定义了多根轴线(多行)在交叉轴上的对齐方式
如果项目只有一根轴线(一行),该属性不起作用
.box { align-content: flex-start | flex-end | center | space-between | space-around | stretch; }
flex-start:交叉轴的起点对齐123456789
flex-end:与交叉轴的终点对齐123456789
center:与交叉轴的中点对齐123456789
space-between:与交叉轴两端对齐,轴线之间的间隔平均分布123456789
space-around:每根轴线两侧的间隔都相等
所以,轴线之间的间隔比轴线与边框的间隔大一倍123456789
stretch(默认值):轴线占满整个交叉轴123456789
四、项目的属性
1. order
2. flex-grow
3. flex-shrink
4. flex-basis
5. flex
6. align-self
1、order 属性
order 属性定义项目的排列顺序
数值越小,排列越靠前,默认为0
.item { order: <integer>; }1234(order:-1)
2、flex-grow 属性
flex-grow 属性定义项目的放大比例,默认为0,即如果存在剩余空间,也不放大
如果所有项目的 flex-grow 属性都为1,则它们将等分剩余空间(如果有的话)
如果一个项目的 flex-grow 属性为2,其他项目都为1,则前者占据的剩余空间将比其他项多一倍
.item { flex-grow: <number>; /* default 0 */ }1flex-grow: 12flex-grow: 23flex-grow: 1
如果有的项目有 flex-grow 属性,有的项目有 width 属性,
有 flex-grow 属性的项目将等分剩余空间1flex-grow: 12width: 200px3flex-grow: 1
3、flex-shrink 属性
flex-shrink 属性定义了项目的缩小比例,默认为1,即如果空间不足,该项目将缩小
如果所有项目的 flex-shrink 属性都为1,当空间不足时,都将等比例缩小
如果一个项目的 flex-shrink 属性为0,其他项目都为1,则空间不足时,前者不缩小
负值对该属性无效。
.item { flex-shrink: <number>; /* default 1 */ }1flex-shrink: 02345
4、flex-basis 属性
flex-basis 属性定义了在分配多余空间之前,项目占据的主轴空间(main size)
浏览器根据这个属性,计算主轴是否有多余空间
它的默认值为auto,即项目的本来大小
.item { flex-basis: <length>; | auto; /* default auto */ }123
5、flex 属性
flex 属性是 flex-grow, flex-shrink 和 flex-basis 的简写,默认值为0 1 auto
后两个属性可选
该属性有两个快捷值:auto (1 1 auto) 和 none (0 0 auto)
.item { flex: none | [ <flex-grow> <flex-shrink>? || <flex-basis> ] }123456
6、align-self 属性
align-self 属性允许单个项目有与其他项目不一样的对齐方式,可覆盖align-items属性
默认值为auto,表示继承父元素的align-items属性,如果没有父元素,则等同于stretch
.item { align-self: auto | flex-start | flex-end | center | baseline | stretch; }123flex-end4