.wrapper {
border: 5px solid pink;
display: flex;
flex-wrap: wrap;
justify-content: center;
}
.a-fc {
background-color: purple;
width: 300px;
height: 100px;
}
.b-fc {
background-color: orange;
flex-basis:70px;
flex-grow:1;
display: flex;
flex-wrap: wrap;
}
.b-fc > * {
flex-grow: 1;
flex-basis: 100px;
}
.b-fc > *:nth-child(1) {
background-color: red;
}
.b-fc > *:nth-child(2) {
background-color: blue;
}
.b-fc > *:nth-child(3) {
background-color: green;
}
<div class="wrapper">
<div class="a-fc">
<div>a1</div>
</div>
<div class="b-fc">
<div>b1</div><div>b2</div><div>b3</div>
</div>
</div>
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…