<html>
<div class="div1">
<div class="left"></div>
<p class="right">111</div>
</div>
</html>
.div1{
width: 200px;
height: 200px;
border: 1px solid;
display: flex;
}
.left{
width: 50px;
height: 50px;
border: 1px solid red;
}
.right{
width: 50px;
height: 50px;
border: 1px solid green;
/* margin-left: auto; */
flex:1;
text-align: right;
}