Вместо добавления max-width
к .bar
Я думаю, вы должны добавить max-width
к .row-item-bar
проверить фрагмент.
.container{
border: 1px solid lightgrey;
max-width: 900px;
}
.row{
display: flex;
justify-content: space-between;
//flex-wrap:wrap;
}
.row-item{
padding: 10px 5px;
border-left: 1px solid grey;
}
.row:nth-child(even){
background: lightgrey;
}
.mobile-nav{
display: none;
}
.row-item-bar{
flex-grow: 1;
max-width: 300px;
box-sizing: border-box;
}
.bar{
background: lightgrey;
height: 20px;
max-width: 300px;
}
@media(max-width: 500px){
.row{
display: block;
}
.sc-left{
float: left;
}
.sc-right{
float: right;
}
.row-item{
border-bottom: 1px solid grey;
}
.mobile-nav{
display: inline-block;
}
}
<div class="container">
<div class="row">
<div class="row-item sc-left">
3456789
</div>
<div class="row-item">
Test Test Test Test Test
</div>
<div class="row-item sc-left">
10/12/73
</div>
<!-- <div class="row-item row-item-bar">
<div class="bar"></div>
</div> -->
</div>
</div>
<div class="container">
<div class="row">
<div class="row-item sc-left">
3456789
</div>
<div class="row-item">
Test Test Test Test Test
</div>
<div class="row-item sc-left">
10/12/73
</div>
<div class="row-item row-item-bar">
<div class="bar"></div>
</div>
</div>
</div>