CSS3 introduced flexible boxes (aka. flex box) which can also achieve this behavior.
Simply define the width of the first div, and then give the second a flex-grow
value of 1
which will allow it to fill the remaining width of the parent.
.container{
display: flex;
}
.fixed{
width: 200px;
}
.flex-item{
flex-grow: 1;
}
<div class="container">
<div class="fixed"></div>
<div class="flex-item"></div>
</div>
Demo:
div {
color: #fff;
font-family: Tahoma, Verdana, Segoe, sans-serif;
padding: 10px;
}
.container {
background-color:#2E4272;
display:flex;
}
.fixed {
background-color:#4F628E;
width: 200px;
}
.flex-item {
background-color:#7887AB;
flex-grow: 1;
}
_x000D_
<div class="container">
<div class="fixed">Fixed width</div>
<div class="flex-item">Dynamically sized content</div>
</div>
_x000D_
Note that flex boxes are not backwards compatible with old browsers, but is a great option for targeting modern browsers (see also Caniuse and MDN). A great comprehensive guide on how to use flex boxes is available on CSS Tricks.