Q:

Fixed height div + strechy height div = 100% screen height. Is it possible?

I have this template in my mind

And i dont know how i can implement second "stretchy div". It must fill with his height all remaining space on the screen (not bigger, because I don`t want to see y-scroll). Is it possible?

A:

viewport units and calc make this simpler.

* {
  margin: 0;
  padding: 0;
}
.one {
  height: 50px; /* demo height */
  background: red;
}
.two {
  height: calc(100vh - 50px);
  background: blue;
}
<div class="one"></div>
<div class="two"></div>

EDIT: Flexbox version

* {
  margin: 0;
  padding: 0;
}
body {
  height: 100vh;
  display: flex;
  flex-direction: column;
}
.one {
  height: 50px;
  background: red;
}
.two {
  background: blue;
  flex-grow: 1;
}
<div class="one"></div>
<div class="two"></div>

