<div class="one-above-all">
  <div class="top-block"></div>
  <div class="headline"></div>
  <!-- <div class="stretch-test"> -->
    <div class="row-elements">
      <div class="sideline"></div>
      <div class="main-contents">jhjkdhfjksdhafjksdahfl</div>
  <!--</div> -->
  </div>

</div>
  <div class="bottom-block">footer</div>

/* body {
  display:flex;
  flex-direction:column;
} */
.one-above-all {
  display: flex;
  flex-direction: column;
/*   flex: 1 0 auto; */
/*   min-height: 1100px; */
  border: solid black 1px;
}
.top-block {
  margin: 0 auto;
  border: solid black 1px;
  width: 300px;
  height: 30px;
  margin-top: -15px;

}
.headline {
  border: solid black 1px;
  width: 90%;
  align-self: flex-end;
  margin-top: 40px;
  margin-right: 10px;
  height: 160px;
  display: flex;
  box-sizing: border-box;
}
.row-elements {
  display: flex;
  flex-direction: row;
  margin-top: 40px;
  align-items: stretch;
/*   min-height: 900px;
     flex: 1 0 auto;
   */
}

.sideline {
  width: 160px;
  border: solid 1px;
  margin-left: calc(10% - 10px);
  box-sizing: border-box;
  flex-shrink: 1
}
.main-contents {
  border: solid 1px;
  margin-left: 40px;
/*   align-self: stretch; */
  flex: 1 1 auto;
  margin-right: 10px;
  box-sizing: border-box;
}
.bottom-block {
  align-self: flex-end;
  margin-top:auto;
  border: black solid 1px;
  margin: auto;
  width: 300px;
  height: 30px;
  margin-bottom: -10px;
/*   margin-top: 880px; */
}
/* .stretch-test {
  border:solid, 1px;
  display: flex;
  flex-direction: column;

  flex: 1 0 auto;
} */