Creating A Sidebar Within A Flexbox With CSS

on my page I want to have a header and below this I want to have a sidebar on the left side and the content page on the right side. The sidebar should have a width of X (maybe 100

Solution 1:

You can set the height and width in a flexible way.

• Height is set to 100% of the height of the viewport minus the height of the header.
• Width is set to 100px for the sidebar. The content is now allowed to grow to fill the rest of the screen.

Hope this helps.

html {
  height: 100%;
}

body {
  height: 100%;
  margin: 0;
  font-family: Ubuntu;
  background: linear-gradient(#b3ffab, #67fffc);
}

#header {
  height: 30px;
  display: flex;
  align-items: center;
  background: linear-gradient(#444444, #333333);
  color: #bbbbbb;
}

#headerContent {
  margin-left: 10px;
}

#page {
  display: flex;
  height: calc( 100vh - 30px);
  /* calculate the height. Header is 30px */
}

#sideBar {
  width: 100px;
  background: red;
}

#content {
  background: blue;
  flex: 1 0 auto;
  /* enable grow, disable shrink */
}

<link rel="stylesheet" type="text/css" href="//fonts.googleapis.com/css?family=Ubuntu" />

<div id="header">
  <div id="headerContent">
    Desktop
  </div>
</div>

<div id="page">
  <div id="sideBar">
    <div>
      box 1
    </div>
    <div>
      box 2
    </div>
  </div>
  <div id="content">
    content
  </div>
</div>