fixed header with left floating

by Ea Bangalore

HTML

<div id="wrapper" class="toggled hidden-xs">
        <!-- Sidebar -->
        <div id="sidebar-wrapper">
             <div class="header">
                 <h4>
                    Heading 1
                 </h4>
              </div>
                <ul class="sidebar-nav">
                  <li>hello world repeated long word</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  
                  <li>hello world hello world repeated long word</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                  <li>hello world</li>
                </ul>
        </div>
 </div>

CSS

#wrapper {
    padding-left: 0;
    transition: all 0.5s ease;
    height: 100%;
}
#sidebar-wrapper {
    z-index: 1000;
    position: fixed;
    top: 0;
    left: 0;
    max-width: 180px;
    width:175px;
    height: calc(80vh - 6px); /* As you give a border of 3px */
    overflow:auto;
    background: rgba(0,0,0,0.9);
    transition: all 0.5s ease;
    border: 3px solid red;
    color:white;
}

.header{
    z-index: 100001;
    color: #fff;
    background-color: #000000;
    padding: 5px;
    display: block;
    position: sticky;
    top: 0;
    text-align: center;
    border-bottom: 1px solid red;
}