JSFiddle - React, Tailwind, and code Playground

HTML

<nav id="hexNav">
  <div id="menuBtn">
    <svg viewbox="0 0 100 100">
      <polygon points="50 2 7 26 7 74 50 98 93 74 93 26" fill="none" stroke-width="4" stroke="#585247" stroke-dasharray="0,0,300"/>
    </svg>
    <span></span>
  </div>
  <ul id="hex">
    <li class="tr"><div class="clip"><a href="#" class="content">
      <img src="https://farm8.staticflickr.com/7435/13629508935_62a5ddf8ec_c.jpg" alt="" />
      <h2 class="title">Title</h2><p>Catch phrase</p>
    </a></div></li>
    <li class="tr"><div class="clip"><a href="#" class="content">
      <img src="https://farm3.staticflickr.com/2827/10384422264_d9c7299146.jpg" alt="" />
      <h2 class="title">Title</h2><p>Catch phrase</p>
    </a></div></li>
    <li class="tr"><div class="clip"><a href="#" class="content">
      <img src="https://farm7.staticflickr.com/6083/6055581292_d94c2d90e3.jpg" alt="" />
      <h2 class="title">Title</h2><p>Catch phrase</p>
    </a></div></li>
    <li class="tr"><div class="clip"><a href="#" class="content">
      <img src="https://farm7.staticflickr.com/6092/6227418584_d5883b0948.jpg" alt="" />
      <h2 class="title">Title</h2><p>Catch phrase</p>
    </a></div></li>
    <li class="tr"><div class="clip"><a href="#" class="content">
      <img src="https://farm8.staticflickr.com/7187/6895047173_d4b1a0d798.jpg" alt="" />
      <h2 class="title">Title</h2><p>Catch phrase</p>
    </a></div></li>
    <li class="tr"><div class="clip"><a href="#" class="content">
      <img src="https://farm4.staticflickr.com/3766/12953056854_b8cdf14f21.jpg" alt="" />
      <h2 class="title">Title</h2><p>Catch phrase</p>
    </a></div></li>
  </ul>
</nav>

CSS

* {
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
}

body {
  font-family: 'Open Sans', sans-serif;
  background: #E3DFD2;
}

ul {
  list-style-type: none;
}

a, a:hover, a:focus, a:visited {
  text-decoration: none;
}

nav {
  position: relative;
  width: 70vmin;
  height: 70vmin;
  min-width: 500px;
  min-height: 500px;
  margin: 0 auto;
  overflow: hidden;
}

/** MENU BUTTON ******************************************/
#menuBtn {
  position: absolute;
  top: 45%;
  left: 45%;
  width: 10%;
  height: 10%;
  cursor: pointer;
  z-index: 2;
  will-change: transform;
}
#menuBtn svg {
  display: block;
}
#menuBtn:hover svg polygon {
  -webkit-animation: hexHover 0.7s;
          animation: hexHover 0.7s;
}
#menuBtn span {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 20px;
  height: 2px;
  padding: 8px 0;
  background-clip: content-box;
  background-color: #585247;
  -webkit-transform: translate(-50%, -50%);
      -ms-transform: translate(-50%, -50%);
          transform: translate(-50%, -50%);
  -webkit-transition: background-color 0.5s;
          transition: background-color 0.5s;
}
#menuBtn span:before, #menuBtn span:after {
  position: absolute;
  background-color: #585247;
  content: '';
  width: 20px;
  height: 2px;
  -webkit-transition: -webkit-transform 0.5s;
          transition: transform 0.5s;
}
#menuBtn span:before {
  top: 0;
}
#menuBtn span:after {
  bottom: 0px;
}

@-webkit-keyframes hexHover {
  0% {
    stroke-dasharray: 0,0,300;
  }
  10% {
    stroke-dasharray: 0,20,300;
  }
  100% {
    stroke-dasharray: 300,20,300;
  }
}

@keyframes hexHover {
  0% {
    stroke-dasharray: 0,0,300;
  }
  10% {
    stroke-dasharray: 0,20,300;
  }
  100% {
    stroke-dasharray: 300,20,300;
  }
}
/** MENU ITEMS *******************************************/
#hex {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  -webkit-transform: scale(0.1) translatez(0);
      -ms-transform: scale(0.1) translatez(0);
         ...

JavaScript

var hexNav = document.getElementById('hexNav');

document.getElementById('menuBtn').onclick = function() {
    var className = ' ' + hexNav.className + ' ';
    if ( ~className.indexOf(' active ') ) {
        hexNav.className = className.replace(' active ', ' ');
    } else {
        hexNav.className += ' active';
    }              
}