Using 2 slightly rotated SVGs as a navigation background?

Question

I am creating the nav menu for my website and what I would like to do is have the background be a combination of 2 rectangular SVGs, each slightly rotated off axis and overlaid. The edges would extend beyond the edges of the screen so that they cannot be seen. The SVGs should remain the same height(120px) at all breakpoints and the navigation should be centered vertically within the container(even though it will appear off center due to the rotation). My current attempt has the SVGs heights shrinking as I resize the browser window, additionally I am having some issues with the alignment. Is there a better way to accomplish this?

.hero-bg {
  height:20vh;
  min-height:200px;
  max-height:350px;
  width:100%;
  background:url('http://placehold.it/1920x1080');
  background-size:cover;
}
.navigation {
	position:relative;
  height:120px;
  overflow:hidden;
}
.nav-bg-1 {
  fill:red;
}
.nav-bg-2 {
  fill:black;
}
.navigation svg {
	position:absolute;
	top:-10px;
	width:110%;
	left:-5%;
}
.navigation ul {
  list-style-type:none;
  padding:0;
  margin:0;
  position:absolute;
  top:50%;
  transform:translateY(-50%);
}
  .navigation ul > li {
    display:inline-block;
  }
    .navigation ul > li > a{
      color:#fff;
      text-transform:uppercase;
      text-decoration:none;
    }

<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.3/css/bootstrap.min.css" rel="stylesheet"/>
<section id="hero">
  <div class="hero-bg"></div>
  <div class="navigation">
      <svg viewBox="0 0 2027.79 155.34">
          <rect class="nav-bg-1" x="953.89" y="-935.33" width="120" height="2026" transform="translate(918.54 1090.05) rotate(-89)"/>
          <rect class="nav-bg-2" x="0.89" y="14.67" width="2026" height="120" transform="translate(-0.32 4.42) rotate(-0.25)"/>
      </svg>
      <div class="container">
          <div class="row">
              <div class="col-sm-4 hidden-xs">
                <!-- LOGO -->
              </div>
              <div class="col-sm-8">
                  <ul>
                      <li><a href="#">Home</a></li>
                      <li><a href="#">About</a></li>
                      <li><a href="#">Products</a></li>
                      <li><a href="#">Contact</a></li>
                  </ul>
              </div>
          </div>
      </div>
  </div>
</section>

Once I am able to accomplish these background bars, my plan is to animate them and slightly change the shape(make them not perfect rectangles), as the user scrolls, using MorphSVG. Because of this, the solution must use SVG in place of alternate solutions.

Here's a mockup of my desired result. The nav will be within a container, but the red/black bars should extend to the edge of the screen at any screen size:

Answer 1

I would probably go with pseudo element and skew transformation like this:

.navigation {
  display: flex;
  justify-content:center;
  margin-top:50px;
  height:80px;
  padding:30px 0;
  position:relative;
  margin-bottom:50px;
}
.navigation:before {
  content:"";
  position:absolute;
  right:0;
  left:0;
  top:10px;
  bottom:0;
  background:#000;
  transform:skewY(-3deg);
  z-index:2;
}
.navigation:after {
  content:"";
  position:absolute;
  right:0;
  left:0;
  top:10px;
  bottom:0;
  background:red;
  transform:skewY(3deg);
  z-index:1;
}
.navigation ul {
 position:relative;
 z-index:3;
}

.navigation ul>li {
  display: inline-block;
}

.navigation ul>li>a {
  color: #fff;
  text-transform: uppercase;
  text-decoration: none;
}

<div class="navigation">
  <ul>
    <li><a href="#">Home</a></li>
    <li><a href="#">About</a></li>
    <li><a href="#">Products</a></li>
    <li><a href="#">Contact</a></li>
  </ul>
</div>

Update

Since the solution should be using SVG, here is a solution that involve some js. The idea is to create what I have done previously using skew and svg but with a fixed width. Then I simply use the JS code to scale on widow resize so it remains full width:

$('.back-nav').css('transform', 'scaleX(' + $('.navigation').width() / 500 + ')');
$(window).resize(function() {
  $('.back-nav').css('transform', 'scaleX(' + $('.navigation').width() / 500 + ')');
});

body {
  margin: 0;
}

.navigation {
  display: flex;
  justify-content: center;
  margin-top: 50px;
  height: 80px;
  width: 100%;
  padding: 30px 0;
  position: relative;
  margin-bottom: 50px;
}

.back-nav {
  position: absolute;
  top: 0;
  left: 0;
  transform-origin: left;
}

.navigation ul {
  position: relative;
  z-index: 3;
}

.navigation ul>li {
  display: inline-block;
}

.navigation ul>li>a {
  color: #fff;
  text-transform: uppercase;
  text-decoration: none;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="navigation">
  <ul>
    <li><a href="#">Home</a></li>
    <li><a href="#">About</a></li>
    <li><a href="#">Products</a></li>
    <li><a href="#">Contact</a></li>
  </ul>
  <svg class="back-nav" width="500" height="200" xmlns="http://www.w3.org/2000/svg">
  <rect x="0" y="20" width="500" fill="red" height="120" transform="skewY(3)"/>
  <rect x="0" y="50" width="500" height="120" transform="skewY(-3)"/>
</svg>
</div>

Another idea using background and without any JS (but you won't be able to apply morphing on it as it's a background)

body {
 margin:0;
}
.navigation {
  display: flex;
  justify-content:center;
  margin-top:50px;
  height:120px;
  width:100%;
  position:relative;
  margin-bottom:50px;
  background-image: url('data:image/svg+xml;charset=UTF-8,<svg version="1.1"  xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" preserveAspectRatio="none" viewBox="0 0 25.1 30" style="enable-background:new 0 0 25.1 30;" xml:space="preserve"><polygon points="25,0 25,20 0,25 0,5" fill="red"/><polygon points="25,5 25,25 0,20 0,0" fill="black"/></svg>');
  background-size:100%;
}

.navigation ul {
 position:relative;
 z-index:3;
}

.navigation ul>li {
  display: inline-block;
}

.navigation ul>li>a {
  color: #fff;
  text-transform: uppercase;
  text-decoration: none;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="navigation">
  <ul>
    <li><a href="#">Home</a></li>
    <li><a href="#">About</a></li>
    <li><a href="#">Products</a></li>
    <li><a href="#">Contact</a></li>
  </ul>

</div>