A CodePen by fernandomgross. Responsive Menu - Part of my [Responsive Menu Concepts](http://css-tricks.com/responsive-menu-concepts) article on CSS-Tricks. with border-radius on hover

index.html

<input type="checkbox" id="menu">
<label for="menu" onclick></label>


<nav role="off-canvas">
    <ul>
        <li><a href="#">Stream</a></li>
        <li><a href="#">Lab</a></li>
        <li><a href="#">Projects</a></li>
        <li><a href="#">About</a></li>
        <li><a href="#">Contact</a></li>
    </ul>
</nav>

script.js

 /**
  Off Canvas
  
  # What? #
  Part of my "Responsive Menu Concepts" article on CSS-Tricks
  http://css-tricks.com/responsive-menu-concepts


  # 2012 by Tim Pietrusky
  # timpietrusky.com
**/

style.scss

@import "compass";
@import url(http://fonts.googleapis.com/css?family=Open+Sans:400,600,700);

* {
   box-sizing:border-box;
}

html,
body {
    width:100%;
    height:100%;
}

body {
    margin:.55em;
    color: rgb(0, 0, 0);
    background: url(http://subtlepatterns.subtlepatterns.netdna-cdn.com/patterns/shattered.png);
}

/* custom scrollbar */
::-webkit-scrollbar {
  width: .95em;
}
 
::-webkit-scrollbar-track {
  background-color: rgba(217, 217, 217, .5);
}

::-webkit-scrollbar-thumb {
  background: rgba(184, 184, 184, .5);
  box-shadow:
    inset .05em .05em 0 rgba(0, 0, 0, .1),
    inset 0 -.05em 0 rgba(0, 0, 0, .07)
  ;
}


/* Advanced Checkbox Hack */
body { -webkit-animation: bugfix infinite 1s; }
@-webkit-keyframes bugfix { from {padding:0;} to {padding:0;} }

input[type=checkbox] {
  position: absolute;
  top: -9999px;
  left: -9999px;
}

label {
  position: absolute;
  left:0;
  display:none;
  width:2em;
  height:2.25em;
  padding:.35em;
  font-size:1.1em;
  color:#fff;
  transition:color .3s ease-in-out;
  cursor: pointer;
  user-select:none;
  margin:0;
  background:rgba(0, 0, 0, .4); 
}

/* big screens */
nav[role="off-canvas"] {
    position:relative;
    width: 60em;
    margin: 0 auto;
    transition-duration: .3s, .5s;
    transition-timing-function: ease-in-out;
    transition-property: left, opacity, box-shadow;
    
    a {
      color:#000;
      text-decoration:none;
      font: 1.4em 'Open Sans', sans-serif;
      transition:color .3s ease-in-out;
      display:table-cell;
      vertical-align: middle;
    }
    
    ul {
      padding: 0;  
      margin: 0 auto;  
      width:100%;
    
      > li {
        float:left;
        padding:.55em .55em;
        width:8em;
        height:8em;
        margin:1.250em; 
        opacity:.8;
    
        text-transform:uppercase;
        display: table;
        background:hsla(11, 94%, 50%, .65);
        cursor: pointer;
    
        text-align:center;
        transition-duration: .3s;
        transition-timing-function: ease-in-out;
        transition-property: box-shadow, color, opacity, padding-left;
        cursor: pointer;
        transform: rotate(45deg);
    
        &:hover {
            color:#000;
            opacity:1;
            box-shadow:0 0 0 .5em rgba(255, 255, 255, .95);
        border-radius:4em; 
    
          > a {
             color:#fff;
            transform: rotate(-45deg); 
          }
        }

        &:nth-child(2) {
          background:hsla(44, 94%, 50%, .65);
        }
        &:nth-child(3) {
          background:hsla(114, 94%, 50%, .65);  
        }
        &:nth-child(4) {
          background:hsla(184, 94%, 50%, .65);  
        }
        &:nth-child(5) {
          background:hsla(224, 94%, 50%, .65);  
        }
      }
    }
}

/* small screens */
@media screen and (max-width: 44em) {
  $menu_width: 20em;
  $content_offset : .5em;
    
  html,
  body {
    margin:0;
    overflow-x:hidden;
  }

  .content {
    margin:2.5em .5em 0 .5em;
  }
    
  nav[role="off-canvas"] {
    position:absolute;
    top:3em;
    left:-$menu_width;
    width: $menu_width;
    opacity:0;
    
    ul > li {
      height:100%;
      width:100%;
      text-align:left;
      margin:0;
    
      &:hover {
        box-shadow:inset 0 0 0 .15em rgba(255, 255, 255, .45);
      }
    }
  }

  label {
    display:block;
  }

  label:after {
    position: absolute;
    right: .25em;  
    top: 0;
    content:"\2261";
    font-size:1.8em;
  }

  label:hover,
  input:checked ~ label {
    color:#000;
  }

  input:checked ~ nav[role="off-canvas"] {
    opacity:1;
    left:0;
    box-shadow:-30em 0 0 30em rgba(0, 0, 0, .3);
    
    ul > li {
      padding: .55em .55em .55em 1.5em;
       
      &:hover {
        padding-left:3.5em;
      }
        
      &:after {
        position:absolute;
        right:.25em;
        content:"\203A";
        font: bold 1.4em sans-serif;
        color:inherit;
      }
    }
  }

  input:checked ~ .content {
    margin-left: $menu_width + $content_offset;
    margin-right:-($menu_width + $content_offset);
  }
}