@color-accent:                      #177E89;
@color-light:                       #ffffff;
@color-dark:                        #2a2a2a;
@menu-link-padding:                 20px 25px;
@breakpoint:                        950px;
@mega-menu-multiLevel-colWidth:     100/3 + 0%;
@mobile-menu-back-height:           ~"calc(1.4em + 40px)";
@mobile-menu-back-offset:           ~"calc(0px - (1.4em + 40px))";
@menu-mobile-width:                 350px;

body {
  font-family: 'Noto Sans', sans-serif;
  background: #fafafa;
  padding: 0;
  margin: 0;
}

*, *:before, *:after {
    -webkit-box-sizing: border-box;
    -moz-box-sizing: border-box;
    box-sizing: border-box;
}


// ------------------ SHARED STYLES

nav {
   ul, li {
     list-style: none;
     padding: 0;
     margin: 0;
  } 
  a {
    display: block;
    text-decoration: none;
    &:hover, &:visited {
      text-decoration: none;
    }
  }
}

.menu-bar {
  background: @color-light;
  display: flex;
}

.menu-link {
  padding: @menu-link-padding;
  background: @color-light;
  color: @color-accent;
  transition: background .2s, color .2s;
  position: relative;
  z-index: 1;
  &[aria-haspopup="true"] {
    padding-right: 40px;
    &:after {
      content: "";
      background-image: url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/1397521/arrowRight.svg#accent');
      background-size: 14px;
      width: 14px;
      height: 14px;
      font-size:12px;
      position: absolute;
      right: 10px;
      top:50%;
      transform: translateY(-50%);
    }
  }
}

.mega-menu-header {
  font-size: 1.2em;
  text-transform: uppercase;
  font-weight: bold;
  color: darken(@color-accent, 5%);
}

.mega-menu {
  background: @color-light;
  z-index: 10;
}

.mega-menu--multiLevel {
  flex-direction: column;
}


// ------------------ MEDIA QUERIES

@media all and (min-width: @breakpoint + 1px) {
  // Desktop only
  
  .nav {
    margin-top: 50px;
    background: @color-light;
    > nav {
      max-width: 900px;
      margin: 0 auto;
    }
  }
  
  .menu {
    [aria-haspopup="true"] {
      ~ ul {
        display: none;
      }
    }
  }
  
  .menu-bar {
    position: relative;
    > li {
      > [aria-haspopup="true"] {
        // STYLING: Down arrow on desktop
        &:after {
            background-image: url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/1397521/arrowBottom.svg#accent');
        }
        &:hover {
          &:after {
            background-image: url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/1397521/arrowBottom.svg#light');
          }
        }
        
        // FUNCTIONALITY: Open mega menu
        &:focus {
          ~ ul {
            display: flex;
            transform-origin: top;
            animation: dropdown .2s ease-out;
          }
        }
        // FUNCTIONALITY: Keep mega menu open
        ~ ul {
          &:hover {
            display: flex;
          }
        }
      }
      
      // FUNCTIONALITY: Keep mega menu open
      &:focus-within {
        > [aria-haspopup="true"] {
          ~ ul {
            display: flex;
          }
        }
      }
      
      // STYLING: Hover/Active state
      > [aria-haspopup="true"]:focus,
      &:focus-within > [aria-haspopup="true"],
      &:hover > a {
        background: @color-accent;
        color: @color-light;
        &:after {
          background-image: url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/1397521/arrowTop.svg#light');
        }
      }
    }
  }
  
  .mega-menu {
    // LAYOUT: Mega menu
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    // FUNCTIONALITY: Keep mega menu open
    &:hover {
      display: flex;
    }
    a {
      &:hover {
        background: tint(@color-accent, 85%);
        color: darken(@color-accent, 5%);
      }
    }
  }
 
  
  .mega-menu--multiLevel {
    // LAYOUT: Multi level columns
    > li {
      width: @mega-menu-multiLevel-colWidth;
      > [aria-haspopup="true"] {
        ~ ul {
          left: @mega-menu-multiLevel-colWidth;
          width: @mega-menu-multiLevel-colWidth;
          ul {
            width: 100%;
            left: 100%;
          }
        }
      }
    }
    
    li {
      // FUNCTIONALITY: Opening flyouts
      &:hover {
        > [aria-haspopup="true"] {
          ~ ul {
            display: block;
            transform-origin: left;
            animation: flyout .2s ease-out;
          }
        }
      }
      
      // FUNCTIONALITY: Keeping flyouts open
      &:focus-within {
        > [aria-haspopup="true"] {
          ~ ul {
            display: block;
          }
        }
      }
      
      // STYLING: Flyout link active states
      &:hover, &:focus-within {
        > [aria-haspopup="true"], > a {
          background: tint(@color-accent, 85%);
          color: darken(@color-accent, 5%);
        }
      }
    }
    [aria-haspopup="true"] {
      ~ ul, & {
        border-left: 1px solid #f0f0f0;
        // FUNCTIONALITY: Keeping flyouts open
        &:hover {
          display: block;
        }
      }
      // LAYOUT: Flyouts
      ~ ul {
        position: absolute;
        top: 0;
        height: 100%;
      }
    }
  }
  
  
  // STYLING: Flat mega menu columns
  .mega-menu--flat {
    > * {
      flex: 1;
    }
  }
  
  // Hide mobile specific elements
  .mobile-menu-trigger, .mobile-menu-header, .mobile-menu-back-item {
    display: none;
  }

}

@media all and (max-width: @breakpoint) {
    
  .nav {
    padding: 20px;
  }
  
  .mobile-menu-trigger, .mobile-menu-header, .mobile-menu-back-item {
    display: block;
  }
  
  .mobile-menu-trigger {
    background: @color-accent;
    color: @color-light;
    border: 0;
    padding: 10px;
    font-size: 1.2em;
    border-radius: 4px;
  }
  
  .mobile-menu-header {
    order: -1;
    background: grey;
    a {
      padding: @menu-link-padding;
      color: @color-light;
      visibility: visible;
    }
  }
  
  .menu-bar {
    flex-direction: column;
    position: fixed;
    top: 0;
    left: -100%;
    height: 100vh;
    width: @menu-mobile-width;
    max-width: @menu-mobile-width;
    max-width: 90%;
    overflow-x: hidden;
    transition: left .3s;
    box-shadow: 1px 0px 2px 0px rgba(0,0,0,0.25);
    > li {
      > [aria-haspopup="true"] {
        ~ ul {
          display: flex;
          flex-direction: column;
          background: @color-light;
          position: absolute;
          left: 100%;
          top: 0;
          max-height: 100vh;
          width: 100%;
          transition: left .3s;
          // Second level
          > li {
            > [aria-haspopup="true"] {
              font-size: 1.2em;
              ~ ul {
                a {
                  padding-left: 40px;
                }
                // Third level
                > li {
                  > [aria-haspopup="true"] {
                    ~ ul {
                      a {
                        padding-left: 80px;
                      }
                    }
                  }
                }
              }
            }
          }
          [aria-haspopup="true"] {
            color: @color-dark;
            &:after {
              content: "+";
              background: none;
              font-size: 1em;
              font-weight: normal;
              height: 20px;
              line-height: 1;
            }
            ~ ul {
              max-height: 0px;
              transform-origin: top;
              transform: scaleY(0);
              transition: max-height .1s;
            }
          }
        }
      }
    }
  }
 
  
  .mega-menu-content {
    padding: @menu-link-padding;
  }
  
  .mobile-menu-back-item {
    order: -1;
    a {
      background: tint(grey, 70%);
      color: @color-dark;
      max-height: @mobile-menu-back-height;
      margin-top: @mobile-menu-back-offset;
      pointer-events: none;
      &:before {
        content: "";
        width: 14px;
        height: 12px;
        background-image: url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/1397521/arrowLeft.svg#default');
        background-size: 14px;
        margin-right: 10px;
        display: inline-block;
      }
    }
  }
  
  // ------------------------ ALL DEVICES
  
  .mobile-menu-trigger {
    // FUNCTIONALITY: Open mobile menu
    &:focus {
      ~ ul {
        left: 0;
      }
    }
  }
  
  .menu-bar {
    // FUNCTIONALITY: Keep menu open
    &:hover, &:focus-within {
      left: 0;
    }
    > li {
      > [aria-haspopup="true"] {
        // FUNCTIONALITY: Open mega menu
        &:focus {
          ~ ul {
            left: 0;
          }
        }
        ~ ul {
          // STYLING: Back button offset
          margin-top: @mobile-menu-back-height;
      
          // FUNCTIONALITY: Keep mega menu open
          &:hover, &:focus-within {
            left: 0;
          }
          // FUNCTIONALITY: Open dropdowns
          [aria-haspopup="true"] {
            &:focus {
              ~ ul {
                max-height: 500px;
                animation: dropdown .3s forwards;
              }
            }
          }
          // FUNCTIONALITY: Keep dropdowns open
          li {
            &:focus-within {
              > [aria-haspopup="true"] {
                ~ ul {
                  max-height: 500px;
                  transform: scaleY(1);
                }
              }
            }
          }
          
        }
      }
      // FUNCTIONALITY: Prevent clicks on link behind back button
      &:focus-within ~ .mobile-menu-header a {
        visibility: hidden;
      }
    }
  }
  
  // ------------------------ TOUCH DEVICES
  
  @media (hover: none) {
    
    // FUNCTIONALITY: Open mobile menu 
    .mobile-menu-trigger {
      &:hover {
        ~ ul {
          left: 0;
        }
      }
    }
    
    // FUNCTIONALITY: Open mega menu
    .menu-bar {
      > li {
        > [aria-haspopup="true"] {
          &:hover {
            ~ ul {
              left: 0;
            }
          }
          ~ ul {
            &:hover {
              left: 0;
            }
            // FUNCTIONALITY: Open dropdowns
            [aria-haspopup="true"] {
              &:hover {
                ~ ul {
                  max-height: 500px;
                  animation: dropdown .3s forwards;
                }
              }
              ~ ul {
                &:hover {
                  max-height: 500px;
                  transform: scaleY(1);
                }
              }
            }
          }
        }
        &:hover ~ .mobile-menu-header {
          a {
            visibility: hidden;
          }
        }
      }
    }
  }
}


// ------------------ ANIMATIONS

@keyframes dropdown {
  0% {
    opacity: 0;
    transform: scaleY(0);
  }
  50% {
    opacity: 1;
  }
  100% {
    transform: scaleY(1);
  }
}

@keyframes flyout {
  0% {
    opacity: 0;
    transform: scaleX(0);
  }
  100% {
    opacity: 1;
    transform: scaleX(1);
  }
}