edx-platform/sass/courseware/_sequence-nav.scss

nav.sequence-nav {
  @extend .topbar;
  @include box-sizing(border-box);
  margin-bottom: $body-line-height;
  position: relative;

  ol {
    border-bottom: 1px solid darken($cream, 20%);
    @include box-sizing(border-box);
    display: table;
    padding-right: flex-grid(1, 9);
    width: 100%;

    a {
      @extend .block-link;
    }

    li {
      border-left: 1px solid darken($cream, 20%);
      display: table-cell;
      min-width: 20px;

      &:first-child {
        border-left: none;
      }

      .inactive {
        background-repeat: no-repeat;

        &:hover {
          background-color: lighten($cream, 3%);
        }
      }

      .visited {
        background-color: #DCCDA2;
        background-repeat: no-repeat;
        @include box-shadow(inset 0 0 3px darken(#dccda2, 10%));

        &:hover {
          background-color: $cream;
          background-position: center center;
        }
      }

      .active {
        background-color: #fff;
        background-repeat: no-repeat;
        @include box-shadow(0 1px 0 #fff);

        &:hover {
          background-color: #fff;
          background-position: center;
        }
      }

      a {
        background-position: center center;
        border: none;
        cursor: pointer;
        display: block;
        height: 17px;
        padding: 15px 0 14px;
        @include transition(all, .4s, $ease-in-out-quad);
        width: 100%;

        // @media screen and (max-width: 800px) {
          //   padding: 12px 8px;
          // }

          //video
          &.seq_video_inactive {
            @extend .inactive;
            background-image: url('../images/sequence-nav/video-icon-normal.png');
            background-position: center;
          }

          &.seq_video_visited {
            @extend .visited;
            background-image: url('../images/sequence-nav/video-icon-visited.png');
            background-position: center;
          }

          &.seq_video_active {
            @extend .active;
            background-image: url('../images/sequence-nav/video-icon-current.png');
            background-position: center;
          }

          //other
          &.seq_other_inactive {
            @extend .inactive;
            background-image: url('../images/sequence-nav/document-icon-normal.png');
            background-position: center;
          }

          &.seq_other_visited {
            @extend .visited;
            background-image: url('../images/sequence-nav/document-icon-visited.png');
            background-position: center;
          }

          &.seq_other_active {
            @extend .active;
            background-image: url('../images/sequence-nav/document-icon-current.png');
            background-position: center;
          }

          //vertical & problems
          &.seq_vertical_inactive, &.seq_problem_inactive {
            @extend .inactive;
            background-image: url('../images/sequence-nav/list-icon-normal.png');
            background-position: center;
          }

          &.seq_vertical_visited, &.seq_problem_visited {
            @extend .visited;
            background-image: url('../images/sequence-nav/list-icon-visited.png');
            background-position: center;
          }

          &.seq_vertical_active, &.seq_problem_active {
            @extend .active;
            background-image: url('../images/sequence-nav/list-icon-current.png');
            background-position: center;
          }
        }

      p {
        // display: none;
        // visibility: hidden;
        background: #333;
        color: #fff;
        line-height: lh();
        margin: 0px 0 0 -5px;
        opacity: 0;
        padding: 6px;
        position: absolute;
        text-shadow: 0 -1px 0 #000;
        @include transition(all, .6s, $ease-in-out-quart);
        white-space: pre-wrap;
        z-index: 99;

        &.shown {
          margin-top: 4px;
          opacity: 1;
        }

        &:empty {
          background: none;

          &::after {
            display: none;
          }
        }

        &::after {
          background: #333;
          content: " ";
          display: block;
          height: 10px;
          left: 18px;
          position: absolute;
          top: -5px;
          @include transform(rotate(45deg));
          width: 10px;
        }
      }
    }
  }

  ul {
    margin-right: 1px;
    position: absolute;
    right: 0;
    top: 0;
    width: flex-grid(1, 9);

    li {
      float: left;
      width: 50%;

      &.prev, &.next {

        a {
          background-color: darken($cream, 5%);
          background-position: center center;
          background-repeat: no-repeat;
          border-left: 1px solid darken(#f6efd4, 20%);
          @include box-shadow(inset 1px 0 0 lighten(#f6efd4, 5%));
          @include box-sizing(border-box);
          cursor: pointer;
          display: block;
          text-indent: -9999px;

          &:hover {
            background-color: none;
            color: darken($cream, 60%);
            text-decoration: none;
            text-decoration: none;
          }

          &.disabled {
            cursor: normal;
            opacity: .4;
          }
        }
      }

      &.prev {
        a {
          background-image: url('../images/sequence-nav/previous-icon.png');

          &:hover {
            background-color: none;
          }
        }
      }

      &.next {
        a {
          background-image: url('../images/sequence-nav/next-icon.png');

          &:hover {
            background-color: none;
          }
        }
      }
    }
  }
}


section.course-content {

  div#seq_content {
    margin-bottom: 60px;
  }

  nav.sequence-bottom {
    bottom: (-(lh()));
    position: relative;

    ul {
      @extend .clearfix;
      background-color: darken(#F6EFD4, 5%);
      background-color: darken($cream, 5%);
      border: 1px solid darken(#f6efd4, 20%);
      border-bottom: 0;
      @include border-radius(3px 3px 0 0);
      @include box-shadow(inset 0 0 0 1px lighten(#f6efd4, 5%));
      margin: 0 auto;
      overflow: hidden;
      width: 106px;

      li {
        float: left;

        &.prev, &.next {
          margin-bottom: 0;

          a {
            background-position: center center;
            background-repeat: no-repeat;
            border-bottom: none;
            display: block;
            display: block;
            padding: lh(.75) 4px;
            text-indent: -9999px;
            @include transition(all, .4s, $ease-in-out-quad);
            width: 45px;

            &:hover {
              background-color: darken($cream, 10%);
              color: darken(#F6EFD4, 60%);
              color: darken($cream, 60%);
              opacity: .5;
              text-decoration: none;
            }

            &.disabled {
              background-color: lighten($cream, 10%);
              opacity: .4;
            }
          }
        }

        &.prev {
          a {
            background-image: url('../images/sequence-nav/previous-icon.png');

            &:hover {
              background-color: none;
            }
          }
        }

        &.next {
          a {
            background-image: url('../images/sequence-nav/next-icon.png');

            &:hover {
              background-color: none;
            }
          }
        }
      }
    }
  }
}