Bootstrap/scss/_nav.scss

//
// Navs
// --------------------------------------------------

.nav {
  margin-bottom: 0;
  @extend .list-unstyled;
  @include clearfix();
}

.nav-item {
  position: relative;
  display: inline-block;
}

.nav-link {
  display: inline-block;
  padding: $nav-link-padding;
  line-height: $line-height-base;

  @include hover-focus {
    text-decoration: none;
    background-color: $nav-link-hover-bg;
  }

  // Disabled state sets text to gray and nukes hover/tab effects
  .disabled > &,
  &.disabled {
    color: $nav-disabled-link-color;

    @include plain-hover-focus {
      color: $nav-disabled-link-hover-color;
      cursor: $cursor-disabled;
      background-color: transparent;
    }
  }
}


//
// Tabs
//

.nav-tabs {
  border-bottom: 1px solid $nav-tabs-border-color;

  .nav-item {
    float: left;
    // Make the list-items overlay the bottom border
    margin-bottom: -1px;

    + .nav-item {
      margin-left: .2rem;
    }
  }

  .nav-link {
    display: block;
    border: 1px solid transparent;
    @include border-radius($border-radius-base $border-radius-base 0 0);

    @include hover-focus {
      border-color: $nav-tabs-link-hover-border-color $nav-tabs-link-hover-border-color $nav-tabs-border-color;
    }
  }

  .open > .nav-link,
  .active > .nav-link,
  .nav-link.open,
  .nav-link.active {
    @include plain-hover-focus {
      color: $nav-tabs-active-link-hover-color;
      background-color: $nav-tabs-active-link-hover-bg;
      border-color: $nav-tabs-active-link-hover-border-color $nav-tabs-active-link-hover-border-color transparent;
    }
  }

  .disabled > .nav-link,
  .nav-link.disabled {
    @include plain-hover-focus {
      color: $nav-disabled-link-color;
      background-color: transparent;
      border-color: transparent;
    }
  }
}


//
// Pills
//

.nav-pills {
  .nav-item {
    float: left;

    + .nav-item {
      margin-left: .2rem;
    }
  }

  .nav-link {
    display: block;
    @include border-radius($nav-pills-border-radius);
  }

  .open > .nav-link,
  .active > .nav-link,
  .nav-link.open,
  .nav-link.active {
    @include plain-hover-focus {
      color: $component-active-color;
      cursor: default;
      background-color: $component-active-bg;
    }
  }
}

.nav-stacked {
  .nav-item {
    display: block;
    float: none;

    + .nav-item {
      margin-top: .2rem;
      margin-left: 0;
    }
  }
}


//
// Tabbable tabs
//

// Hide tabbable panes to start, show them when `.active`
.tab-content {
  > .tab-pane {
    display: none;
    visibility: hidden;
  }
  > .active {
    display: block;
    visibility: visible;
  }
}


//
// Dropdowns
//

.nav-tabs .dropdown-menu {
  // Make dropdown border overlap tab border
  margin-top: -1px;
  // Remove the top rounded corners here since there is a hard edge above the menu
  @include border-top-radius(0);
}