message: Layout cleanup: Use variables instead of hard-coding 40px/60px. Fix bug where cluster picker was hidden in sidebar. Make header fixed positioned.
diff: $sidebar-width: 220px;
  +$masthead-height-mobile: 40px;
  +$masthead-height-desktop: 60px;
  html {
  height: 100%;
  @@ -37,13 +39,14 @@ body {
  .os-masthead {
  background-color: $color-pf-black;
  color: $color-os-nav-title;
  - @media (max-width: $grid-float-breakpoint) {
  position: fixed;
  top: 0;
  left: $sidebar-width;
  right: 0;
  - height: 40px;
  + height: $masthead-height-desktop;
  z-index: $zindex-navbar;
  + @media (max-width: $grid-float-breakpoint) {
  + height: $masthead-height-mobile;
  }
  }
  @@ -65,7 +68,7 @@ body {
  display: none;
  flex: 1 1 auto;
  flex-direction: column;
  - overflow-y: auto;
  + overflow-y: visible;
  }
  &.open {
  bottom: 0;
  @@ -79,13 +82,13 @@ body {
  }
  .sidebar__header {
  - height: 40px;
  + height: $masthead-height-mobile;
  display: flex;
  flex-direction: row;
  flex: 0 0 auto;
  background-color: $color-pf-black;
  @media (min-width: $grid-float-breakpoint) {
  - height: 60px;
  + height: $masthead-height-desktop;
  }
  }
  .sidebar__logo {
  @@ -132,9 +135,9 @@ body {
  #sidebar + #content {
  @media (min-width: $grid-float-breakpoint) {
  margin-left: $sidebar-width;
  - margin-top: 0;
  + margin-top: $masthead-height-desktop;
  }
  - margin-top: 40px;
  + margin-top: $masthead-height-mobile;
  }
  .absolute-zero {
  