admin/React_Starter/scss/core/_layout.scss

// IE10&11 Flexbox fix
@media all and (-ms-high-contrast:none) {
  html {
    display: flex;
    flex-direction: column;
  }
}

// app-dashboard and app-root are Angular2+ selectors. You can add here your own selectors if you need.
.app,
app-dashboard,
app-root {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.app-header {
  flex: 0 0 $navbar-height;
}

.app-footer {
  flex: 0 0 $footer-height;
}

.app-body {
  display: flex;
  flex-direction: row;
  flex-grow: 1;
  overflow-x: hidden;

  .main {
    flex: 1;
    min-width: 0;
  }

  .sidebar {
    // $sidebar-width is the width of the columns
    flex: 0 0 $sidebar-width;
    // put the nav on the left
    order: -1;
  }

  .aside-menu {
    // $aside-menu-width is the width of the columns
    flex: 0 0 $aside-menu-width;
  }
}

//
// header
//
.header-fixed {
  .app-header {
    position: fixed;
    z-index: $zindex-sticky;
    width: 100%;
  }
  .app-body {
    margin-top: $navbar-height;
  }
}

//
// Sidebar
//
.sidebar-hidden {
  .sidebar {
    margin-left: - $sidebar-width;
  }
}

.sidebar-fixed {
  .sidebar {
    position: fixed;
    z-index: $zindex-sticky - 1;
    width: $sidebar-width;
    height: calc(100vh - #{$navbar-height});
    // margin-top: - $navbar-height;

    // .sidebar-nav {
    //   height: calc(100vh - #{$navbar-height});
    // }
  }

  .main, .app-footer {
    margin-left: $sidebar-width;
  }

  &.sidebar-hidden {
    .main, .app-footer {
      margin-left: 0;
    }
  }
}

.sidebar-off-canvas {
  .sidebar {
    position: fixed;
    z-index: $zindex-sticky - 1;
    height: calc(100vh - #{$navbar-height});
  }
}

@include media-breakpoint-up(lg) {
  .sidebar-compact {
    .sidebar {
      flex: 0 0 $sidebar-compact-width;
    }

    &.sidebar-hidden {
      .sidebar {
        margin-left: - $sidebar-compact-width;
      }
    }

    &.sidebar-fixed {
      .main, .app-footer {
        margin-left: $sidebar-compact-width;
      }

      .sidebar {
        width: $sidebar-compact-width;
      }

      &.sidebar-hidden {
        .main, .app-footer {
          margin-left: 0;
        }
      }
    }
  }

  .sidebar-minimized {
    .sidebar {
      flex: 0 0 $sidebar-minimized-width;
    }

    &.sidebar-hidden {
      .sidebar {
        margin-left: - $sidebar-minimized-width;
      }
    }

    &.sidebar-fixed {
      .main, .app-footer {
        margin-left: $sidebar-minimized-width;
      }

      .sidebar {
        width: $sidebar-minimized-width;
      }

      &.sidebar-hidden {
        .main, .app-footer {
          margin-left: 0;
        }
      }
    }
  }
}

//
// Aside Menu
//
.aside-menu-hidden {
  .aside-menu {
    margin-right: - $aside-menu-width;
  }
}

.aside-menu-fixed {
  .aside-menu {
    position: fixed;
    right: 0;
    height: 100%;

    .tab-content {
      height: calc(100vh - #{$aside-menu-nav-padding-y * 2 + $font-size-base} - #{$navbar-height});
    }
  }

  .main, .app-footer {
    margin-right: $aside-menu-width;
  }

  &.aside-menu-hidden {
    .main, .app-footer {
      margin-right: 0;
    }
  }
}

.aside-menu-off-canvas {
  .aside-menu {
    position: fixed;
    right: 0;
    z-index: $zindex-sticky - 1;
    height: 100%;

    .tab-content {
      height: calc(100vh - #{$aside-menu-nav-padding-y * 2 + $font-size-base} - #{$navbar-height});
    }
  }
}

//
// Breadcrumb
//
.breadcrumb-fixed {
  .main {
    $breadcrumb-height: 2 * $breadcrumb-padding-y + $font-size-base + 1.5 * $spacer;
    padding-top: $breadcrumb-height;
  }

  .breadcrumb {
    position: fixed;
    top: $navbar-height;
    right: 0;
    left: 0;
    z-index: $zindex-sticky - 2;
  }

  // if sidebar + main + aside
  .main:nth-child(2) {
    .breadcrumb {
      right: $aside-menu-width;
      left: $sidebar-width;
    }
  }

  // if sidebar + main
  .main:first-child {
    .breadcrumb {
      right: $aside-menu-width;
      left: 0;
    }
  }

  // if  main + aside
  .main:last-child {
    .breadcrumb {
      right: 0;
    }
  }

  &.sidebar-minimized {
    .main .breadcrumb {
      left: $sidebar-minimized-width;
    }
  }

  &.sidebar-hidden, &.sidebar-off-canvas {
    .main .breadcrumb {
      left: 0;
    }
  }

  &.aside-menu-hidden, &.aside-menu-off-canvas {
    .main .breadcrumb {
      right: 0;
    }
  }
}

//
// Footer
//
.footer-fixed {
  .app-footer {
    position: fixed;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: $zindex-sticky;
    height: $footer-height;
  }

  .app-body {
    margin-bottom: $footer-height;
  }
}

//
// Animations
//
.app-header,
.app-footer,
.sidebar,
.main,
.aside-menu {
  transition: margin-left $layout-transition-speed, margin-right $layout-transition-speed, width $layout-transition-speed, flex $layout-transition-speed;
}
.sidebar-nav {
  transition: width $layout-transition-speed;
}
.breadcrumb {
  transition: left $layout-transition-speed, right $layout-transition-speed, width $layout-transition-speed;
}

//
// Mobile layout
//

@include media-breakpoint-down(md) {
  .app-header.navbar {
    position: fixed !important;
    z-index: $zindex-sticky;
    width: 100%;
    text-align: center;
    background-color: $navbar-brand-bg;
    @include borders($navbar-brand-border);

    .navbar-toggler {
      @if (lightness( $navbar-brand-bg ) > 40) {
        color: $navbar-color;
      } @else {
        color: #fff;
      }
    }

    .navbar-brand {
      position: absolute;
      left: 50%;
      margin-left: - ($navbar-brand-width / 2);
    }
  }

  .app-body {
    margin-top: $navbar-height;
  }

  .breadcrumb-fixed {
    .main:nth-child(2) .breadcrumb {
      right: auto;
      left: auto;
      width: 100%;
    }
  }

  .sidebar {
    position: fixed;
    z-index: $zindex-sticky - 1;
    width: $mobile-sidebar-width;
    height: calc(100vh - #{$navbar-height});
    margin-left: - $mobile-sidebar-width;

    .sidebar-nav,
    .nav {
      width: $mobile-sidebar-width;
      min-height: calc(100vh - #{$navbar-height});
    }

    .sidebar-minimizer {
      display: none;
    }
  }

  .main, .app-footer {
    margin-left: 0 !important;
  }

  // .aside-menu {
  //   margin-right: - $aside-menu-width;
  // }

  .sidebar-hidden {
    .sidebar {
      margin-left: - $mobile-sidebar-width;
    }
  }

  .sidebar-mobile-show {
    .sidebar {
      width: $mobile-sidebar-width;
      margin-left: 0;
    }

    .main {
      margin-right: - $mobile-sidebar-width !important;
      margin-left: $mobile-sidebar-width !important;
    }
  }
}