AdminLTE/build/scss/pages/_iframe.scss

body.iframe-mode {
  .main-sidebar {
    display: none;
  }
  .content-wrapper {
    margin-left: 0 !important;
    margin-top: 0 !important;
    padding-bottom: 0 !important;
  }
  .main-header,
  .main-footer {
    display: none;
  }
}

body.iframe-mode-fullscreen {
  overflow: hidden;
}

.content-wrapper {
  height: 100%;

  &.iframe-mode {
    .btn-iframe-close {
      color: $danger;
      position: absolute;
      line-height: 1;
      right: .125rem;
      top: .125rem;
      z-index: 10;
      visibility: hidden;

      &:hover,
      &:focus {
        animation-name: fadeIn;
        animation-duration: $transition-speed;
        animation-fill-mode: both;
        visibility: visible;
      }

      @include on-touch-device () {
        visibility: visible;
      }
    }
    .navbar-nav {
      overflow-y: auto;
      width: 100%;

      .nav-link {
        white-space: nowrap;
      }
      .nav-item {
        position: relative;

        &:hover,
        &:focus {
          .btn-iframe-close {
            animation-name: fadeIn;
            animation-duration: $transition-speed;
            animation-fill-mode: both;
            visibility: visible;

            @include on-touch-device () {
              visibility: visible;
            }
          }
        }
      }
    }
    .tab-content {
      position: relative;
    }
    .tab-pane + .tab-empty {
      display: none;
    }
    .tab-empty {
      width: 100%;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .tab-loading {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      display: none;
      background-color: $main-bg;

      > div {
        display: flex;
        justify-content: center;
        align-items: center;
        width: 100%;
        height: 100%;
      }
    }

    iframe {
      border: 0;
      width: 100%;
      height: 100%;
      margin-bottom: -8px;

      .content-wrapper {
        padding-bottom: 0 !important;
      }
    }

    body.iframe-mode-fullscreen & {
      position: absolute;
      left: 0;
      top: 0;
      right: 0;
      bottom: 0;
      margin-left: 0 !important;
      height: 100%;
      min-height: 100%;
      z-index: $zindex-main-sidebar + 10;
    }
  }
}

.permanent-btn-iframe-close {
  .btn-iframe-close {
    animation: none !important;
    visibility: visible !important;
    opacity: 1;
  }
}