AdminLTE/scss/layout/_layout-fixed.scss

.layout-fixed:not(.sidebar-horizontal) {
  .main-sidebar {
    bottom: 0;
    float: none;
    left: 0;
    position: fixed;
    top: 0;
  }

  .main-header,
  .content-wrapper,
  .main-footer {
    margin-left: $sidebar-width;
    transition: $transition-speed $transition-fn;
  }

  &.sidebar-collapse {
    .main-header,
    .content-wrapper,
    .main-footer {
      margin-left: $sidebar-mini-width;
    }
  }

  &.sidebar-close {
    .main-header,
    .content-wrapper,
    .main-footer {
      margin-left: 0;
    }
  }
}

.layout-fixed .wrapper .sidebar {
  // stylelint-disable-next-line
  height: calc(100vh - (#{$main-header-height-inner} + #{$main-header-bottom-border-width}));
}
.layout-fixed.text-sm .wrapper .sidebar {
  // stylelint-disable-next-line
  height: calc(100vh - (#{$main-header-height-sm-inner} + #{$main-header-bottom-border-width}));
}

//