.px-container {
  display: flex;
  flex-direction: column;
  flex: 1;
  box-sizing: border-box;
}
.px-container.px-container__has-aside {
  flex-direction: row;
}
.px-container.px-container__horizontal {
  flex-direction: row;
}
.px-container.px-container__vertical {
  flex-direction: column;
}