.flex_row {
  display: flex;
  flex-flow: row nowrap;
}

.flex_col, .C_main {
  display: flex;
  flex-flow: column nowrap;
}

.fill, .C_main {
  width: 100%;
  height: 100%;
}

.C_main {
  padding: 1rem;
  overflow: auto;
}
@media only screen and (orientation: portrait) {
  .C_main {
    width: 100%;
  }
}