message: PanelHeaderContent: design fixes
diff: display: flex;
  align-items: center;
  justify-content: flex-start;
  + font-family: var(--font-common);
  }
  .PanelHeaderContent__before {
  width: 1000px;
  }
  +/**
  + * iOS
  + */
  +
  .PanelHeaderContent--ios .PanelHeaderContent__before ~ .PanelHeaderContent__in {
  align-items: flex-start;
  }
  align-items: center;
  }
  -/**
  - * iOS
  - */
  -
  .PanelHeaderContent--ios .PanelHeaderContent__children-in {
  font-size: 21px;
  font-family: var(--font-display);
  }
  /**
  - * vkcom
  + * VKCOM
  */
  +
  +.PanelHeaderContent--vkcom
  + .PanelHeaderContent__before
  + ~ .PanelHeaderContent__in {
  + align-items: flex-start;
  +}
  +
  +.PanelHeaderContent--vkcom .PanelHeaderContent__in {
  + align-items: center;
  +}
  