css - Angular 2 material and flex-layout alignment

Question

I am trying to use angular 2 material and flex-layout to create a responsive gallery of elements. After hours and hours, I still can't have my elements centered:

This is the source code:

<div fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
  <md-card fxFlex.gt-md="20" fxFlex.md="28"  fxFlex.sm="40" fxFlex.xs="100" *ngFor="let recipe of recipes" [routerLink]="['/details', recipe.id]" class="recipe-card">
    <md-card-header>
      <md-card-title>element</md-card-title>
    </md-card-header>
    <img md-card-image src="http://placehold.it/350x200">
    <md-card-content>
      <p>
        Lorem Ipsum
      </p>
    </md-card-content>
  </md-card>
</div>

I have tried different values for fxFlexAlign (https://github.com/angular/flex-layout/wiki/API-Documentation) but none of them achieves what I need, that is, having the elements centered or, in other words, distribute the red square space between the right and the left side.

Is there a way of achieving this?

EDIT

Unfortunately, justify-content: space-between; doesn't work if I have a dynamic number of items. Eventually, they will be wrapped in a new line, and then the item in the last row won't look as expected:

.container {
  display:flex;
  width:100%;
  flex-flow:row wrap;
  justify-content: space-between;

  
}
.block {
  width:100px;
  height:100px;
  border:1px solid red;
}

<div class="container">
  <div class="block" fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
   ... you content
  </div>
  <div class="block" fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
   ... you content
  </div>
  <div class="block" fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
   ... you content
  </div>
  <div class="block" fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
   ... you content
  </div>
  <div class="block" fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
   ... you content
  </div>
  <div class="block" fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
   ... you content
  </div>
  <div class="block" fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
   ... you content
  </div>
  <div class="block" fxLayout='row' fxLayoutWrap fxLayoutGap="2rem">
   ... you content
  </div>
</div>

Answer 1

<div fxLayout="row" fxLayoutWrap fxLayoutGap="2rem" fxLayoutAlign="center">

Adding fxLayoutAlign="center" worked out for me, the results are now positioned in center.