Animation that reveals element from left to right

Question

I have a <mat-divider></mat-divider> and I need to get it revealed from left to right, as if it were a progress bar being filled

Does anyone have an example to introduce me? I could only find with javascript

@Edit:

Adding example:

@-moz-keyframes roll {
	0% { width:0; }
  100% { width:100%; }
}

@-webkit-keyframes roll {
	0% { width:0; }
  100% { width:100%; }
}

.multi-steps > li.is-active:before, .multi-steps > li.is-active ~ li:before {
    content: counter(stepNum);
    font-family: inherit;
    font-weight: 700;
  }
  .multi-steps > li.is-active:after, .multi-steps > li.is-active ~ li:after {
    background-color: #ededed;
  }

  .multi-steps > li.is-active-acao-lojista:before, .multi-steps > li.is-active-acao-lojista ~ li:before {
    content: counter(stepNum);
    font-family: inherit;
    font-weight: 700;
  }
  .multi-steps > li.is-active-acao-lojista:after, .multi-steps > li.is-active-acao-lojista ~ li:after {
    background-color: #ededed;
  }
  
  .multi-steps {
    display: table;
    table-layout: fixed;
    width: 100%;
  }
  
  .multi-steps > li {
    counter-increment: stepNum;
    text-align: center;
    display: table-cell;
    position: relative;
    color: #a1c642;
    z-index:99!important;
    
  }

  .multi-steps > li.is-active {
    color: #a1c642!important;
    
  }

  .multi-steps > li.is-active-acao-lojista {
    color: darkorange!important;
    
  }

  .multi-steps > li:before {
    content: '\f00c';
    content: '\2713;';
    content: '\10003';
    content: '\10004';
    content: '\2713';
    display: block;
    margin: 0 auto 4px;
    background-color: #fff;
    width: 36px;
    height: 36px;
    line-height: 32px;
    text-align: center;
    font-weight: bold;
    border-width: 2px;
    border-style: solid;
    border-color: #a1c642;
    border-radius: 50%;

  }
  .multi-steps > li:after {
    content: '';
    height: 2px;
    width: 100%;
    background-color: #a1c642;
    position: absolute;
    top: 16px;
    left: 50%;
    z-index: -1;
  }


  .multi-steps > li:last-child:after {
    display: none;
  }
  .multi-steps > li.is-active-acao-lojista:before {
    background-color: #fff;
    border-color: darkorange;
  }
  .multi-steps > li.is-active:before {
    background-color: #fff;
    border-color: #a1c642;;
    
  }
  .multi-steps > li.is-active ~ li {
    color: #808080;
    
  }
  .multi-steps > li.is-active ~ li:before {
    background-color: #ededed;
    border-color: #ededed;
    
  }

  .multi-steps > li.is-active-acao-lojista ~ li {
    color: #808080;
  }
  .multi-steps > li.is-active-acao-lojista ~ li:before {
    background-color: #ededed;
    border-color: #ededed;
  }

                                    <ul class="list-unstyled multi-steps">
                                      <li>Pedido recebido</li>
                                      <li [class.is-active]="pedido.status == 'book_product' && pedido.id_Nota_fiscal == null">Pagamento aprovado</li>
                                      <li [class.is-active-acao-lojista]="pedido.status == 'payment_received' && pedido.id_Nota_fiscal == null">Faturar pedido</li>
                                      <li [class.is-active-acao-lojista]="pedido.status == 'payment_received' && pedido.id_Nota_fiscal !== null">Enviar dados rastreio</li>
                                      <li>Confirmar entrega</li>
                                    </ul>

I need to apply the roll animation to the last li:after element that has the background-color #a1c642

I tried to:

  .multi-steps > li:after:last-child{
      animation-name: roll;
      animation-duration: 5s;
      animation-timing-function: linear;
  }

but nothing happens

Answer 1

Your CSS has a problem building this class.

That:

.multi-steps > li:after:last-child

That should be it:

.multi-steps > li:last-child:after

Note the position of ::after

Another problem is the logic of what you want to do, notice that if you will animate the ::after of last-child he’ll cheer out the "component"... I don’t know if that’s what you want.

---

EDIT

Note that in the CSS of your comment you wrote wrong! In the last line you ended up zeroing out all the values of your animation when writing

animation: forwards !important; 

This way you leave everything "zeroed" and the only parameter of the animation is the forwards then the animation doesn’t work!

The right thing would be:

animation-fill-mode: forwards !important; 

I recommend this reading: CSS must be Shorthand or Longhand

Follow the code of the image above, I believe that with it you can reach the result you expect.

@-moz-keyframes roll {
  0% { width:0; }
  100% { width:100%; }
}

@-webkit-keyframes roll {
  0% { width:0; }
  100% { width:100%; }
}

.multi-steps > li.is-active:before, .multi-steps > li.is-active ~ li:before {
    content: counter(stepNum);
    font-family: inherit;
    font-weight: 700;
  }
  .multi-steps > li.is-active:after, .multi-steps > li.is-active ~ li:after {
    background-color: #ededed;
  }

  .multi-steps > li.is-active-acao-lojista:before, .multi-steps > li.is-active-acao-lojista ~ li:before {
    content: counter(stepNum);
    font-family: inherit;
    font-weight: 700;
  }
  .multi-steps > li.is-active-acao-lojista:after, .multi-steps > li.is-active-acao-lojista ~ li:after {
    background-color: #ededed;
  }
  
  .multi-steps {
    display: table;
    table-layout: fixed;
    width: 100%;
  }
  
  .multi-steps > li {
    counter-increment: stepNum;
    text-align: center;
    display: table-cell;
    position: relative;
    color: #a1c642;
    z-index:99!important;
    
  }

  .multi-steps > li.is-active {
    color: #a1c642!important;
    
  }

  .multi-steps > li.is-active-acao-lojista {
    color: darkorange!important;
    
  }

  .multi-steps > li:before {
    content: '\f00c';
    content: '\2713;';
    content: '\10003';
    content: '\10004';
    content: '\2713';
    display: block;
    margin: 0 auto 4px;
    background-color: #fff;
    width: 36px;
    height: 36px;
    line-height: 32px;
    text-align: center;
    font-weight: bold;
    border-width: 2px;
    border-style: solid;
    border-color: #a1c642;
    border-radius: 50%;

  }
  .multi-steps > li:after {
    content: '';
    height: 2px;
    width: 100%;
    background-color: #a1c642;
    position: absolute;
    top: 16px;
    left: 50%;
    z-index: -1;
  }


  .multi-steps > li:last-child:after {
    display: none;
  }
  .multi-steps > li.is-active-acao-lojista:before {
    background-color: #fff;
    border-color: darkorange;
  }
  .multi-steps > li.is-active:before {
    background-color: #fff;
    border-color: #a1c642;;
    
  }
  .multi-steps > li.is-active ~ li {
    color: #808080;
    
  }
  .multi-steps > li.is-active ~ li:before {
    background-color: #ededed;
    border-color: #ededed;
    
  }

  .multi-steps > li.is-active-acao-lojista ~ li {
    color: #808080;
  }
  .multi-steps > li.is-active-acao-lojista ~ li:before {
    background-color: #ededed;
    border-color: #ededed;
  }
  
  .multi-steps > li:after{ 
  width: 0!important; 
  animation-name: roll !important; 
  animation-timing-function: linear !important; 
  animation-duration:5s !important; 
  animation-fill-mode: forwards !important; 
}

  

<ul class="list-unstyled multi-steps">
  <li>Pedido recebido</li>
  <li [class.is-active]="pedido.status == 'book_product' && pedido.id_Nota_fiscal == null">Pagamento aprovado</li>
  <li [class.is-active-acao-lojista]="pedido.status == 'payment_received' && pedido.id_Nota_fiscal == null">Faturar pedido</li>
  <li [class.is-active-acao-lojista]="pedido.status == 'payment_received' && pedido.id_Nota_fiscal !== null">Enviar dados rastreio</li>
  <li>Confirmar entrega</li>
</ul>