Embedding ion-card in ion-slides ends up with wrong width

I am facing an issue with the layout when using ion-slides. I am using this HTML code to create a simple card:

<ion-header>
   <ion-navbar>
      <ion-title style="text-align:center;">Title</ion-title>
   </ion-navbar>
</ion-header>
<ion-content class="tutorial-page">

  <ion-card>
    <ion-card-content>
      <ion-card-title style="color:#000000;text-align:center;padding-top:10px; font-size: 24px; font-weight: bold;">
        Title
      </ion-card-title>
    </ion-card-content>

  </ion-card>

</ion-content>

Which rightfully results in this: Correct display of card

But when I try to embed this card in ion-slides the width is strange. It looks fine on landscape and looks like it has some fixed width. I cant figure out how to make it work in Portrait. Code here:

<ion-header>
   <ion-navbar>
      <ion-title style="text-align:center;">Title</ion-title>
   </ion-navbar>
</ion-header>
<ion-content class="tutorial-page">

  <ion-slides>
    <ion-slide>
      <ion-card>
        <ion-card-content>
          <ion-card-title style="color:#000000;text-align:center;padding-top:10px; font-size: 24px; font-weight: bold;">
            Title
          </ion-card-title>
        </ion-card-content>

      </ion-card>
    </ion-slide>
  </ion-slides>

</ion-content>

Result looks like this: Strange width

CSS here:

.tutorial-page {

  .toolbar-background {
    background: #fff;
    border-color: transparent;
  }

  .slide-zoom {
    width: 100%;
    height: 100%;
  }

  .slide-title {
    margin-top: 2.8rem;
  }

  .slide-image {
    max-height: 50%;
    max-width: 60%;
    margin: 18px 0;
  }

  b {
    font-weight: 500;
  }

  p {
    padding: 0 40px;
    font-size: 14px;
    line-height: 1.5;
    color: #60646B;

    b {
      color: #000000;
    }
  }

}

Appreciate any help I can get, Andre

Found the solution myself...

I had some snippet in some css file:

.swiper-container {
    width: 600px;
    height: 300px;
}

Being a beginner in Ionic, I thought the css files are separated from each page. So I had this piece of code lying around on some other page which apparently affected it. Also making changes to css files didn't always live-reload the UI.