当我浏览页面时，为什么整个页面都会向上推几个像素？

Question

I am implementing a feature on a web page which allows the user to navigate using the tab key.

When I am tabbing through the page, eventually the page will have to automatically scroll down to tab to the new content. When this happens, the entire page moves itself up a few pixels, this is proven by the navigation bar disappearing from the top of the page. (stays in the DOM, just out of view).

Demo:

Code:

app.component.html :

<div *ngIf="token" class="route-container">
  <app-search [token]="token"></app-search>
  <router-outlet></router-outlet>
</div>

app.component.scss :

.route-container {
  height: 100%;
  flex-direction: column;
  justify-content: space-between;
}
app-search{
  position: relative;
  z-index: 1;
}

search.component.html :

<nav class="navHeader">
    ...
</nav>

search.component.scss :

.navHeader {
  height: 48px;
  display: flex;
  align-items: center;
  color: #808080;
  box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.2), 0 2px 1px -1px rgba(0, 0, 0, 0.12), 0 1px 1px 0 rgba(0, 0, 0, 0.14);
}

Why does this happen and how do I fix it?

Other information:

• Angular 8 (8.0.2)
• Tested this in 3 browsers (Edge, IE11, Chrome). The bug appears in all 3.

EDIT

After trying @Eliseo 's solution I changed the title of the question from 'why is the navigation moving' to 'Why does the whole page push itself' as I realised that it isn't just the menu being pushed up a few pixels.

Thanks

Answer 1

are you asking about?

.navHeader {
  position: fixed; /* Set the navbar to fixed position */
  top: 0; /* Position the navbar at the top of the page */
  width: 100%; /* Full width */
}