When giving a textfield an icon the vertical icon alignment is off.
<div class="input-field">
<i class="material-icons prefix">vpn_key</i>
<input id="token" type="text" class="validate" maxlength="10">
<label for="token">Anmeldecode</label>
</div>
Please try the code from the CSS tab.
That works nicely, why is it not that way by default?
@tomscholz Hm, should we pick this or another value?
I think .5 rem is actually perfect since it is aligned with the label.

@Fylipp right, this is what I tested in the ChromeDevTools but I did not test further how other icons react and if another approach is better.
The @DanielRuf's solution is perfect!
The team will probably merge the PR.
Fixed in 3b8cf2d463db63444e73c8157660379ef3f64c6f
Most helpful comment
Please try the code from the CSS tab.
https://codepen.io/anon/pen/rwjVba