Sizing of Custom-Select Labels in Bootstrap 4 - css

Question

I have a problem with sizing of input elements. When iam creating an input-group (with bootstrap 4.5) and then want them to be input-group-sm, only the custom select fields are in small size, the labels in front of them are in normal size.
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" rel="stylesheet"/>
<form>
<div class="input-group input-group-sm mb-2">
<div class="input-group-prepend">
<label class="input-group-text" for="newsAnzahl">Anzahl</label>
</div>
<select class="custom-select" id="newsAnzahl" name="newsAnzahl">
<option value="3" selected>3</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
<option value="100">100</option>
<option value="200">200</option>
</select>
<div class="input-group-prepend">
<label class="input-group-text" for="newsSortierung">Sortierung</label>
</div>
<select class="custom-select" id="newsSortierung" name="newsSortierung">
<option value="ASC">Aufsteigend</option>
<option value="DESC" selected>Absteigend</option>
</select>
<button id="button_getnewslist" type="button" class="btn btn-primary">Liste aktualisieren</button>
</div>
</form>
Examples are taken from here at headlines "Sizing" and "Custom Select"
Thanks for help!

Answer 1

The problem is that you defined multiple elements inside your .input-group element.
Just add multiple .input-group's around your elements as shown in this fiddle:
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" rel="stylesheet"/>
<form>
<div class="input-group input-group-sm mb-2">
<div class="input-group-prepend">
<label class="input-group-text" for="newsAnzahl">Anzahl</label>
</div>
<select class="custom-select" id="newsAnzahl" name="newsAnzahl">
<option value="3" selected>3</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
<option value="100">100</option>
<option value="200">200</option>
</select>
</div>
<div class="input-group input-group-sm mb-2">
<div class="input-group-prepend">
<label class="input-group-text" for="newsSortierung">Sortierung</label>
</div>
<select class="custom-select" id="newsSortierung" name="newsSortierung">
<option value="ASC">Aufsteigend</option>
<option value="DESC" selected>Absteigend</option>
</select>
</div>
<button id="button_getnewslist" type="button" class="btn btn-primary">Liste aktualisieren</button>
</form>
If you want to align it in one line, just use Bootstrap's grid system as shown in this fiddle:
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" rel="stylesheet"/>
<form class="row mt-2">
<div class="col">
<div class="input-group input-group-sm mb-2">
<div class="input-group-prepend">
<label class="input-group-text" for="newsAnzahl">Anzahl</label>
</div>
<select class="custom-select" id="newsAnzahl" name="newsAnzahl">
<option value="3" selected>3</option>
<option value="10">10</option>
<option value="20">20</option>
<option value="50">50</option>
<option value="100">100</option>
<option value="200">200</option>
</select>
</div>
</div>
<div class="col">
<div class="input-group input-group-sm mb-2">
<div class="input-group-prepend">
<label class="input-group-text" for="newsSortierung">Sortierung</label>
</div>
<select class="custom-select" id="newsSortierung" name="newsSortierung">
<option value="ASC">Aufsteigend</option>
<option value="DESC" selected>Absteigend</option>
</select>
</div>
</div>
<div class="col-3">
<button id="button_getnewslist" type="button" class="btn btn-sm btn-primary">Liste aktualisieren</button>
</div>
</form>
Good luck!

Answer 2

I hope that helped.
<!-- CSS only -->
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
<!-- JS, Popper.js, and jQuery -->
<script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/popper.js#1.16.1/dist/umd/popper.min.js" integrity="sha384-9/reFTGAW83EW2RDu2S0VKaIzap3H66lZH81PoYlFhbGU+6BZp6G7niu735Sk7lN" crossorigin="anonymous"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js" integrity="sha384-B4gt1jrGC7Jh4AgTPSdUtOBvfO8shuf57BaghqFfPlYxofvL8/KUEfYiJOMMV+rV" crossorigin="anonymous"></script>
<div class="container">
<form>
<div class="input-group input-group-sm mb-2">
<div class="input-group-prepend">
<span class="input-group-text " for=" newsAnzahl ">Anzahl</span>
</div>
<select class=" custom-select " id=" newsAnzahl " name=" newsAnzahl ">
<option value=" 3 " selected>3</option>
<option value=" 10 ">10</option>
<option value=" 20 ">20</option>
<option value=" 50 ">50</option>
<option value=" 100 ">100</option>
<option value=" 200 ">200</option>
</select>
</div>
<div class="input-group input-group-sm ">
<div class=" input-group-prepend ">
<span class=" input-group-text " for=" newsSortierung ">Sortierung</span>
</div>
<select class=" custom-select " id=" newsSortierung " name=" newsSortierung ">
<option value=" ASC ">Aufsteigend</option>
<option value=" DESC " selected>Absteigend</option>
</select>
</div>
<button id=" button_getnewslist " type=" button " class=" btn btn-primary mt-3 ">Liste aktualisieren</button>
</form>
</div>