<form action="">
<div class="form-group">
<label for="company">Firma:</label>
<input type="text" id="company" class="input-control">
<label for="phone" class="right-inline">Telefon:</label>
<input type="text" id="phone" class="input-control">
<button>Lang</button>
</div>
<div class="form-group">
<label for="company">Firma:</label>
<input type="text" id="company" class="input-control">
</div>
</form>
.form-group {
display: flex;
flex-direction: row;
align-items: center;
}
.form-group label {
flex: none;
display: block;
}
.form-group label.right-inline {
text-align: right;
width: auto;
}
.form-group .input-control {
flex: 1 1 auto;
display: block;
}