I'm attempting to design some form elements and align the inputs vertically within the columns. I've experimented with vertical-align:middle; and margin:auto 0;, however, neither of these solutions seem to be effective.
input {
vertical-align:middle;
margin:auto 0;
}<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" rel="stylesheet"/>
<div class="container">
<div class="row">
<div class="col-sm-9">
<div class="form-group">
<div class="row">
<label for="phonenum" class="col-sm-2">Please enter your phone number</label>p>
<div class="col-sm-10">
<input type="text" name="phonenum" />
</div>
</div>
</div>
</div>
</div>
</div>