forms_12_responsive_disclosure_animated_1.html

<form>
    <div class="row">
        <div class="medium-8 medium-offset-2 columns">
            <p class="fake">(Other form stuff goes here.)</p>
            <div class="row">
                <div class="small-12 columns">
                    <input type="checkbox" id="cb" name="cb">
                    <label for="cb">Yes! Please text me your special offers.</label>
                </div>
            </div>
            <div class="row" id="mobile_container">
                <div class="small-3 medium-3 columns">
                    <label class="right inline" for="mobile" id="mobilelabel">Mobile number</label>
                </div>
                <div class="small-9 medium-6 columns end">
                    <input type="tel" id="mobile" name="mobile">
                </div>
            </div>
            <div class="row">
                <div class="small-12 columns">
                    <p>Here's some more text.</p>
                </div>
            </div>
        </div>
    </div>
</form>