Тег для
<div class="intro"> не закрыт
<div class="intro">
<div class="container">
<div class="intro__inner">
<h2 class="intro__suptitle">Creative Template</h2>
<h1 class="intro__title">Welcome to Mogo</h1>
<a href="#" class="btn">Learn More</a>
</div>
<div class="slider">
<div class="container">
<div class="slider__inner">
<div class="slider__item active">
<span class="slider__num">01</span>Intro
</div>
<div class="slider__item">
<span class="slider__num">02</span>Work
</div>
<div class="slider__item">
<span class="slider__num">03</span>About
</div>
<div class="slider__item">
<span class="slider__num">04</span>Contacts
</div>
</div>
</div>
</div>
</div>
</div> <!-- <== -->
