How to set cookie to only show intro animation once per session I'm a Craft beginner, so forgive me if this is an easy question. 

I have an intro animation, that I'd only like to show on the first visit to the site, so that it doesn't load again when the user navigates back to the homepage after visiting other pages. Then I'd like it to expire when a user closes their browser.

I'd like to use secure cookies via the Cookies Plugin

The id of the intro animation is id="preloader"

I've put {{ setSecureCookie('intro-animation') }} above the html tag and {{ getSecureCookie('intro-animation') }} with the preloader section.

So how I do I set it up to only show the intro animation on first visit?
You could try something like 

  {% set vidAlreadyPlayed = getSecureCookie('intro-animation') %}
        {% if not vidAlreadyPlayed %}
            {{ setSecureCookie('intro-animation', 'hey', now | date_modify("+60 seconds").timestamp ) }}
            &lt;h1&gt;No cookie set&lt;/h1&gt;
            &lt;!-- do your animation logic here --&gt;
        {% else %}
          &lt;!-- do something else --&gt;
          &lt;h1&gt;Cookie set already&lt;/h1&gt;
        {% endif %}