{#- chirp-ui: Aurora Background
    Drifting gradient blobs behind content. Pure CSS.

    Usage:
        from "chirpui/aurora.html" import aurora

        {% call aurora() %}
            <h1>Content over aurora</h1>
        {% end %}

        {% call aurora(variant="intense") %}
            <div>Vivid background</div>
        {% end %}
-#}

{% def aurora(variant="", cls="") %}
{% set variant_cls = " chirpui-aurora--" ~ variant if variant in ("intense", "subtle") else "" %}
<div class="chirpui-aurora{{ variant_cls }}{{ " " ~ cls if cls else "" }}">
    <div class="chirpui-aurora__blobs" aria-hidden="true">
        <div class="chirpui-aurora__blob"></div>
        <div class="chirpui-aurora__blob"></div>
        <div class="chirpui-aurora__blob"></div>
    </div>
    <div class="chirpui-aurora__content">
        {% slot %}
    </div>
</div>
{% end %}