{#- chirp-ui: Constellation
    Twinkling ASCII starfield background with gentle drift. Pure CSS.

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

        {% call constellation() %}
            <h1>Starfield hero</h1>
        {% end %}

        {% call constellation(variant="warm", density="dense") %}
            <p>Dense warm starfield</p>
        {% end %}
-#}

{% def constellation(density="", variant="", cls="") %}
{% set variant = variant | validate_variant(("", "default", "warm", "cool", "mono"), "") %}
{% set density = density | validate_variant(("", "default", "sparse", "dense"), "") %}
{% set variant_class = " chirpui-constellation--" ~ variant if variant else "" %}
{% set density_class = " chirpui-constellation--" ~ density if density else "" %}
{% set count = 16 if density == "dense" else (6 if density == "sparse" else 10) %}
{% set glyphs = ["·", "✦", "·", "★", "·", "·", "✦", "·", "●", "·", "✦", "·", "·", "★", "·", "✦"] %}
<div class="chirpui-constellation{{ variant_class }}{{ density_class }}{{ " " ~ cls if cls else "" }}">
    <div class="chirpui-constellation__field" aria-hidden="true">
        {% for i in range(count) %}
        <span class="chirpui-constellation__star" style="left: {{ (i * 7 + 3) % 95 }}%; top: {{ (i * 11 + 5) % 92 }}%">{{ glyphs[i % 16] }}</span>
        {% end %}
    </div>
    <div class="chirpui-constellation__content">
        {% slot %}
    </div>
</div>
{% end %}