void mainImage(out vec4 fragColor, in vec2 fragCoord)
{
    vec2 uv = fragCoord.xy / iResolution.xy;
    vec2 p = uv * 2.0 - 1.0;

    p.x *= iResolution.x / iResolution.y;

    float raw = 0.5 + 0.5 * sin(iTime * 6.0);

    float smoothAudio =
        0.5 +
        0.3 * sin(iTime * 2.0) +
        0.2 * sin(iTime * 1.2);

    float d = length(p);

    float rawRing =
        smoothstep(0.28 + raw * 0.12, 0.27, d);

    float smoothRing =
        smoothstep(0.55 + smoothAudio * 0.08, 0.54, d);

    vec3 color = vec3(0.02, 0.04, 0.08);

    color += rawRing * vec3(1.0, 0.15, 0.2);
    color += smoothRing * vec3(0.1, 0.7, 1.0);

    fragColor = vec4(color, 1.0);
}