/* Full-viewport fixed backdrop. Sits behind the detail content (.mix-detail-foreground is z-index:1)
   and never intercepts pointer events — except the zoom slider, which re-enables them on itself. */
.mix-waveform-bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

/* The canvas fills the viewport. All ribbon shading (luminous depth, soft edges) is drawn inside the
   canvas by the WebGL2 fragment shader. NO CSS backdrop-filter: it was a confirmed per-frame perf killer
   on the Canvas predecessor and is exactly the cost the GPU move exists to eliminate (spec §2, §5.2);
   the glass treatment returns in-shader in Wave 3. */
.mix-waveform-canvas {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    display: block;
}