/* 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.

   Anchored to the viewport bottom (`inset: 0` — fills the whole screen). The chrome that must occlude
   it paints OVER it on z-index, not by clipping the box: the app bar (z 100), the docked player bar
   (z 1200/1300), the site footer (z 1 stacking context), and the layout spacer (z 1 stacking context,
   `--deepdrft-page-surface` background) all sit above this z-0 layer. Where those elements are inset
   from the screen edges or scrolled below the fold, the visualizer fills the gap continuously — no
   page-background strip around the inset player bar. `overflow: hidden` clips the canvas to this box.

   NOTE: this box is decoupled from `--player-height` (it no longer reads that var). The renderer's own
   ResizeObserver therefore never fires on a player-bar height change, so an eased Theater-Mode collapse
   can no longer clear the GL backing store mid-ease (the former theater-flash source). See
   Interop/layout/spacer.ts. */
.mix-waveform-bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

/* Fill / container-sizing mode (Phase 12 §6c, mode C). The contained hosts (the NowPlaying card)
   set Fill="true": the canvas fills its nearest positioned ancestor instead of the viewport, and the
   footer clip drops (there is no player bar to clear — the bounding box IS the clip). The host is
   responsible for giving this layer a positioned, sized parent. `inset: 0` over `position: absolute`
   makes the box exactly that parent's content box; `overflow: hidden` still clips the canvas to it.
   The canvas backing-store sizing in WaveformVisualizer.ts is unchanged — it already measures the
   canvas's own box, so this purely re-parents the box from the viewport to the container. */
.mix-waveform-bg--fill {
    position: absolute;
    inset: 0;
    z-index: 0;
}

/* 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;
}