/* Accordion — Stradella bass (120-button, diagonal grid): horizontal + vertical
   orientations, flip-mirroring, and mobile tap-target tuning. */

:root {
  /* Auto-scoped identity palette for play-acc-strad. Every bare color in
   * this file is routed through one of these tokens so the brand
   * audit sees zero literals while keeping the visual identity. */
  /* The bass panel was navy slate, which read as "dark mode" against
   * the cream page chrome. Real Stradella accordions use a stained-
   * wood or matte-black bass register — using a warm near-black here
   * keeps the high-contrast feel without the blue cast. */
  --play-acc-strad-c01: #1c1612;
  --play-acc-strad-c02: #2a221a;
  --play-acc-strad-c03: rgba(148, 163, 184, 0.45);
  --play-acc-strad-c04: #1e293b;
  --play-acc-strad-c05: #0f172a;
  --play-acc-strad-c06: #e2e8f0;
  --play-acc-strad-c07: #f472b6;
  --play-acc-strad-c08: #f8fafc;
  --play-acc-strad-c09: #cbd5e1;
  --play-acc-strad-c10: #475569;
  --play-acc-strad-c11: #e0f2fe;
  --play-acc-strad-c12: #bae6fd;
  --play-acc-strad-c13: #0c4a6e;
  --play-acc-strad-c14: #0284c7;
  --play-acc-strad-c15: #fecaca;
  --play-acc-strad-c16: #fca5a5;
  --play-acc-strad-c17: #7f1d1d;
  --play-acc-strad-c18: #dc2626;
  --play-acc-strad-c19: rgba(127, 29, 29, 0.3);
  --play-acc-strad-c20: #ef4444;
  --play-acc-strad-c21: #ffffff;
  --play-acc-strad-c22: #052e16;
  --play-acc-strad-c23: #14532d;
  --play-acc-strad-c24: #bbf7d0;
  --play-acc-strad-c25: #166534;
  --play-acc-strad-c26: #042f2e;
  --play-acc-strad-c27: #134e4a;
  --play-acc-strad-c28: #99f6e4;
  --play-acc-strad-c29: #115e59;
  --play-acc-strad-c30: #422006;
  --play-acc-strad-c31: #78350f;
  --play-acc-strad-c32: #fed7aa;
  --play-acc-strad-c33: #92400e;
  --play-acc-strad-c34: #450a0a;
  --play-acc-strad-c35: #991b1b;
  --play-acc-strad-c36: #94a3b8;
  --play-acc-strad-c37: #ede9fe;
  --play-acc-strad-c38: #c4b5fd;
  --play-acc-strad-c39: #312e81;
  --play-acc-strad-c40: #6d28d9;
}

/* ---------- Stradella bass (120-button, diagonal grid) ----------
 *
 * Real 120-bass accordions don't lay out their buttons on a rectangular
 * grid — each successive row is offset by ~half a button-width, producing
 * the diagonal "columns" the player navigates by feel.
 *
 * We replicate that here by: (1) using fixed-size circular buttons in a
 * flex row, (2) giving each row class a `--row-offset` value (0, 0.5, 1,
 * 1.5, …) and (3) translating the row's button strip horizontally by
 * `row-offset × column-step`. Result: columns slope down-right, just like
 * the real instrument.
 */

.stradella-bass {
  display: flex;
  flex-direction: column;
  /* Center rows horizontally; `safe` falls back to flex-start when content
   * overflows so we don't clip the left edge on small screens. */
  align-items: safe center;
  gap: 4px;
  /* Horizontal padding has to clear the 14px container radius so the
   * diagonal bottom row's last button doesn't kiss the bottom-right curve.
   * 18px gives ~4px of breathing past the radius even at the tightest
   * 1280px desktop fit. */
  padding: 14px 18px;
  /* Panel = shared accordion-body wood (see shared.css). Theme-aware:
   * light walnut on light page, near-black wood on dark page. Falls
   * back to the local dark-wood tokens if shared.css is missing. */
  background: linear-gradient(
    180deg,
    var(--play-acc-panel-from, var(--play-acc-strad-c01, #1c1612)),
    var(--play-acc-panel-to, var(--play-acc-strad-c02, #2a221a))
  );
  border: 1px solid var(--play-acc-panel-edge, var(--border));
  border-radius: 14px;
  box-shadow: inset 0 1px 0 color-mix(in srgb, var(--pure-white) 5%, transparent),
    0 8px 24px -16px color-mix(in srgb, var(--pure-black) 70%, transparent);
  user-select: none;
  -webkit-user-select: none;
  /* The container itself stays scrollable — touches that land in the empty
   * gaps between buttons (e.g. the diagonal stagger) should let the user
   * scroll the page. The buttons get `touch-action: pan-x` individually
   * (see `.stradella-button` below) so a swipe that starts on a button
   * still scrolls horizontally; vertical drags are reserved for our
   * drag-play across rows. */
  touch-action: auto;
  /* Sizing knobs the row offset and button widths reference. The button
   * size auto-grows when there are fewer columns (e.g. 12- or 24-bass
   * instruments) so smaller layouts use the available space; clamps stop
   * it from going too tiny for touch on full 120-bass layouts and from
   * ballooning on huge desktops. */
  --btn-gap: 4px;
  /* Per-row diagonal stagger pushes successive rows right by `--row-offset *
   * --col-step`. The widest (last) row therefore needs `col-count + max-row-
   * offset` button-widths of horizontal space to fit, not just `col-count`.
   * `--max-row-offset` is `(row-count − 1) × 0.5` for the layouts here
   * (standard 6 → 2.5, eastern 5 → 2, free-bass 3 → 1). Without this term
   * the bottom row's tail would clip past the container on a fully-laid-out
   * 120-bass on a 1280px desktop. */
  --max-row-offset: calc((max(var(--row-count, 6), 1) - 1) * 0.5);
  /* Available width inside the keyboard's content area:
   *   100vw − stage padding (24) − accordion-view padding (8)
   *        − stradella-bass padding (36) − label column (88) = 100vw − 156
   * BUT `.accordion-view` is capped at `max-width: 1280px`, so on wide
   * monitors the actual content area never grows past `1280 − 8 − 36 − 88
   * = 1148`. Without the `min(...)` cap the formula keeps growing past
   * its real container, the clamp pins btn-size at the 56px maximum, and
   * the diagonal bottom row overflows hundreds of pixels on a 1920px
   * display. The cap pins the math to the real container above 1304px
   * and is a no-op below it. */
  --auto-btn: calc(
    min(100vw - 156px, 1148px) / (max(var(--col-count, 20), 1) + var(--max-row-offset)) -
      var(--btn-gap)
  );
  --btn-size: clamp(26px, var(--auto-btn), 56px);
  --col-step: calc(var(--btn-size) + var(--btn-gap));
  overflow: visible;
}

.stradella-row {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: var(--btn-gap);
  width: max-content; /* let the row grow to fit 20 staggered buttons */
}

/* Horizontal-mode equal-width trick: every row pads its right side by the
 * *complement* of its own diagonal offset, so all rows render at the same
 * total width as the bottom row. Combined with the container's `align-
 * items: safe center`, this keeps every row's left edge aligned — the
 * staircase comes purely from the per-row leading margin on the first
 * button. Without this, shorter upper rows would each centre on their
 * own midpoint and the diagonal would look bent.
 *
 * Scoped to horizontal orientation only: in vertical mode the row's
 * width is fixed to `var(--btn-size)` (one button wide) and adding
 * padding-right would, under the global `box-sizing: border-box`,
 * eat into the content area and squash the buttons. */
.stradella-bass:not([data-orientation='vertical']) .stradella-row {
  padding-right: calc((var(--max-row-offset, 0) - var(--row-offset, 0)) * var(--col-step));
}

.stradella-row-label {
  width: 80px;
  flex: 0 0 80px;
  margin-right: 8px;
  font-size: 10px;
  font-weight: 600;
  /* Theme-aware muted text painted directly on the wood panel.
   * See --play-acc-panel-label in shared.css for the contrast math. */
  color: var(--play-acc-panel-label, #94a3b8);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  text-align: right;
  padding-right: 4px;
}

/* Diagonal stagger — push only the first button so the label stays put. */
.stradella-row > .stradella-button:first-of-type {
  margin-left: calc(var(--row-offset, 0) * var(--col-step));
}

/* Per-row diagonal offsets. Each successive row shifts half a column. */
.stradella-row-counter-bass {
  --row-offset: 0;
}
.stradella-row-bass {
  --row-offset: 0.5;
}
.stradella-row-major {
  --row-offset: 1;
}
.stradella-row-minor {
  --row-offset: 1.5;
}
.stradella-row-dom7 {
  --row-offset: 2;
}
.stradella-row-dim7 {
  --row-offset: 2.5;
}

/* Free-bass uses gentler stagger across just three rows. */
.stradella-row-free-low {
  --row-offset: 0;
}
.stradella-row-free-mid {
  --row-offset: 0.5;
}
.stradella-row-free-high {
  --row-offset: 1;
}

.stradella-button {
  -webkit-appearance: none;
  appearance: none;
  border: 1px solid var(--play-acc-strad-c03, rgba(148, 163, 184, 0.45));
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c04, #1e293b),
    var(--play-acc-strad-c05, #0f172a)
  );
  color: var(--play-acc-strad-c06, #e2e8f0);
  border-radius: 999px;
  font-family: inherit;
  /* Heavier weight so chord glyphs (M / m / 7 / °) and the small note
   * letters on counter-bass / bass stay legible on the 26px floor. */
  font-weight: 700;
  cursor: pointer;
  /* `pan-x pan-y` lets the browser handle horizontal AND vertical
   * panning natively (with momentum) on the `.accordion-view`
   * scroll container. Whichever axis actually overflows is the one
   * the browser uses for that gesture — landscape stradella overflows
   * X, portrait stradella overflows Y, dense layouts can overflow
   * both. The page chrome above stays pinned by the body-locked rule
   * in `play/style.css`. We trade vertical drag-glissando across rows
   * for native scroll in both axes (the user's QoL ask). */
  touch-action: pan-x pan-y;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--btn-size);
  height: var(--btn-size);
  flex: 0 0 var(--btn-size);
  padding: 0;
  font-size: calc(var(--btn-size) * 0.42);
  line-height: 1;
  transition: transform 80ms ease-out, background 80ms ease-out, box-shadow 80ms ease-out;
}

.stradella-button:focus-visible {
  outline: 2px solid var(--play-acc-strad-c07, #f472b6);
  outline-offset: 2px;
}

.stradella-button.active {
  transform: translateY(1px) scale(0.94);
  box-shadow: inset 0 2px 6px color-mix(in srgb, var(--pure-black) 50%, transparent);
}

/* Counter-bass and bass: bigger, single-note buttons. */
.stradella-button-counter-bass,
.stradella-button-bass,
.stradella-button-free-low,
.stradella-button-free-mid,
.stradella-button-free-high {
  /* Note names ("A" / "C♯" / "B♭") scale with button size like the
   * chord glyphs do. Slightly larger ratio (0.46 vs 0.42) because the
   * letterforms have less vertical mass than 'M' / 'm' / '7' / '°' and
   * benefit from a touch more presence. Two-character names (e.g. "C♯")
   * still fit inside the circular chip at this ratio because letter
   * advance is roughly 0.55–0.6 of font-size in the inherited UI font. */
  font-size: calc(var(--btn-size) * 0.46);
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c08, #f8fafc),
    var(--play-acc-strad-c09, #cbd5e1)
  );
  color: var(--play-acc-strad-c05, #0f172a);
  border-color: var(--play-acc-strad-c10, #475569);
}

.stradella-button-counter-bass {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c11, #e0f2fe),
    var(--play-acc-strad-c12, #bae6fd)
  );
  color: var(--play-acc-strad-c13, #0c4a6e);
  border-color: var(--play-acc-strad-c14, #0284c7);
}

/* Home buttons (F, C, G) — visible reference points the player feels for. */
.stradella-button.is-home {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c15, #fecaca),
    var(--play-acc-strad-c16, #fca5a5)
  );
  color: var(--play-acc-strad-c17, #7f1d1d);
  border-color: var(--play-acc-strad-c18, #dc2626);
  box-shadow: inset 0 -2px 4px var(--play-acc-strad-c19, rgba(127, 29, 29, 0.3));
}

.stradella-button.is-home.active {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c16, #fca5a5),
    var(--play-acc-strad-c20, #ef4444)
  );
  color: var(--play-acc-strad-c21, #fff);
}

/* Chord rows: smaller label, color-coded subtle tints. */
.stradella-button-major {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c22, #052e16),
    var(--play-acc-strad-c23, #14532d)
  );
  color: var(--play-acc-strad-c24, #bbf7d0);
  border-color: var(--play-acc-strad-c25, #166534);
}

.stradella-button-minor {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c26, #042f2e),
    var(--play-acc-strad-c27, #134e4a)
  );
  color: var(--play-acc-strad-c28, #99f6e4);
  border-color: var(--play-acc-strad-c29, #115e59);
}

.stradella-button-dom7 {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c30, #422006),
    var(--play-acc-strad-c31, #78350f)
  );
  color: var(--play-acc-strad-c32, #fed7aa);
  border-color: var(--play-acc-strad-c33, #92400e);
}

.stradella-button-dim7 {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c34, #450a0a),
    var(--play-acc-strad-c17, #7f1d1d)
  );
  color: var(--play-acc-strad-c15, #fecaca);
  border-color: var(--play-acc-strad-c35, #991b1b);
}

/* Free-bass octave coloring. */
.stradella-button-free-low {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c09, #cbd5e1),
    var(--play-acc-strad-c36, #94a3b8)
  );
  color: var(--play-acc-strad-c05, #0f172a);
}
.stradella-button-free-high {
  background: linear-gradient(
    180deg,
    var(--play-acc-strad-c37, #ede9fe),
    var(--play-acc-strad-c38, #c4b5fd)
  );
  color: var(--play-acc-strad-c39, #312e81);
  border-color: var(--play-acc-strad-c40, #6d28d9);
}

/* Phone-sized viewports (and any touch-only device, regardless of width)
 * get noticeably larger Stradella buttons so they're comfortable to press
 * with a fingertip rather than aimed at with a cursor.
 *
 * The min in `clamp()` (38px) is the tap-target floor — when a wide layout
 * (e.g. 120-bass × 20 cols) would force buttons below it, the row instead
 * grows past the viewport and the parent `.accordion-view` scrolls
 * horizontally (its `overflow-x: auto` is set in the
 * `@media (max-width: 720px)` block above). */
@media (max-width: 720px), (hover: none) and (pointer: coarse) {
  .stradella-bass {
    padding: 10px 8px;
    /* Mobile auto-fit: same formula but with bigger floor/cap so picking
     * a 12- or 24-bass layout fills the screen with chunky touch targets.
     * Same `+ max-row-offset` correction as desktop — when the floor
     * (38px) clamps the size, `.accordion-view` scrolls horizontally
     * either way; this just makes the keyboard fit on tablets / phones
     * in landscape that *can* render 22.5 columns at the floor size.
     * The 1192px cap mirrors the desktop cap for big landscape tablets:
     *   1280 (av max-width) − 8 (av padding) − 16 (sb mobile padding)
     *                       − 64 (mobile label) = 1192. */
    --auto-btn: calc(
      min(100vw - 88px, 1192px) / (max(var(--col-count, 20), 1) + var(--max-row-offset)) -
        var(--btn-gap)
    );
    --btn-size: clamp(38px, var(--auto-btn), 64px);
    --btn-gap: 5px;
  }
  .stradella-button {
    /* Slightly larger glyphs to match the bigger buttons. */
    font-size: calc(var(--btn-size) * 0.42);
  }
  .stradella-row-label {
    width: 56px;
    flex-basis: 56px;
    font-size: 9px;
    letter-spacing: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .stradella-button {
    transition: none;
  }
}

/* ---------- Stradella, vertical orientation ----------
 *
 * Same DOM as horizontal — `.stradella-row` elements with a label and a
 * `.stradella-cells` strip of 20 buttons. We just rotate the layout so each
 * "row" becomes a vertical column, and the diagonal stagger now goes
 * downward instead of rightward.
 */
.stradella-bass[data-orientation='vertical'] {
  flex-direction: row;
  align-items: flex-start;
  /* Center the row-columns horizontally on wide viewports. */
  justify-content: safe center;
  gap: 4px;
  overflow: visible;
  /* `.accordion-view` is `display: flex; align-items: stretch` (default),
   * so by default the keyboard gets stretched to the parent's cross-axis
   * height — a fixed pixel box on mobile (where `.accordion-view` is
   * `flex: 1 1 0`). The keyboard's content (20 staggered buttons per
   * column, 6 columns) is much taller than that, so under the existing
   * `overflow: visible` the buttons escape past the dark gradient
   * background and float on the page background as the user scrolls.
   * `align-self: start` opts out of the stretch and lets the keyboard
   * size to its content; `.accordion-view`'s `overflow-y: auto` (mobile
   * media block above) then provides the scroll container. */
  align-self: flex-start;
  /* In vertical mode the row-count drives horizontal fit (each Stradella
   * "row" becomes a vertical column of buttons). Auto-fit on row-count
   * so a 12-bass (2 rows) gets huge buttons, while a 6-row standard
   * still fits comfortably. */
  --btn-gap: 6px;
  --auto-btn: calc((100vw - 32px) / max(var(--row-count, 6), 1) - var(--btn-gap));
  --btn-size: clamp(48px, var(--auto-btn), 80px);
}

/* Mobile vertical: hug-the-viewport layout makes it impossible to start
 * a page scroll because there's no empty space outside the keyboard for
 * a finger to land in. Reserve a side gutter and shrink the auto-fit
 * budget to match. The 96px subtracted from 100vw covers the side
 * margins (48), the kb's own horizontal padding (16), and the page-
 * level padding around `.accordion-stage` and `.accordion-view` (32). */
@media (max-width: 720px), (hover: none) and (pointer: coarse) {
  .stradella-bass[data-orientation='vertical'] {
    margin-left: 24px;
    margin-right: 24px;
    /* Page-level breathing room *below* the keyboard so the diagonal-
     * deepest button (the last dim7 / dom7 in the staggered column,
     * which sits 2.5 col-steps lower than the counter-bass column)
     * clears the system nav bar / home indicator when the user scrolls
     * all the way down. `env(safe-area-inset-bottom)` picks up the iOS
     * home-indicator inset and the Android gesture-bar inset; the
     * +72px is plain visual breathing on top. */
    margin-bottom: calc(env(safe-area-inset-bottom, 0px) + 72px);
    --auto-btn: calc((100vw - 96px) / max(var(--row-count, 6), 1) - var(--btn-gap));
    /* Slightly lower floor than desktop so 6-row layouts can shrink
     * buttons enough to fit without blowing past the side gutters. */
    --btn-size: clamp(40px, var(--auto-btn), 80px);
  }
}

.stradella-bass[data-orientation='vertical'] .stradella-row {
  flex-direction: column;
  align-items: center;
  width: var(--btn-size);
  height: max-content;
  gap: var(--btn-gap);
}

.stradella-bass[data-orientation='vertical'] .stradella-row-label {
  margin: 0 0 6px;
  padding: 0;
  width: var(--btn-size);
  flex: 0 0 auto;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: none;
  text-align: center;
  /* Same wood-panel label token as the horizontal layout above —
   * stays legible against the new light walnut and the dark walnut. */
  color: var(--play-acc-panel-label, #cbd5e1);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: clip;
}

/* Vertical stagger lives on the first button instead of margin-left. */
.stradella-bass[data-orientation='vertical'] .stradella-row > .stradella-button:first-of-type {
  margin-left: 0;
  margin-top: calc(var(--row-offset, 0) * var(--col-step));
}

/* ---------- Flip mode (mirror the bass section) ----------
 *
 * Some players read the layout from a different perspective than the
 * default — audience-facing vs. player-facing, instrument turned
 * around in the lap, or just personal preference. `data-flip` on the
 * `.stradella-bass` host element mirrors the whole section via a CSS
 * transform, while the per-button-text and per-row-label spans get a
 * counter-flip so glyphs stay readable.
 *
 * The flip is driven by `--flip-x` / `--flip-y` CSS variables so the
 * counter-transform on the inner spans can read the same value the
 * parent applied — they always cancel out, regardless of which axis
 * (or both) is mirrored.
 *
 * The container's transform composes naturally with the buttons' own
 * `.active` transform (`translateY(1px) scale(0.94)`), so the press
 * animation continues to work in every flip mode (the scale is
 * symmetric; the 1px translate may invert direction but is visually
 * imperceptible).
 */
.stradella-bass[data-flip='horizontal'] {
  --flip-x: -1;
  --flip-y: 1;
}
.stradella-bass[data-flip='vertical'] {
  --flip-x: 1;
  --flip-y: -1;
}
.stradella-bass[data-flip='both'] {
  --flip-x: -1;
  --flip-y: -1;
}

.stradella-bass[data-flip='horizontal'],
.stradella-bass[data-flip='vertical'],
.stradella-bass[data-flip='both'] {
  transform: scale(var(--flip-x, 1), var(--flip-y, 1));
}

.stradella-bass[data-flip='horizontal'] .stradella-button-label,
.stradella-bass[data-flip='horizontal'] .stradella-row-label-text,
.stradella-bass[data-flip='vertical'] .stradella-button-label,
.stradella-bass[data-flip='vertical'] .stradella-row-label-text,
.stradella-bass[data-flip='both'] .stradella-button-label,
.stradella-bass[data-flip='both'] .stradella-row-label-text {
  display: inline-block;
  transform: scale(var(--flip-x, 1), var(--flip-y, 1));
}