/* Layout: header bar, collapsible panels, settings toolbar, then a full-width
   scrolling piano roll with sticky chord row, bar ruler and key column. */
:root {
  --bg: #100e16;
  --surface: #1a1723;
  --surface2: #15121d;
  --raised: #24202f;
  --line: #322c42;
  --fg: #ece8f5;
  --muted: #9a92ad;
  --accent: #b48cff;
  --accent2: #ffcf6b;
  --noteText: #100e16;
  --danger: #ff7a8a;
  --font-display: "Pixelify Sans", ui-monospace, "Cascadia Mono", Consolas, monospace;
  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color-scheme: dark;
}
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f4f2f8; --surface: #ffffff; --surface2: #f0edf6; --raised: #ffffff; --line: #dcd6e8;
    --fg: #1c1826; --muted: #6b6380; --accent: #7a4fd6; --accent2: #d99a00; --noteText: #ffffff; --danger: #c8334a;
    color-scheme: light;
  }
}
:root[data-theme="light"] {
  --bg: #f4f2f8; --surface: #ffffff; --surface2: #f0edf6; --raised: #ffffff; --line: #dcd6e8;
  --fg: #1c1826; --muted: #6b6380; --accent: #7a4fd6; --accent2: #d99a00; --noteText: #ffffff; --danger: #c8334a;
  color-scheme: light;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 14px/1.45 var(--font-body);
  display: flex;
  flex-direction: column;
}
.topbar, .panel, .toolbar { flex: none; }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

button, input, select { font: inherit; color: var(--fg); }
button, select, input[type="text"], input[type="number"] {
  background: var(--raised);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 6px 11px;
}
button { cursor: pointer; white-space: nowrap; }
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent); border-color: var(--accent); color: var(--noteText); font-weight: 600; min-width: 72px; }
button.ghost { background: transparent; }
button.danger { color: var(--danger); }
:is(button, input, select):focus-visible { outline: 2px solid var(--accent2); outline-offset: 2px; }
input[type="number"] { width: 68px; font-variant-numeric: tabular-nums; }
input[type="range"] { accent-color: var(--accent); width: 72px; }
kbd {
  font: 12px var(--font-mono);
  background: var(--surface2);
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 0 5px;
}

/* ---------- header ---------- */
.topbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  padding-block: 12px;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  border-bottom: 1px solid var(--line);
  background: var(--surface);
}
.brand { display: flex; align-items: baseline; gap: 8px; }
.logo { font: 700 24px/1 var(--font-display); color: var(--accent); letter-spacing: 0.02em; }
.logo-sub { font: 500 15px/1 var(--font-display); color: var(--muted); letter-spacing: 0.06em; text-transform: uppercase; }
.song-title { display: flex; align-items: center; gap: 10px; flex: 1 1 220px; min-width: 0; }
#songName { flex: 1; min-width: 0; max-width: 340px; font-weight: 600; }
.save-state { font-size: 12px; color: var(--muted); white-space: nowrap; }
.save-state[data-state="dirty"]::before { content: "● "; color: var(--accent2); }
.file-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.divider { width: 1px; height: 22px; background: var(--line); margin-inline: 4px; }
.download-group { display: inline-flex; align-items: center; gap: 4px; }
.group-label { color: var(--muted); font-size: 12px; text-transform: uppercase; letter-spacing: 0.06em; margin-right: 2px; }

/* ---------- panels ---------- */
.panel {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding-block: 14px 18px;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  max-height: 50vh;
  overflow-y: auto;
}
.panel-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.panel h2 { font: 700 18px var(--font-display); margin: 0; letter-spacing: 0.02em; }
.panel h3 { font-size: 12px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin: 18px 0 8px; }
.muted { color: var(--muted); }
.small { font-size: 12.5px; max-width: 70ch; }
.song-list { list-style: none; margin: 10px 0 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 320px), 1fr)); gap: 8px; }
.song-list li {
  display: flex; justify-content: space-between; align-items: center; gap: 10px;
  padding: 10px 12px; background: var(--surface2); border: 1px solid var(--line); border-radius: 8px;
}
.song-meta { display: flex; flex-direction: column; min-width: 0; }
.song-meta strong { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.song-meta span { font-size: 12px; color: var(--muted); font-variant-numeric: tabular-nums; }
.song-actions { display: flex; gap: 6px; flex: none; }
.help-cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 8px 32px; }
.keys-table { border-collapse: collapse; width: 100%; }
.keys-table td { padding: 5px 0; border-bottom: 1px solid var(--line); vertical-align: top; }
.keys-table td:first-child { padding-right: 16px; white-space: nowrap; color: var(--fg); }
.keys-table td:last-child { color: var(--muted); }

/* ---------- toolbar ---------- */
.toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  padding-block: 10px;
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
  border-bottom: 1px solid var(--line);
}
.toolbar label { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 13px; }
.toolbar label.check { gap: 5px; }
.mixer { display: inline-flex; flex-wrap: wrap; gap: 8px 12px; padding-inline: 12px; border-inline: 1px solid var(--line); }

/* ---------- piano roll ---------- */
.editor { flex: 1 1 auto; min-height: 280px; overflow: auto; position: relative; background: var(--surface); }
.sheet {
  display: grid;
  grid-template-columns: 53px max-content;
  grid-template-rows: 34px 22px max-content;
  width: max-content;
}
.corner {
  position: sticky; left: 0; z-index: 4;
  background: var(--surface); color: var(--muted);
  font-size: 10px; text-transform: uppercase; letter-spacing: 0.08em;
  display: flex; align-items: center; padding-left: 8px;
  border-right: 1px solid var(--line);
}
.corner-chord { top: 0; border-bottom: 1px solid var(--line); }
.corner-bar { top: 34px; border-bottom: 1px solid var(--line); }
.chord-row { position: sticky; top: 0; z-index: 3; height: 34px; background: var(--surface); border-bottom: 1px solid var(--line); }
.chord-row select { position: absolute; top: 4px; height: 26px; padding: 0 4px; font-size: 12px; border-radius: 4px; background: var(--surface2); }
.ruler-wrap { position: sticky; top: 34px; z-index: 3; height: 22px; }
.ruler { position: sticky; left: 53px; display: block; }
.keys { position: sticky; left: 0; z-index: 2; display: block; border-right: 1px solid var(--line); cursor: pointer; }
.grid-wrap { position: relative; }
.grid-view { position: sticky; top: 56px; left: 53px; z-index: 1; }
.grid-view canvas { display: block; cursor: crosshair; touch-action: none; }
.playhead { position: absolute; z-index: 2; top: 0; left: -5px; width: 12px; cursor: ew-resize; touch-action: none; }
.playhead::before { content: ""; position: absolute; top: 0; bottom: 0; left: 5px; width: 2px; background: var(--accent2); box-shadow: 0 0 8px var(--accent2); }
.playhead-handle {
  position: absolute; z-index: 2; top: 2px; left: -7px; width: 16px; height: 18px;
  background: var(--accent2); cursor: ew-resize; touch-action: none;
  clip-path: polygon(0 0, 100% 0, 100% 55%, 50% 100%, 0 55%);
}
.ruler-wrap { cursor: ew-resize; touch-action: none; }
body.scrubbing, body.scrubbing * { cursor: ew-resize !important; user-select: none; }
body.erasing .grid-view canvas { cursor: not-allowed; }
body.playing .playhead { pointer-events: none; } /* while playing, drag the handle above instead */
.icon-btn { display: inline-grid; place-items: center; padding-inline: 9px; }
.transport { display: inline-flex; gap: 6px; }
.select-box { position: absolute; z-index: 2; border: 1px dashed var(--accent2); background: color-mix(in srgb, var(--accent2) 12%, transparent); pointer-events: none; }

/* ---------- toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: calc(18px + env(safe-area-inset-bottom, 0px));
  transform: translateX(-50%);
  max-width: min(520px, calc(100vw - 32px));
  background: var(--raised);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  padding: 9px 14px;
  border-radius: 8px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
  z-index: 20;
}
.toast[data-kind="error"] { border-left-color: var(--danger); }

@media (max-width: 720px) {
  .divider { display: none; }
  .mixer { border-inline: 0; padding-inline: 0; }
}
@media (prefers-reduced-motion: reduce) {
  .playhead::before { box-shadow: none; }
}