/* بیت‌ساز — هماهنگ با تم پردآوا؛ روشن و تاریب */
:root,
[data-theme="dark"] {
  --bt-bg: #07111f;
  --bt-bg-grad: radial-gradient(ellipse at 50% 0%, #15233a 0%, #07111f 70%);
  --bt-panel: #0f172a;
  --bt-panel-grad: linear-gradient(160deg, #15233a, #0f172a);
  --bt-line: rgba(148, 163, 184, 0.22);
  --bt-cell-bg: rgba(7, 17, 31, 0.65);
  --bt-cell-hover: rgba(148, 163, 184, 0.18);
  --bt-text: #e8edf5;
  --bt-muted: #94a3b8;
  --bt-head-l: #93c5fd;
  --bt-drum: #3b82f6;
  --bt-drum-hi: #60a5fa;
  --bt-drum-soft: rgba(59, 130, 246, 0.35);
  --bt-melody: #fbbf24;
  --bt-melody-hi: #fde68a;
  --bt-melody-soft: rgba(251, 191, 36, 0.35);
  --bt-bass: #a78bfa;
  --bt-bass-hi: #c4b5fd;
  --bt-bass-soft: rgba(167, 139, 250, 0.35);
  --bt-label-bg: #12203a;
  --bt-now: rgba(232, 237, 245, 0.85);
  --bt-now-glow: rgba(148, 197, 253, 0.45);
  --bt-shadow: 0 16px 40px rgba(0, 0, 0, 0.35);
}

[data-theme="light"] {
  --bt-bg: #eef2f8;
  --bt-bg-grad: radial-gradient(ellipse at 50% 0%, #ffffff 0%, #e6edf6 70%);
  --bt-panel: #ffffff;
  --bt-panel-grad: linear-gradient(160deg, #ffffff, #f2f6fb);
  --bt-line: rgba(15, 35, 60, 0.14);
  --bt-cell-bg: #e3eaf3;
  --bt-cell-hover: #d3deec;
  --bt-text: #1a2332;
  --bt-muted: #5a6d85;
  --bt-head-l: #2563eb;
  --bt-drum: #2563eb;
  --bt-drum-hi: #60a5fa;
  --bt-drum-soft: rgba(37, 99, 235, 0.28);
  --bt-melody: #d97706;
  --bt-melody-hi: #f59e0b;
  --bt-melody-soft: rgba(217, 119, 6, 0.28);
  --bt-bass: #7c3aed;
  --bt-bass-hi: #a78bfa;
  --bt-bass-soft: rgba(124, 58, 237, 0.26);
  --bt-label-bg: #ffffff;
  --bt-now: rgba(26, 35, 50, 0.8);
  --bt-now-glow: rgba(37, 99, 235, 0.35);
  --bt-shadow: 0 16px 40px rgba(30, 50, 80, 0.12);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
  min-height: 100%;
  background: var(--bt-bg-grad);
  background-attachment: fixed;
  color: var(--bt-text);
  font-family: "Vazirmatn", sans-serif;
  overflow-x: hidden;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

body { min-height: 100vh; min-height: 100dvh; transition: background 0.3s, color 0.3s; }

.bt-stage {
  position: relative;
  z-index: 1;
  max-width: 860px;
  margin: 0 auto;
  padding: 16px 12px 28px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.bt-masthead {
  width: 100%;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px solid var(--bt-line);
  padding-bottom: 10px;
}

.bt-masthead h1 { font-size: clamp(1.2rem, 4vw, 1.6rem); font-weight: 800; }
.bt-masthead p { color: var(--bt-muted); font-size: 0.82rem; margin-top: 2px; }

.bt-head-side { display: flex; align-items: center; gap: 16px; }
.bt-stats { display: flex; gap: 18px; }
.bt-stat { text-align: center; min-width: 54px; }
.bt-stat .l { font-size: 0.7rem; color: var(--bt-head-l); letter-spacing: 0.06em; }
.bt-stat .v {
  font-size: 1.1rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--bt-melody);
}
.bt-stat .v.is-idle { color: var(--bt-muted); }

.bt-theme {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  border: 1px solid var(--bt-line);
  background: var(--bt-panel);
  color: var(--bt-melody);
  font-size: 1.05rem;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: transform 0.15s;
}

.bt-theme:hover { transform: rotate(15deg) scale(1.06); }

/* نوار پخش */
.bt-transport {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 14px 22px;
  background: var(--bt-panel-grad);
  border: 1px solid var(--bt-line);
  border-radius: 14px;
  padding: 12px 16px;
  box-shadow: var(--bt-shadow);
}

.bt-play {
  width: 58px;
  height: 58px;
  border-radius: 50%;
  border: 1px solid rgba(59, 130, 246, 0.55);
  background: radial-gradient(circle at 34% 30%, #2563eb, #1d4ed8);
  color: #eff6ff;
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
  display: grid;
  place-items: center;
  padding-right: 4px;
  box-shadow: 0 8px 22px rgba(37, 99, 235, 0.4);
  transition: transform 0.15s;
}

.bt-play:active { transform: scale(0.94); }
.bt-play.is-playing {
  background: radial-gradient(circle at 34% 30%, #f59e0b, #d97706);
  border-color: rgba(251, 191, 36, 0.6);
  box-shadow: 0 8px 22px rgba(217, 119, 6, 0.4);
  padding-right: 0;
}

.bt-slider {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.78rem;
  color: var(--bt-muted);
}

.bt-slider input[type="range"] { width: 110px; accent-color: var(--bt-drum); cursor: pointer; }

.bt-slider .bt-val {
  min-width: 34px;
  text-align: center;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--bt-text);
}

.bt-mode {
  display: flex;
  border: 1px solid var(--bt-line);
  border-radius: 999px;
  overflow: hidden;
}

.bt-mode button {
  border: none;
  background: transparent;
  color: var(--bt-muted);
  font-family: inherit;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 7px 18px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.bt-mode button.active {
  background: var(--bt-drum);
  color: #fff;
}

/* ردیف پترن */
.bt-patterns {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px 10px;
}

.bt-inline-label,
.bt-patterns-label {
  font-size: 0.74rem;
  font-weight: 700;
  color: var(--bt-muted);
  letter-spacing: 0.04em;
}

.bt-tabs { display: flex; gap: 6px; }

.bt-tabs button {
  width: 40px;
  height: 34px;
  border-radius: 9px;
  border: 1px solid var(--bt-line);
  background: var(--bt-panel);
  color: var(--bt-muted);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 800;
  cursor: pointer;
  transition: all 0.15s;
}

.bt-tabs button.active {
  background: var(--bt-drum);
  border-color: var(--bt-drum);
  color: #fff;
  box-shadow: 0 4px 14px var(--bt-drum-soft);
}

.bt-pattern-tools { display: flex; flex-wrap: wrap; gap: 6px; }

.bt-pattern-tools button,
.bt-io button {
  background: var(--bt-panel);
  color: var(--bt-muted);
  border: 1px solid var(--bt-line);
  border-radius: 9px;
  padding: 6px 13px;
  font-family: inherit;
  font-size: 0.76rem;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
}

.bt-pattern-tools button:hover { color: var(--bt-text); border-color: var(--bt-drum); }

#btUndo.has-items { color: var(--bt-melody); border-color: var(--bt-melody-soft); }

/* شبکهٔ گام‌ها */
.bt-scroll { width: 100%; overflow-x: auto; border-radius: 14px; }

.bt-grid {
  min-width: 620px;
  background: var(--bt-panel-grad);
  border: 1px solid var(--bt-line);
  border-radius: 14px;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  box-shadow: var(--bt-shadow);
}

.bt-section-name {
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--bt-muted);
  padding-right: 4px;
  margin-top: 2px;
}

.bt-section-name::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  margin-left: 6px;
  vertical-align: 1px;
}

.bt-section--drum .bt-section-name::before { background: var(--bt-drum); }
.bt-section--melody .bt-section-name::before { background: var(--bt-melody); }
.bt-section--bass .bt-section-name::before { background: var(--bt-bass); }

.bt-row { display: flex; align-items: center; gap: 6px; }

.bt-row-label {
  position: sticky;
  right: 0;
  z-index: 2;
  flex: 0 0 74px;
  width: 74px;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--bt-muted);
  background: var(--bt-label-bg);
  border: 1px solid var(--bt-line);
  border-radius: 7px;
  padding: 6px 6px;
  text-align: center;
  white-space: nowrap;
}

.bt-cells { display: flex; gap: 4px; flex: 1; }

.bt-cell {
  flex: 1;
  min-width: 26px;
  aspect-ratio: 1 / 1.15;
  border: 1px solid var(--bt-line);
  border-radius: 6px;
  background: var(--bt-cell-bg);
  cursor: pointer;
  padding: 0;
  transition: background 0.12s, transform 0.08s;
}

.bt-cell:hover { background: var(--bt-cell-hover); }
.bt-cell:active { transform: scale(0.9); }
.bt-cell[data-first="1"] { margin-inline-start: 8px; }

.bt-cell.is-now {
  border-color: var(--bt-now);
  box-shadow: 0 0 0 1.5px var(--bt-now), 0 0 14px var(--bt-now-glow);
}

.bt-cell.on.drum {
  background: linear-gradient(160deg, var(--bt-drum-hi), var(--bt-drum));
  border-color: var(--bt-drum-hi);
  box-shadow: 0 3px 10px var(--bt-drum-soft);
}

.bt-cell.on.melody {
  background: linear-gradient(160deg, var(--bt-melody-hi), var(--bt-melody));
  border-color: var(--bt-melody-hi);
  box-shadow: 0 3px 10px var(--bt-melody-soft);
}

.bt-cell.on.bass {
  background: linear-gradient(160deg, var(--bt-bass-hi), var(--bt-bass));
  border-color: var(--bt-bass-hi);
  box-shadow: 0 3px 10px var(--bt-bass-soft);
}

/* خطکش */
.bt-ruler .bt-row-label { background: transparent; border: none; font-weight: 700; color: var(--bt-head-l); }

.bt-ruler .bt-ruler-cell {
  flex: 1;
  min-width: 26px;
  text-align: center;
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--bt-muted);
  opacity: 0.65;
  font-variant-numeric: tabular-nums;
}

.bt-ruler .bt-ruler-cell.bt-beat { color: var(--bt-head-l); opacity: 1; }
.bt-ruler .bt-ruler-cell[data-first="1"] { margin-inline-start: 8px; }

/* تایم‌لاین آهنگ */
.bt-song {
  width: 100%;
  background: var(--bt-panel-grad);
  border: 1px solid var(--bt-line);
  border-radius: 14px;
  padding: 10px 12px;
  box-shadow: var(--bt-shadow);
}

.bt-song-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 8px;
}

.bt-song-title { font-size: 0.78rem; font-weight: 800; color: var(--bt-text); }
.bt-song-hint { font-size: 0.68rem; color: var(--bt-muted); }

.bt-song-strip { display: flex; gap: 5px; }

.bt-song-slot {
  flex: 1;
  min-width: 30px;
  aspect-ratio: 1 / 1.2;
  border-radius: 7px;
  border: 1px dashed var(--bt-line);
  background: var(--bt-cell-bg);
  color: var(--bt-muted);
  font-family: inherit;
  font-size: 0.78rem;
  font-weight: 800;
  cursor: pointer;
  padding: 0;
  transition: all 0.12s;
}

.bt-song-slot:hover { border-color: var(--bt-drum); color: var(--bt-text); }

.bt-song-slot.filled {
  border-style: solid;
  border-color: var(--bt-drum);
  background: var(--bt-drum);
  color: #fff;
  box-shadow: 0 3px 8px var(--bt-drum-soft);
}

.bt-song-slot.is-now {
  outline: 2px solid var(--bt-melody);
  outline-offset: 1px;
  transform: scale(1.06);
}

/* ریتم‌ها و نمونه‌ها */
.bt-presets {
  width: 100%;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 8px;
}

.bt-presets button {
  background: var(--bt-panel);
  color: var(--bt-muted);
  border: 1px solid var(--bt-line);
  border-radius: 999px;
  padding: 7px 16px;
  font-family: inherit;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
}

.bt-presets button:hover { color: var(--bt-text); border-color: var(--bt-drum); }

.bt-presets .bt-danger:hover { color: #ef4444; border-color: rgba(239, 68, 68, 0.5); }
[data-theme="dark"] .bt-presets .bt-danger:hover { color: #fca5a5; }

.bt-presets .bt-magic { color: var(--bt-melody); border-color: var(--bt-melody-soft); }
.bt-presets .bt-magic:hover { color: var(--bt-melody-hi); }

.bt-presets .bt-demo {
  color: var(--bt-bass);
  border-color: var(--bt-bass-soft);
  font-weight: 700;
}

.bt-presets .bt-demo:hover { color: var(--bt-bass-hi); border-color: var(--bt-bass); }

/* خروجی و درون‌ریزی */
.bt-io {
  width: 100%;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}

.bt-io button { font-size: 0.84rem; padding: 8px 20px; border-radius: 999px; }
.bt-io button:hover { color: var(--bt-text); border-color: var(--bt-drum); }

.bt-io .bt-primary {
  background: var(--bt-drum);
  border-color: var(--bt-drum);
  color: #fff;
  font-weight: 700;
}

.bt-io .bt-primary:hover { color: #fff; filter: brightness(1.1); }

/* مودال‌ها */
.bt-modal {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(7, 17, 31, 0.66);
  backdrop-filter: blur(4px);
  padding: 16px;
}

.bt-modal[hidden] { display: none; }

.bt-modal-card {
  width: 100%;
  max-width: 420px;
  background: var(--bt-panel);
  border: 1px solid var(--bt-line);
  border-radius: 16px;
  padding: 18px 20px 20px;
  box-shadow: var(--bt-shadow);
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-height: 86vh;
  overflow-y: auto;
}

.bt-modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.bt-modal-head h2 { font-size: 1.05rem; font-weight: 800; }

.bt-modal-close {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  border: 1px solid var(--bt-line);
  background: transparent;
  color: var(--bt-muted);
  font-size: 1.1rem;
  cursor: pointer;
}

.bt-modal-close:hover { color: var(--bt-text); }

.bt-modal-hint { font-size: 0.76rem; color: var(--bt-muted); line-height: 1.8; }

.bt-export-list { display: flex; flex-direction: column; gap: 8px; }

.bt-export-list button {
  display: flex;
  align-items: center;
  gap: 12px;
  border: 1px solid var(--bt-line);
  border-radius: 11px;
  background: var(--bt-cell-bg);
  padding: 11px 14px;
  cursor: pointer;
  text-align: right;
  font-family: inherit;
  transition: border-color 0.15s, transform 0.1s;
}

.bt-export-list button:hover { border-color: var(--bt-drum); transform: translateX(-2px); }

.bt-export-list b {
  min-width: 48px;
  color: var(--bt-drum);
  font-size: 0.9rem;
  font-weight: 800;
  direction: ltr;
  text-align: left;
}

.bt-export-list span { font-size: 0.76rem; color: var(--bt-muted); }

.bt-export-status { min-height: 18px; font-size: 0.78rem; color: var(--bt-melody); text-align: center; }

#btImportFile { font-size: 0.76rem; color: var(--bt-muted); font-family: inherit; }

#btImportText {
  width: 100%;
  border: 1px solid var(--bt-line);
  border-radius: 10px;
  background: var(--bt-cell-bg);
  color: var(--bt-text);
  font-family: inherit;
  font-size: 0.76rem;
  padding: 9px 11px;
  resize: vertical;
  direction: ltr;
  text-align: left;
}

#btImportText:focus { outline: 1px solid var(--bt-drum); }

#btImportGo { border-radius: 10px; }

/* پیام شناور */
.bt-toast {
  position: fixed;
  bottom: 18px;
  right: 50%;
  transform: translateX(50%) translateY(16px);
  background: var(--bt-drum);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 600;
  padding: 9px 18px;
  border-radius: 999px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, transform 0.25s;
  z-index: 60;
  max-width: 90%;
  text-align: center;
}

.bt-toast.show { opacity: 1; transform: translateX(50%) translateY(0); }

/* راهنما */
.bt-legend {
  width: 100%;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 18px;
  color: var(--bt-muted);
  font-size: 0.74rem;
}

.bt-legend .i { display: inline-flex; align-items: center; gap: 6px; }

.bt-legend .sw { width: 12px; height: 12px; border-radius: 4px; display: inline-block; }
.bt-legend .sw-drum { background: var(--bt-drum); }
.bt-legend .sw-melody { background: var(--bt-melody); }
.bt-legend .sw-bass { background: var(--bt-bass); }
.bt-legend .ky {
  border: 1px solid var(--bt-line);
  border-radius: 5px;
  padding: 1px 7px;
  font-size: 0.68rem;
}

@media (max-width: 640px) {
  .bt-transport { gap: 10px 14px; padding: 10px 12px; }
  .bt-play { width: 52px; height: 52px; }
  .bt-slider input[type="range"] { width: 84px; }
  .bt-row-label { flex-basis: 64px; width: 64px; font-size: 0.66rem; }
  .bt-song-slot { min-width: 22px; font-size: 0.68rem; }
  .bt-song-hint { display: none; }
}