/* ============================================================
   Playtude · clean light/dark theme
   ============================================================ */

:root {
  /* Spacing (4px base) */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;

  /* Radius — all sharp */
  --radius-sm: 0;
  --radius-md: 0;
  --radius-lg: 0;
  --radius-pill: 0;

  /* Typography */
  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, Menlo, monospace;
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-md: 1.125rem;
  --text-lg: 1.25rem;
  --text-xl: 1.5rem;
  --text-2xl: 1.875rem;
  --text-3xl: 2.25rem;
  --leading-tight: 1.25;
  --leading-normal: 1.5;
  --leading-relaxed: 1.65;

  /* Motion */
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --duration: 150ms;

  /* Container */
  --container-max: 1200px;
}

/* Dark theme (default) — charcoal monochrome, 4-shade tier scale */
:root,
:root[data-theme="dark"] {
  --color-bg: #1c1c1c;
  --color-surface-1: #242424;
  --color-surface-2: #2d2d2d;
  --color-surface-3: #3a3a3a;

  --color-text: #f2f2f2;
  --color-text-dim: #b5b5b5;
  --color-text-muted: #7a7a7a;

  --color-border: #3a3a3a;
  --color-border-strong: #5a5a5a;

  --color-accent: #ffffff;
  --color-accent-hover: #ffffff;
  --color-accent-soft: rgba(255, 255, 255, 0.10);
  --color-on-accent: #1c1c1c;

  --color-success: #cfcfcf;
  --color-success-soft: rgba(207, 207, 207, 0.08);
  --color-warn: #909090;
  --color-warn-soft: rgba(144, 144, 144, 0.08);
  --color-danger: #5a5a5a;
  --color-danger-soft: rgba(90, 90, 90, 0.10);

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
}

/* Light theme — pure black & white, 4-shade tier scale */
:root[data-theme="light"] {
  --color-bg: #ffffff;
  --color-surface-1: #ffffff;
  --color-surface-2: #f5f5f5;
  --color-surface-3: #e8e8e8;

  --color-text: #000000;
  --color-text-dim: #4a4a4a;
  --color-text-muted: #888888;

  --color-border: #d0d0d0;
  --color-border-strong: #999999;

  --color-accent: #000000;
  --color-accent-hover: #333333;
  --color-accent-soft: rgba(0, 0, 0, 0.08);
  --color-on-accent: #ffffff;

  --color-success: #3a3a3a;
  --color-success-soft: rgba(0, 0, 0, 0.05);
  --color-warn: #707070;
  --color-warn-soft: rgba(0, 0, 0, 0.04);
  --color-danger: #a8a8a8;
  --color-danger-soft: rgba(0, 0, 0, 0.03);

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
}

/* ============================================================
   Base
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: var(--leading-normal);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

p {
  margin: 0;
  line-height: var(--leading-relaxed);
}

button {
  font-family: inherit;
  font-size: inherit;
}

button:focus-visible,
select:focus-visible,
summary:focus-visible,
[role="listitem"] *:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ============================================================
   Header
   ============================================================ */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 10;
}

.logo {
  margin: 0;
  font-size: var(--text-lg);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.logo-mark {
  width: 1.4em;
  height: 1.4em;
  flex-shrink: 0;
  display: block;
}

.header-toggles {
  display: flex;
  gap: var(--space-3);
  align-items: flex-end;
  flex-wrap: wrap;
}

.settings-btn {
  background: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text-dim);
  padding: var(--space-2);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: color var(--duration), border-color var(--duration);
}

.settings-btn:hover {
  color: var(--color-text);
  border-color: var(--color-border-strong);
}

.drawer-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  z-index: 90;
  opacity: 0;
  transition: opacity 220ms var(--ease);
}

body.drawer-open .drawer-backdrop {
  opacity: 1;
}

.settings-drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: min(360px, 100%);
  background: var(--color-surface-1);
  border-left: 1px solid var(--color-border);
  z-index: 100;
  display: flex;
  flex-direction: column;
  transform: translateX(100%);
  transition: transform 220ms var(--ease);
  box-shadow: var(--shadow-md);
}

.settings-drawer.is-open {
  transform: translateX(0);
}

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--color-border);
}

.drawer-title {
  margin: 0;
  font-size: var(--text-md);
  font-weight: 700;
}

.drawer-close {
  background: transparent;
  border: 0;
  color: var(--color-text-dim);
  font-size: var(--text-lg);
  cursor: pointer;
  padding: var(--space-1) var(--space-2);
  transition: color var(--duration);
}

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

.drawer-body {
  padding: var(--space-4) var(--space-5);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  overflow-y: auto;
  flex: 1;
}

.drawer-body .toggle-field {
  flex-direction: column;
  align-items: stretch;
  gap: var(--space-1);
}

.starter-example {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4) var(--space-5);
}

.starter-hint {
  margin: 0;
  color: var(--color-text-dim);
  font-size: var(--text-sm);
}

.starter-btn {
  background: var(--color-accent);
  color: var(--color-on-accent);
  border: 0;
  padding: 0.6rem 1.2rem;
  font-family: var(--font-mono);
  font-size: var(--text-base);
  font-weight: 600;
  cursor: pointer;
  transition: background var(--duration);
}

.starter-btn:hover {
  background: var(--color-accent-hover);
}

.toggle-field {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.toggle-caption {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  padding-left: var(--space-1);
}

.locale-toggle,
.notation-toggle,
.theme-toggle,
.staff-toggle {
  display: inline-flex;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2px;
  gap: 1px;
}

.locale-toggle button,
.notation-toggle button,
.theme-toggle button,
.staff-toggle button {
  background: transparent;
  color: var(--color-text-dim);
  border: 0;
  padding: 0.375rem 0.7rem;
  font-size: var(--text-sm);
  font-weight: 500;
  border-radius: 0;
  cursor: pointer;
  transition: background var(--duration) var(--ease), color var(--duration) var(--ease);
}

.locale-toggle button:hover,
.notation-toggle button:hover,
.theme-toggle button:hover,
.staff-toggle button:hover {
  color: var(--color-text);
}

.locale-toggle button.is-active,
.notation-toggle button.is-active,
.theme-toggle button.is-active,
.staff-toggle button.is-active {
  background: var(--color-surface-1);
  color: var(--color-text);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}

.instr-select {
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  padding: 0.4rem 0.7rem;
  cursor: pointer;
  outline: none;
  font-weight: 500;
}

.instr-select:hover {
  border-color: var(--color-border-strong);
}

/* ============================================================
   Layout
   ============================================================ */
.app-main {
  flex: 1;
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--space-6) var(--space-5);
}

/* ============================================================
   Chord input
   ============================================================ */
.chord-input-section {
  background: var(--color-surface-1);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  margin-bottom: var(--space-6);
}

.chord-chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.chord-chips:empty {
  margin-bottom: 0;
}

.chord-chip {
  display: inline-flex;
  align-items: center;
  background: var(--color-accent-soft);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  padding: 2px 4px;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}

.chord-chip-label {
  padding: 0 var(--space-2);
  color: var(--color-text);
  font-weight: 600;
}

.chord-chip-move,
.chord-chip-remove {
  background: transparent;
  border: 0;
  color: var(--color-text-dim);
  cursor: pointer;
  padding: 4px 6px;
  border-radius: var(--radius-pill);
  font-size: var(--text-sm);
  line-height: 1;
  transition: color var(--duration), background var(--duration);
}

.chord-chip-move:hover:not(:disabled),
.chord-chip-remove:hover {
  color: var(--color-text);
  background: var(--color-surface-3);
}

.chord-chip-move:disabled {
  opacity: 0.3;
  cursor: default;
}

.chord-builder {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}

.chord-builder-group {
  display: inline-flex;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2px;
  gap: 1px;
}

.chord-builder-group button {
  background: transparent;
  color: var(--color-text-dim);
  border: 0;
  padding: 0.4rem 0.7rem;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 500;
  border-radius: 0;
  cursor: pointer;
  min-width: 2.1rem;
  transition: background var(--duration), color var(--duration);
}

.chord-builder-group button:hover {
  color: var(--color-text);
}

.chord-builder-group button.is-active {
  background: var(--color-surface-1);
  color: var(--color-accent);
  font-weight: 600;
  box-shadow: var(--shadow-sm);
}

.chord-builder-quality {
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  padding: 0.45rem 0.7rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  outline: none;
}

.chord-builder-quality:hover {
  border-color: var(--color-border-strong);
}

.chord-preview {
  font-family: var(--font-mono);
  font-size: var(--text-md);
  font-weight: 600;
  color: var(--color-accent);
  padding: 0 var(--space-2);
  min-width: 3rem;
}

.chord-preview.is-invalid {
  color: var(--color-danger);
  animation: shake 0.35s var(--ease);
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-3px); }
  75% { transform: translateX(3px); }
}

.chord-add {
  background: var(--color-accent);
  color: var(--color-on-accent);
  border: 0;
  padding: 0.5rem 1.1rem;
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  margin-left: auto;
  transition: background var(--duration);
}

.chord-add:hover {
  background: var(--color-accent-hover);
}

/* ============================================================
   Page nav — primary
   ============================================================ */
.page-nav {
  display: flex;
  gap: var(--space-5);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-5);
}

.page-nav button {
  background: transparent;
  color: var(--color-text-dim);
  border: 0;
  border-bottom: 2px solid transparent;
  padding: var(--space-3) 0;
  margin-bottom: -1px;
  font-size: var(--text-md);
  font-weight: 700;
  letter-spacing: -0.01em;
  cursor: pointer;
  transition: color var(--duration), border-color var(--duration);
}

.page-nav button:hover {
  color: var(--color-text);
}

.page-nav button.is-active {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* Page-aware visibility */
body[data-page="scales"] .chord-input-section,
body[data-page="scales"] .view-tabs,
body[data-page="scales"] .toggle-field--instr {
  display: none;
}

.scales-controls {
  display: none;
  margin-bottom: var(--space-5);
}

body[data-page="scales"] .scales-controls {
  display: block;
}

/* ============================================================
   View tabs
   ============================================================ */
.view-tabs {
  display: flex;
  background: transparent;
  border-bottom: 1px solid var(--color-border);
  padding: 0;
  margin-bottom: var(--space-5);
  gap: var(--space-4);
}

.view-tabs button {
  background: transparent;
  color: var(--color-text-dim);
  border: 0;
  border-bottom: 2px solid transparent;
  padding: var(--space-2) 0;
  margin-bottom: -1px;
  font-size: var(--text-base);
  font-weight: 600;
  border-radius: 0;
  cursor: pointer;
  transition: color var(--duration), border-color var(--duration);
}

.view-tabs button:hover {
  color: var(--color-text);
}

.view-tabs button.is-active {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* ============================================================
   Results
   ============================================================ */
.results {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.results[data-view="chord"] {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-4);
  align-items: start;
}

.placeholder {
  color: var(--color-text-dim);
  text-align: center;
  padding: var(--space-6);
  font-size: var(--text-base);
  max-width: 50ch;
  margin: 0 auto;
  line-height: var(--leading-relaxed);
}

.placeholder-small {
  padding: var(--space-3);
  font-size: var(--text-sm);
}

/* ============================================================
   Parent card
   ============================================================ */
.parent-card {
  background: var(--color-surface-1);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}

.parent-card.is-hero {
  border-color: var(--color-accent);
  border-left-width: 4px;
  padding: var(--space-6);
  box-shadow: var(--shadow-md);
}

.parent-card + .parent-card,
.alt-parents .parent-card + .parent-card {
  margin-top: var(--space-3);
}

.parent-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.parent-card-title {
  margin: 0;
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--color-text);
}

.parent-card.is-hero .parent-card-title {
  font-size: var(--text-2xl);
}

.parent-card h3.parent-card-title {
  font-size: var(--text-md);
}

.parent-tag {
  font-size: var(--text-xs);
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-pill);
  font-weight: 600;
  white-space: nowrap;
}

.transposed-badge {
  display: inline-block;
  margin-left: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  font-style: italic;
  letter-spacing: 0;
}

.parent-tag-ok {
  background: var(--color-success-soft);
  color: var(--color-success);
}

.parent-tag-warn {
  background: var(--color-warn-soft);
  color: var(--color-warn);
}

.parent-card-notes {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-base);
  margin-bottom: var(--space-4);
}

.parent-card-notes span {
  padding: 0.3rem 0.6rem;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-weight: 600;
}

.parent-card-desc {
  margin: 0 0 var(--space-4) 0;
  color: var(--color-text-dim);
  max-width: 65ch;
}

.chord-mapping {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-2);
}

.chord-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
  padding: 0.5rem 0.75rem;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
}

.chord-row-out {
  opacity: 0.5;
}

.chord-row-symbol {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--color-text);
}

.chord-row-mode {
  color: var(--color-accent);
  font-weight: 500;
}

.chord-row-degree {
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  margin-left: var(--space-1);
  font-variant-numeric: tabular-nums;
}

/* Alt parents */
.alt-parents {
  background: var(--color-surface-1);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-2) var(--space-4);
}

.alt-parents summary {
  cursor: pointer;
  font-size: var(--text-sm);
  color: var(--color-text-dim);
  padding: var(--space-2) 0;
  list-style: none;
  font-weight: 500;
  user-select: none;
}

.alt-parents summary::-webkit-details-marker { display: none; }

.alt-parents summary::before {
  content: "▸";
  display: inline-block;
  color: var(--color-accent);
  margin-right: var(--space-1);
  transition: transform var(--duration);
}

.alt-parents[open] summary::before { transform: rotate(90deg); }

.alt-parents summary:hover { color: var(--color-text); }

.alt-parents .parent-card {
  border: 0;
  background: var(--color-surface-2);
  padding: var(--space-3) var(--space-4);
  margin-top: var(--space-2);
}

/* ============================================================
   Outsiders
   ============================================================ */
.outsiders {
  margin-top: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-warn);
  border-radius: var(--radius-lg);
  background: var(--color-surface-1);
}

.outsiders-title {
  margin: 0 0 var(--space-1) 0;
  font-size: var(--text-md);
  color: var(--color-warn);
  font-weight: 700;
}

.outsiders-desc {
  margin: 0 0 var(--space-4) 0;
  color: var(--color-text-dim);
  font-size: var(--text-sm);
  max-width: 65ch;
}

.outsider-group {
  margin-top: var(--space-3);
}

.outsider-title {
  margin: 0 0 var(--space-2) 0;
  font-family: var(--font-mono);
  font-size: var(--text-base);
  color: var(--color-text);
  font-weight: 600;
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
}

.outsider-tag {
  font-family: var(--font-sans);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 500;
}

.outsider-empty {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-text-dim);
}

/* ============================================================
   By-chord groups
   ============================================================ */
.chord-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.chord-group-title {
  margin: 0;
  font-size: var(--text-lg);
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--color-text);
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--color-border);
}

.chord-group-tonic {
  font-family: var(--font-sans);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
}

.scale-card-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.tier-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.tier-section:first-child {
  margin-top: 0;
}

.tier-section-header {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) 0;
}

.tier-section-label {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 700;
  color: var(--color-text-dim);
}

.tier-section-count {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-muted);
  padding: 1px 7px;
  border-radius: var(--radius-pill);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
}

.tier-fit-section .tier-section-label { color: var(--color-accent); font-weight: 800; }
.tier-compatible-section .tier-section-label { color: var(--color-success); font-weight: 700; }
.tier-color-section .tier-section-label { color: var(--color-warn); font-weight: 600; }
.tier-outside-section .tier-section-label { color: var(--color-danger); font-weight: 500; }

/* ============================================================
   Scale card
   ============================================================ */
.scale-card {
  background: var(--color-surface-1);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  border-left-width: 4px;
}

/* Fit — primary, filled accent, thickest border */
.scale-card.tier-fit {
  background: var(--color-accent-soft);
  border-color: var(--color-accent);
  border-left-color: var(--color-accent);
  border-left-width: 6px;
}

/* Compatible — neutral but emphasized */
.scale-card.tier-compatible {
  border-left-color: var(--color-success);
  border-left-width: 4px;
}

/* Color — warm tint */
.scale-card.tier-color {
  background: var(--color-warn-soft);
  border-color: var(--color-warn);
  border-left-color: var(--color-warn);
  border-left-width: 3px;
}

/* Outside — dashed, dimmer, compact */
.scale-card.tier-outside {
  background: transparent;
  border: 1px dashed var(--color-border-strong);
  border-left: 3px dashed var(--color-danger);
  padding: var(--space-3);
  opacity: 0.65;
}

.scale-card.tier-outside:hover { opacity: 1; }
.scale-card.tier-outside .scale-name { font-weight: 500; }
.scale-card.tier-outside .scale-theory { display: none; }

/* Icon prefix per tier */
.scale-name::before {
  display: inline-block;
  margin-right: 0.4rem;
  font-weight: 700;
  font-family: var(--font-mono);
}
.tier-fit .scale-name::before { content: "✓"; color: var(--color-accent); }
.tier-compatible .scale-name::before { content: "◐"; color: var(--color-success); }
.tier-color .scale-name::before { content: "★"; color: var(--color-warn); }
.tier-outside .scale-name::before { content: "⚠"; color: var(--color-danger); }

.scale-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
}

.scale-name {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-text);
}

.tier-badge {
  font-size: var(--text-xs);
  font-weight: 600;
  padding: 0.15rem 0.55rem;
  border-radius: var(--radius-pill);
  white-space: nowrap;
}

.tier-badge-fit { background: var(--color-accent-soft); color: var(--color-accent); }
.tier-badge-compatible { background: var(--color-success-soft); color: var(--color-success); }
.tier-badge-color { background: var(--color-warn-soft); color: var(--color-warn); }
.tier-badge-outside { background: var(--color-danger-soft); color: var(--color-danger); }

.scale-staff {
  margin: var(--space-2) 0 var(--space-3);
  overflow-x: auto;
}

.scale-staff svg {
  display: block;
  max-width: 100%;
  height: auto;
}

:root[data-theme="dark"] .scale-staff svg path,
:root[data-theme="dark"] .scale-staff svg line,
:root[data-theme="dark"] .scale-staff svg rect {
  stroke: var(--color-text);
  fill: var(--color-text);
}

:root[data-theme="dark"] .scale-staff svg text {
  fill: var(--color-text);
}

.scale-card.tier-outside .scale-staff { display: none; }

/* Staff visible only when Staff toggle is on */
.scale-staff { display: none; }

body[data-staff="on"] .scale-staff {
  display: block;
}

body[data-staff="on"] .scale-card.tier-outside .scale-staff {
  display: none;
}

body[data-staff="on"] .mode-notes,
body[data-staff="on"] .parent-card-notes,
body[data-staff="on"] .mode-characteristic {
  display: none;
}

.mode-notes {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  margin-bottom: var(--space-3);
}

.mode-notes span {
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  background: var(--color-surface-2);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  font-weight: 500;
}

.mode-notes span.is-characteristic {
  background: var(--color-warn-soft);
  border-color: var(--color-warn);
  color: var(--color-text);
  font-weight: 700;
}

.mode-characteristic {
  margin: 0 0 var(--space-3) 0;
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface-2);
  border-left: 2px solid var(--color-warn);
  border-radius: 0;
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
}

.mode-characteristic strong {
  font-family: var(--font-mono);
  color: var(--color-warn);
  font-weight: 700;
  margin-right: var(--space-1);
}

.mode-desc {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-text-dim);
  line-height: var(--leading-relaxed);
}

/* ============================================================
   Theory panel
   ============================================================ */
.scale-theory {
  margin-top: var(--space-3);
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-2);
}

.scale-theory summary {
  cursor: pointer;
  font-size: var(--text-xs);
  color: var(--color-text-dim);
  list-style: none;
  padding: var(--space-1) 0;
  user-select: none;
  font-weight: 600;
}

.scale-theory summary::-webkit-details-marker { display: none; }

.scale-theory summary::before {
  content: "▸";
  display: inline-block;
  color: var(--color-accent);
  margin-right: var(--space-1);
  transition: transform var(--duration);
}

.scale-theory[open] summary::before { transform: rotate(90deg); }

.scale-theory summary:hover { color: var(--color-text); }

.theory-body {
  padding: var(--space-3) 0 var(--space-1) 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  font-size: var(--text-sm);
}

.theory-intro {
  margin: 0;
  color: var(--color-text);
  line-height: var(--leading-relaxed);
}

.theory-intro code {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  padding: 0.1rem 0.35rem;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-warn);
  font-weight: 600;
}

.theory-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.theory-h {
  margin: 0;
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.theory-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.theory-note {
  display: inline-flex;
  align-items: baseline;
  gap: var(--space-1);
  padding: 0.2rem 0.55rem;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.theory-note strong {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-text);
  font-weight: 600;
}

.theory-deg {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.theory-clash {
  border-color: var(--color-danger);
}

.theory-clash .theory-deg { color: var(--color-danger); }

.theory-char {
  border-color: var(--color-warn);
}

.theory-char strong { color: var(--color-warn); }

.theory-tip {
  margin: 0;
  color: var(--color-text-dim);
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
}

.construction-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.construction-label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  min-width: 4.5em;
}

.construction-values {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.construction-pill {
  display: inline-block;
  padding: 0.15rem 0.45rem;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text);
  font-weight: 600;
  min-width: 1.6em;
  text-align: center;
}

.construction-step {
  color: var(--color-text-dim);
  font-weight: 500;
}

/* ============================================================
   Footer
   ============================================================ */
.app-footer {
  padding: var(--space-5);
  text-align: center;
  color: var(--color-text-muted);
  font-size: var(--text-xs);
  border-top: 1px solid var(--color-border);
}

/* ============================================================
   Responsive
   ============================================================ */
/* Tablet & below */
@media (max-width: 720px) {
  .app-header {
    padding: var(--space-3) var(--space-4);
  }

  .logo {
    font-size: var(--text-md);
  }

  .app-main {
    padding: var(--space-4);
  }

  .parent-card.is-hero {
    padding: var(--space-4);
  }

  .parent-card.is-hero .parent-card-title {
    font-size: var(--text-xl);
  }

  .scale-card {
    padding: var(--space-3);
  }

  .chord-input-section {
    padding: var(--space-3);
  }

  .page-nav {
    gap: var(--space-4);
  }

  .page-nav button {
    flex: 1;
    text-align: center;
    padding: var(--space-3) var(--space-2);
  }
}

/* Phones */
@media (max-width: 480px) {
  .app-header {
    padding: var(--space-3);
  }

  .logo-mark {
    width: 1.2em;
    height: 1.2em;
  }

  .app-main {
    padding: var(--space-3);
  }

  /* Chord builder — full-width stack */
  .chord-builder {
    gap: var(--space-2);
  }

  .chord-builder-group {
    width: 100%;
    justify-content: space-between;
  }

  .chord-builder-group button {
    flex: 1;
    min-height: 44px;
    min-width: 0;
  }

  .chord-builder-quality {
    width: 100%;
    min-height: 44px;
  }

  .chord-preview {
    flex-basis: 100%;
    text-align: center;
    order: -1;
    padding: var(--space-2) 0;
    font-size: var(--text-lg);
    min-width: 0;
  }

  .chord-add {
    flex-basis: 100%;
    margin-left: 0;
    padding: var(--space-3);
    min-height: 44px;
    font-size: var(--text-base);
  }

  /* Tonic picker — wrap into 2 rows */
  #scales-tonic-group {
    flex-wrap: wrap;
    gap: 2px;
  }

  #scales-tonic-group button {
    flex: 0 0 calc(16.66% - 2px);
    min-height: 40px;
  }

  /* Chord chips — bigger tap targets */
  .chord-chip-move,
  .chord-chip-remove {
    min-width: 32px;
    min-height: 32px;
    padding: var(--space-2);
  }

  /* Parent card title fits */
  .parent-card.is-hero .parent-card-title {
    font-size: var(--text-lg);
  }

  .parent-card-notes {
    font-size: var(--text-sm);
  }

  /* Settings drawer full screen on phone */
  .settings-drawer {
    width: 100%;
  }

  /* Tier sections spacing tighter */
  .tier-section {
    margin-top: var(--space-2);
  }

  /* Theory panel — slightly smaller */
  .theory-body {
    font-size: var(--text-xs);
  }

  /* Hide drawer captions to save vertical room — keep field aria-label */
  .drawer-body .toggle-caption {
    font-size: var(--text-xs);
  }

  /* Page nav buttons stretch full width */
  .page-nav {
    gap: 0;
  }

  .page-nav button {
    padding: var(--space-3) 0;
  }

  /* Footer compact */
  .app-footer {
    padding: var(--space-4);
    font-size: var(--text-xs);
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}