/* ==========================================================================
   Music Learning Tools — one theme for the whole site.
   Change the tokens in :root to restyle everything (including fretboards).
   ========================================================================== */

:root {
  --font: 'Inter', ui-sans-serif, system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --mono: ui-monospace, 'SF Mono', 'Cascadia Code', Menlo, monospace;

  --bg: #f6f5f2;
  --surface: #ffffff;
  --surface-2: #f1efea;
  --border: #e6e3dc;
  --text: #1c1b18;
  --muted: #706c64;

  --accent: #e8590c;
  --accent-soft: #fdebe0;
  --accent-ink: #ffffff;
  --chord: #2f6fd6;
  --changed: #8b5cf6;

  /* fretboard */
  --neck: #f3efe7;
  --fret: #cbc5b9;
  --string: #a39d91;
  --nut: #2f2d29;
  --inlay: #e2ddd2;
  --note-bg: #2b2a27;
  --note-ink: #ffffff;

  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.04), 0 4px 16px rgb(0 0 0 / 0.04);
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
    --bg: #0f1012;
    --surface: #17191c;
    --surface-2: #1f2226;
    --border: #2b2e33;
    --text: #edebe7;
    --muted: #9b978f;
    --accent: #ff7a33;
    --accent-soft: #3a2116;
    --accent-ink: #160b05;
    --chord: #5d9cf5;
    --changed: #a78bfa;
    --neck: #1a1c20;
    --fret: #3b3f45;
    --string: #6e727a;
    --nut: #d8d4cc;
    --inlay: #2a2d32;
    --note-bg: #ebe8e2;
    --note-ink: #131313;
    --shadow: 0 1px 2px rgb(0 0 0 / 0.3), 0 6px 20px rgb(0 0 0 / 0.25);
    color-scheme: dark;
  }
}
:root[data-theme='dark'] {
  --bg: #0f1012;
  --surface: #17191c;
  --surface-2: #1f2226;
  --border: #2b2e33;
  --text: #edebe7;
  --muted: #9b978f;
  --accent: #ff7a33;
  --accent-soft: #3a2116;
  --accent-ink: #160b05;
  --chord: #5d9cf5;
  --changed: #a78bfa;
  --neck: #1a1c20;
  --fret: #3b3f45;
  --string: #6e727a;
  --nut: #d8d4cc;
  --inlay: #2a2d32;
  --note-bg: #ebe8e2;
  --note-ink: #131313;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.3), 0 6px 20px rgb(0 0 0 / 0.25);
  color-scheme: dark;
}

/* --- base ---------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}
html {
  -webkit-text-size-adjust: 100%;
}
body {
  margin: 0;
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.55;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  transition: background 0.25s var(--ease), color 0.25s var(--ease);
}
a {
  color: inherit;
}
h1,
h2,
h3 {
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0;
}
p {
  margin: 0;
}
button {
  font: inherit;
  color: inherit;
}
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.muted {
  color: var(--muted);
}
.accent-text {
  color: var(--accent);
}

.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 16px;
}
@media (min-width: 720px) {
  .container {
    padding: 0 28px;
  }
}

/* --- site header --------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--border);
}
.site-header .container {
  display: flex;
  align-items: center;
  gap: 12px;
  height: 58px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  font-weight: 650;
  letter-spacing: -0.01em;
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: var(--accent);
  color: var(--accent-ink);
}
.header-spacer {
  flex: 1;
}
.icon-btn {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  cursor: pointer;
  transition: border-color 0.15s;
}
.icon-btn:hover {
  border-color: var(--muted);
}
.icon-btn svg {
  width: 18px;
  height: 18px;
}
.icon-sun {
  display: none;
}
:root[data-theme='dark'] .icon-sun {
  display: block;
}
:root[data-theme='dark'] .icon-moon {
  display: none;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) .icon-sun {
    display: block;
  }
  :root:not([data-theme='light']) .icon-moon {
    display: none;
  }
}

main {
  padding-top: 28px;
  padding-bottom: 64px;
}
.site-footer {
  border-top: 1px solid var(--border);
  padding: 22px 0 32px;
  color: var(--muted);
  font-size: 13px;
}

/* --- home ---------------------------------------------------------------- */
.hero {
  padding: 28px 0 24px;
}
.hero h1 {
  font-size: clamp(28px, 5vw, 44px);
  font-weight: 700;
}
.lede {
  margin-top: 10px;
  color: var(--muted);
  font-size: 16px;
  max-width: 60ch;
}
.filters {
  display: grid;
  gap: 14px;
  margin-bottom: 18px;
}
.filters-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: flex-end;
}
.search {
  flex: 1 1 260px;
  height: 40px;
  padding: 0 14px;
  border-radius: 11px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font: inherit;
}
.search:focus {
  outline: none;
  border-color: var(--accent);
}
.result-count {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 10px;
}
.card-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 290px), 1fr));
}
.card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
  text-decoration: none;
  box-shadow: var(--shadow);
  transition: transform 0.2s var(--ease), border-color 0.2s;
}
a.card:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}
.card.planned {
  opacity: 0.6;
  box-shadow: none;
  background: transparent;
  border-style: dashed;
}
.card-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.card-title {
  font-size: 18px;
  font-weight: 650;
}
.card-summary {
  color: var(--muted);
  flex: 1;
}
.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.tag {
  font-size: 12px;
  color: var(--muted);
}
.type-pill {
  font-size: 11px;
  font-weight: 650;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 99px;
  background: var(--accent-soft);
  color: var(--accent);
}
.type-game {
  background: color-mix(in srgb, var(--changed) 15%, transparent);
  color: var(--changed);
}
.type-lesson {
  background: color-mix(in srgb, var(--chord) 15%, transparent);
  color: var(--chord);
}
.soon {
  font-size: 12px;
  color: var(--muted);
}
.empty {
  padding: 40px;
  text-align: center;
  color: var(--muted);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
}

/* --- lesson page ---------------------------------------------------------- */
.lesson-head {
  margin-bottom: 22px;
}
.lesson-head h1 {
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 700;
  margin-top: 8px;
}
.back {
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
}
.back:hover {
  color: var(--accent);
}
.lesson-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}
.lesson-body > * {
  min-width: 0;
}
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 16px;
}
@media (min-width: 720px) {
  .panel {
    padding: 20px;
  }
}

/* --- controls ------------------------------------------------------------- */
.field {
  display: grid;
  gap: 6px;
  min-width: 0;
}
.field-label {
  font-size: 11px;
  font-weight: 650;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.segmented {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 2px;
  padding: 3px;
  border-radius: 11px;
  background: var(--surface-2);
  border: 1px solid var(--border);
}
.seg-btn {
  border: 0;
  background: transparent;
  padding: 6px 12px;
  min-height: 32px;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 550;
  font-size: 14px;
  color: var(--muted);
  transition: background 0.15s, color 0.15s, box-shadow 0.15s;
}
.seg-btn:hover {
  color: var(--text);
}
.seg-btn.active {
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 1px 3px rgb(0 0 0 / 0.12);
}
.segmented.compact .seg-btn {
  min-width: 40px;
  padding: 6px 8px;
}
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.chip {
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 5px 12px;
  border-radius: 99px;
  font-size: 13px;
  cursor: pointer;
  color: var(--muted);
  transition: all 0.15s;
}
.chip:hover {
  color: var(--text);
  border-color: var(--muted);
}
.chip.active {
  background: var(--text);
  border-color: var(--text);
  color: var(--bg);
}
.select {
  height: 36px;
  padding: 0 32px 0 12px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface-2)
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' fill='none' stroke='%23888' stroke-width='1.5'%3E%3Cpath d='M1 1l4 4 4-4'/%3E%3C/svg%3E")
    no-repeat right 12px center;
  color: var(--text);
  font: inherit;
  font-size: 14px;
  appearance: none;
  cursor: pointer;
}
.switch {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  cursor: pointer;
  user-select: none;
  font-size: 14px;
  font-weight: 500;
}
.switch input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
.switch-track {
  position: relative;
  width: 36px;
  height: 21px;
  border-radius: 99px;
  background: var(--border);
  transition: background 0.2s var(--ease);
  flex: none;
}
.switch-thumb {
  position: absolute;
  top: 2.5px;
  left: 2.5px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 1px 3px rgb(0 0 0 / 0.25);
  transition: transform 0.2s var(--ease);
}
.switch input:checked + .switch-track {
  background: var(--accent);
}
.switch input:checked + .switch-track .switch-thumb {
  transform: translateX(15px);
}
.switch input:focus-visible + .switch-track {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  height: 36px;
  padding: 0 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface-2);
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  white-space: nowrap;
  transition: border-color 0.15s, transform 0.1s;
}
.btn:hover {
  border-color: var(--muted);
}
.btn:active {
  transform: scale(0.97);
}
.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}
.btn-primary:hover {
  border-color: var(--accent);
  filter: brightness(1.06);
}
.link {
  border: 0;
  background: none;
  padding: 0;
  color: var(--accent);
  font-weight: 600;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
}
kbd {
  font-family: var(--mono);
  font-size: 12px;
  padding: 2px 6px;
  border-radius: 6px;
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  background: var(--surface-2);
}

/* --- fretboard (shared component) ----------------------------------------- */
.board-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: 0 -4px;
  padding: 0 4px;
  scrollbar-width: thin;
}
.fretboard {
  display: block;
  width: 100%;
  height: auto;
  font-family: var(--font);
  user-select: none;
}
.fb-neck {
  fill: var(--neck);
}
.fb-fret {
  stroke: var(--fret);
  stroke-width: 2;
}
.fb-nut {
  fill: var(--nut);
}
.fb-string {
  stroke: var(--string);
}
.fb-inlay {
  fill: var(--inlay);
}
.fb-fretnum {
  fill: var(--muted);
  font-size: 12px;
  text-anchor: middle;
  opacity: 0.55;
}
.fb-fretnum.marked {
  opacity: 1;
  font-weight: 600;
}

.fb-region-band {
  fill: var(--accent);
  opacity: 0.09;
  pointer-events: none;
  transition: opacity 0.25s var(--ease);
}
.fb-region.soft .fb-region-band,
.fb-region.hidden-band .fb-region-band {
  opacity: 0;
}
.fb-region.soft:hover .fb-region-band {
  opacity: 0.1;
}
.fb-region-pill {
  fill: var(--surface-2);
  stroke: var(--border);
  transition: fill 0.2s;
}
.fb-region-label {
  fill: var(--muted);
  font-size: 12px;
  font-weight: 700;
  text-anchor: middle;
  pointer-events: none;
}
.fb-region.clickable {
  cursor: pointer;
}
.fb-region.clickable:hover .fb-region-pill {
  stroke: var(--accent);
}
.fb-region.active .fb-region-pill {
  fill: var(--accent);
  stroke: var(--accent);
}
.fb-region.active .fb-region-label {
  fill: var(--accent-ink);
}

.note {
  cursor: pointer;
}
.note-hit {
  fill: transparent;
}
.note-body {
  opacity: 0;
  transform: scale(0.35);
  transform-box: fill-box;
  transform-origin: center;
  pointer-events: none;
  transition: opacity 0.2s var(--ease), transform 0.28s cubic-bezier(0.34, 1.5, 0.5, 1);
}
.note:not(.on):hover .note-body {
  opacity: 0.18;
  transform: scale(0.75);
}
.note.on .note-body {
  opacity: 1;
  transform: scale(1);
}
.note.on.faint .note-body {
  opacity: 0.16;
  transform: scale(0.82);
}
.note.on.faint:hover .note-body {
  opacity: 0.5;
}
.note-dot {
  fill: var(--note-bg);
  stroke: var(--neck);
  stroke-width: 2;
  transition: fill 0.2s, stroke 0.2s;
}
.note-label {
  fill: var(--note-ink);
  font-size: 12.5px;
  font-weight: 650;
  text-anchor: middle;
  letter-spacing: -0.02em;
}
.note-label.small {
  font-size: 10.5px;
}
.note.root .note-dot {
  fill: var(--accent);
}
.note.root .note-label {
  fill: var(--accent-ink);
}
.note.chord .note-dot {
  fill: var(--chord);
}
.note.chord .note-label {
  fill: #fff;
}
.note.changed .note-dot {
  stroke: var(--changed);
  stroke-width: 3.5;
}
.note.ghost .note-dot {
  fill: var(--neck);
  stroke: var(--muted);
  stroke-width: 1.5;
  stroke-dasharray: 3 3;
}
.note.ghost .note-label {
  fill: var(--muted);
}
.note.ghost .note-body {
  opacity: 0.85;
  transform: scale(0.85);
}
.note.playing .note-body {
  opacity: 1;
  transform: scale(1.3);
}
.note.playing .note-dot {
  stroke: var(--accent);
  stroke-width: 3;
}

/* chord-tone kinds (chord tools): root · guide (3/7) · color (extensions) · fifth · bass */
.note.guide .note-dot {
  fill: var(--chord);
}
.note.color .note-dot {
  fill: var(--changed);
}
.note.guide .note-label,
.note.color .note-label {
  fill: #fff;
}
.note.bass .note-dot {
  fill: var(--muted);
}
.note.common .note-dot {
  stroke: var(--accent);
  stroke-width: 3.5;
}

/* --- chord diagram (shared component) -------------------------------------- */
.chord-diagram {
  display: block;
  width: 100%;
  height: auto;
  font-family: var(--font);
  user-select: none;
}
.cd-fret,
.cd-string {
  stroke: var(--fret);
  stroke-width: 1.2;
}
.cd-nut {
  fill: var(--nut);
}
.cd-start {
  fill: var(--muted);
  font-size: 11px;
  font-weight: 650;
  text-anchor: middle;
}
.cd-mute {
  fill: var(--muted);
  font-size: 15px;
  text-anchor: middle;
}
.cd-barre {
  fill: var(--note-bg);
  opacity: 0.12;
}
.cd-dot circle {
  fill: var(--note-bg);
}
.cd-dot text,
.cd-open text {
  fill: var(--note-ink);
  font-size: 9.5px;
  font-weight: 700;
  text-anchor: middle;
  letter-spacing: -0.03em;
}
.cd-dot text.small {
  font-size: 8px;
}
.cd-dot.root circle {
  fill: var(--accent);
}
.cd-dot.root text {
  fill: var(--accent-ink);
}
.cd-dot.guide circle {
  fill: var(--chord);
}
.cd-dot.color circle {
  fill: var(--changed);
}
.cd-dot.guide text,
.cd-dot.color text {
  fill: #fff;
}
.cd-dot.bass circle {
  fill: var(--muted);
}
.cd-open circle {
  fill: var(--surface);
  stroke: var(--note-bg);
  stroke-width: 1.5;
}
.cd-open text {
  fill: var(--text);
  font-size: 7.5px;
}
.cd-open.root circle {
  stroke: var(--accent);
}
.cd-open.guide circle {
  stroke: var(--chord);
}
.cd-open.color circle {
  stroke: var(--changed);
}
.legend-dot.guide {
  background: var(--chord);
}
.legend-dot.color {
  background: var(--changed);
}
.legend-dot.common {
  box-shadow: 0 0 0 2.5px var(--accent);
}

/* legend */
.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 10px;
  font-size: 13px;
  color: var(--muted);
}
.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}
.legend-dot {
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--note-bg);
}
.legend-dot.root {
  background: var(--accent);
}
.legend-dot.chord {
  background: var(--chord);
}
.legend-dot.changed {
  box-shadow: 0 0 0 2.5px var(--changed);
}
.legend-dot.ghost {
  background: transparent;
  border: 1.5px dashed var(--muted);
}
.legend-dot.faint {
  opacity: 0.2;
}

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

/* --- home: songs ------------------------------------------------------------ */
.home-subhead {
  font-size: 13px;
  font-weight: 650;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 8px 0 12px;
}
.songs-home {
  margin-bottom: 28px;
}
.song-cards {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 220px), 1fr));
}
.song-card {
  display: grid;
  gap: 4px;
  align-content: start;
  padding: 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  text-decoration: none;
  box-shadow: var(--shadow);
  transition: transform 0.2s var(--ease), border-color 0.2s;
}
.song-card:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
}
.song-card .muted {
  font-size: 13px;
}
.song-card-icon {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  margin-bottom: 6px;
  border-radius: 10px;
  background: var(--surface-2);
  font-size: 16px;
}
.song-card.new .song-card-icon,
.song-card.continue .song-card-icon {
  background: var(--accent);
  color: var(--accent-ink);
}
.lesson-head.compact {
  margin-bottom: 10px;
}

/* melody notes on the fretboard (song practice) */
.note.melody .note-body {
  opacity: 1;
  transform: scale(1.15);
}
.note.melody .note-dot {
  fill: var(--text);
  stroke: var(--accent);
  stroke-width: 3.5;
}
.note.melody .note-label {
  fill: var(--bg);
}
.note.upcoming .note-label {
  fill: var(--accent);
  font-weight: 800;
}
.note.on.quiet .note-body {
  opacity: 0.55;
  transform: scale(0.82);
}
.legend-dot.melody {
  background: var(--text);
  box-shadow: 0 0 0 2.5px var(--accent);
}