:root {
  color-scheme: light;
  --ink: #221b16;
  --ink-soft: #57483b;
  --paper: #f6f1e8;
  --paper-strong: #efe7da;
  --surface: rgba(255, 251, 244, 0.82);
  --surface-solid: #fffaf2;
  --border: rgba(62, 45, 30, 0.2);
  --border-strong: rgba(62, 45, 30, 0.36);
  --accent: #8c3b2f;
  --accent-strong: #6f1f16;
  --gold: #b27a37;
  --in-tune: #6f8f52;
  --in-tune-strong: #4f6a38;
  --tune-gray: #9c9186;
  --shadow-soft: 0 10px 30px rgba(34, 27, 22, 0.1);
  --shadow-strong: 0 18px 45px rgba(34, 27, 22, 0.18);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Inter, "Segoe UI", Roboto, system-ui, sans-serif;
  color: var(--ink);
  line-height: 1.55;
  background:
    radial-gradient(circle at 85% 8%, rgba(178, 122, 55, 0.16), transparent 35%),
    radial-gradient(circle at 12% 22%, rgba(140, 59, 47, 0.1), transparent 34%),
    repeating-linear-gradient(
      180deg,
      rgba(57, 43, 31, 0.035) 0,
      rgba(57, 43, 31, 0.035) 1px,
      transparent 1px,
      transparent 36px
    ),
    linear-gradient(180deg, #fcf7ef 0%, #f3eadb 100%);
}

.page {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2.6rem 1.1rem 3.4rem;
  display: grid;
  gap: 1.35rem;
}

.hero {
  text-align: center;
  position: relative;
  padding: 1.4rem 0.7rem 0.1rem;
}

.hero::before,
.hero::after {
  content: "";
  position: absolute;
  left: 50%;
  width: min(520px, 78vw);
  height: 1px;
  transform: translateX(-50%);
  background: linear-gradient(90deg, transparent, rgba(62, 45, 30, 0.46), transparent);
}

.hero::before {
  top: 0.3rem;
}

.hero::after {
  bottom: -0.2rem;
}

.eyebrow {
  margin: 0;
  font-family: "Marck Script", "Brush Script MT", cursive;
  font-size: clamp(1.2rem, 2.6vw, 1.7rem);
  color: var(--accent);
}

.hero h1 {
  margin: 0.2rem 0 0.55rem;
  font-family: "Cormorant Garamond", Georgia, serif;
  font-size: clamp(2.4rem, 5.2vw, 4rem);
  line-height: 1.05;
  letter-spacing: 0.02em;
  color: #2d221b;
}

.stroboscope {
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-soft);
  border-radius: 1.05rem;
  padding: 1.2rem;
  display: grid;
  gap: 1rem;
  min-width: 0;
}

/* ---- sticky "live" area: the current reading and Start/Stop control stay
   pinned at the top of the viewport as the settings below scroll past,
   matching /tuner/'s .tuner-live. ---- */
.stroboscope-live {
  position: sticky;
  top: 0;
  z-index: 5;
  display: grid;
  gap: 1rem;
  margin: -1.2rem -1.2rem 0;
  padding: 1.2rem 1.2rem 0.9rem;
  background: var(--surface-solid);
  border-radius: 1.05rem 1.05rem 0 0;
  border-bottom: 1px solid var(--border);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.transport-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.6rem;
}

.tap-status {
  text-align: center;
  min-height: 1.1em;
}

.tuning-statement {
  margin: 0;
  text-align: center;
  color: var(--accent-strong);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.01em;
}

.control-block {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: 0.85rem;
  padding: 0.9rem;
  display: grid;
  gap: 0.7rem;
  align-content: start;
  max-width: 26rem;
  margin: 0 auto;
  width: 100%;
}

/* The chromatic keyboard needs the full card width for 7 natural-key
   columns to have any breathing room, unlike Reference Pitch's narrower
   compact panel. */
.control-block.keyboard-block {
  max-width: none;
}

.panel-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.panel-title {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--ink);
  /* Pushes whatever follows (the collapse toggle) to the right edge of
     the header, rather than sitting right next to the title text. */
  margin-right: auto;
}

.hint {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.82rem;
}

.hint.is-error {
  color: var(--accent-strong);
}

/* ---- collapsible frames: every panel-header carries a toggle; clicking
   it hides everything in the .control-block except the header itself,
   collapsing the frame down to a title bar. ---- */
.collapse-toggle {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  padding: 0;
  border: none;
  background: none;
  color: var(--ink-soft);
  cursor: pointer;
  border-radius: 0.5rem;
}

.collapse-toggle:hover {
  background: var(--paper-strong);
  color: var(--ink);
}

.collapse-icon {
  display: inline-block;
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1;
  transition: transform 150ms ease;
}

.collapse-toggle[aria-expanded="false"] .collapse-icon {
  transform: rotate(-90deg);
}

.control-block.is-collapsed > *:not(.panel-header) {
  display: none;
}

.fine-freq-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.6rem;
}

.fine-freq-value {
  font-variant-numeric: tabular-nums;
  color: var(--ink-soft);
  font-size: 0.85rem;
  white-space: nowrap;
}

.fine-freq-value input[type="number"] {
  width: 3.2ch;
  border: none;
  background: none;
  padding: 0;
  text-align: right;
  font: inherit;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--accent-strong);
  -moz-appearance: textfield;
  appearance: textfield;
  border-radius: 0.65rem;
}

.fine-freq-value input[type="number"]::-webkit-inner-spin-button,
.fine-freq-value input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.panel-slider {
  width: 100%;
}

/* ---- shared primitives ---- */
input,
select,
button {
  font: inherit;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.toggle-btn {
  width: min(170px, 100%);
  justify-self: center;
  border: 1px solid rgba(123, 71, 32, 0.55);
  border-radius: 999px;
  padding: 0.35rem 1rem;
  background: linear-gradient(145deg, #b57a38, #885123);
  color: #fffdf8;
  font-family: "Cormorant Garamond", Georgia, serif;
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: 0.05em;
  cursor: pointer;
  box-shadow: 0 3px 9px rgba(82, 47, 20, 0.2);
}

.toggle-btn:hover {
  filter: brightness(1.04);
}

.toggle-btn[aria-pressed="true"] {
  background: linear-gradient(145deg, #d1453a, #9c2620);
  border-color: rgba(156, 38, 32, 0.65);
  box-shadow: 0 3px 10px rgba(156, 38, 32, 0.35);
}

.small-btn {
  border: 1px solid var(--border-strong);
  background: #fff9f1;
  color: var(--ink);
  border-radius: 0.65rem;
  padding: 0.35rem 0.7rem;
  cursor: pointer;
}

.small-btn:hover {
  background: #fff3e3;
}

.toggle-btn:focus-visible,
.small-btn:focus-visible,
input:focus-visible {
  outline: 2px solid rgba(163, 86, 34, 0.9);
  outline-offset: 2px;
}

/* ============================================================
   CHROMATIC KEYBOARD — 12 discs laid out like a piano: 5 sharps in a row
   above, 7 naturals in a row below. Each disc shows only the top 90° of
   its wheel (see DISC_VIEWBOX in script.js — a wide-short viewBox, not a
   square one) and holds one concentric ring per octave-instance of that
   note in the 88-key range (see midiListForPitchClass) — every ring is
   independently analyzed, so several rings across several discs can be
   lit at once (e.g. a note's non-octave harmonics land on *other* discs'
   rings), not just one "the detected note" disc at a time.

   Showing only the top quarter of each wheel (rather than a full circle)
   is what makes discs holding 7-8 distinguishable concentric bands
   affordable at all — the same DOM/layout budget that a full circle would
   need just to stay legible instead buys roughly 4x the effective size.
   ============================================================ */
.stroboscope-keyboard {
  position: relative;
  /* Room for the sharps row to float above the naturals row without
     overlapping it — matches .stroboscope-sharps' own height below. */
  padding-top: clamp(3.6rem, 10vw, 5.2rem);
}

.stroboscope-naturals {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  row-gap: 0.6rem;
}

.stroboscope-sharps {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: clamp(3.6rem, 10vw, 5.2rem);
}

.strobe-disc {
  display: grid;
  justify-items: center;
  gap: 0.3rem;
}

/* Sharps are positioned at the boundary between two natural columns (e.g.
   C♯ sits between C and D) — the exact left% for each is set inline in
   script.js from SHARP_BOUNDARY, the same way a piano's black keys sit
   between, not on top of, the white keys beneath them. */
.stroboscope-sharps .strobe-disc {
  position: absolute;
  top: 0;
  transform: translateX(-50%);
}

.disc-device {
  display: block;
  width: min(180px, 17vw, 100%);
  overflow: visible;
}

.stroboscope-sharps .disc-device {
  width: min(140px, 13vw, 100%);
}

.disc-case {
  fill: url(#discCaseGradient);
  filter: drop-shadow(0 2px 4px rgba(61, 31, 15, 0.14));
}

.disc-window {
  fill: url(#discWindowGradient);
}

/* Idle (default): dim and gray-blue — deliberately distinct from the
   green "in tune" state below, so a ring at rest is never mistaken for a
   ring that's confidently in tune. */
.disc-ring path {
  fill: var(--tune-gray);
  opacity: 0.32;
  transition: fill 160ms ease, opacity 160ms ease;
}

.disc-ring.is-active path {
  fill: color-mix(in srgb, var(--tune-gray) calc(var(--tune-mix, 0) * 1%), #a8cdf0);
  opacity: 1;
}

.disc-ring.in-tune path {
  fill: var(--in-tune);
}

.disc-hub {
  fill: #f6f1e8;
}

.disc-label {
  font-family: "Cormorant Garamond", Georgia, serif;
  font-weight: 700;
  font-size: clamp(0.8rem, 2.2vw, 0.95rem);
  color: var(--ink-soft);
  transition: color 160ms ease;
}

/* The label reflects the disc as a whole: brightens once any of its
   rings has a confident reading, turns green once any of them is
   specifically in tune (the .in-tune rule must win when both are true,
   hence it's declared after .is-active here). */
.strobe-disc.is-active .disc-label {
  color: var(--accent-strong);
}

.strobe-disc.in-tune .disc-label {
  color: var(--in-tune-strong);
}

/* ---- Input Monitor: gain boost + level meter, same as /tuner/'s. ---- */
.signal-block .hint {
  text-align: center;
}

.signal-meters-row {
  display: flex;
  justify-content: center;
  align-items: flex-end;
  gap: 2.2rem;
  padding-top: 0.2rem;
}

.vertical-control {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.vertical-control-label {
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.vertical-control-value {
  font-variant-numeric: tabular-nums;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--accent-strong);
  /* Fixed (not min-) width, sized for the longest reading ("-60.0 dB"),
     so the level text changing length can't re-center the flex row and
     nudge the gain slider sideways. */
  width: 4.6rem;
  text-align: center;
  white-space: nowrap;
}

/* The classic rotated-range-input technique for a vertical slider: the
   input keeps its normal horizontal layout box, centered then rotated
   -90deg so dragging up (visually) still means dragging toward the max
   end (originally the right) — the natural "higher fader = more gain" feel. */
.vertical-slider-wrap {
  position: relative;
  width: 44px;
  height: 160px;
}

.vertical-slider-wrap .vertical-slider {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 160px;
  height: 32px;
  margin: 0;
  transform: translate(-50%, -50%) rotate(-90deg);
  accent-color: var(--accent);
}

/* Same golden-case-over-dark-track language as the disc bezels, just
   without segments — a single continuous fill rising from the bottom,
   colored gold at safe levels and warming toward the accent red as it
   nears clipping. */
.level-meter-case {
  width: 44px;
  height: 160px;
  padding: 4px;
  border-radius: 1rem;
  background: linear-gradient(145deg, #caa06a, #8a5a30);
  box-shadow: 0 2px 5px rgba(61, 31, 15, 0.14);
}

.level-meter-track {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 0.7rem;
  background: linear-gradient(180deg, #241b14, #171310);
  box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.35);
  overflow: hidden;
}

.level-meter-fill {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 0%;
  background: color-mix(in srgb, var(--accent) calc(var(--level-mix, 0) * 1%), var(--gold));
  transition: height 90ms linear;
}

.footer {
  text-align: center;
  color: var(--ink-soft);
  font-family: "Cormorant Garamond", Georgia, serif;
  font-size: 1.22rem;
}

.footer-links,
.footer-contact {
  margin: 0.3rem 0 0;
  font-family: Inter, "Segoe UI", Roboto, system-ui, sans-serif;
  font-size: 0.85rem;
}

.footer-links a,
.footer-contact a {
  color: var(--ink-soft);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.05rem;
  transition: color 120ms ease, border-color 120ms ease;
}

.footer-links a:hover,
.footer-contact a:hover {
  color: var(--accent);
  border-color: var(--accent);
}

@media (max-width: 720px) {
  .page {
    padding-top: 2rem;
  }

  .stroboscope {
    padding: 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}