:root {
  color-scheme: dark;
  --night: #06111a;
  --night-deep: #02070c;
  --panel: #0a1720;
  --ink: #f4f1e9;
  --muted: #aab7bd;
  --quiet: #718087;
  --line: rgb(244 241 233 / 13%);
  --aqua: #52dbe2;
  --signal: #ff795c;
  --magenta: #ec23bc;
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-width: 20rem;
  height: 100%;
  margin: 0;
}

html {
  background: var(--night);
}

body {
  isolation: isolate;
  overflow-x: hidden;
  overflow-y: auto;
  background:
    radial-gradient(circle at 50% 46%, rgb(31 93 119 / 15%), transparent 32rem),
    radial-gradient(circle at 82% 22%, rgb(82 219 226 / 6%), transparent 24rem),
    linear-gradient(145deg, var(--night-deep), var(--night) 58%, #07131c);
  color: var(--ink);
  font: 16px/1.5 "Avenir Next", Avenir, "Century Gothic", sans-serif;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgb(255 255 255 / 1.5%) 1px, transparent 1px),
    linear-gradient(90deg, rgb(255 255 255 / 1.5%) 1px, transparent 1px);
  background-size: 4rem 4rem;
  content: "";
  mask-image: radial-gradient(circle at 50% 50%, black, transparent 76%);
  pointer-events: none;
}

body::after {
  position: fixed;
  inset: -12%;
  z-index: -1;
  background:
    radial-gradient(ellipse at 16% 78%, rgb(236 35 188 / 13%), transparent 28%),
    radial-gradient(ellipse at 83% 66%, rgb(82 219 226 / 14%), transparent 30%),
    radial-gradient(ellipse at 52% 18%, rgb(255 121 92 / 8%), transparent 22%);
  content: "";
  filter: blur(2rem);
  pointer-events: none;
}

a {
  color: inherit;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--aqua);
  outline-offset: 4px;
}

button {
  font: inherit;
  touch-action: manipulation;
}

[hidden] {
  display: none !important;
}

.skip-link {
  position: fixed;
  top: -5rem;
  left: 1rem;
  z-index: 30;
  padding: 0.7rem 1rem;
  border-radius: 0.55rem;
  background: var(--ink);
  color: var(--night);
}

.skip-link:focus {
  top: 1rem;
}

.test-shell {
  display: grid;
  width: min(90rem, calc(100% - 3rem));
  height: 100vh;
  height: 100svh;
  margin-inline: auto;
  grid-template-rows: auto minmax(0, 1fr);
}

.site-header {
  display: grid;
  min-height: 5.15rem;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 2rem;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  width: max-content;
  min-height: 44px;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.98rem;
  font-weight: 750;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.brand img {
  border-radius: 0.78rem;
  box-shadow: 0 0 1.8rem rgb(82 219 226 / 18%);
}

.site-header nav {
  display: flex;
  gap: 1.5rem;
}

.site-header nav a {
  display: inline-flex;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  color: #c0c9cc;
  font-size: 0.86rem;
  text-decoration: none;
}

.site-header nav a:hover {
  color: var(--ink);
}

main {
  position: relative;
  display: grid;
  min-height: 0;
  padding: 1.1rem 0 1.25rem;
  grid-template-rows: auto minmax(0, 1fr);
}

.progress {
  position: relative;
  display: grid;
  min-height: 3.15rem;
  margin-inline: 0.5rem;
  grid-template-columns: repeat(4, 1fr);
  align-items: start;
}

.progress::before {
  position: absolute;
  top: 1.65rem;
  right: 8%;
  left: 8%;
  height: 2px;
  background: linear-gradient(
    90deg,
    rgb(82 219 226 / 72%),
    rgb(82 219 226 / 18%) 28%,
    #34434d 54%,
    rgb(236 35 188 / 24%)
  );
  box-shadow: 0 0 1rem rgb(82 219 226 / 12%);
  content: "";
}

.progress-step {
  position: relative;
  z-index: 2;
  display: grid;
  justify-items: center;
  gap: 0.32rem;
  color: #7c898f;
  font-size: 0.78rem;
  font-weight: 650;
}

.progress-step b {
  display: block;
  width: 1.05rem;
  aspect-ratio: 1;
  border: 2px solid #42515b;
  border-radius: 50%;
  background: var(--night);
  box-shadow: 0 0 0 0.28rem var(--night);
}

.progress-step.is-complete,
.progress-step.is-current {
  color: var(--aqua);
}

.progress-step.is-complete b,
.progress-step.is-current b {
  border-color: var(--aqua);
  background: var(--aqua);
  box-shadow:
    0 0 0 0.28rem var(--night),
    0 0 1rem rgb(82 219 226 / 42%);
}

.progress-step.is-current b {
  background: var(--night);
  box-shadow:
    0 0 0 0.28rem var(--night),
    0 0 0 0.12rem rgb(82 219 226 / 20%),
    0 0 1.4rem rgb(82 219 226 / 60%);
}

.screen {
  min-height: 0;
}

.eyebrow {
  margin: 0;
  color: var(--aqua);
  font: 760 0.67rem/1 "SFMono-Regular", Consolas, monospace;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1,
h2 {
  margin: 0;
  font-size: clamp(2.5rem, 4.2vw, 4.2rem);
  font-weight: 760;
  letter-spacing: -0.06em;
  line-height: 0.98;
}

.screen h1[tabindex="-1"]:focus {
  outline: none;
}

h1 span,
h1 em,
h2 span,
h2 em {
  color: var(--signal);
  font-style: normal;
  font-weight: 620;
}

.ready-screen {
  display: grid;
  width: min(62rem, 100%);
  height: 100%;
  min-height: 0;
  margin-inline: auto;
  padding-block: clamp(0.5rem, 2vh, 1.25rem);
  grid-template-rows: auto minmax(12rem, 1fr) auto;
  align-content: stretch;
  justify-items: center;
  gap: clamp(0.55rem, 1.5vh, 1rem);
  text-align: center;
}

.ready-heading {
  max-width: 44rem;
}

.ready-heading h1 {
  font-size: clamp(2.35rem, 4vw, 3.75rem);
  text-shadow: 0 1rem 4rem rgb(82 219 226 / 10%);
}

.ready-heading > p:last-child {
  margin: 0.55rem auto 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.ready-scene {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 12rem;
  max-height: 24rem;
  /* Keep the 3:2 illustration close to its own shape so the couple and the
     laptop stay in frame instead of being cropped to a thin letterbox. */
  aspect-ratio: 16 / 9;
  max-width: calc((100vh - 24rem) * 16 / 9);
  margin: 0;
  align-self: center;
  overflow: hidden;
  border: 1px solid rgb(82 219 226 / 32%);
  border-radius: 1.35rem;
  background: #020912;
  box-shadow:
    inset 0 0 4rem rgb(30 109 137 / 12%),
    0 1rem 3rem rgb(0 0 0 / 38%),
    -1rem 0 3rem rgb(236 35 188 / 7%),
    1rem 0 3rem rgb(82 219 226 / 10%);
}

.ready-scene > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 54%;
}

.text-action {
  min-height: 44px;
  padding: 0.4rem 0.6rem;
  border: 0;
  background: transparent;
  color: var(--aqua);
  cursor: pointer;
  font-weight: 700;
}

.ready-actions {
  display: grid;
  width: min(48rem, 100%);
  justify-items: center;
}

.primary-action {
  display: inline-grid;
  width: min(48rem, 100%);
  min-height: 4.35rem;
  padding: 0.82rem 1.3rem;
  border: 1px solid rgb(255 255 255 / 42%);
  border-radius: 1.25rem;
  background: linear-gradient(96deg, #ff7458 0%, #ff8a64 28%, #73c5c2 68%, #45d5df 100%);
  box-shadow:
    0 0.9rem 2rem rgb(0 0 0 / 35%),
    -0.6rem 0.5rem 2.4rem rgb(255 121 92 / 15%),
    0.6rem 0.5rem 2.4rem rgb(82 219 226 / 15%),
    inset 0 1px rgb(255 255 255 / 18%);
  color: var(--night);
  cursor: pointer;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  font-size: clamp(1rem, 1.6vw, 1.25rem);
  font-weight: 760;
  text-align: center;
  text-decoration: none;
  text-shadow: none;
}

.primary-action img {
  width: 1.8rem;
  height: 1.8rem;
}

.ready-actions [data-start-preview] {
  display: flex;
  min-height: 6.5rem;
  padding: 1.1rem 1.6rem;
  justify-content: center;
  gap: 1rem;
  border-radius: 1.75rem;
  font-size: clamp(1.55rem, 2.4vw, 2rem);
  letter-spacing: -0.025em;
}

.ready-actions [data-start-preview] img {
  width: 3.25rem;
  height: 3.25rem;
  padding: 0.9rem;
  border: 1px solid rgb(6 17 26 / 18%);
  border-radius: 50%;
  background: rgb(6 17 26 / 12%);
  box-shadow: inset 0 1px rgb(255 255 255 / 20%);
}

.primary-action:disabled {
  cursor: not-allowed;
  filter: grayscale(0.4);
  opacity: 0.5;
}

.preview-limit {
  margin: 0;
  color: #88969d;
  font-size: 0.72rem;
  text-align: center;
}

.listen-screen {
  display: grid;
  height: 100%;
  min-height: 0;
  padding-top: 0.5rem;
  grid-template-columns: minmax(17rem, 0.38fr) minmax(28rem, 1fr);
  grid-template-rows: minmax(0, 1fr) auto;
  gap: 1.5rem 3rem;
}

.listen-copy {
  align-self: center;
}

.listen-copy h2 {
  margin-top: 0.75rem;
  font-size: clamp(2.7rem, 4.8vw, 4.5rem);
}

.listen-copy > p:not(.eyebrow) {
  max-width: 25rem;
  margin: 1rem 0 0;
  color: var(--muted);
}

.listening-stage {
  position: relative;
  display: grid;
  min-height: 0;
  padding: clamp(1rem, 3vw, 2rem);
  overflow: hidden;
  border: 1px solid rgb(82 219 226 / 18%);
  border-radius: 1.5rem;
  background:
    radial-gradient(circle at 67% 38%, rgb(82 219 226 / 10%), transparent 30%),
    radial-gradient(circle at 35% 65%, rgb(236 35 188 / 7%), transparent 32%),
    rgb(3 10 17 / 62%);
  box-shadow:
    inset 0 0 4rem rgb(30 109 137 / 10%),
    0 1rem 3rem rgb(0 0 0 / 22%);
  grid-template-rows: minmax(8rem, 1fr) auto auto auto auto;
  justify-items: center;
  gap: 0.75rem;
}

.tone-visualizer {
  display: block;
  width: 100%;
  height: auto;
  max-height: 100%;
  /* Matching the viewBox keeps the wave spanning the full stage width instead
     of letterboxing itself into a narrow strip. */
  aspect-ratio: 960 / 300;
  align-self: center;
  overflow: visible;
  pointer-events: none;
}

.tone-descent-guide,
.tone-wave,
.tone-wave-glow,
.tone-emit,
.tone-head-halo {
  fill: none;
  stroke: url("#tone-spectrum");
  stroke-linecap: round;
}

.tone-descent-guide {
  stroke: rgb(244 241 233 / 14%);
  stroke-dasharray: 2 14;
  stroke-width: 2;
}

.tone-wave {
  stroke-width: 4;
  filter: url("#tone-glow");
  opacity: 0.92;
}

.tone-wave-glow {
  stroke-width: 15;
  filter: url("#tone-glow");
  opacity: 0.13;
}

/* The whole wave group is stretched horizontally across the sweep, so every
   wavelength widens together — the visual analogue of the pitch dropping. */
.tone-wave-group {
  transform: scaleX(1) translateY(0);
  transform-box: view-box;
  transform-origin: 40px 214px;
}

.tone-beam {
  fill: url("#tone-beam");
}

.listening-stage.is-sweeping .tone-wave-group {
  animation: tone-stretch var(--sweep-duration, 20000ms) linear forwards;
}

@keyframes tone-stretch {
  to {
    transform: scaleX(3.15) translateY(34px);
  }
}

/* The head rides the same descent curve the dotted guide traces. */
.tone-head {
  offset-path: path("M92 62 C332 54 626 112 876 188");
  offset-distance: 0%;
  offset-rotate: 0deg;
  opacity: 0;
}

.listening-stage.is-sweeping .tone-head {
  animation: tone-travel var(--sweep-duration, 20000ms) linear forwards;
}

@keyframes tone-travel {
  from {
    offset-distance: 0%;
    opacity: 1;
  }

  to {
    offset-distance: 100%;
    opacity: 1;
  }
}

.tone-head-core {
  fill: #f4f1e9;
  filter: url("#tone-glow");
}

.tone-head-halo {
  stroke-width: 3;
  filter: url("#tone-glow");
  opacity: 0.9;
}

.tone-emit {
  stroke-width: 2.5;
  opacity: 0;
  transform-box: fill-box;
  transform-origin: center;
}

.listening-stage.is-sweeping .tone-emit {
  animation: tone-emit 1.9s ease-out infinite;
}

.listening-stage.is-sweeping .tone-emit-late {
  animation-delay: -0.95s;
}

@keyframes tone-emit {
  from {
    opacity: 0.55;
    transform: scale(0.55);
  }

  to {
    opacity: 0;
    transform: scale(2.9);
  }
}

.tone-readout {
  margin: 0;
  color: var(--aqua);
  font: 760 clamp(1.5rem, 2.6vw, 2.1rem)/1 "SFMono-Regular", Consolas, monospace;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  opacity: 0;
}

.listening-stage.is-sweeping .tone-readout {
  opacity: 1;
}

.sweep-scale {
  display: grid;
  width: min(38rem, 100%);
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.7rem;
  opacity: 0;
}

.listening-stage.is-sweeping .sweep-scale {
  opacity: 1;
}

.sweep-cap {
  color: #7d8b92;
  font: 760 0.62rem/1 "SFMono-Regular", Consolas, monospace;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.sweep-track {
  height: 0.4rem;
  overflow: hidden;
  border-radius: 999px;
  background: rgb(244 241 233 / 10%);
}

.sweep-fill {
  display: block;
  width: 100%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #52dbe2, #9b7de7 52%, #ff795c);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform linear;
}

.listening-status {
  display: grid;
  justify-items: center;
  gap: 0.1rem;
  text-align: center;
}

/* While the start overlay is up, its own label is the only call to action —
   the status line underneath would otherwise ghost through the scrim. */
.listening-stage.is-idle .listening-status {
  opacity: 0;
}

.listening-status strong {
  color: var(--aqua);
  font-size: 1.1rem;
}

.listening-action {
  position: relative;
  min-height: 9rem;
  border-width: 2px;
  border-radius: 2rem;
  background:
    linear-gradient(115deg, rgb(255 255 255 / 18%), transparent 28% 72%, rgb(255 255 255 / 12%)),
    linear-gradient(96deg, #ff7458 0%, #ff8a64 28%, #73c5c2 68%, #45d5df 100%);
  box-shadow:
    0 1.1rem 2.6rem rgb(0 0 0 / 38%),
    -0.8rem 0.7rem 2.8rem rgb(255 121 92 / 20%),
    0.8rem 0.7rem 2.8rem rgb(82 219 226 / 20%),
    inset 0 1px rgb(255 255 255 / 28%);
  grid-template-columns: 1fr;
  gap: 0.4rem;
  font-size: 1.5rem;
}

.listening-action-kicker {
  font: 800 0.68rem/1 "SFMono-Regular", Consolas, monospace;
  letter-spacing: 0.17em;
  text-transform: uppercase;
}

.listening-action-main {
  font-size: clamp(2rem, 3.6vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1;
}

.listening-action-sub {
  color: rgb(6 17 26 / 76%);
  font-size: clamp(0.82rem, 1.15vw, 0.98rem);
  font-weight: 600;
  letter-spacing: 0;
  text-shadow: none;
}

/* A slow halo on the live button so the stage reads as waiting for a tap. */
.listening-action::after {
  position: absolute;
  border-radius: inherit;
  content: "";
  inset: -0.35rem;
  pointer-events: none;
}

.listening-stage.is-sweeping .listening-action::after {
  animation: listening-invite 2.1s ease-out infinite;
  box-shadow: 0 0 0 0 rgb(244 241 233 / 34%);
}

@keyframes listening-invite {
  to {
    box-shadow: 0 0 0 1.15rem rgb(244 241 233 / 0%);
  }
}

.listening-action:active {
  filter: brightness(1.12);
  transform: scale(0.988);
}

.listening-stage > .text-action {
  width: 100%;
  min-height: 4rem;
  padding: 0.8rem 1.1rem;
  border: 1px solid rgb(82 219 226 / 48%);
  border-radius: 1rem;
  background: rgb(82 219 226 / 9%);
  color: #dffcff;
  font-size: 1rem;
}

.start-tone {
  position: absolute;
  inset: 0;
  z-index: 3;
  display: grid;
  width: 100%;
  border: 0;
  background: rgb(3 10 17 / 72%);
  color: var(--ink);
  cursor: pointer;
  touch-action: manipulation;
  backdrop-filter: blur(4px);
  place-content: center;
}

.start-tone-control {
  display: grid;
  width: min(26rem, calc(100vw - 4rem));
  min-height: 7rem;
  padding: 1rem 1.2rem;
  border: 1px solid transparent;
  border-radius: 1.5rem;
  background:
    linear-gradient(145deg, rgb(10 23 32 / 96%), rgb(4 12 19 / 96%)) padding-box,
    linear-gradient(105deg, var(--signal), #ffb075 43%, var(--aqua)) border-box;
  box-shadow:
    0 1.2rem 3rem rgb(0 0 0 / 42%),
    -0.8rem 0.8rem 2.5rem rgb(255 121 92 / 15%),
    0.8rem 0.8rem 2.5rem rgb(82 219 226 / 15%),
    inset 0 1px rgb(255 255 255 / 9%);
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 1rem;
  text-align: left;
}

.start-tone-icon {
  display: grid;
  width: 3.7rem;
  aspect-ratio: 1;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--signal), #ff9f73 43%, var(--aqua));
  box-shadow:
    0 0.8rem 1.8rem rgb(0 0 0 / 28%),
    0 0 1.6rem rgb(82 219 226 / 22%);
  place-items: center;
}

.start-tone-icon img {
  width: 1.35rem;
  height: 1.35rem;
}

.start-tone-copy {
  display: grid;
  gap: 0.16rem;
}

.start-tone-kicker {
  color: var(--aqua);
  font: 800 0.62rem/1 "SFMono-Regular", Consolas, monospace;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.start-tone-copy strong {
  font-size: clamp(1.55rem, 2.5vw, 2rem);
  letter-spacing: -0.03em;
  line-height: 1.05;
}

.start-tone-detail {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 560;
}

.start-tone:focus-visible {
  outline-offset: -0.4rem;
}

.listen-screen > .preview-limit {
  align-self: end;
}

.handoff-screen {
  display: grid;
  width: min(68rem, 100%);
  height: 100%;
  min-height: 0;
  margin-inline: auto;
  grid-template-columns: minmax(20rem, 1fr) minmax(22rem, 1fr);
  align-items: center;
  gap: 3rem;
}

.handoff-screen figure {
  height: min(52vh, 29rem);
  margin: 0;
}

.handoff-screen figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.handoff-screen h2 {
  margin-top: 0.75rem;
}

.handoff-result {
  display: grid;
  width: 100%;
  margin: 1.1rem 0 0.65rem;
  padding: clamp(0.9rem, 2vw, 1.15rem);
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 1rem;
  border: 1px solid rgb(82 219 226 / 24%);
  border-radius: 1.35rem;
  background: linear-gradient(
    135deg,
    rgb(82 219 226 / 14%),
    rgb(3 10 17 / 62%) 48%,
    rgb(236 35 188 / 12%)
  );
  box-shadow:
    inset 0 1px rgb(255 255 255 / 8%),
    0 1.1rem 2.8rem rgb(0 0 0 / 24%);
}

.handoff-result-graphic {
  display: grid;
  width: clamp(4.4rem, 7vw, 5.6rem);
  aspect-ratio: 1;
  place-items: center;
  border: 1px solid rgb(255 255 255 / 28%);
  border-radius: 1.35rem;
  background: linear-gradient(145deg, var(--signal), #9b7de7 52%, var(--aqua));
  box-shadow: 0 0.7rem 2rem rgb(82 219 226 / 22%);
}

.handoff-result-graphic img {
  width: 52%;
  height: 52%;
}

.handoff-result p {
  min-width: 0;
  margin: 0;
}

.handoff-result-label {
  display: block;
  color: var(--aqua);
  font: 760 0.68rem/1 "SFMono-Regular", Consolas, monospace;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.handoff-result [data-first-result] {
  display: block;
  margin-top: 0.3rem;
  color: var(--ink);
  font: 760 clamp(2.9rem, 5.3vw, 4.6rem)/0.9 "Avenir Next", Avenir, sans-serif;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.055em;
}

.handoff-volume {
  margin: 0 0 1.15rem;
  color: var(--muted);
  font-size: 0.88rem;
}

.handoff-screen .primary-action {
  width: 100%;
}

.result-screen {
  position: relative;
  display: grid;
  width: min(54rem, 100%);
  height: 100%;
  min-height: 0;
  margin-inline: auto;
  align-content: center;
  justify-items: center;
  gap: clamp(0.45rem, 1.2vh, 0.85rem);
  text-align: center;
}

.result-glow {
  position: absolute;
  top: 14%;
  left: 50%;
  z-index: -1;
  width: min(42rem, 90vw);
  aspect-ratio: 1.5;
  border-radius: 50%;
  background: radial-gradient(circle, rgb(82 219 226 / 17%), transparent 66%);
  transform: translateX(-50%);
}

.result-screen h2 {
  max-width: 18ch;
}

.result-range {
  margin-top: 0.35rem;
  color: var(--ink);
  font: 760 clamp(2.8rem, 7vw, 5rem)/0.95 "Avenir Next", Avenir, sans-serif;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.055em;
}

.result-spectrum {
  display: grid;
  width: min(38rem, 100%);
  margin-block: 0.2rem 0.35rem;
  gap: 0.65rem;
}

.result-spectrum-track {
  position: relative;
  height: 0.78rem;
  margin: 2rem 0.3rem 1.25rem;
  border-radius: 999px;
  background: var(--line);
  box-shadow: inset 0 0 0 1px rgb(244 241 233 / 8%);
}

.sweet-spot-band {
  position: absolute;
  inset-block: 0;
  left: 25%;
  width: 50%;
  min-width: 6px;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--magenta), #6d33ef 52%, var(--aqua));
  box-shadow: 0 0 1rem rgb(82 219 226 / 38%);
}

.result-marker {
  position: absolute;
  top: 50%;
  width: 3px;
  height: 2rem;
  border-radius: 999px;
  background: var(--ink);
  color: var(--ink);
  box-shadow: 0 0 0.7rem currentcolor;
  transform: translate(-50%, -50%);
}

.result-marker-one {
  color: var(--aqua);
}

.result-marker-two {
  color: var(--signal);
}

.result-marker b {
  position: absolute;
  left: 50%;
  padding: 0.12rem 0.32rem;
  border: 1px solid currentcolor;
  border-radius: 0.35rem;
  background: var(--night);
  color: currentcolor;
  font: 800 0.58rem/1 "SFMono-Regular", Consolas, monospace;
  transform: translateX(-50%);
}

.result-marker-one b {
  bottom: calc(100% + 0.3rem);
}

.result-marker-two b {
  top: calc(100% + 0.3rem);
}

.result-spectrum-labels {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 0.5rem;
  color: var(--quiet);
  font: 650 0.62rem/1 "SFMono-Regular", Consolas, monospace;
}

.result-spectrum-labels span:first-child {
  text-align: left;
}

.result-spectrum-labels span:last-child {
  text-align: right;
}

.result-spectrum-labels strong {
  color: var(--ink);
  font-size: 0.62rem;
  opacity: 0;
  text-transform: uppercase;
}

.result-spectrum.has-range .result-spectrum-labels strong {
  opacity: 1;
}

.result-partners {
  display: flex;
  width: 100%;
  margin: 0;
  border: 0;
}

.result-partners div {
  display: grid;
  flex: 1;
  padding: 0;
  justify-items: center;
  gap: 0.15rem;
}

.result-partners div:first-child {
  color: var(--aqua);
}

.result-partners div:last-child {
  color: var(--signal);
}

.result-partners div + div {
  border: 0;
}

.result-partners span {
  color: currentcolor;
  font-size: 0.72rem;
  font-weight: 760;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.result-partners strong {
  color: var(--ink);
  font: 760 clamp(1.3rem, 3vw, 1.8rem)/1 "SFMono-Regular", Consolas, monospace;
  font-variant-numeric: tabular-nums;
}

.result-partners .is-missing strong {
  color: var(--muted);
}

.result-limit {
  max-width: 34rem;
  margin: 0;
  color: var(--muted);
  font-size: 0.78rem;
}

.result-actions {
  display: grid;
  width: min(32rem, 100%);
  justify-items: center;
  gap: 0.2rem;
}

.result-actions .primary-action {
  min-height: 3.8rem;
}

.error-message {
  position: absolute;
  right: 1rem;
  bottom: 1rem;
  left: 1rem;
  z-index: 20;
  max-width: 42rem;
  margin: auto;
  padding: 0.8rem 1rem;
  border: 1px solid rgb(255 121 92 / 50%);
  border-radius: 0.8rem;
  background: #321611;
  color: #ffd4ca;
  text-align: center;
}

@media (prefers-reduced-motion: no-preference) {
  .screen:not([hidden]) {
    animation: reveal 350ms ease both;
  }

  .primary-action,
  .site-header a,
  .start-tone-control,
  .start-tone-icon {
    transition:
      color 150ms ease,
      filter 150ms ease,
      transform 150ms ease;
  }

  .listening-stage.is-sweeping .listening-action {
    animation: response-glow 2.4s ease-in-out infinite alternate;
  }
}

@keyframes response-glow {
  to {
    box-shadow:
      0 1.1rem 2.8rem rgb(0 0 0 / 42%),
      -0.9rem 0.8rem 3.2rem rgb(255 121 92 / 30%),
      0.9rem 0.8rem 3.2rem rgb(82 219 226 / 30%),
      inset 0 1px rgb(255 255 255 / 32%);
  }
}

@media (prefers-reduced-motion: reduce) {
  /* Drop the decorative loops but keep the two sweep-linked animations: they
     are the only cue for how much of the 20 seconds is left. */
  .listening-stage.is-sweeping .tone-emit,
  .listening-stage.is-sweeping .listening-action::after {
    animation: none;
  }

  .tone-emit {
    opacity: 0.25;
  }
}

@media (hover: hover) {
  .primary-action:hover {
    filter: brightness(1.08);
    transform: translateY(-0.1rem);
  }

  .listening-stage > .text-action:hover {
    border-color: var(--aqua);
    background: rgb(82 219 226 / 15%);
  }

  .start-tone:hover .start-tone-control {
    filter: brightness(1.08);
    transform: translateY(-0.12rem);
  }

  .start-tone:hover .start-tone-icon {
    transform: scale(1.06);
  }
}

.primary-action:active,
.listening-stage > .text-action:active {
  filter: brightness(0.88);
}

.start-tone:active .start-tone-control {
  filter: brightness(0.9);
  transform: scale(0.985);
}

@keyframes reveal {
  from {
    opacity: 0;
    transform: translateY(0.5rem);
  }
}

@media (max-width: 760px) {
  body {
    overflow-x: hidden;
    overflow-y: auto;
  }

  .test-shell {
    width: calc(100% - 1rem);
  }

  .site-header {
    min-height: 3.75rem;
  }

  .brand {
    gap: 0.52rem;
    font-size: 0.8rem;
  }

  .brand img {
    width: 2.1rem;
    height: 2.1rem;
    border-radius: 0.62rem;
  }

  .site-header nav {
    gap: 0.35rem;
  }

  .site-header nav a {
    min-width: 48px;
    padding-inline: 0.3rem;
    font-size: 0.78rem;
  }

  main {
    padding: 0.45rem 0 0.55rem;
  }

  .progress {
    min-height: 2.45rem;
    margin-inline: 0;
  }

  .progress::before {
    top: 1.08rem;
    right: 7%;
    left: 7%;
  }

  .progress-step {
    gap: 0.18rem;
    font-size: 0.7rem;
  }

  .progress-step b {
    width: 0.78rem;
  }

  .ready-screen {
    padding-block: 0.35rem;
    grid-template-rows: auto minmax(11rem, 1fr) auto;
    gap: clamp(0.4rem, 1.5vh, 0.75rem);
  }

  .eyebrow {
    font-size: 0.65rem;
  }

  .ready-heading h1 {
    font-size: clamp(2.2rem, 10vw, 3rem);
  }

  .ready-heading > p:last-child {
    margin-top: 0.35rem;
    font-size: 0.82rem;
  }

  .ready-scene {
    min-height: 11rem;
    max-height: 18rem;
    border-radius: 1rem;
  }

  .primary-action {
    min-height: 4rem;
    padding: 0.75rem 0.9rem;
    border-radius: 0.9rem;
    font-size: 1rem;
  }

  .primary-action img {
    width: 1.4rem;
    height: 1.4rem;
  }

  .ready-actions [data-start-preview] {
    min-height: 5.75rem;
    border-radius: 1.35rem;
    font-size: 1.55rem;
  }

  .ready-actions [data-start-preview] img {
    width: 2.75rem;
    height: 2.75rem;
    padding: 0.75rem;
  }

  .preview-limit {
    font-size: 0.78rem;
    line-height: 1.3;
  }

  .listen-screen {
    padding-top: 0.1rem;
    grid-template-columns: 1fr;
    grid-template-rows: auto minmax(0, 1fr) auto;
    gap: 0.45rem;
  }

  .listen-copy {
    text-align: center;
  }

  .listen-copy h2 {
    margin-top: 0;
    font-size: clamp(2rem, 9vw, 2.6rem);
  }

  .listen-copy > p:not(.eyebrow) {
    max-width: none;
    margin: 0.25rem 0 0;
    font-size: 0.82rem;
    line-height: 1.35;
  }

  .listening-stage {
    padding: 0.85rem;
    border-radius: 1rem;
    /* The visualizer is width-bound here, so a 1fr first row would leave a tall
       band of empty card above it. Size to content and centre the cluster. */
    grid-template-rows: auto auto auto auto auto;
    align-content: center;
    gap: 1.1rem;
  }

  .tone-visualizer {
    max-height: 11rem;
  }

  .listening-status strong {
    font-size: 1rem;
  }

  .listening-action {
    min-height: 6.5rem;
    border-radius: 1.4rem;
    font-size: 1.35rem;
  }

  .listening-action-kicker {
    font-size: 0.62rem;
  }

  .listening-action-main {
    font-size: clamp(1.8rem, 8.5vw, 2.3rem);
  }

  .listening-action-sub {
    font-size: 0.78rem;
  }

  .listening-stage > .text-action {
    min-height: 4rem;
    font-size: 1rem;
  }

  .start-tone-control {
    width: min(26rem, calc(100vw - 2.4rem));
  }

  .handoff-screen {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(8rem, 0.9fr) auto;
    gap: 0.5rem;
    text-align: center;
  }

  .handoff-screen figure {
    height: 100%;
    min-height: 0;
  }

  .handoff-screen h2 {
    margin-top: 0.3rem;
    font-size: clamp(2rem, 9vw, 2.5rem);
  }

  .handoff-result {
    margin: 0.65rem 0 0.45rem;
    padding: 0.75rem;
    text-align: left;
  }

  .handoff-result-graphic {
    width: 4rem;
    border-radius: 1rem;
  }

  .handoff-result [data-first-result] {
    font-size: clamp(2.6rem, 12vw, 3.25rem);
  }

  .handoff-volume {
    margin: 0 auto 0.75rem;
    font-size: 0.75rem;
  }

  .result-screen {
    gap: 0.6rem;
  }

  .result-screen h2 {
    font-size: clamp(2.2rem, 10vw, 2.9rem);
  }

  .result-range {
    font-size: clamp(2.65rem, 12vw, 3.7rem);
  }

  .result-spectrum {
    gap: 0.55rem;
  }

  .result-spectrum-track {
    margin-block: 1.85rem 1.15rem;
  }

  .result-spectrum-labels,
  .result-spectrum-labels strong {
    font-size: 0.58rem;
  }

  .result-partners span {
    font-size: 0.66rem;
  }

  .result-partners strong {
    font-size: 1.2rem;
  }

  .result-limit {
    font-size: 0.78rem;
  }

  .result-actions .primary-action {
    min-height: 3.2rem;
  }
}

@media (max-width: 760px) and (max-height: 700px) {
  body {
    overflow-y: auto;
  }

  .test-shell {
    height: auto;
    min-height: 100svh;
  }

  main {
    min-height: calc(100svh - 3.4rem);
  }

  .ready-heading h1 {
    font-size: clamp(1.75rem, 7.6vw, 2.25rem);
  }

  .ready-heading > p:last-child {
    margin-top: 0.2rem;
  }

  .primary-action {
    min-height: 4rem;
  }

  .preview-limit {
    font-size: 0.72rem;
  }
}

/* Wide screens use one composed panel instead of stretching each step to the
   full viewport height. The illustration stays the visual anchor while the
   copy and action remain a compact, readable decision column. */
@media (min-width: 761px) {
  .progress {
    width: min(75rem, 100%);
    margin-inline: auto;
  }

  .ready-screen {
    width: min(68rem, 100%);
    grid-template-columns: minmax(20rem, 0.8fr) minmax(28rem, 1.2fr);
    grid-template-rows: auto auto;
    align-content: center;
    align-items: center;
    justify-items: stretch;
    gap: 0.6rem 2.5rem;
    text-align: left;
  }

  .ready-heading {
    grid-column: 1;
    grid-row: 1;
  }

  .ready-heading > p:last-child {
    margin-inline: 0;
  }

  .ready-scene {
    width: 100%;
    height: auto;
    min-height: 0;
    max-width: none;
    max-height: none;
    grid-column: 2;
    grid-row: 1 / span 2;
  }

  .ready-actions {
    width: 100%;
    grid-column: 1;
    grid-row: 2;
  }

  .listen-screen {
    width: min(68rem, 100%);
    max-height: min(38rem, 100%);
    margin-inline: auto;
    align-self: center;
    grid-template-columns: minmax(18rem, 0.46fr) minmax(30rem, 1fr);
    gap: 1rem 2.25rem;
  }

  .listen-copy h2 {
    font-size: clamp(2.5rem, 4vw, 3.8rem);
  }
}

@media (max-height: 640px) and (min-width: 761px) {
  body {
    overflow: auto;
  }

  .test-shell {
    width: calc(100% - 1.5rem);
    height: 100svh;
    min-height: 22rem;
  }

  .site-header {
    min-height: 3rem;
  }

  .brand {
    gap: 0.5rem;
    font-size: 0.8rem;
  }

  .brand img {
    width: 2rem;
    height: 2rem;
    border-radius: 0.6rem;
  }

  .site-header nav {
    gap: 0.35rem;
  }

  .site-header nav a {
    padding-inline: 0.3rem;
    font-size: 0.72rem;
  }

  main {
    padding: 0.25rem 0 0.35rem;
  }

  .progress {
    min-height: 2.15rem;
    margin-inline: 0;
  }

  .progress::before {
    top: 0.92rem;
  }

  .progress-step {
    gap: 0.12rem;
    font-size: 0.64rem;
  }

  .progress-step b {
    width: 0.72rem;
  }

  .ready-screen {
    width: 100%;
    padding-block: 0;
    grid-template-columns: minmax(16rem, 0.76fr) minmax(22rem, 1.24fr);
    grid-template-rows: auto auto;
    align-items: center;
    justify-items: stretch;
    gap: 0.3rem 1rem;
    text-align: left;
  }

  .ready-heading {
    grid-column: 1;
    grid-row: 1;
  }

  .ready-heading h1 {
    font-size: clamp(1.75rem, 4vw, 2.35rem);
  }

  .ready-heading > p:last-child {
    margin-top: 0.25rem;
    margin-inline: 0;
    font-size: 0.75rem;
  }

  .ready-scene {
    width: 100%;
    height: min(14rem, 100%);
    min-height: 0;
    max-width: none;
    max-height: 14rem;
    align-self: center;
    grid-column: 2;
    grid-row: 1 / span 2;
  }

  .ready-actions {
    grid-column: 1;
    grid-row: 2;
  }

  .ready-actions [data-start-preview] {
    min-height: 4.35rem;
    padding: 0.65rem 1rem;
    border-radius: 1rem;
    font-size: 1.25rem;
  }

  .ready-actions [data-start-preview] img {
    width: 1.55rem;
    height: 1.55rem;
  }

  .listen-screen {
    width: 100%;
    height: 100%;
    max-height: none;
    align-self: stretch;
    grid-template-columns: minmax(15rem, 0.5fr) minmax(24rem, 1fr);
    gap: 0.45rem 1rem;
  }

  .listen-copy h2 {
    margin-top: 0;
    font-size: clamp(1.8rem, 4vw, 2.25rem);
  }

  .listen-copy > p:not(.eyebrow) {
    margin-top: 0.45rem;
    font-size: 0.74rem;
    line-height: 1.35;
  }

  .listening-stage {
    padding: 0.55rem;
    grid-template-rows: minmax(5rem, 1fr) auto auto auto;
    gap: 0.3rem;
    border-radius: 1rem;
  }

  .tone-visualizer {
    max-height: 6rem;
  }

  .listening-action {
    min-height: 4.6rem;
    border-radius: 1.15rem;
  }

  .listening-action-main {
    font-size: 1.65rem;
  }

  /* Too little height here for a second line — the big label carries it. */
  .listening-action-sub {
    display: none;
  }

  .listening-stage > .text-action {
    min-height: 3rem;
  }

  .start-tone-control {
    width: min(24rem, calc(100vw - 2.7rem));
    min-height: 5.6rem;
    padding: 0.65rem 0.8rem;
    border-radius: 1rem;
    gap: 0.7rem;
  }

  .start-tone-icon {
    width: 2.8rem;
  }

  .start-tone-icon img {
    width: 1rem;
    height: 1rem;
  }

  .start-tone-kicker {
    font-size: 0.5rem;
  }

  .start-tone-copy strong {
    font-size: 1.3rem;
  }

  .start-tone-detail {
    font-size: 0.64rem;
  }

  .listen-screen > .preview-limit {
    font-size: 0.64rem;
    text-align: left;
  }

  .handoff-screen {
    width: min(52rem, 100%);
    grid-template-columns: minmax(14rem, 0.8fr) minmax(18rem, 1fr);
    gap: 1rem;
  }

  .handoff-screen figure {
    height: min(15rem, 100%);
  }

  .handoff-screen h2 {
    margin-top: 0.35rem;
    font-size: clamp(1.8rem, 4vw, 2.3rem);
  }

  .handoff-result {
    margin: 0.45rem 0 0.35rem;
    padding: 0.55rem;
    gap: 0.65rem;
    border-radius: 1rem;
  }

  .handoff-result-graphic {
    width: 3.2rem;
    border-radius: 0.85rem;
  }

  .handoff-result [data-first-result] {
    margin-top: 0.15rem;
    font-size: 2.3rem;
  }

  .handoff-volume {
    margin: 0 0 0.55rem;
    font-size: 0.7rem;
  }

  .handoff-screen .primary-action {
    min-height: 3.5rem;
  }

  .result-screen {
    width: min(48rem, 100%);
    gap: 0.3rem;
  }

  .result-glow {
    top: 0;
    width: min(32rem, 72vw);
    aspect-ratio: 1.8;
  }

  .result-screen h2 {
    max-width: 24ch;
    font-size: clamp(1.75rem, 4vw, 2.25rem);
  }

  .result-range {
    margin-top: 0;
    font-size: clamp(2.5rem, 6vw, 3.5rem);
  }

  .result-spectrum {
    margin-block: 0;
    gap: 0.35rem;
  }

  .result-spectrum-track {
    margin-block: 1.45rem 0.8rem;
  }

  .result-limit {
    font-size: 0.68rem;
  }

  .result-actions {
    width: min(26rem, 100%);
  }

  .result-actions .primary-action {
    min-height: 3.2rem;
  }
}