:root {
  color-scheme: light;
  --cosine-blue: #245d8f;
  --cosine-blue-soft: #e8f0f6;
  --sine-coral: #cf6158;
  --sine-coral-ink: #9f403b;
  --sine-coral-soft: #f9ebe7;
  --unit-violet: #7256a4;
  --unit-violet-soft: #eee9f6;
  --radius-teal: #187b77;
  --radius-teal-soft: #e4f1ef;
  --angle-amber: #bc7a1e;
  --angle-amber-ink: #8f570e;
  --angle-amber-soft: #f8eedb;
  --derived-emerald: #216b55;
  --reference-slate: #4f5b63;

  --canvas: #f3eee5;
  --canvas-deep: #e9e1d4;
  --paper: #fffdf8;
  --paper-warm: #fbf7ef;
  --paper-strong: #ffffff;
  --ink: #27251f;
  --ink-soft: #4b4841;
  --muted: #716c62;
  --line: #ded5c7;
  --line-strong: #c8bcaa;
  --grid: rgba(76, 70, 61, 0.09);
  --axis-color: #625e57;
  --focus-ring: #174f78;

  /* Shared palette consumed by the inline SVG views. */
  --vt-ink: var(--ink);
  --vt-muted: var(--muted);
  --vt-grid: var(--reference-slate);
  --vt-cosine: var(--cosine-blue);
  --vt-sine: var(--sine-coral);
  --vt-unit: var(--unit-violet);
  --vt-polar: var(--radius-teal);
  --vt-angle: var(--angle-amber);
  --vt-surface: transparent;
  --vt-handle-outline: var(--paper-strong);

  --font-ui: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-editorial: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --font-math: "STIX Two Text", "Cambria Math", Cambria, Georgia, serif;

  --card-radius: 14px;
  --control-radius: 8px;
  --shadow-soft: 0 1px 2px rgba(51, 43, 31, 0.05), 0 10px 30px rgba(67, 53, 32, 0.045);
  --shadow-raised: 0 16px 44px rgba(50, 39, 25, 0.15);
}

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

html {
  min-width: 320px;
  min-height: 100%;
  background: var(--canvas);
  text-size-adjust: 100%;
}

body {
  min-width: 320px;
  min-height: 100vh;
  min-height: 100svh;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 10% 0%, rgba(255, 253, 248, 0.86), transparent 34rem),
    radial-gradient(circle at 94% 100%, rgba(220, 207, 187, 0.34), transparent 36rem),
    var(--canvas);
  font-family: var(--font-ui);
  font-size: 15px;
  line-height: 1.45;
  -webkit-font-smoothing: antialiased;
}

button,
input,
select,
summary {
  font: inherit;
}

button,
select,
summary,
input[type="range"] {
  cursor: pointer;
}

button,
input,
select {
  color: inherit;
}

button:focus-visible,
input:focus-visible,
select:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--focus-ring);
  outline-offset: 2px;
  box-shadow: 0 0 0 2px var(--paper);
}

button:disabled,
input:disabled,
select:disabled {
  cursor: not-allowed;
  opacity: 0.52;
}

h1,
h2,
h3,
p,
dl,
dd,
figure,
fieldset,
ol,
ul {
  margin: 0;
}

ol,
ul {
  padding: 0;
  list-style: none;
}

var {
  font-family: var(--font-math);
  font-style: italic;
}

sup {
  font-size: 0.68em;
  line-height: 0;
}

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

.skip-link {
  position: fixed;
  z-index: 1000;
  top: 10px;
  left: 12px;
  padding: 9px 13px;
  color: #fff;
  background: var(--ink);
  border-radius: 8px;
  font-size: 0.82rem;
  font-weight: 700;
  text-decoration: none;
  transform: translateY(-160%);
  transition: transform 140ms ease;
}

.skip-link:focus {
  transform: translateY(0);
}

.instrument-shell {
  width: min(100%, 1600px);
  min-height: 100vh;
  min-height: 100svh;
  margin: 0 auto;
  padding: 12px 16px;
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr);
  gap: 10px;
}

.instrument-main {
  min-width: 0;
  min-height: 0;
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr);
  gap: 10px;
}

.eyebrow,
.view-kicker,
.control-label,
.coordinate-label {
  color: var(--muted);
  font-size: 0.66rem;
  font-weight: 750;
  line-height: 1.1;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.toolbar,
.exact-angle-strip,
.coordinate-strip,
.view-card,
.relationship-dock {
  border: 1px solid var(--line);
  background: rgba(255, 253, 248, 0.92);
  box-shadow: var(--shadow-soft);
}

.toolbar {
  min-width: 0;
  min-height: 58px;
  padding: 8px 10px 8px 12px;
  display: grid;
  grid-template-columns: max-content minmax(0, 1fr);
  align-items: center;
  gap: 18px;
  border-radius: var(--card-radius);
  backdrop-filter: blur(14px);
}

.brand-lockup {
  min-width: 172px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-rule {
  width: 3px;
  height: 31px;
  flex: 0 0 auto;
  border-radius: 999px;
  background: linear-gradient(to bottom, var(--angle-amber), var(--unit-violet));
}

.brand-lockup h1 {
  margin-top: 2px;
  font-family: var(--font-editorial);
  font-size: 1.16rem;
  font-weight: 650;
  line-height: 1.05;
  letter-spacing: -0.015em;
}

.exact-angle-strip {
  min-width: 0;
  min-height: 48px;
  padding: 6px 9px 6px 11px;
  display: grid;
  grid-template-columns: max-content minmax(390px, 1fr) max-content;
  align-items: center;
  gap: 11px;
  border-radius: var(--card-radius);
}

.exact-angle-strip__heading {
  min-width: 116px;
  padding-right: 12px;
  border-right: 1px solid var(--line);
}

.exact-angle-strip__heading h2 {
  margin-top: 2px;
  font-family: var(--font-editorial);
  font-size: 0.92rem;
  font-weight: 650;
  line-height: 1.05;
}

.exact-angle-chips {
  min-width: 0;
  display: grid;
  grid-template-columns: repeat(8, minmax(38px, 1fr));
  gap: 4px;
}

.exact-angle-chip {
  min-width: 0;
  height: 30px;
  padding: 0 7px;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--paper-warm);
  font-family: var(--font-math);
  font-size: 0.76rem;
  font-weight: 650;
  line-height: 1;
  white-space: nowrap;
  transition: border-color 140ms ease, color 140ms ease, background-color 140ms ease, box-shadow 140ms ease;
}

.exact-angle-chip.is-active,
.exact-angle-chip[aria-pressed="true"] {
  color: var(--angle-amber-ink);
  border-color: var(--angle-amber);
  background: #f3dfb8;
  box-shadow: inset 0 -3px 0 rgba(188, 122, 30, 0.34);
  font-weight: 800;
}

.exact-angle-actions {
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 9px;
}

.snap-toggle {
  min-width: 86px;
  height: 32px;
  padding: 0 9px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  color: var(--ink-soft);
  border: 1px solid var(--line-strong);
  border-radius: 8px;
  background: var(--paper-strong);
  font-size: 0.72rem;
  font-weight: 700;
  line-height: 1;
}

.snap-toggle strong {
  color: var(--muted);
  font-size: 0.66rem;
  text-transform: uppercase;
}

.snap-toggle__marker {
  width: 9px;
  height: 9px;
  border: 2px solid var(--angle-amber);
  border-radius: 50%;
  box-shadow: 0 0 0 2px var(--paper-strong);
}

.snap-toggle.is-active,
.snap-toggle[aria-pressed="true"] {
  color: var(--angle-amber-ink);
  border-color: var(--angle-amber);
  background: var(--angle-amber-soft);
}

.snap-toggle.is-active .snap-toggle__marker,
.snap-toggle[aria-pressed="true"] .snap-toggle__marker {
  background: var(--angle-amber);
  box-shadow: 0 0 0 2px var(--paper-strong), 0 0 0 3px rgba(188, 122, 30, 0.3);
}

.snap-toggle.is-active strong,
.snap-toggle[aria-pressed="true"] strong {
  color: var(--angle-amber-ink);
}

.exact-angle-status {
  min-width: 156px;
}

.exact-angle-status .control-label {
  margin-bottom: 2px;
}

.exact-angle-status output {
  display: block;
  overflow: hidden;
  color: var(--muted);
  font-family: var(--font-math);
  font-size: 0.7rem;
  font-weight: 650;
  line-height: 1.15;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.exact-angle-status output[data-exact="true"] {
  color: var(--angle-amber-ink);
}

.toolbar-controls {
  min-width: 0;
  display: grid;
  grid-template-columns: auto minmax(76px, 0.35fr) minmax(250px, 1.5fr) minmax(200px, 1fr) auto;
  align-items: end;
  gap: 8px;
}

.playback-controls {
  height: 34px;
  display: flex;
  align-items: stretch;
  gap: 5px;
}

.button,
.segment-button {
  border: 1px solid var(--line-strong);
  border-radius: var(--control-radius);
  background: var(--paper-strong);
  font-size: 0.76rem;
  font-weight: 720;
  line-height: 1;
  transition: border-color 140ms ease, background-color 140ms ease, color 140ms ease, transform 140ms ease;
}

.button {
  min-height: 34px;
  padding: 0 11px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
}

.button--primary {
  min-width: 76px;
  color: #fff;
  background: var(--ink);
  border-color: var(--ink);
}

.button--quiet {
  color: var(--ink-soft);
  background: var(--paper-warm);
}

.direction-button {
  min-width: 68px;
}

.button-icon {
  display: inline-grid;
  place-items: center;
  font-size: 0.72rem;
}

.direction-glyph {
  color: var(--angle-amber);
  font-size: 1rem;
  line-height: 1;
}

.control-field {
  min-width: 0;
  border: 0;
  padding: 0;
}

.control-label {
  display: block;
  margin: 0 0 4px 2px;
}

.math-symbol {
  font-family: var(--font-math);
  font-size: 1.12em;
  font-style: italic;
  letter-spacing: 0;
  text-transform: none;
}

select,
.number-input {
  height: 34px;
  border: 1px solid var(--line-strong);
  border-radius: var(--control-radius);
  background: var(--paper-strong);
}

select {
  width: 100%;
  min-width: 72px;
  padding: 0 28px 0 9px;
  font-size: 0.78rem;
  font-weight: 650;
}

.range-input-pair {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(96px, 1fr) 76px;
  align-items: center;
  gap: 7px;
}

.range-input-pair--radius {
  grid-template-columns: minmax(78px, 1fr) 68px;
}

.number-input {
  width: 100%;
  min-width: 0;
  padding: 0 5px 0 7px;
  font-family: var(--font-math);
  font-size: 0.77rem;
  font-variant-numeric: tabular-nums;
}

input[type="number"] {
  appearance: textfield;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  margin: 0;
}

input[type="range"] {
  width: 100%;
  min-width: 0;
  height: 34px;
  margin: 0;
  padding: 0;
  appearance: none;
  background: transparent;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 4px;
  border: 0;
  border-radius: 999px;
  background: var(--line-strong);
}

input[type="range"]::-webkit-slider-thumb {
  width: 16px;
  height: 16px;
  margin-top: -6px;
  appearance: none;
  border: 3px solid var(--paper-strong);
  border-radius: 50%;
  background: var(--angle-amber);
  box-shadow: 0 0 0 1px var(--angle-amber), 0 2px 6px rgba(66, 49, 24, 0.22);
}

input[type="range"]::-moz-range-track {
  height: 4px;
  border: 0;
  border-radius: 999px;
  background: var(--line-strong);
}

input[type="range"]::-moz-range-progress {
  height: 4px;
  border-radius: 999px;
  background: var(--angle-amber);
}

input[type="range"]::-moz-range-thumb {
  width: 12px;
  height: 12px;
  border: 3px solid var(--paper-strong);
  border-radius: 50%;
  background: var(--angle-amber);
  box-shadow: 0 0 0 1px var(--angle-amber), 0 2px 6px rgba(66, 49, 24, 0.22);
}

#angleRange::-webkit-slider-runnable-track {
  background: linear-gradient(to right, rgba(188, 122, 30, 0.48), var(--angle-amber-soft));
}

#radiusRange::-webkit-slider-runnable-track {
  background: linear-gradient(to right, rgba(24, 123, 119, 0.52), var(--radius-teal-soft));
}

#radiusRange::-webkit-slider-thumb {
  background: var(--radius-teal);
  box-shadow: 0 0 0 1px var(--radius-teal), 0 2px 6px rgba(21, 80, 77, 0.22);
}

#radiusRange::-moz-range-progress {
  background: var(--radius-teal);
}

#radiusRange::-moz-range-thumb {
  background: var(--radius-teal);
  box-shadow: 0 0 0 1px var(--radius-teal), 0 2px 6px rgba(21, 80, 77, 0.22);
}

.unit-controls legend {
  padding: 0;
}

.segmented-control {
  height: 34px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  padding: 2px;
  border: 1px solid var(--line-strong);
  border-radius: var(--control-radius);
  background: var(--paper-warm);
}

.segment-button {
  min-width: 45px;
  padding: 0 8px;
  color: var(--muted);
  border-color: transparent;
  background: transparent;
}

.segment-button.is-active,
.segment-button[aria-pressed="true"] {
  color: var(--ink);
  border-color: var(--line);
  background: var(--paper-strong);
  box-shadow: 0 1px 4px rgba(62, 51, 36, 0.1);
}

.coordinate-strip {
  min-width: 0;
  padding: 8px 10px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: stretch;
  gap: 10px;
  border-radius: var(--card-radius);
}

.coordinate-strip__core {
  min-width: 0;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 13px;
}

.strip-heading {
  min-width: 122px;
  padding-right: 12px;
  border-right: 1px solid var(--line);
}

.strip-heading h2 {
  margin-top: 3px;
  font-family: var(--font-editorial);
  font-size: 0.95rem;
  font-weight: 650;
  line-height: 1.05;
  letter-spacing: -0.01em;
}

.equivalence-chain {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(112px, 1fr) auto minmax(145px, 1.12fr) auto minmax(145px, 1.12fr) auto minmax(112px, 0.92fr);
  align-items: center;
  gap: 6px;
}

.coordinate-reading {
  min-width: 0;
  padding: 2px 6px;
}

.coordinate-label {
  display: block;
  margin-bottom: 3px;
}

.math-expression,
.readout dd {
  font-family: var(--font-math);
  font-variant-numeric: tabular-nums;
}

.math-expression {
  display: block;
  overflow: hidden;
  color: var(--ink);
  font-size: 0.87rem;
  line-height: 1.25;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.coordinate-arrow {
  color: var(--line-strong);
  font-family: var(--font-editorial);
  font-size: 1rem;
}

.readout-grid {
  min-width: 320px;
  display: grid;
  grid-template-columns: repeat(4, minmax(66px, 1fr));
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--paper-warm);
}

.readout {
  min-width: 0;
  padding: 5px 9px;
  border-left: 1px solid var(--line);
}

.readout:first-child {
  border-left: 0;
}

.readout dt {
  color: var(--muted);
  font-size: 0.62rem;
  font-weight: 750;
  letter-spacing: 0.055em;
  text-transform: uppercase;
}

.readout dd {
  margin-top: 1px;
  overflow: hidden;
  font-size: 0.93rem;
  font-weight: 650;
  line-height: 1.2;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.readout--angle dd {
  color: var(--angle-amber-ink);
}

.readout--cosine dd {
  color: var(--cosine-blue);
}

.readout--sine dd {
  color: var(--sine-coral);
}

.readout.is-exact {
  background: linear-gradient(to bottom, rgba(248, 238, 219, 0.55), transparent);
}

.readout.is-exact dd .katex {
  font-size: 0.98em;
}

.visual-stage {
  min-width: 0;
  min-height: 0;
  display: grid;
  grid-template-columns: minmax(360px, 42fr) minmax(0, 58fr);
  gap: 10px;
}

.view-card {
  position: relative;
  min-width: 0;
  min-height: 0;
  display: grid;
  grid-template-rows: auto minmax(0, 1fr);
  overflow: hidden;
  border-radius: var(--card-radius);
}

.circle-card {
  --view-accent: var(--unit-violet);
  box-shadow: inset 0 3px 0 var(--unit-violet), var(--shadow-soft);
}

.cosine-card {
  --view-accent: var(--cosine-blue);
  box-shadow: inset 0 3px 0 var(--cosine-blue), var(--shadow-soft);
}

.sine-card {
  --view-accent: var(--sine-coral);
  box-shadow: inset 0 3px 0 var(--sine-coral), var(--shadow-soft);
}

.view-card__header {
  min-width: 0;
  min-height: 49px;
  padding: 9px 11px 7px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(to bottom, rgba(255, 255, 255, 0.72), rgba(251, 247, 239, 0.65));
}

.view-heading {
  min-width: 0;
}

.view-heading h3 {
  margin-top: 2px;
  font-family: var(--font-editorial);
  font-size: 1rem;
  font-weight: 650;
  line-height: 1.08;
  letter-spacing: -0.01em;
}

.view-header-meta {
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 13px;
}

.quantity-key {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 650;
}

.quantity-key li {
  display: flex;
  align-items: center;
  gap: 4px;
}

.key-dot {
  width: 8px;
  height: 8px;
  border: 2px solid var(--paper-strong);
  border-radius: 50%;
  box-shadow: 0 0 0 1px currentColor;
}

.key-dot--unit {
  color: var(--unit-violet);
  background: var(--unit-violet);
}

.key-dot--radius {
  color: var(--radius-teal);
  background: var(--radius-teal);
}

.drag-instruction {
  display: flex;
  align-items: center;
  gap: 5px;
  color: var(--muted);
  font-size: 0.7rem;
  font-weight: 600;
  line-height: 1.2;
  white-space: nowrap;
}

.drag-instruction > span {
  color: var(--view-accent);
  font-size: 0.88rem;
  font-weight: 800;
}

.view-frame {
  min-width: 0;
  min-height: 0;
  padding: 7px;
  background: var(--paper-warm);
}

.circle-frame {
  display: grid;
  place-items: center;
}

.view-surface {
  position: relative;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  border: 1px solid rgba(200, 188, 170, 0.72);
  border-radius: 10px;
  background-color: var(--paper);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.55);
  isolation: isolate;
}

.view-surface:focus-visible {
  outline-offset: -2px;
}

.view-surface > svg {
  width: 100%;
  height: 100%;
  display: block;
  overflow: visible;
  touch-action: none;
}

.circle-surface {
  width: auto;
  max-width: 100%;
  height: 100%;
  aspect-ratio: 1;
}

.wave-stack {
  min-width: 0;
  min-height: 0;
  display: grid;
  grid-template-rows: minmax(0, 1fr) minmax(0, 1fr);
  gap: 10px;
}

.wave-card__header {
  min-height: 43px;
  padding-top: 7px;
  padding-bottom: 6px;
}

.wave-surface {
  width: 100%;
  height: 100%;
}

#circleView:empty {
  background:
    linear-gradient(to right, transparent calc(50% - 0.5px), rgba(98, 94, 87, 0.26) 50%, transparent calc(50% + 0.5px)),
    linear-gradient(to bottom, transparent calc(50% - 0.5px), rgba(98, 94, 87, 0.26) 50%, transparent calc(50% + 0.5px)),
    radial-gradient(circle at center, transparent 0 35%, rgba(114, 86, 164, 0.26) 35.2% 35.65%, transparent 35.9%),
    radial-gradient(circle at center, transparent 0 17%, rgba(105, 116, 123, 0.1) 17.2% 17.5%, transparent 17.8%),
    var(--paper);
}

.wave-surface:empty {
  background:
    linear-gradient(to right, transparent calc(50% - 0.5px), rgba(188, 122, 30, 0.2) 50%, transparent calc(50% + 0.5px)),
    linear-gradient(to bottom, transparent calc(50% - 0.5px), rgba(98, 94, 87, 0.22) 50%, transparent calc(50% + 0.5px)),
    repeating-linear-gradient(to right, transparent 0 calc(12.5% - 0.5px), var(--grid) 12.5% calc(12.5% + 0.5px)),
    repeating-linear-gradient(to bottom, transparent 0 calc(50% - 0.5px), var(--grid) 50% calc(50% + 0.5px)),
    var(--paper);
}

.relationship-dock {
  position: relative;
  min-width: 0;
  padding: 10px 11px;
  display: grid;
  grid-template-columns: minmax(230px, 0.9fr) minmax(0, 4fr);
  align-items: stretch;
  gap: 10px;
  border-radius: var(--card-radius);
}



.identity-lens-dock {
  min-width: 0;
  display: grid;
  align-content: center;
}

.identity-lens-selector {
  min-width: 0;
  margin-top: 6px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 3px;
}

.identity-lens-button {
  min-width: 0;
  height: 24px;
  padding: 0 5px;
  overflow: hidden;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper-warm);
  font-size: 0.59rem;
  font-weight: 720;
  line-height: 1;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.identity-lens-button.is-active,
.identity-lens-button[aria-pressed="true"] {
  color: var(--derived-emerald);
  border-color: rgba(45, 128, 102, 0.62);
  background: #e4f1eb;
  box-shadow: inset 0 -2px 0 rgba(45, 128, 102, 0.3);
}

.identity-panel {
  position: relative;
  min-width: 0;
  padding: 6px 8px;
  display: grid;
  align-content: center;
  gap: 4px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--paper-warm);
}

.identity-panel__header {
  min-width: 0;
  min-height: 25px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.identity-panel__title {
  min-width: 0;
}

.identity-panel__title h3 {
  margin-top: 1px;
  overflow: hidden;
  font-family: var(--font-editorial);
  font-size: 0.78rem;
  font-weight: 700;
  line-height: 1.05;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.identity-badge {
  flex: 0 0 auto;
  padding: 3px 6px;
  color: var(--derived-emerald);
  border: 1px solid rgba(45, 128, 102, 0.3);
  border-radius: 999px;
  background: rgba(228, 241, 235, 0.72);
  font-family: var(--font-math);
  font-size: 0.56rem;
  font-weight: 750;
  line-height: 1;
  white-space: nowrap;
}

.identity-parameters {
  min-width: 0;
  margin-left: auto;
}

.addition-parameters,
.power-parameters {
  min-width: 0;
  margin: 0;
  border: 0;
  padding: 0;
}

.addition-parameters {
  display: flex;
  align-items: center;
  gap: 4px;
}

.addition-parameters label,
.power-parameters {
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--muted);
  font-family: var(--font-math);
  font-size: 0.65rem;
  font-weight: 700;
}

.identity-number-input,
.power-parameters select {
  height: 25px;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background: var(--paper-strong);
  font-family: var(--font-math);
  font-size: 0.66rem;
  font-variant-numeric: tabular-nums;
}

.identity-number-input {
  width: 58px;
  padding: 0 5px;
}

.power-parameters select {
  width: 48px;
  min-width: 48px;
  padding: 0 18px 0 7px;
}

.parameter-operator {
  color: var(--angle-amber-ink);
  font-family: var(--font-math);
  font-weight: 800;
}

.addition-parameters[hidden],
.power-parameters[hidden],
.identity-exact-companion[hidden],
.identity-algebra[hidden] {
  display: none !important;
}

.identity-layers {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(150px, 0.85fr) minmax(190px, 1fr) minmax(260px, 1.45fr);
  border: 1px solid var(--line);
  border-radius: 7px;
  background: rgba(255, 253, 248, 0.76);
}

.identity-layer {
  min-width: 0;
  min-height: 38px;
  padding: 4px 7px;
  border-left: 1px solid var(--line);
}

.identity-layer:first-child {
  border-left: 0;
}

.identity-layer__label,
.identity-exact-label {
  display: block;
  color: var(--muted);
  font-size: 0.5rem;
  font-weight: 780;
  line-height: 1;
  letter-spacing: 0.075em;
  text-transform: uppercase;
}

.identity-layer p {
  margin-top: 3px;
  display: -webkit-box;
  overflow: hidden;
  color: var(--ink-soft);
  font-size: 0.58rem;
  line-height: 1.16;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  line-clamp: 2;
}

.identity-layer .math-expression {
  margin-top: 4px;
  color: var(--ink-soft);
  font-size: 0.65rem;
  font-weight: 650;
}

.identity-layer--complex .math-expression {
  color: var(--unit-violet);
}

.identity-layer--trig .math-expression {
  color: var(--derived-emerald);
}

.identity-exact-companion {
  flex: 1 1 460px;
  min-width: 0;
  min-height: 0;
  height: 25px;
  padding: 0 5px;
  display: grid;
  grid-template-columns: minmax(105px, 1fr) auto minmax(100px, 1.1fr) minmax(116px, 1.2fr);
  align-items: center;
  gap: 5px;
  overflow: hidden;
  border-left: 1px dashed rgba(188, 122, 30, 0.34);
}

.identity-exact-companion .identity-exact-label,
.identity-exact-companion small {
  display: none;
}

.identity-exact-companion strong {
  overflow: hidden;
  font-family: var(--font-editorial);
  font-size: 0.58rem;
  line-height: 1;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.identity-exact-companion .math-expression {
  color: var(--ink-soft);
  font-size: 0.58rem;
  font-weight: 650;
}

.identity-exact-companion small {
  color: var(--muted);
  font-size: 0.52rem;
  white-space: nowrap;
}

.identity-panel[data-has-algebra="true"] .identity-exact-companion {
  display: none;
}

.identity-algebra {
  flex: 1 1 360px;
  min-width: 0;
  height: 25px;
  padding: 0 6px;
  display: flex;
  align-items: center;
  gap: 6px;
  overflow: hidden;
  border-left: 1px dashed rgba(114, 86, 164, 0.3);
}

.identity-algebra__label {
  flex: 0 0 auto;
  color: var(--muted);
  font-size: 0.5rem;
  font-weight: 780;
  line-height: 1;
  letter-spacing: 0.075em;
  text-transform: uppercase;
}

.identity-algebra-expression {
  min-width: 0;
  margin: 0;
  overflow-x: auto;
  color: var(--ink-soft);
  font-size: 0.6rem;
  font-weight: 650;
  scrollbar-width: none;
  white-space: nowrap;
}

.identity-algebra-expression::-webkit-scrollbar {
  display: none;
}

.exact-derivation-card {
  min-width: 0;
  padding: 6px 9px;
  border: 1px solid rgba(188, 122, 30, 0.28);
  border-radius: 10px;
  background: linear-gradient(135deg, rgba(248, 238, 219, 0.62), var(--paper-warm) 60%);
}

.exact-derivation-card[data-exact="false"] {
  border-color: var(--line);
  background: var(--paper-warm);
}

.exact-derivation-card__header {
  min-width: 0;
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 8px;
}

.exact-derivation-card__header > div {
  min-width: 0;
}

.exact-derivation-card h3 {
  margin-top: 2px;
  overflow: hidden;
  font-family: var(--font-editorial);
  font-size: 0.78rem;
  font-weight: 700;
  line-height: 1.08;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.quadrant-badge {
  max-width: 126px;
  padding: 3px 5px;
  overflow: hidden;
  color: var(--angle-amber-ink);
  border: 1px solid rgba(188, 122, 30, 0.35);
  border-radius: 5px;
  background: rgba(255, 253, 248, 0.72);
  font-size: 0.55rem;
  font-weight: 750;
  line-height: 1.05;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.exact-derivation-card[data-exact="false"] .quadrant-badge {
  color: var(--muted);
  border-color: var(--line);
}

.exact-equation {
  margin-top: 4px;
  color: var(--unit-violet);
  font-size: 0.8rem;
  font-weight: 650;
}

.exact-result-line {
  min-width: 0;
  margin-top: 3px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
}

.exact-result-line .math-expression {
  color: var(--ink-soft);
  font-size: 0.67rem;
  font-weight: 650;
}

.exact-result-line small {
  flex: 0 0 auto;
  color: var(--muted);
  font-size: 0.56rem;
  white-space: nowrap;
}

.notation-flow {
  min-width: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--paper-warm);
}

.notation-flow li {
  position: relative;
  min-width: 0;
  padding: 7px 13px 7px 10px;
  border-left: 1px solid var(--line);
}

.notation-flow li:first-child {
  border-left: 0;
}

.notation-flow li:not(:last-child)::after {
  content: "→";
  position: absolute;
  z-index: 1;
  top: 50%;
  right: -8px;
  width: 15px;
  color: var(--angle-amber);
  background: var(--paper-warm);
  font-size: 0.76rem;
  font-weight: 800;
  line-height: 1;
  text-align: center;
  transform: translateY(-50%);
}

.notation-flow span,
.notation-flow small {
  display: block;
  overflow: hidden;
  color: var(--muted);
  line-height: 1.15;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.notation-flow span {
  font-size: 0.61rem;
  font-weight: 750;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.notation-flow strong {
  display: block;
  margin: 2px 0;
  overflow: hidden;
  font-family: var(--font-math);
  font-size: 0.82rem;
  font-weight: 650;
  line-height: 1.15;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.notation-flow small {
  font-size: 0.59rem;
}

.euler-card {
  min-width: 0;
  padding: 2px 0 2px 11px;
  border-left: 3px solid var(--angle-amber);
}

.euler-card h3 {
  margin-top: 2px;
  font-family: var(--font-editorial);
  font-size: 0.82rem;
  font-weight: 650;
  line-height: 1.05;
}

.euler-equation {
  margin-top: 5px;
  color: var(--unit-violet);
  font-size: 0.98rem;
  font-weight: 650;
}

.euler-card > p {
  margin-top: 3px;
  color: var(--muted);
  font-size: 0.64rem;
  line-height: 1.25;
}

/* Shared SVG vocabulary used by the circle and waveform views. */
.axis,
.grid-line,
.unit-circle,
.polar-ring,
.angle-ray,
.angle-arc,
.cos-segment,
.sin-segment,
.projection-line,
.wave-path,
.wave-cursor {
  fill: none;
  vector-effect: non-scaling-stroke;
}

.axis {
  stroke: var(--axis-color);
  stroke-width: 1.2;
  opacity: 0.75;
}

.axis.x-axis,
.axis.real-axis {
  stroke: var(--cosine-blue);
}

.axis.y-axis,
.axis.imaginary-axis {
  stroke: var(--sine-coral);
  stroke-dasharray: 4 3;
}

.grid-line {
  stroke: rgba(105, 116, 123, 0.24);
  stroke-width: 0.8;
}

.unit-circle {
  stroke: var(--unit-violet);
  stroke-width: 2.1;
}

.polar-ring {
  stroke: var(--reference-slate);
  stroke-width: 0.8;
  stroke-dasharray: 2 5;
  opacity: 0.36;
}

.angle-ray {
  stroke: var(--angle-amber);
  stroke-width: 1.5;
  opacity: 0.86;
}

.angle-arc {
  stroke: var(--angle-amber);
  stroke-width: 2;
  stroke-linecap: round;
}

.cos-segment {
  stroke: var(--cosine-blue);
  stroke-width: 3.2;
  stroke-linecap: round;
}

.sin-segment {
  stroke: var(--sine-coral);
  stroke-width: 3.2;
  stroke-linecap: round;
  stroke-dasharray: 7 4;
}

.projection-line {
  stroke: var(--reference-slate);
  stroke-width: 1.25;
  stroke-dasharray: 4 4;
  opacity: 0.58;
}

.cos-segment.projection-line {
  stroke: var(--cosine-blue);
}

.sin-segment.projection-line {
  stroke: var(--sine-coral);
}

.unit-handle,
.polar-point,
.wave-point {
  vector-effect: non-scaling-stroke;
}

.unit-handle {
  fill: var(--paper-strong);
  stroke: var(--unit-violet);
  stroke-width: 3.2;
  cursor: grab;
  filter: drop-shadow(0 2px 3px rgba(52, 38, 78, 0.2));
}

.unit-handle:active {
  cursor: grabbing;
}

.polar-point {
  fill: var(--radius-teal);
  stroke: var(--paper-strong);
  stroke-width: 2.4;
  filter: drop-shadow(0 2px 3px rgba(20, 79, 76, 0.18));
}

.wave-path {
  stroke: var(--view-accent, var(--cosine-blue));
  stroke-width: 2.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.sine-card .wave-path {
  stroke-dasharray: 9 4;
}

.wave-cursor {
  stroke: var(--angle-amber);
  stroke-width: 1.5;
  stroke-dasharray: 4 4;
  opacity: 0.9;
}

.wave-point {
  fill: var(--view-accent, var(--cosine-blue));
  stroke: var(--paper-strong);
  stroke-width: 2.5;
  filter: drop-shadow(0 2px 3px rgba(45, 38, 30, 0.18));
}

.plot-hit-area {
  fill: transparent;
  pointer-events: all;
  cursor: ew-resize;
}

.vt-exact-guide-ray,
.vt-exact-guide-tick,
.wave-exact-guide-line,
.wave-exact-guide-tick,
.wave-exact-point-halo {
  transition: opacity 120ms ease, stroke-width 120ms ease;
}

.vt-exact-construction text {
  font-family: var(--font-ui);
}

.visual-trigonometry-circle-view[data-identity-active="true"]:not([data-identity-mode="coordinates"]) .vt-coordinate-construction {
  opacity: 0.62;
}

.visual-trigonometry-circle-view[data-identity-active="true"]:not([data-identity-mode="coordinates"]) .vt-angle-ray {
  stroke-width: 1.4;
  opacity: 0.55;
}

.visual-trigonometry-circle-view[data-identity-active="true"]:not([data-identity-mode="coordinates"]) .vt-angle-arc {
  stroke-width: 2.2;
  opacity: 0.62;
}

.visual-trigonometry-circle-view[data-identity-active="true"]:not([data-identity-mode="coordinates"]) .vt-exact-construction text {
  display: none;
}

.visual-trigonometry-circle-view[data-identity-mode="norm"] .vt-exact-construction,
.visual-trigonometry-circle-view[data-identity-mode="addition"] .vt-exact-construction,
.visual-trigonometry-circle-view[data-identity-mode="powers"] .vt-exact-construction,
.visual-trigonometry-circle-view[data-identity-mode="conjugate"] .vt-exact-construction,
.visual-trigonometry-circle-view[data-identity-mode="quarter-turn"] .vt-exact-construction {
  opacity: 0.26;
}

.wave-exact-point-halo-active {
  filter: drop-shadow(0 0 2px rgba(188, 122, 30, 0.32));
}

.svg-label,
.tick-label,
.current-value-label {
  font-family: var(--font-ui);
  paint-order: stroke;
  stroke: var(--paper);
  stroke-width: 3px;
  stroke-linejoin: round;
}

.svg-label {
  fill: var(--ink-soft);
  font-size: 11px;
  font-weight: 650;
}

.tick-label {
  fill: var(--muted);
  font-size: 10px;
  font-weight: 550;
}

.current-value-label {
  fill: var(--view-accent, var(--ink));
  font-size: 11px;
  font-weight: 800;
}

.wave-value-background {
  fill: rgba(255, 253, 248, 0.94);
  stroke: var(--line-strong);
  stroke-width: 1;
  vector-effect: non-scaling-stroke;
}

.unit-handle:focus-visible,
.polar-point:focus-visible,
.wave-point:focus-visible,
.plot-hit-area:focus-visible {
  outline: none;
  stroke: var(--focus-ring);
  stroke-width: 4;
  filter: drop-shadow(0 0 3px rgba(23, 79, 120, 0.55));
}

@media (hover: hover) {
  .button:hover,
  .segment-button:hover,
  .exact-angle-chip:hover,
  .snap-toggle:hover,
  .identity-lens-button:hover {
    border-color: var(--ink-soft);
  }

  .button--primary:hover {
    background: #3a3730;
  }

  .button--quiet:hover,
  .segment-button:hover {
    background: var(--paper-strong);
  }

  .unit-handle:hover,
  .wave-point:hover {
    filter: drop-shadow(0 2px 5px rgba(46, 35, 61, 0.3));
  }

}

@media (min-width: 1101px) and (min-height: 720px) {
  body {
    overflow: hidden;
  }

  .instrument-shell {
    height: 100vh;
    height: 100svh;
    min-height: 0;
  }

  .coordinate-strip {
    height: 67px;
  }

  .identity-layers {
    min-height: 60px;
  }

}

@media (min-width: 1101px) and (max-width: 1199px) {
  .identity-exact-companion {
    flex-basis: 300px;
    grid-template-columns: auto minmax(82px, 1fr) minmax(96px, 1.15fr);
  }

  .identity-exact-companion strong {
    display: none;
  }
}

@media (max-width: 1260px) {
  .toolbar {
    gap: 12px;
  }

  .brand-lockup {
    min-width: 150px;
  }

  .toolbar-controls {
    grid-template-columns: auto minmax(70px, 0.28fr) minmax(220px, 1.35fr) minmax(180px, 0.9fr) auto;
  }

  .exact-angle-strip {
    grid-template-columns: max-content minmax(350px, 1fr) max-content;
    gap: 8px;
  }

  .exact-angle-status {
    min-width: 132px;
  }

  .strip-heading {
    min-width: 104px;
  }

  .strip-heading h2 {
    font-size: 0.86rem;
  }

  .coordinate-strip__core {
    gap: 8px;
  }

  .equivalence-chain {
    gap: 3px;
  }

  .coordinate-reading {
    padding-inline: 3px;
  }

  .relationship-dock {
    grid-template-columns: minmax(215px, 0.85fr) minmax(0, 3.75fr);
    gap: 8px;
  }

  .identity-layers {
    grid-template-columns: minmax(135px, 0.8fr) minmax(170px, 0.95fr) minmax(225px, 1.35fr);
  }
}

@media (max-width: 1100px) {
  body {
    overflow: auto;
  }

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

  .toolbar {
    grid-template-columns: 1fr;
    align-items: start;
  }

  .brand-lockup {
    min-width: 0;
  }

  .toolbar-controls {
    grid-template-columns: auto minmax(78px, 0.35fr) minmax(240px, 1.35fr) minmax(210px, 1fr) auto;
  }

  .exact-angle-strip {
    grid-template-columns: max-content minmax(0, 1fr);
    align-items: stretch;
  }

  .exact-angle-strip__heading {
    grid-row: 1 / 3;
    align-self: stretch;
    display: grid;
    align-content: center;
  }

  .exact-angle-actions {
    justify-content: flex-start;
  }

  .coordinate-strip {
    grid-template-columns: 1fr;
  }

  .readout-grid {
    min-width: 0;
  }

  .visual-stage {
    grid-template-columns: minmax(0, 1fr);
  }

  .circle-card {
    min-height: clamp(500px, 67vw, 660px);
  }

  .circle-surface {
    width: min(100%, 600px);
    height: auto;
    max-height: 100%;
  }

  .wave-card {
    min-height: 290px;
  }

  .relationship-dock {
    grid-template-columns: 1fr;
    align-items: stretch;
  }

  .identity-lens-selector {
    max-width: 520px;
  }

  .identity-layers {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .euler-card {
    display: grid;
    align-content: center;
  }

}

@media (max-width: 760px) {
  .instrument-shell {
    padding: 8px;
    gap: 8px;
  }

  .instrument-main {
    gap: 8px;
  }

  .toolbar {
    padding: 10px;
  }

  .toolbar-controls {
    grid-template-columns: minmax(0, 1fr) minmax(90px, 0.72fr);
    gap: 9px;
  }

  .exact-angle-strip {
    grid-template-columns: 1fr;
    padding: 9px;
  }

  .exact-angle-strip__heading {
    grid-row: auto;
    padding: 0 0 7px;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .exact-angle-chips {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .exact-angle-actions {
    justify-content: space-between;
  }

  .exact-angle-status {
    flex: 1;
  }

  .playback-controls {
    grid-column: 1;
  }

  .speed-control {
    grid-column: 2;
  }

  .angle-control,
  .radius-control,
  .unit-controls {
    grid-column: 1 / -1;
  }

  .unit-controls .segmented-control {
    max-width: 220px;
  }

  .coordinate-strip__core {
    grid-template-columns: 1fr;
  }

  .strip-heading {
    min-width: 0;
    padding: 0 0 7px;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .equivalence-chain {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 6px;
  }

  .coordinate-reading {
    padding: 6px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--paper-warm);
  }

  .coordinate-arrow {
    display: none;
  }

  .readout-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .readout:nth-child(3) {
    border-left: 0;
  }

  .readout:nth-child(n + 3) {
    border-top: 1px solid var(--line);
  }

  .circle-card {
    min-height: min(620px, calc(100vw + 58px));
  }

  .wave-card {
    min-height: 260px;
  }

  .relationship-dock {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .identity-panel__header {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .identity-parameters {
    order: 4;
    width: 100%;
    margin-left: 0;
  }

  .identity-layers {
    grid-template-columns: 1fr;
  }

  .identity-layer,
  .identity-layer:first-child {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .identity-layer:first-child {
    border-top: 0;
  }

  .identity-exact-companion {
    order: 3;
    flex: 1 0 100%;
    width: 100%;
    height: auto;
    min-height: 25px;
    padding: 4px 0 0;
    grid-template-columns: auto minmax(0, 1fr) auto;
    border-top: 1px dashed rgba(188, 122, 30, 0.34);
    border-left: 0;
  }

  .identity-algebra {
    order: 3;
    flex: 1 0 100%;
    width: 100%;
    height: auto;
    min-height: 25px;
    padding: 4px 0 0;
    border-top: 1px dashed rgba(114, 86, 164, 0.3);
    border-left: 0;
  }

  .euler-card {
    min-height: 72px;
  }

}

@media (max-width: 520px) {
  .brand-lockup h1 {
    font-size: 1.08rem;
  }

  .playback-controls .button {
    flex: 1;
  }

  .exact-angle-actions {
    align-items: stretch;
    flex-direction: column;
  }

  .snap-toggle {
    width: 100%;
  }

  .direction-button {
    min-width: 62px;
  }

  .range-input-pair,
  .range-input-pair--radius {
    grid-template-columns: minmax(0, 1fr) 72px;
  }

  .view-card__header {
    align-items: flex-start;
    gap: 8px;
  }

  .view-header-meta {
    align-items: flex-end;
    flex-direction: column;
    gap: 3px;
  }

  .quantity-key {
    display: none;
  }

  .drag-instruction {
    font-size: 0.63rem;
  }

  .notation-flow {
    grid-template-columns: 1fr;
  }

  .notation-flow li,
  .notation-flow li:first-child {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .notation-flow li:first-child {
    border-top: 0;
  }

  .notation-flow li:not(:last-child)::after {
    content: "↓";
    top: auto;
    right: 12px;
    bottom: -8px;
    transform: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

@media (forced-colors: active) {
  .brand-rule,
  .key-dot {
    forced-color-adjust: none;
  }

  .view-card,
  .toolbar,
  .exact-angle-strip,
  .coordinate-strip,
  .relationship-dock {
    box-shadow: none;
  }
}