:root {
  --fa-navy: #103d60;
  --fa-teal: #187786;
  --fa-bronze: #927153;
  --fa-text: #4c6572;
  --fa-muted: #72858f;
  --fa-border: #d6e3e8;
  --fa-border-strong: #bed3dc;
  --fa-pale: #f6fafb;
  --fa-white: #ffffff;
  --fa-shadow: 0 18px 50px rgba(16, 61, 96, 0.08);
  --fa-shadow-soft: 0 10px 30px rgba(16, 61, 96, 0.055);
  --fa-radius: 20px;
  --fa-ui-font: Verdana, Geneva, sans-serif;
  --fa-math-font: "Cambria Math", "STIX Two Math", "STIXGeneral", "DejaVu Serif", "Times New Roman", serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: #fbfdfe;
  color: var(--fa-text);
  font-family: var(--fa-ui-font);
  font-size: 16px;
  line-height: 1.55;
}

button,
input,
select { font: inherit; }

button,
a,
input,
select { -webkit-tap-highlight-color: transparent; }

a { color: inherit; }
button { cursor: pointer; }

.fa-site-header {
  position: relative;
  z-index: 10;
  border-bottom: 1px solid var(--fa-border);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
}

.fa-site-header-inner,
.fa-shell,
.fa-footer-main,
.fa-footer-bottom {
  width: min(1440px, calc(100% - 40px));
  margin: 0 auto;
}

.fa-site-header-inner {
  min-height: 78px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.fa-brand {
  display: inline-flex;
  align-items: center;
  gap: 13px;
  text-decoration: none;
}

.fa-brand-mark {
  width: 42px;
  height: 42px;
  border: 1px solid var(--fa-border-strong);
  border-radius: 12px;
  background: var(--fa-pale);
  display: grid;
  place-items: center;
  position: relative;
  flex: 0 0 auto;
}

.fa-brand-mark span {
  position: absolute;
  width: 24px;
  height: 2px;
  border-radius: 999px;
  background: var(--fa-teal);
  transform-origin: center;
}

.fa-brand-mark span:nth-child(1) { transform: rotate(-34deg) translateY(-4px); }
.fa-brand-mark span:nth-child(2) { transform: rotate(18deg); }
.fa-brand-mark span:nth-child(3) { transform: rotate(-62deg) translateY(4px); background: var(--fa-bronze); }

.fa-brand-copy { display: grid; gap: 1px; }
.fa-brand-copy strong { color: var(--fa-navy); font-size: 18px; letter-spacing: -0.02em; }
.fa-brand-copy small { color: var(--fa-muted); font-size: 12px; }

.fa-geometry-link {
  color: var(--fa-teal);
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
}
.fa-geometry-link:hover { color: var(--fa-navy); }

.fa-shell { padding: 54px 0 72px; }
.fa-intro { max-width: 900px; margin-bottom: 34px; }

.fa-eyebrow,
.fa-panel-kicker,
.fa-footer-kicker {
  margin: 0 0 6px;
  color: var(--fa-bronze);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.fa-intro h1 {
  margin: 0;
  color: var(--fa-navy);
  font-size: clamp(44px, 7vw, 76px);
  line-height: 1;
  letter-spacing: -0.045em;
}

.fa-intro-copy {
  max-width: 840px;
  margin: 20px 0 0;
  color: var(--fa-text);
  font-size: clamp(17px, 2.2vw, 21px);
}

.fa-workspace {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 26px;
  align-items: start;
}

.fa-catalogue {
  position: sticky;
  top: 18px;
  min-width: 0;
  padding: 20px;
  border: 1px solid var(--fa-border);
  border-radius: var(--fa-radius);
  background: var(--fa-white);
  box-shadow: var(--fa-shadow);
}

.fa-catalogue-head,
.fa-control-heading,
.fa-export-heading-row,
.fa-function-header,
.fa-graph-toolbar {
  display: flex;
  justify-content: space-between;
  gap: 20px;
}

.fa-catalogue-head { align-items: center; margin-bottom: 18px; }

.fa-catalogue h2,
.fa-control-card h3,
.fa-export-section h2,
.fa-export-card h3,
.fa-function-header h2,
.fa-legal-heading h2,
.fa-footer-brand h2 {
  margin: 0;
  color: var(--fa-navy);
}

.fa-count {
  min-width: 38px;
  padding: 4px 9px;
  border-radius: 999px;
  background: var(--fa-pale);
  color: var(--fa-teal);
  font-size: 12px;
  font-weight: 700;
  text-align: center;
}

.fa-search-label,
.fa-mobile-picker label {
  display: block;
  margin-bottom: 6px;
  color: var(--fa-muted);
  font-size: 12px;
  font-weight: 700;
}

.fa-search-wrap { position: relative; margin-bottom: 20px; }

.fa-search-wrap svg {
  position: absolute;
  left: 12px;
  top: 50%;
  width: 18px;
  height: 18px;
  transform: translateY(-50%);
  fill: none;
  stroke: var(--fa-muted);
  stroke-width: 1.8;
  pointer-events: none;
}

.fa-search-wrap input,
.fa-mobile-picker select {
  width: 100%;
  min-height: 44px;
  border: 1px solid var(--fa-border-strong);
  border-radius: 10px;
  background: var(--fa-white);
  color: var(--fa-navy);
  outline: none;
}

.fa-search-wrap input { padding: 10px 12px 10px 40px; }
.fa-mobile-picker select { padding: 9px 36px 9px 11px; }

.fa-search-wrap input:focus,
.fa-mobile-picker select:focus,
.fa-colour-field:focus-within,
.fa-thickness-field:focus-within,
.fa-toolbar-button:focus-visible,
.fa-primary-button:focus-visible,
.fa-secondary-button:focus-visible,
.fa-text-button:focus-visible,
.fa-function-button:focus-visible,
.fa-legal a:focus-visible,
.fa-footer-brand a:focus-visible {
  outline: 2px solid rgba(24, 119, 134, 0.28);
  outline-offset: 2px;
}

.fa-mobile-picker { display: none; }
.fa-function-nav { display: grid; gap: 16px; }
.fa-family-group { display: grid; gap: 4px; }

.fa-family-title {
  margin: 0 0 3px;
  color: var(--fa-muted);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.fa-function-button {
  width: 100%;
  min-height: 38px;
  padding: 8px 10px;
  border: 1px solid transparent;
  border-radius: 9px;
  background: transparent;
  color: var(--fa-text);
  text-align: left;
  transition: background .16s ease, border-color .16s ease, color .16s ease, transform .16s ease;
}

.fa-function-button:hover { background: var(--fa-pale); color: var(--fa-teal); transform: translateX(2px); }
.fa-function-button.is-active {
  border-color: rgba(24, 119, 134, 0.18);
  background: rgba(24, 119, 134, 0.08);
  color: var(--fa-navy);
  font-weight: 700;
}

.fa-no-functions,
.fa-muted-note { margin: 12px 0 0; color: var(--fa-muted); font-size: 13px; }

.fa-explorer { min-width: 0; }
.fa-function-header { align-items: end; margin-bottom: 18px; }
.fa-function-heading { min-width: 0; }

.fa-function-header h2 {
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1.05;
  letter-spacing: -0.03em;
}

.fa-equation,
.fa-math-text,
.fa-export-equation {
  font-family: var(--fa-math-font);
  font-variant-numeric: lining-nums tabular-nums;
}

.fa-equation {
  margin: 7px 0 0;
  color: var(--fa-teal);
  font-size: clamp(22px, 2.8vw, 30px);
  line-height: 1.35;
}

.fa-function-description { max-width: 470px; margin: 0; color: var(--fa-muted); }

.fa-graph-card,
.fa-control-card,
.fa-export-section {
  border: 1px solid var(--fa-border);
  border-radius: var(--fa-radius);
  background: var(--fa-white);
  box-shadow: var(--fa-shadow);
}

.fa-graph-card { overflow: hidden; }

.fa-graph-toolbar {
  align-items: center;
  padding: 12px 14px;
  border-bottom: 1px solid var(--fa-border);
  background: var(--fa-pale);
}

.fa-view-actions,
.fa-button-row { display: flex; flex-wrap: wrap; gap: 8px; }

.fa-toolbar-button,
.fa-primary-button,
.fa-secondary-button,
.fa-text-button {
  min-height: 38px;
  border-radius: 9px;
  font-weight: 700;
}

.fa-toolbar-button,
.fa-secondary-button {
  border: 1px solid var(--fa-border-strong);
  background: var(--fa-white);
  color: var(--fa-navy);
}

.fa-toolbar-button { padding: 7px 11px; font-size: 12px; }
.fa-toolbar-button:hover,
.fa-secondary-button:hover { border-color: rgba(24, 119, 134, 0.45); color: var(--fa-teal); }
.fa-gesture-hint { color: var(--fa-muted); font-size: 12px; text-align: right; }

.fa-graph-stage {
  position: relative;
  min-height: 610px;
  overflow: hidden;
  background:
    radial-gradient(circle at 52% 38%, rgba(24, 119, 134, 0.045), transparent 34%),
    linear-gradient(#ffffff, #f8fbfc);
}

.fa-canvas-host,
.fa-canvas-host canvas { display: block; width: 100%; height: 100%; }
.fa-canvas-host { position: absolute; inset: 0; touch-action: none; }

.fa-graph-message {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  padding: 30px;
  background: rgba(255,255,255,.94);
  color: var(--fa-muted);
  text-align: center;
  pointer-events: none;
  z-index: 5;
}
.fa-graph-message[hidden] { display: none !important; }

.fa-axis-key {
  position: absolute;
  left: 14px;
  bottom: 12px;
  display: flex;
  gap: 12px;
  padding: 7px 9px;
  border: 1px solid rgba(190,211,220,.8);
  border-radius: 9px;
  background: rgba(255,255,255,.92);
  color: var(--fa-muted);
  font-size: 11px;
  backdrop-filter: blur(8px);
  pointer-events: none;
}

.fa-axis-key span { display: inline-flex; align-items: center; gap: 5px; }
.fa-axis-key i { width: 14px; height: 2px; display: inline-block; }
.fa-axis-x { background: #aa4e4e; }
.fa-axis-y { background: #3e7f59; }
.fa-axis-z { background: #496c9b; }

.fa-control-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  margin-top: 16px;
}

.fa-control-card { min-width: 0; padding: 18px; }
.fa-control-heading { align-items: start; margin-bottom: 14px; }

.fa-text-button {
  min-height: 32px;
  padding: 4px 8px;
  border: 0;
  background: transparent;
  color: var(--fa-teal);
  font-size: 12px;
}

.fa-parameters { display: grid; gap: 14px; }
.fa-parameter-row {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr) 58px;
  gap: 9px;
  align-items: center;
}
.fa-parameter-row label { color: var(--fa-navy); font-weight: 700; }

.fa-parameter-row input[type="range"],
.fa-thickness-field input[type="range"] { width: 100%; accent-color: var(--fa-teal); }

.fa-parameter-value,
#fa-thickness-value {
  padding: 4px 6px;
  border: 1px solid var(--fa-border);
  border-radius: 7px;
  background: var(--fa-pale);
  color: var(--fa-navy);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  text-align: center;
}

.fa-appearance-controls { display: grid; gap: 0; }

.fa-colour-control,
.fa-thickness-control,
.fa-switch-row {
  min-height: 62px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 10px 0;
  border-bottom: 1px solid var(--fa-border);
}
.fa-switch-row:last-child { border-bottom: 0; }

.fa-control-copy,
.fa-switch-row > span { display: grid; gap: 2px; min-width: 0; }
.fa-control-copy strong,
.fa-switch-row strong { color: var(--fa-navy); font-size: 13px; }
.fa-control-copy small,
.fa-switch-row small { color: var(--fa-muted); font-size: 11px; }

.fa-switch-row input {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
  accent-color: var(--fa-teal);
}

.fa-colour-field {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 7px 4px 4px;
  border: 1px solid var(--fa-border);
  border-radius: 9px;
  background: var(--fa-pale);
  color: var(--fa-muted);
  font-size: 11px;
  flex: 0 0 auto;
}
.fa-colour-field input { width: 34px; height: 28px; padding: 0; border: 0; background: transparent; }

.fa-thickness-field {
  min-width: 152px;
  display: grid;
  grid-template-columns: minmax(88px, 1fr) 58px;
  align-items: center;
  gap: 8px;
}

.fa-details-list { margin: 0; display: grid; gap: 12px; }
.fa-details-list div {
  display: grid;
  grid-template-columns: 76px minmax(0, 1fr);
  gap: 10px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--fa-border);
}
.fa-details-list div:last-child { border-bottom: 0; }
.fa-details-list dt { color: var(--fa-muted); font-size: 12px; font-weight: 700; }
.fa-details-list dd { margin: 0; color: var(--fa-navy); font-size: 16px; line-height: 1.5; }

.fa-export-section { margin-top: 16px; padding: 22px; }
.fa-export-heading-row { align-items: end; margin-bottom: 16px; }
.fa-export-heading-row > p { max-width: 520px; margin: 0; color: var(--fa-muted); text-align: right; }
.fa-export-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; }

.fa-export-card {
  min-width: 0;
  padding: 17px;
  border: 1px solid var(--fa-border);
  border-radius: 14px;
  background: var(--fa-pale);
}

.fa-export-card-copy { display: flex; gap: 12px; align-items: start; margin-bottom: 14px; }
.fa-export-icon {
  width: 36px;
  height: 36px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border: 1px solid var(--fa-border-strong);
  border-radius: 10px;
  background: var(--fa-white);
  color: var(--fa-teal);
  font-size: 19px;
  font-weight: 700;
}

.fa-export-card p { margin: 3px 0 0; color: var(--fa-muted); font-size: 13px; }
.fa-export-card .fa-export-equation { color: var(--fa-teal); font-size: 16px; }
.fa-primary-button,
.fa-secondary-button { padding: 8px 12px; }
.fa-primary-button { border: 1px solid var(--fa-teal); background: var(--fa-teal); color: var(--fa-white); }
.fa-primary-button:hover { background: var(--fa-navy); border-color: var(--fa-navy); }
.fa-secondary-button { font-size: 13px; }
.fa-export-status { min-height: 21px; margin: 12px 0 0; color: var(--fa-teal); font-size: 12px; font-weight: 700; }

/* Footer: deliberately simple, rigid and aligned. */
.fa-footer {
  border-top: 1px solid #0b314e;
  background: var(--fa-navy);
  color: #eaf2f5;
}

.fa-footer-main {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 460px);
  gap: 72px;
  align-items: start;
  padding: 42px 0 34px;
}

.fa-footer-brand,
.fa-legal-panel { min-width: 0; }

.fa-footer-brand h2 {
  color: #ffffff;
  font-size: 24px;
  line-height: 1.2;
  margin-bottom: 10px;
}

.fa-footer-brand p:not(.fa-footer-kicker) {
  max-width: 560px;
  margin: 0 0 16px;
  color: #c5d5dd;
  font-size: 13px;
  line-height: 1.65;
}

.fa-footer-brand a {
  display: inline-flex;
  gap: 6px;
  align-items: center;
  color: #ffffff;
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
}
.fa-footer-brand a:hover { color: #bfe6ea; }

.fa-footer .fa-footer-kicker { color: #c8a98c; }

.fa-legal-heading {
  padding-bottom: 12px;
  margin-bottom: 4px;
  border-bottom: 1px solid rgba(255,255,255,.18);
}
.fa-legal-heading h2 { color: #ffffff; font-size: 18px; line-height: 1.25; }

.fa-legal {
  display: grid;
  grid-template-columns: 1fr;
}

.fa-legal a {
  min-width: 0;
  min-height: 43px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 10px 2px;
  border-bottom: 1px solid rgba(255,255,255,.12);
  color: #eaf2f5;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.35;
  text-decoration: none;
}

.fa-legal a span:first-child {
  min-width: 0;
  overflow-wrap: normal;
  word-break: normal;
}

.fa-legal a span:last-child {
  color: #91c8cf;
  font-size: 12px;
}

.fa-legal a:hover { color: #ffffff; }
.fa-legal a:hover span:last-child { transform: translate(1px, -1px); }

.fa-footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 18px 0 24px;
  border-top: 1px solid rgba(255,255,255,.18);
}

.fa-footer-bottom p {
  margin: 0;
  color: #aebfc8;
  font-size: 11px;
  line-height: 1.5;
}

@media (max-width: 1100px) {
  .fa-workspace { grid-template-columns: 235px minmax(0, 1fr); gap: 18px; }
  .fa-control-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .fa-details-card { grid-column: 1 / -1; }
  .fa-footer-main { grid-template-columns: minmax(0,1fr) minmax(300px,400px); gap: 42px; }
}

@media (max-width: 860px) {
  .fa-site-header-inner,
  .fa-shell,
  .fa-footer-main,
  .fa-footer-bottom { width: min(100% - 28px, 1440px); }

  .fa-shell { padding-top: 38px; }
  .fa-workspace { display: block; }
  .fa-catalogue { position: static; margin-bottom: 18px; }
  .fa-function-nav { display: none; }
  .fa-mobile-picker { display: block; }
  .fa-search-wrap { margin-bottom: 12px; }
  .fa-function-header { align-items: start; flex-direction: column; }
  .fa-function-description { max-width: none; }
  .fa-graph-stage { min-height: 520px; }
  .fa-footer-main { grid-template-columns: 1fr; gap: 30px; }
  .fa-legal-panel { max-width: 560px; }
}

@media (max-width: 680px) {
  .fa-site-header-inner { min-height: 68px; }
  .fa-brand-copy small { display: none; }
  .fa-geometry-link { font-size: 12px; }
  .fa-intro h1 { font-size: clamp(42px, 15vw, 62px); }

  .fa-graph-toolbar,
  .fa-export-heading-row,
  .fa-footer-bottom { align-items: start; flex-direction: column; }

  .fa-gesture-hint,
  .fa-export-heading-row > p { text-align: left; }

  .fa-control-grid,
  .fa-export-grid { grid-template-columns: 1fr; }

  .fa-details-card { grid-column: auto; }
  .fa-graph-stage { min-height: 445px; }
  .fa-button-row > * { flex: 1 1 140px; }
  .fa-footer-main { padding-top: 34px; }
}

@media (max-width: 430px) {
  .fa-site-header-inner,
  .fa-shell,
  .fa-footer-main,
  .fa-footer-bottom { width: min(100% - 20px, 1440px); }

  .fa-geometry-link span { display: none; }
  .fa-brand-mark { width: 38px; height: 38px; }

  .fa-catalogue,
  .fa-control-card,
  .fa-export-section { padding: 15px; }

  .fa-graph-stage { min-height: 390px; }

  .fa-view-actions {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    width: 100%;
  }
  .fa-view-actions .fa-toolbar-button:last-child { grid-column: 1 / -1; }
  .fa-parameter-row { grid-template-columns: 24px minmax(0, 1fr) 52px; }

  .fa-colour-control,
  .fa-thickness-control { align-items: stretch; flex-direction: column; }
  .fa-thickness-field { min-width: 0; width: 100%; }
  .fa-footer-main { gap: 26px; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}