/* FPA — Design tokens + component styles
   Art direction: editorial medical authority with an innovation edge.
   Instrument Serif (display) + DM Sans (body).
   Saturated cyan-teal primary + warm amber accent, cool paper / near-black surfaces. */

:root, [data-theme='light'] {
  /* Type */
  --text-2xs: 0.6875rem;
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
  --text-3xl: clamp(2.5rem, 1rem + 4vw, 5rem);
  --text-hero: clamp(3rem, 0.5rem + 7vw, 7rem);

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Fonts */
  --font-display: 'Instrument Serif', 'Iowan Old Style', Georgia, serif;
  --font-body: 'DM Sans', 'Helvetica Neue', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', ui-monospace, monospace;

  /* Surfaces — cool paper with subtle cyan undertone */
  --color-bg: #F6F8F9;
  --color-surface: #FBFCFD;
  --color-surface-2: #FFFFFF;
  --color-surface-offset: #EEF2F4;
  --color-divider: #DAE0E4;
  --color-border: #C4CBD1;

  /* Text — near-black with cyan undertone */
  --color-text: #0F172A;
  --color-text-muted: #4B5563;
  --color-text-faint: #94A3B8;
  --color-text-inverse: #FBFCFD;

  /* Primary — deep cyan-teal (saturated, forward) */
  --color-primary: #0891B2;
  --color-primary-hover: #0E7490;
  --color-primary-active: #164E63;
  --color-primary-highlight: #CFFAFE;

  /* Accent — warm amber for callouts, priority markers, data highlights */
  --color-accent: #B45309;
  --color-accent-hover: #92400E;
  --color-accent-highlight: #FEF3C7;

  /* Semantic */
  --color-error: #B91C1C;
  --color-success: #15803D;
  --color-warning: #B45309;

  /* Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 220ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Shadows */
  --shadow-sm: 0 1px 2px oklch(0.2 0.01 60 / 0.08);
  --shadow-md: 0 6px 20px oklch(0.2 0.01 60 / 0.09);
  --shadow-lg: 0 20px 50px oklch(0.2 0.01 60 / 0.14);

  /* Widths */
  --content-narrow: 640px;
  --content-default: 1000px;
  --content-wide: 1240px;
}

[data-theme='dark'] {
  --color-bg: #0B1220;
  --color-surface: #111827;
  --color-surface-2: #1B2436;
  --color-surface-offset: #1F2A3F;
  --color-divider: #24314A;
  --color-border: #334155;

  --color-text: #F1F5F9;
  --color-text-muted: #94A3B8;
  --color-text-faint: #64748B;
  --color-text-inverse: #0B1220;

  --color-primary: #22D3EE;
  --color-primary-hover: #67E8F9;
  --color-primary-active: #A5F3FC;
  --color-primary-highlight: #164E63;

  --color-accent: #F59E0B;
  --color-accent-hover: #FBBF24;
  --color-accent-highlight: #78350F;

  --color-error: #F87171;
  --color-success: #4ADE80;
  --color-warning: #FBBF24;

  --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.4);
  --shadow-md: 0 6px 20px oklch(0 0 0 / 0.5);
  --shadow-lg: 0 20px 50px oklch(0 0 0 / 0.6);
}

/* Layout containers */
.container {
  width: 100%;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-5), 4vw, var(--space-10));
}
.container--narrow { max-width: var(--content-narrow); }
.container--default { max-width: var(--content-default); }

section {
  padding-block: clamp(var(--space-16), 10vw, var(--space-32));
  position: relative;
}
section + section { border-top: 1px solid var(--color-divider); }

/* Header / Nav */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: oklch(from var(--color-bg) l c h / 0.85);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition:
    border-color var(--transition-interactive),
    background var(--transition-interactive);
}
.header--scrolled { border-bottom-color: var(--color-divider); }
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding-block: var(--space-4);
}
.header__brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text);
  text-decoration: none;
  font-family: var(--font-display);
  font-size: var(--text-lg);
  letter-spacing: -0.01em;
  min-width: 0;
}
.header__brand svg { color: var(--color-primary); flex-shrink: 0; }
.header__brand span { white-space: nowrap; }
.header__brand__short { display: inline; }
.header__brand__full { display: none; }
.header__nav {
  display: none;
  gap: var(--space-6);
  align-items: center;
}
.header__nav a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: var(--text-sm);
  font-weight: 500;
}
.header__nav a:hover { color: var(--color-text); }
.header__cta {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}
.header__cta .btn--primary { padding-inline: var(--space-4); font-size: var(--text-sm); }
@media (min-width: 520px) {
  .header__brand__short { display: none; }
  .header__brand__full { display: inline; }
  .header__cta .btn--primary { padding-inline: var(--space-5); font-size: var(--text-base); }
}
@media (min-width: 900px) {
  .header__nav { display: flex; }
}

/* Languages / International demand */
.languages-section {
  background: var(--color-surface);
  border-block: 1px solid var(--color-divider);
}
.lang-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}
@media (min-width: 720px) {
  .lang-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 1080px) {
  .lang-grid { grid-template-columns: repeat(4, 1fr); }
}
.lang-card {
  padding: var(--space-6);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  transition: transform 200ms ease, border-color 200ms ease, box-shadow 200ms ease;
}
.lang-card:hover {
  transform: translateY(-2px);
  border-color: var(--color-text-faint);
}
.lang-card--priority {
  border-color: var(--color-primary);
  background: linear-gradient(180deg, var(--color-bg) 0%, color-mix(in oklch, var(--color-primary) 4%, var(--color-bg)) 100%);
}
[data-theme="dark"] .lang-card--priority {
  background: linear-gradient(180deg, var(--color-bg) 0%, color-mix(in oklch, var(--color-primary) 8%, var(--color-bg)) 100%);
}
.lang-card__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}
.lang-card__code {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-primary);
  letter-spacing: 0.1em;
  padding: var(--space-1) var(--space-2);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-sm);
}
.lang-card__status {
  font-family: var(--font-mono);
  font-size: var(--text-2xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.lang-card__status--priority { color: var(--color-primary); }
.lang-card__name {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  line-height: 1.15;
  color: var(--color-text);
  margin: var(--space-1) 0 var(--space-2);
}
.lang-card__body {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  line-height: 1.55;
  flex-grow: 1;
}
.lang-card .btn--link { margin-top: var(--space-2); align-self: flex-start; }
.lang-note {
  margin-top: clamp(var(--space-10), 5vw, var(--space-16));
  padding: var(--space-6) var(--space-8);
  border-left: 3px solid var(--color-primary);
  background: var(--color-bg);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  max-width: 780px;
}
.lang-note p {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  line-height: 1.65;
  margin: 0;
}
.lang-note strong { color: var(--color-text); font-weight: 600; }

/* Flash animation for language field when arriving via lang vote */
@keyframes field-flash {
  0%, 100% { box-shadow: 0 0 0 0 transparent; }
  30%, 70% { box-shadow: 0 0 0 4px color-mix(in oklch, var(--color-primary) 20%, transparent); }
}
.field--flash select,
.field--flash input,
.field--flash textarea {
  animation: field-flash 1.2s ease-out;
  border-color: var(--color-primary);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.7rem 1.25rem;
  font-size: var(--text-sm);
  font-weight: 500;
  border-radius: var(--radius-md);
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  line-height: 1;
}
.btn--primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}
.btn--primary:hover { background: var(--color-primary-hover); }
.btn--ghost {
  color: var(--color-text);
  border-color: var(--color-border);
  background: transparent;
}
.btn--ghost:hover {
  border-color: var(--color-text);
  background: oklch(from var(--color-text) l c h / 0.04);
}
.btn--link {
  color: var(--color-text);
  padding: 0;
  border: none;
  background: none;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
  text-decoration-color: var(--color-divider);
}
.btn--link:hover { text-decoration-color: var(--color-primary); }
.btn__arrow { transition: transform var(--transition-interactive); }
.btn:hover .btn__arrow { transform: translateX(2px); }
.btn--lg { padding: 0.9rem 1.6rem; font-size: var(--text-base); }

/* Theme toggle */
.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.theme-toggle:hover {
  color: var(--color-text);
  border-color: var(--color-text-muted);
}

/* Hero */
.hero { padding-block: clamp(var(--space-16), 12vw, var(--space-32)); }
.hero__kicker {
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-6);
}
.hero__title {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: var(--text-hero);
  line-height: 1.02;
  letter-spacing: -0.025em;
  color: var(--color-text);
  margin-bottom: var(--space-6);
  max-width: 22ch;
}
.hero__title em {
  font-style: italic;
  color: var(--color-primary);
}
.hero__sub {
  font-size: var(--text-lg);
  line-height: 1.5;
  color: var(--color-text-muted);
  max-width: 58ch;
  margin-bottom: var(--space-10);
}
.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  align-items: center;
  margin-bottom: var(--space-12);
}
.hero__trust {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-6) var(--space-8);
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-divider);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.hero__trust strong {
  color: var(--color-text);
  font-weight: 500;
}
.hero__trust > div {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
}

/* Section titles */
.section__eyebrow {
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}
.section__title {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: var(--text-2xl);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: var(--space-6);
  max-width: 22ch;
}
.section__lede {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 62ch;
  margin-bottom: var(--space-16);
}

/* Problem — 3 columns */
.problem-grid {
  display: grid;
  gap: var(--space-8);
  grid-template-columns: 1fr;
}
@media (min-width: 800px) {
  .problem-grid { grid-template-columns: repeat(3, 1fr); gap: var(--space-10); }
}
.problem-item {
  padding-top: var(--space-6);
  border-top: 2px solid var(--color-text);
}
.problem-item__num {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}
.problem-item__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  line-height: 1.15;
  margin-bottom: var(--space-4);
  color: var(--color-text);
}
.problem-item__body {
  color: var(--color-text-muted);
  font-size: var(--text-base);
}

/* Solution — three constraint rows */
.constraint-list {
  display: grid;
  gap: 0;
}
.constraint {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  padding-block: var(--space-10);
  border-top: 1px solid var(--color-divider);
}
.constraint:last-child { border-bottom: 1px solid var(--color-divider); }
@media (min-width: 800px) {
  .constraint {
    grid-template-columns: 220px 1fr 2fr;
    gap: var(--space-10);
    align-items: baseline;
  }
}
.constraint__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}
.constraint__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  line-height: 1.15;
  color: var(--color-text);
}
.constraint__body {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* Coverage stats block */
.coverage-block {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(var(--space-10), 6vw, var(--space-20));
  display: grid;
  gap: var(--space-8);
  grid-template-columns: 1fr;
}
@media (min-width: 800px) {
  .coverage-block { grid-template-columns: 1fr 1fr; align-items: center; }
}
.coverage-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6) var(--space-4);
}
.coverage-stat {
  border-left: 2px solid var(--color-primary);
  padding-left: var(--space-4);
}
.coverage-stat__value {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  line-height: 1;
  color: var(--color-text);
  font-variant-numeric: tabular-nums lining-nums;
}
.coverage-stat__label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: var(--space-2);
}

/* Audience cards */
.audience-grid {
  display: grid;
  gap: var(--space-6);
  grid-template-columns: 1fr;
}
@media (min-width: 700px) {
  .audience-grid { grid-template-columns: repeat(2, 1fr); }
}
.audience-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  transition: transform var(--transition-interactive), border-color var(--transition-interactive), box-shadow var(--transition-interactive);
}
.audience-card:hover {
  transform: translateY(-2px);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
}
.audience-card__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.audience-card__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-text);
  margin-top: var(--space-2);
}
.audience-card__desc {
  color: var(--color-text-muted);
  font-size: var(--text-base);
  flex: 1;
}
.audience-card__price {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-divider);
  margin-top: var(--space-4);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}
.audience-card__price span {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* Waitlist */
.waitlist-section {
  background: var(--color-surface-offset);
}
.waitlist-toggle {
  display: inline-flex;
  gap: 0;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  padding: 4px;
  margin-bottom: var(--space-10);
}
.waitlist-toggle button {
  padding: 0.55rem 1.25rem;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  border-radius: var(--radius-full);
  background: transparent;
}
.waitlist-toggle button[aria-pressed='true'] {
  background: var(--color-text);
  color: var(--color-text-inverse);
}

.form {
  display: grid;
  gap: var(--space-5);
}
.form-row {
  display: grid;
  gap: var(--space-5);
  grid-template-columns: 1fr;
}
@media (min-width: 700px) {
  .form-row--two { grid-template-columns: 1fr 1fr; }
}
.field label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}
.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: var(--text-base);
  color: var(--color-text);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-family: inherit;
}
.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: var(--color-primary);
  outline: none;
  box-shadow: 0 0 0 3px var(--color-primary-highlight);
}
.field__hint {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-2);
}
.form__submit {
  padding-top: var(--space-4);
}
.form-success {
  display: none;
  padding: var(--space-8);
  background: var(--color-surface-2);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-lg);
  text-align: center;
}
.form-success.is-visible { display: block; }
.form-success h3 {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-text);
  margin-bottom: var(--space-3);
}
.form-success p {
  color: var(--color-text-muted);
  margin-inline: auto;
}

/* Founder block */
.founder {
  display: grid;
  gap: var(--space-10);
  grid-template-columns: 1fr;
  align-items: start;
}
@media (min-width: 800px) {
  .founder { grid-template-columns: 1fr 2fr; gap: var(--space-16); }
}
.founder__mark {
  aspect-ratio: 1;
  max-width: 260px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
}
.founder__name {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  line-height: 1.1;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}
.founder__role {
  font-size: var(--text-sm);
  color: var(--color-primary);
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-6);
}
.founder__bio {
  font-size: var(--text-lg);
  line-height: 1.55;
  color: var(--color-text);
  margin-bottom: var(--space-6);
}
.founder__path {
  list-style: none;
  padding: 0;
  margin: var(--space-6) 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  border-left: 2px solid var(--color-primary);
  padding-left: var(--space-5);
}
.founder__path li {
  font-size: var(--text-base);
  line-height: 1.4;
  color: var(--color-text);
  position: relative;
}
.founder__path li::before {
  content: '';
  position: absolute;
  left: calc(var(--space-5) * -1 - 5px);
  top: 0.6em;
  width: 8px;
  height: 8px;
  background: var(--color-primary);
  border-radius: 50%;
}
.founder__path__degree {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 500;
  margin-right: var(--space-2);
}
.founder__current {
  list-style: none;
  padding: var(--space-5) var(--space-6);
  margin: var(--space-6) 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  background: color-mix(in oklch, var(--color-accent) 8%, var(--color-surface));
  border: 1px solid color-mix(in oklch, var(--color-accent) 20%, var(--color-divider));
  border-radius: var(--radius-md);
}
[data-theme='dark'] .founder__current {
  background: color-mix(in oklch, var(--color-accent) 12%, var(--color-surface));
  border-color: color-mix(in oklch, var(--color-accent) 30%, var(--color-divider));
}
.founder__current li {
  font-size: var(--text-base);
  line-height: 1.5;
  color: var(--color-text);
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: var(--space-4);
  align-items: start;
}
@media (max-width: 600px) {
  .founder__current li {
    grid-template-columns: 1fr;
    gap: var(--space-1);
  }
}
.founder__current li em {
  font-family: var(--font-display);
  font-style: italic;
  color: var(--color-text);
}
.founder__current__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 500;
  padding-top: 0.15em;
}
.founder__meta {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-divider);
}

/* Footer */
footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-divider);
  padding-block: var(--space-16) var(--space-10);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}
.footer__inner {
  display: grid;
  gap: var(--space-10);
  grid-template-columns: 1fr;
}
@media (min-width: 800px) {
  .footer__inner { grid-template-columns: 1.5fr 1fr 1fr 1fr; }
}
.footer__brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: var(--text-lg);
  margin-bottom: var(--space-4);
  text-decoration: none;
}
.footer__brand svg { color: var(--color-primary); }
.footer__tagline {
  color: var(--color-text-muted);
  max-width: 32ch;
}
.footer__col h4 {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-text);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-4);
}
.footer__col ul {
  list-style: none;
  display: grid;
  gap: var(--space-3);
}
.footer__col a {
  color: var(--color-text-muted);
  text-decoration: none;
}
.footer__col a:hover { color: var(--color-text); }
.footer__bottom {
  margin-top: var(--space-16);
  padding-top: var(--space-6);
  border-top: 1px solid var(--color-divider);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-4);
  color: var(--color-text-faint);
  font-size: var(--text-xs);
}

/* Utility */
.two-col-lede {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-10);
}
@media (min-width: 900px) {
  .two-col-lede {
    grid-template-columns: 1fr 1.4fr;
    gap: var(--space-20);
    align-items: end;
  }
}

/* Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 600ms cubic-bezier(0.16, 1, 0.3, 1), transform 600ms cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ============================================================
   POLISH LAYER — motion, gradients, micro-interactions, Tutor CTA
   Additive only. Uses existing tokens. Motion is disabled by the
   prefers-reduced-motion guard in base.css (which uses !important).
   ============================================================ */

/* --- Ambient hero gradient field --- */
.hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: -20% -10% auto -10%;
  height: 140%;
  z-index: -1;
  background:
    radial-gradient(60% 55% at 18% 12%, color-mix(in oklch, var(--color-primary) 20%, transparent) 0%, transparent 60%),
    radial-gradient(45% 45% at 88% 8%, color-mix(in oklch, var(--color-accent) 16%, transparent) 0%, transparent 55%),
    radial-gradient(55% 60% at 60% 100%, color-mix(in oklch, var(--color-primary) 12%, transparent) 0%, transparent 65%);
  filter: blur(8px);
  opacity: 0.9;
  animation: hero-drift 22s ease-in-out infinite alternate;
  pointer-events: none;
}
[data-theme='dark'] .hero::before { opacity: 0.7; }
@keyframes hero-drift {
  0%   { transform: translate3d(0, 0, 0) scale(1); }
  50%  { transform: translate3d(-2%, 1.5%, 0) scale(1.05); }
  100% { transform: translate3d(2%, -1%, 0) scale(1.02); }
}

/* Fine grid texture over the hero, masked to fade out downward */
.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, color-mix(in oklch, var(--color-text) 5%, transparent) 1px, transparent 1px),
    linear-gradient(to bottom, color-mix(in oklch, var(--color-text) 5%, transparent) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: radial-gradient(120% 80% at 50% 0%, #000 20%, transparent 75%);
  mask-image: radial-gradient(120% 80% at 50% 0%, #000 20%, transparent 75%);
  opacity: 0.6;
  pointer-events: none;
}

/* --- Gradient ink on the hero + section display type --- */
.hero__title em {
  background: linear-gradient(100deg, var(--color-primary) 0%, var(--color-accent) 92%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* Animated underline sweep on hero kicker */
.hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}
.hero__kicker::before {
  content: '';
  width: 28px;
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), transparent);
  transform-origin: left center;
  animation: kicker-grow 1.1s cubic-bezier(0.16, 1, 0.3, 1) both;
}
@keyframes kicker-grow { from { transform: scaleX(0); opacity: 0; } to { transform: scaleX(1); opacity: 1; } }

/* --- Hero trust counters: subtle pop-in with primary accent --- */
.hero__trust strong { color: var(--color-primary); }

/* --- Button micro-interactions --- */
.btn { position: relative; overflow: hidden; }
.btn--primary {
  box-shadow: 0 1px 0 color-mix(in oklch, var(--color-primary-active) 40%, transparent);
  transition:
    background var(--transition-interactive),
    transform var(--transition-interactive),
    box-shadow var(--transition-interactive);
}
.btn--primary:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}
.btn--primary:active { transform: translateY(0); }
/* Sheen sweep on primary buttons */
.btn--primary::after {
  content: '';
  position: absolute;
  top: 0;
  left: -120%;
  width: 60%;
  height: 100%;
  background: linear-gradient(100deg, transparent, color-mix(in oklch, white 45%, transparent), transparent);
  transform: skewX(-18deg);
  transition: left 620ms cubic-bezier(0.16, 1, 0.3, 1);
  pointer-events: none;
}
.btn--primary:hover::after { left: 130%; }
.btn--ghost:hover { transform: translateY(-1px); }

/* --- Nav underline reveal --- */
.header__nav a {
  position: relative;
}
.header__nav a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 100%;
  height: 2px;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 220ms cubic-bezier(0.16, 1, 0.3, 1);
}
.header__nav a:hover::after { transform: scaleX(1); }

/* --- Dedicated Tutor tab in header CTA: always visible, all widths --- */
.header__cta__tutor {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 0.4rem 0.85rem;
  border: 1px solid color-mix(in oklch, var(--color-primary) 45%, var(--color-border));
  border-radius: var(--radius-full);
  color: var(--color-primary);
  font-size: var(--text-sm);
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  background: color-mix(in oklch, var(--color-primary) 8%, transparent);
  transition:
    background var(--transition-interactive),
    border-color var(--transition-interactive),
    box-shadow var(--transition-interactive),
    transform var(--transition-interactive);
}
.header__cta__tutor:hover {
  background: color-mix(in oklch, var(--color-primary) 15%, transparent);
  border-color: var(--color-primary);
  box-shadow: 0 4px 14px color-mix(in oklch, var(--color-primary) 18%, transparent);
  transform: translateY(-1px);
}
.header__cta__tutor:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}
.header__cta__tutor:active {
  background: color-mix(in oklch, var(--color-primary) 20%, transparent);
  box-shadow: none;
  transform: translateY(0);
}
.header__cta__tutor__arrow { transition: transform var(--transition-interactive); }
.header__cta__tutor:hover .header__cta__tutor__arrow { transform: translate(1px, -1px); }

/* --- Card micro-interactions: refine existing lift + accent glow --- */
.problem-item {
  transition: transform var(--transition-interactive);
}
.problem-item:hover { transform: translateY(-2px); }
.problem-item:hover .problem-item__num { color: var(--color-accent); }
.problem-item__num { transition: color var(--transition-interactive); }

.coverage-stat { transition: transform var(--transition-interactive); }
.coverage-stat:hover { transform: translateX(3px); }
.coverage-stat:hover .coverage-stat__value { color: var(--color-primary); }
.coverage-stat__value { transition: color var(--transition-interactive); }

.audience-card { position: relative; overflow: hidden; }
.audience-card::before {
  content: '';
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 300ms cubic-bezier(0.16, 1, 0.3, 1);
}
.audience-card:hover::before { transform: scaleX(1); }

.constraint { transition: background var(--transition-interactive); }
.constraint:hover { background: color-mix(in oklch, var(--color-primary) 3%, transparent); }
.constraint:hover .constraint__title { color: var(--color-primary); }
.constraint__title { transition: color var(--transition-interactive); }

/* --- Section title accent sweep --- */
.section__title em {
  font-style: italic;
  background: linear-gradient(100deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

/* --- Reveal: gentle stagger for grid children --- */
.problem-grid .reveal,
.lang-grid .reveal { transition-delay: 60ms; }

/* ============================================================
   TUTOR CTA BAND
   ============================================================ */
.tutor-band {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  background: var(--color-text);
  color: var(--color-text-inverse);
  border-top: 1px solid var(--color-divider);
}
.tutor-band::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(50% 70% at 12% 20%, color-mix(in oklch, var(--color-primary) 55%, transparent) 0%, transparent 60%),
    radial-gradient(45% 65% at 92% 90%, color-mix(in oklch, var(--color-accent) 40%, transparent) 0%, transparent 60%);
  opacity: 0.55;
  animation: hero-drift 26s ease-in-out infinite alternate;
  pointer-events: none;
}
.tutor-band__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-10);
  align-items: center;
}
@media (min-width: 860px) {
  .tutor-band__inner { grid-template-columns: 1.35fr 1fr; gap: var(--space-16); }
}
.tutor-band .section__eyebrow {
  color: color-mix(in oklch, var(--color-primary) 55%, white);
}
.tutor-band__title {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: var(--text-2xl);
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-5);
  color: var(--color-text-inverse);
  max-width: 18ch;
}
.tutor-band__title em {
  font-style: italic;
  background: linear-gradient(100deg, color-mix(in oklch, var(--color-primary) 60%, white), color-mix(in oklch, var(--color-accent) 60%, white));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}
.tutor-band__sub {
  font-size: var(--text-lg);
  line-height: 1.5;
  color: color-mix(in oklch, var(--color-text-inverse) 82%, transparent);
  max-width: 54ch;
  margin-bottom: var(--space-8);
}
.tutor-band__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  align-items: center;
}
.tutor-band__actions .btn--link {
  color: color-mix(in oklch, var(--color-text-inverse) 78%, transparent);
  text-decoration-color: color-mix(in oklch, var(--color-text-inverse) 30%, transparent);
}
.tutor-band__actions .btn--link:hover {
  color: var(--color-text-inverse);
  text-decoration-color: color-mix(in oklch, var(--color-primary) 60%, white);
}
/* Simulated tutor verification chips */
.tutor-band__viz {
  display: grid;
  gap: var(--space-3);
  justify-items: start;
  align-content: center;
}
@media (min-width: 860px) { .tutor-band__viz { justify-items: end; } }
.tutor-band__chip {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  border: 1px solid color-mix(in oklch, white 18%, transparent);
  background: color-mix(in oklch, white 6%, transparent);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  animation: chip-in 700ms cubic-bezier(0.16, 1, 0.3, 1) both;
  white-space: nowrap;
}
.tutor-band__chip--verified {
  color: color-mix(in oklch, var(--color-success) 65%, white);
  border-color: color-mix(in oklch, var(--color-success) 45%, transparent);
}
.tutor-band__chip--verified::before { content: '✓ '; }
.tutor-band__chip--phase {
  color: color-mix(in oklch, var(--color-primary) 55%, white);
  border-color: color-mix(in oklch, var(--color-primary) 45%, transparent);
}
.tutor-band__chip--blocked {
  color: color-mix(in oklch, var(--color-accent) 60%, white);
  border-color: color-mix(in oklch, var(--color-accent) 45%, transparent);
}
.tutor-band__chip--blocked::before { content: '⚠ '; }
.tutor-band__chip:nth-child(1) { animation-delay: 80ms; }
.tutor-band__chip:nth-child(2) { animation-delay: 200ms; }
.tutor-band__chip:nth-child(3) { animation-delay: 320ms; }
.tutor-band__chip:nth-child(4) { animation-delay: 440ms; }
@keyframes chip-in {
  from { opacity: 0; transform: translateY(8px) scale(0.96); }
  to   { opacity: 1; transform: none; }
}

/* Stage F closeout: keyboard parity and compact-header resilience. */
.header__nav a:focus-visible::after { transform: scaleX(1); }
.btn--primary:focus-visible, .btn--ghost:focus-visible, .header__cta__tutor:focus-visible {
  box-shadow: 0 0 0 4px color-mix(in oklch, var(--color-primary) 22%, transparent), var(--shadow-sm);
}
.lang-card:focus-within, .audience-card:focus-within {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}
@media (max-width: 519px) {
  .header__inner { gap: var(--space-2); }
  .header__cta { gap: var(--space-1); }
  .header__cta__tutor { padding-inline: .65rem; }
  .header__cta .btn--primary { padding-inline: .7rem; }
  .theme-toggle { width: 34px; height: 34px; flex: 0 0 34px; }
}
@media (max-width: 380px) {
  .header__cta__tutor__arrow { display: none; }
  .header__cta .btn--primary { font-size: var(--text-xs); }
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; }
  .hero::before, .tutor-band::before, .hero__kicker::before, .tutor-band__chip { animation: none; }
}