/* ============================================================
   Stature Marketing Site — styles.css
   Design tokens → CSS custom properties
   No framework dependencies, pure CSS
   ============================================================ */

/* ---- Design tokens ---- */
:root {
  /* Surfaces */
  --color-surface-base: #f8fafc;       /* slate-50 */
  --color-surface-elevated: #ffffff;   /* white */
  --color-surface-inset: #f1f5f9;      /* slate-100 */

  /* Content / text */
  --color-content-primary: #0f172a;    /* slate-900 */
  --color-content-secondary: #334155;  /* slate-700 */
  --color-content-tertiary: #64748b;   /* slate-500 */
  --color-content-decorative: #94a3b8; /* slate-400 — never for readable text */

  /* Accent (indigo) */
  --color-accent: #4338ca;             /* indigo-700 */
  --color-accent-hover: #3730a3;       /* indigo-800 */
  --color-accent-light: #eef2ff;       /* indigo-50 */
  --color-accent-text: #4338ca;        /* indigo-700 for text links */

  /* Borders */
  --color-border-default: #e2e8f0;     /* slate-200 */
  --color-border-strong: #cbd5e1;      /* slate-300 */

  /* Focus ring */
  --focus-ring: 0 0 0 2px #ffffff, 0 0 0 4px #4f46e5; /* white inner + indigo-600 outer */

  /* Spacing scale */
  --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;

  /* Border radii */
  --radius-sm: 0.25rem;
  --radius-md: 0.375rem;
  --radius-lg: 0.5rem;
  --radius-xl: 0.75rem;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.07), 0 2px 4px -2px rgb(0 0 0 / 0.05);

  /* Typography */
  --font-sans: 'DM Sans', system-ui, sans-serif;
  --leading-tight: 1.25;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;
}

/* ---- Reset & base ---- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

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

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: var(--leading-normal);
  color: var(--color-content-secondary);
  background-color: var(--color-surface-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--color-accent-text);
  text-decoration: underline;
  text-underline-offset: 2px;
}

a:hover {
  color: var(--color-accent-hover);
}

/* ---- Focus rings — WCAG 2.4.7 / 2.4.11 ---- */
:focus-visible {
  outline: 2px solid #4f46e5;
  outline-offset: 2px;
}

/* ---- Layout utilities ---- */
.container {
  width: 100%;
  max-width: 72rem; /* 1152px */
  margin-inline: auto;
  padding-inline: var(--space-6);
}

@media (min-width: 640px) {
  .container {
    padding-inline: var(--space-8);
  }
}

@media (min-width: 1024px) {
  .container {
    padding-inline: var(--space-12);
  }
}

/* ---- Site nav ---- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: var(--color-surface-elevated);
  border-bottom: 1px solid var(--color-border-default);
  box-shadow: var(--shadow-sm);
}

.site-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3.5rem;
}

.site-nav__wordmark {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.04em;
  color: var(--color-content-primary);
  text-decoration: none;
}

.site-nav__wordmark:hover {
  color: var(--color-accent);
}

.site-nav__cta {
  font-size: 0.875rem;
}

/* ---- Button component ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.625rem var(--space-5);
  min-height: 2.75rem; /* 44px touch target */
  min-width: 44px;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: background-color 150ms ease, color 150ms ease, box-shadow 150ms ease;
  white-space: nowrap;
}

.btn:focus-visible {
  outline: 2px solid #4f46e5;
  outline-offset: 2px;
}

.btn-primary {
  background-color: var(--color-accent);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--color-accent-hover);
  color: #ffffff;
}

.btn-secondary {
  background-color: var(--color-surface-elevated);
  color: var(--color-content-secondary);
  border: 1px solid var(--color-border-strong);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background-color: var(--color-surface-inset);
  color: var(--color-content-primary);
}

.btn-lg {
  padding: 0.875rem var(--space-8);
  font-size: 1rem;
  min-height: 3rem;
}

/* ---- Sections ---- */
section {
  padding-block: var(--space-20);
}

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent-text);
  margin-bottom: var(--space-4);
}

/* ---- Hero ---- */
.hero {
  padding-block: var(--space-24);
  background-color: var(--color-surface-elevated);
  border-bottom: 1px solid var(--color-border-default);
}

@media (min-width: 768px) {
  .hero {
    padding-block: clamp(var(--space-24), 10vw, 8rem);
  }
}

.hero__content {
  max-width: 42rem;
  margin-inline: auto;
}

.hero__superheader {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-content-tertiary);
  letter-spacing: 0.01em;
  margin-bottom: var(--space-5);
}

.hero__headline {
  font-size: clamp(1.875rem, 4vw, 2.75rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: var(--leading-tight);
  color: var(--color-content-primary);
  margin-bottom: var(--space-6);
}

.hero__subhead {
  font-size: 1.125rem;
  line-height: var(--leading-relaxed);
  color: var(--color-content-secondary);
  margin-bottom: var(--space-8);
  max-width: 36rem;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-4);
}

.hero__note {
  font-size: 0.8125rem;
  color: var(--color-content-tertiary);
  margin-top: var(--space-4);
}

/* ---- Problem section ---- */
.problem {
  background-color: var(--color-surface-base);
}

.problem__heading {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  letter-spacing: -0.025em;
  color: var(--color-content-primary);
  margin-bottom: var(--space-6);
  max-width: 34rem;
}

.problem__body {
  font-size: 1.0625rem;
  line-height: var(--leading-relaxed);
  color: var(--color-content-secondary);
  max-width: 38rem;
}

.problem__body + .problem__body {
  margin-top: var(--space-4);
}

/* ---- How it works ---- */
.how-it-works {
  background-color: var(--color-surface-elevated);
  border-top: 1px solid var(--color-border-default);
  border-bottom: 1px solid var(--color-border-default);
}

.section-heading {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  letter-spacing: -0.025em;
  color: var(--color-content-primary);
  margin-bottom: var(--space-3);
}

.section-subhead {
  font-size: 1.0625rem;
  color: var(--color-content-tertiary);
  margin-bottom: var(--space-12);
  max-width: 36rem;
}

.steps-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
  list-style: none;
}

@media (min-width: 768px) {
  .steps-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-6);
  }
}

.step-card {
  background-color: var(--color-surface-elevated);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-sm);
  position: relative;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  background-color: var(--color-accent-light);
  color: var(--color-accent-text);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 50%;
  margin-bottom: var(--space-5);
}

.step-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-content-primary);
  letter-spacing: -0.01em;
  margin-bottom: var(--space-3);
}

.step-desc {
  font-size: 0.9375rem;
  line-height: var(--leading-relaxed);
  color: var(--color-content-secondary);
}

/* ---- Differentiation ---- */
.differentiation {
  background-color: var(--color-surface-base);
}

.diff-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  margin-top: var(--space-10);
}

@media (min-width: 640px) {
  .diff-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .diff-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.diff-card {
  background-color: var(--color-surface-elevated);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
}

.diff-card__label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-content-tertiary);
  margin-bottom: var(--space-3);
}

.diff-card__heading {
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--color-content-primary);
  margin-bottom: var(--space-3);
}

.diff-card__body {
  font-size: 0.9375rem;
  line-height: var(--leading-relaxed);
  color: var(--color-content-secondary);
}

/* ---- Social proof ---- */
.social-proof {
  background-color: var(--color-surface-elevated);
  border-top: 1px solid var(--color-border-default);
  border-bottom: 1px solid var(--color-border-default);
}

.founder-block {
  max-width: 40rem;
}

.founder-quote {
  font-size: 1.1875rem;
  line-height: var(--leading-relaxed);
  color: var(--color-content-secondary);
  font-style: italic;
  margin-bottom: var(--space-6);
}

.founder-attr {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-content-tertiary);
}

.founder-attr strong {
  color: var(--color-content-primary);
  font-weight: 600;
}

/* ---- CTA repeat ---- */
.cta-repeat {
  background-color: var(--color-surface-base);
  text-align: center;
}

.cta-repeat__heading {
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 600;
  letter-spacing: -0.025em;
  color: var(--color-content-primary);
  margin-bottom: var(--space-4);
}

.cta-repeat__body {
  font-size: 1.0625rem;
  color: var(--color-content-tertiary);
  max-width: 32rem;
  margin-inline: auto;
  margin-bottom: var(--space-8);
}

.cta-repeat__note {
  margin-top: var(--space-4);
}

/* ---- Early access form ---- */
.signup-form {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 28rem;
  margin-inline: auto;
}

@media (min-width: 480px) {
  .signup-form {
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-2);
  }
}

.signup-form__input {
  flex: 1;
  height: 2.875rem; /* 46px — above 44px touch target */
  padding: 0 var(--space-4);
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  color: var(--color-content-primary);
  background-color: var(--color-surface-elevated);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  transition: border-color 150ms ease, box-shadow 150ms ease;
  appearance: none;
}

.signup-form__input::placeholder {
  color: var(--color-content-decorative);
}

.signup-form__input:focus-visible {
  outline: none;
  border-color: #4f46e5;
  box-shadow: 0 0 0 3px rgb(79 70 229 / 0.15);
}

.signup-form__submit {
  height: 2.875rem;
  padding: 0 var(--space-6);
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 500;
  color: #ffffff;
  background-color: var(--color-accent);
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color 150ms ease;
  white-space: nowrap;
  min-width: 44px;
}

.signup-form__submit:hover {
  background-color: var(--color-accent-hover);
}

.signup-form__submit:focus-visible {
  outline: 2px solid #4f46e5;
  outline-offset: 2px;
}

.signup-form__submit:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Form feedback */
.form-message {
  margin-top: var(--space-4);
  font-size: 0.875rem;
  text-align: center;
  min-height: 1.5rem;
  display: none;
  flex-basis: 100%;
}

.form-message--success {
  color: #166534; /* emerald-800 */
  display: block;
}

.form-message--duplicate {
  color: #92400e; /* amber-800 */
  display: block;
}

.form-message--error {
  color: #991b1b; /* red-800 */
  display: block;
}

/* ---- Footer ---- */
.site-footer {
  background-color: var(--color-surface-elevated);
  border-top: 1px solid var(--color-border-default);
  padding-block: var(--space-10);
}

.site-footer__inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  align-items: flex-start;
}

@media (min-width: 640px) {
  .site-footer__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.site-footer__wordmark {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.025em;
  color: var(--color-content-primary);
  text-decoration: none;
}

.site-footer__wordmark:hover {
  color: var(--color-accent);
}

.site-footer__links {
  display: flex;
  gap: var(--space-6);
  list-style: none;
}

.site-footer__links a {
  font-size: 0.875rem;
  color: var(--color-content-tertiary);
  text-decoration: none;
}

.site-footer__links a:hover {
  color: var(--color-content-secondary);
}

.site-footer__links a:focus-visible {
  outline: 2px solid #4f46e5;
  outline-offset: 2px;
  border-radius: 2px;
}

.site-footer__copy {
  font-size: 0.8125rem;
  color: var(--color-content-decorative);
}

/* ---- Expect page specific ---- */
.expect-hero {
  padding-block: var(--space-16);
  background-color: var(--color-surface-elevated);
  border-bottom: 1px solid var(--color-border-default);
}

.expect-hero__heading {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  color: var(--color-content-primary);
  margin-bottom: var(--space-4);
  max-width: 34rem;
}

.expect-hero__subhead {
  font-size: 1.0625rem;
  color: var(--color-content-secondary);
  max-width: 36rem;
  line-height: var(--leading-relaxed);
}

.expect-content {
  background-color: var(--color-surface-base);
}

.expect-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  margin-bottom: var(--space-12);
}

@media (min-width: 768px) {
  .expect-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-8);
  }
}

.expect-card {
  background-color: var(--color-surface-elevated);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-sm);
}

.expect-card__eyebrow {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent-text);
  margin-bottom: var(--space-3);
}

.expect-card__heading {
  font-size: 1.1875rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--color-content-primary);
  margin-bottom: var(--space-4);
}

.expect-card__body {
  font-size: 0.9375rem;
  line-height: var(--leading-relaxed);
  color: var(--color-content-secondary);
}

.expect-card__body + .expect-card__body {
  margin-top: var(--space-3);
}

/* What Stature is / isn't */
.is-isnt {
  background-color: var(--color-surface-elevated);
  border-top: 1px solid var(--color-border-default);
  border-bottom: 1px solid var(--color-border-default);
}

.is-isnt-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-8);
}

@media (min-width: 768px) {
  .is-isnt-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.is-isnt__column-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-content-primary);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-border-default);
}

.is-isnt__column-label--is {
  border-color: #6ee7b7; /* emerald-300 */
}

.is-isnt__column-label--isnt {
  border-color: var(--color-border-strong);
}

.is-isnt__list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.is-isnt__item {
  display: flex;
  gap: var(--space-3);
  font-size: 0.9375rem;
  line-height: var(--leading-snug);
  color: var(--color-content-secondary);
}

.is-isnt__marker {
  flex-shrink: 0;
  width: 1.25rem;
  height: 1.25rem;
  margin-top: 0.1em;
  font-size: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.is-isnt__marker--is {
  color: #059669; /* emerald-600 */
}

.is-isnt__marker--isnt {
  color: var(--color-content-decorative);
}

/* ---- Privacy note ---- */
.privacy-note {
  background-color: var(--color-accent-light);
  border: 1px solid #c7d2fe; /* indigo-200 */
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  margin-top: var(--space-10);
}

.privacy-note__heading {
  font-size: 1rem;
  font-weight: 600;
  color: #3730a3; /* indigo-800 */
  margin-bottom: var(--space-3);
}

.privacy-note__body {
  font-size: 0.9375rem;
  line-height: var(--leading-relaxed);
  color: #4338ca; /* indigo-700 */
}

/* ---- Back link ---- */
.back-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 0.875rem;
  color: var(--color-content-tertiary);
  text-decoration: none;
  margin-bottom: var(--space-8);
  padding: var(--space-1) 0;
}

.back-link:hover {
  color: var(--color-content-secondary);
}

.back-link:focus-visible {
  outline: 2px solid #4f46e5;
  outline-offset: 2px;
  border-radius: 2px;
}

/* ---- Divider ---- */
.divider {
  border: none;
  border-top: 1px solid var(--color-border-default);
  margin-block: 0;
}

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

/* ---- Skip nav ---- */
.skip-nav {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: 100;
  padding: var(--space-2) var(--space-4);
  background-color: var(--color-accent);
  color: white;
  font-weight: 600;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: top 0.1s;
}

.skip-nav:focus {
  top: var(--space-2);
}