/* ============================================================
   Vantrix Landing Page — Design System & Styles
   Seed: #2563EB | Teal-Indigo Melez theme
   ============================================================ */

/* ----------------------------------------------------------
   1. DESIGN TOKENS (Custom Properties)
   ---------------------------------------------------------- */
:root {
  /* Colors — Brand */
  --color-seed: #2563EB;
  --color-primary: #1F96CF;
  --color-primary-hover: #1A7FB2;
  --color-primary-active: #166D99;
  --color-secondary: #6366F1;
  --color-secondary-hover: #5558E0;
  --color-amber: #D97706;
  --color-green: #15803D;
  --color-green-light: #DCFCE7;

  /* Colors — Neutral */
  --color-navy: #0E2235;
  --color-navy-light: #162D45;
  --color-surface: #F8FAFC;
  --color-surface-container: #EFF6FF;
  --color-surface-elevated: #FFFFFF;
  --color-border: #E2E8F0;
  --color-border-subtle: #F1F5F9;

  /* Colors — Text */
  --color-text-primary: #0F172A;
  --color-text-secondary: #475569;
  --color-text-tertiary: #94A3B8;
  --color-text-on-dark: #F1F5F9;
  --color-text-on-dark-secondary: #CBD5E1;
  --color-text-on-primary: #FFFFFF;

  /* Typography */
  --font-heading: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-body: 'Hanken Grotesk', system-ui, -apple-system, sans-serif;

  --fw-regular: 400;
  --fw-medium: 500;
  --fw-bold: 700;
  --fw-extra-bold: 800;

  --fs-xs: 0.75rem;    /* 12px */
  --fs-sm: 0.8125rem;  /* 13px */
  --fs-base: 1.0625rem; /* 17px */
  --fs-md: 1.125rem;   /* 18px */
  --fs-lg: 1.25rem;    /* 20px */
  --fs-xl: 1.5rem;     /* 24px */
  --fs-2xl: 2rem;      /* 32px */
  --fs-3xl: 2.5rem;    /* 40px */
  --fs-4xl: 3rem;      /* 48px */
  --fs-5xl: 3.5rem;    /* 56px */

  --lh-tight: 1.2;
  --lh-snug: 1.35;
  --lh-normal: 1.7;
  --ls-body: 0.03em;
  --ls-heading: -0.02em;
  --ls-eyebrow: 0.08em;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-section: 72px;

  /* Shape / Radius */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 28px;
  --radius-pill: 9999px;

  /* Elevation */
  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.08), 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 4px 6px rgba(15, 23, 42, 0.08), 0 2px 4px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 10px 15px rgba(15, 23, 42, 0.1), 0 4px 6px rgba(15, 23, 42, 0.05);
  --shadow-xl: 0 20px 25px rgba(15, 23, 42, 0.1), 0 8px 10px rgba(15, 23, 42, 0.04);
  --shadow-glow-primary: 0 0 24px rgba(31, 150, 207, 0.25);
  --shadow-glow-secondary: 0 0 24px rgba(99, 102, 241, 0.2);

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --max-width: 1280px;
  --header-height: 72px;
  --touch-target: 48px;

  /* Gradients */
  --gradient-hero: linear-gradient(135deg, #0E2235 0%, #312E81 50%, #1F96CF 100%);
  --gradient-dark: linear-gradient(135deg, #0E2235 0%, #162D45 50%, #1E3A5F 100%);
  --gradient-cta: linear-gradient(135deg, #1F96CF 0%, #6366F1 100%);
  --gradient-surface: linear-gradient(180deg, var(--color-surface) 0%, var(--color-surface-container) 100%);
}

/* ----------------------------------------------------------
   2. DARK MODE
   ---------------------------------------------------------- */
@media (prefers-color-scheme: dark) {
  :root {
    --color-surface: #0B1929;
    --color-surface-container: #112240;
    --color-surface-elevated: #162D45;
    --color-border: #1E3A5F;
    --color-border-subtle: #162D45;

    --color-text-primary: #F1F5F9;
    --color-text-secondary: #94A3B8;
    --color-text-tertiary: #64748B;

    --color-primary: #38BDF8;
    --color-primary-hover: #56C8FA;
    --color-primary-active: #1F96CF;
    --color-secondary: #818CF8;
    --color-secondary-hover: #A5B4FC;
    --color-amber: #FBBF24;
    --color-green: #4ADE80;
    --color-green-light: #14532D;

    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.35), 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.35), 0 2px 4px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.35), 0 4px 6px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.4), 0 8px 10px rgba(0, 0, 0, 0.2);
    --shadow-glow-primary: 0 0 24px rgba(56, 189, 248, 0.2);
    --shadow-glow-secondary: 0 0 24px rgba(129, 140, 248, 0.15);

    --gradient-surface: linear-gradient(180deg, #0B1929 0%, #112240 100%);
  }
}

/* ----------------------------------------------------------
   3. RESET & BASE
   ---------------------------------------------------------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  font-weight: var(--fw-regular);
  line-height: var(--lh-normal);
  letter-spacing: var(--ls-body);
  color: var(--color-text-primary);
  background-color: var(--color-surface);
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

ul,
ol {
  list-style: none;
}

button,
input,
textarea,
select {
  font: inherit;
  color: inherit;
  border: none;
  background: none;
  outline: none;
}

button {
  cursor: pointer;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--fw-bold);
  line-height: var(--lh-tight);
  letter-spacing: var(--ls-heading);
  color: var(--color-text-primary);
}

/* ----------------------------------------------------------
   4. LAYOUT UTILITIES
   ---------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-lg);
}

.section {
  padding-block: var(--space-section);
}

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

/* ----------------------------------------------------------
   5. TYPOGRAPHY
   ---------------------------------------------------------- */
.text-eyebrow {
  font-family: var(--font-heading);
  font-size: var(--fs-sm);
  font-weight: var(--fw-bold);
  letter-spacing: var(--ls-eyebrow);
  text-transform: uppercase;
  color: var(--color-primary);
}

.text-section-title {
  font-family: var(--font-heading);
  font-size: var(--fs-3xl);
  font-weight: var(--fw-extra-bold);
  line-height: var(--lh-tight);
  letter-spacing: var(--ls-heading);
  color: var(--color-text-primary);
}

.text-section-subtitle {
  font-family: var(--font-body);
  font-size: var(--fs-md);
  font-weight: var(--fw-regular);
  line-height: var(--lh-normal);
  color: var(--color-text-secondary);
  max-width: 640px;
}

.text-body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  font-weight: var(--fw-regular);
  line-height: var(--lh-normal);
  letter-spacing: var(--ls-body);
  color: var(--color-text-secondary);
}

/* ----------------------------------------------------------
   6. EYEBROW BADGE
   ---------------------------------------------------------- */
.eyebrow-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-md);
  background-color: var(--color-surface-container);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  font-family: var(--font-heading);
  font-size: var(--fs-sm);
  font-weight: var(--fw-bold);
  letter-spacing: var(--ls-eyebrow);
  text-transform: uppercase;
  color: var(--color-primary);
}

.eyebrow-badge__icon {
  font-size: var(--fs-base);
  line-height: 1;
}

.eyebrow-badge--on-dark {
  background-color: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.12);
  color: var(--color-primary);
}

/* ----------------------------------------------------------
   7. SECTION HEADER (reusable)
   ---------------------------------------------------------- */
.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-header__eyebrow {
  margin-bottom: var(--space-md);
}

.section-header__title {
  margin-bottom: var(--space-md);
}

.section-header__subtitle {
  margin-inline: auto;
}

/* ----------------------------------------------------------
   8. BUTTONS
   ---------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  min-height: var(--touch-target);
  padding: 12px var(--space-lg);
  font-family: var(--font-heading);
  font-size: var(--fs-sm);
  font-weight: var(--fw-bold);
  letter-spacing: 0.02em;
  border-radius: var(--radius-md);
  transition:
    background-color var(--transition-fast),
    color var(--transition-fast),
    border-color var(--transition-fast),
    box-shadow var(--transition-fast),
    transform var(--transition-fast);
  white-space: nowrap;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.btn:active {
  transform: scale(0.97);
}

/* Filled (Primary — Teal) */
.btn--filled {
  background-color: var(--color-primary);
  color: var(--color-text-on-primary);
}

.btn--filled:hover {
  background-color: var(--color-primary-hover);
  box-shadow: var(--shadow-glow-primary);
}

.btn--filled:active {
  background-color: var(--color-primary-active);
}

/* Outlined */
.btn--outlined {
  background-color: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--color-primary);
}

.btn--outlined:hover {
  background-color: rgba(31, 150, 207, 0.08);
  border-color: var(--color-primary-hover);
}

/* Tonal (light bg) */
.btn--tonal {
  background-color: var(--color-surface-container);
  color: var(--color-primary);
}

.btn--tonal:hover {
  background-color: var(--color-border);
}

/* On-dark variants */
.btn--on-dark.btn--outlined {
  color: var(--color-text-on-dark);
  border-color: rgba(255, 255, 255, 0.3);
}

.btn--on-dark.btn--outlined:hover {
  background-color: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.5);
}

/* Large */
.btn--lg {
  min-height: 56px;
  padding: 16px var(--space-xl);
  font-size: var(--fs-base);
  border-radius: var(--radius-lg);
}

/* Icon inside button */
.btn__icon {
  font-size: 1.2em;
  line-height: 1;
}

/* ----------------------------------------------------------
   9. CARDS (generic)
   ---------------------------------------------------------- */
.card {
  background-color: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  padding: var(--space-lg);
  transition:
    box-shadow var(--transition-base),
    transform var(--transition-base),
    border-color var(--transition-base);
}

.card:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary);
}

.card--elevated {
  box-shadow: var(--shadow-md);
}

.card--elevated:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background-color: var(--color-surface-container);
  font-size: var(--fs-xl);
  margin-bottom: var(--space-md);
}

.card__title {
  font-family: var(--font-heading);
  font-size: var(--fs-lg);
  font-weight: var(--fw-bold);
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
}

.card__text {
  font-size: var(--fs-base);
  color: var(--color-text-secondary);
  line-height: var(--lh-normal);
}

/* ----------------------------------------------------------
   10. HEADER
   ---------------------------------------------------------- */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background-color: rgba(248, 250, 252, 0.8);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--color-border-subtle);
  transition: background-color var(--transition-base), box-shadow var(--transition-base);
}

.header--scrolled {
  box-shadow: var(--shadow-sm);
  background-color: rgba(248, 250, 252, 0.95);
}

@media (prefers-color-scheme: dark) {
  .header {
    background-color: rgba(11, 25, 41, 0.8);
    border-bottom-color: var(--color-border);
  }

  .header--scrolled {
    background-color: rgba(11, 25, 41, 0.95);
  }
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-heading);
  font-size: var(--fs-xl);
  font-weight: var(--fw-extra-bold);
  color: var(--color-text-primary);
  text-decoration: none;
}

.header__logo-img {
  height: 36px;
  width: auto;
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.header__nav-link {
  font-family: var(--font-body);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text-secondary);
  padding: var(--space-sm) var(--space-xs);
  min-height: var(--touch-target);
  display: inline-flex;
  align-items: center;
  transition: color var(--transition-fast);
}

.header__nav-link:hover,
.header__nav-link--active {
  color: var(--color-primary);
}

.header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

/* Mobile menu toggle */
.header__menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: var(--touch-target);
  height: var(--touch-target);
  border-radius: var(--radius-sm);
  color: var(--color-text-primary);
  font-size: var(--fs-xl);
}

/* Mobile nav overlay */
.header__mobile-nav {
  display: none;
}

@media (max-width: 719px) {
  .header__nav,
  .header__actions .btn {
    display: none;
  }

  .header__menu-toggle {
    display: flex;
  }

  .header__mobile-nav {
    display: none;
    position: fixed;
    inset: var(--header-height) 0 0 0;
    background-color: var(--color-surface);
    z-index: 99;
    padding: var(--space-lg);
    flex-direction: column;
    gap: var(--space-sm);
    overflow-y: auto;
  }

  .header__mobile-nav--open {
    display: flex;
  }

  .header__mobile-nav-link {
    display: flex;
    align-items: center;
    min-height: var(--touch-target);
    padding: var(--space-md) var(--space-md);
    font-family: var(--font-body);
    font-size: var(--fs-md);
    font-weight: var(--fw-medium);
    color: var(--color-text-primary);
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast);
  }

  .header__mobile-nav-link:hover {
    background-color: var(--color-surface-container);
  }

  .header__mobile-nav .btn {
    margin-top: var(--space-md);
    width: 100%;
  }
}

@media (min-width: 720px) and (max-width: 1099px) {
  .header__nav {
    gap: var(--space-lg);
  }
}

/* ----------------------------------------------------------
   11. HERO
   ---------------------------------------------------------- */
.hero {
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-section);
}

.hero__card {
  background: var(--gradient-hero);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl) var(--space-2xl);
  overflow: hidden;
  position: relative;
}

/* Subtle grain / noise overlay */
.hero__card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 70% 30%, rgba(99, 102, 241, 0.15) 0%, transparent 60%),
              radial-gradient(circle at 30% 80%, rgba(31, 150, 207, 0.12) 0%, transparent 50%);
  pointer-events: none;
}

.hero__inner {
  display: flex;
  align-items: center;
  gap: var(--space-2xl);
  position: relative;
  z-index: 1;
}

.hero__content {
  flex: 0 0 60%;
  max-width: 60%;
}

.hero__stats {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.hero__eyebrow {
  margin-bottom: var(--space-md);
}

.hero__title {
  font-family: var(--font-heading);
  font-size: var(--fs-4xl);
  font-weight: var(--fw-extra-bold);
  line-height: var(--lh-tight);
  color: var(--color-text-on-dark);
  margin-bottom: var(--space-lg);
}

.hero__title-highlight {
  background: linear-gradient(135deg, #38BDF8, #818CF8);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero__subtitle {
  font-size: var(--fs-md);
  color: var(--color-text-on-dark-secondary);
  line-height: var(--lh-normal);
  margin-bottom: var(--space-xl);
  max-width: 520px;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* Hero stat cards */
.hero__stat-card {
  background-color: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.hero__stat-value {
  font-family: var(--font-heading);
  font-size: var(--fs-2xl);
  font-weight: var(--fw-extra-bold);
  color: var(--color-text-on-dark);
  margin-bottom: var(--space-xs);
}

.hero__stat-label {
  font-size: var(--fs-sm);
  color: var(--color-text-on-dark-secondary);
}

/* Hero responsive */
@media (max-width: 1099px) {
  .hero__title {
    font-size: var(--fs-3xl);
  }
}

@media (max-width: 719px) {
  .hero {
    padding-top: var(--space-lg);
    padding-bottom: var(--space-2xl);
  }

  .hero__card {
    padding: var(--space-xl) var(--space-lg);
    border-radius: var(--radius-lg);
  }

  .hero__inner {
    flex-direction: column;
    gap: var(--space-xl);
  }

  .hero__content {
    flex: 1;
    max-width: 100%;
  }

  .hero__title {
    font-size: var(--fs-2xl);
  }

  .hero__stats {
    width: 100%;
    flex-direction: row;
    flex-wrap: wrap;
  }

  .hero__stat-card {
    flex: 1 1 calc(50% - var(--space-sm));
    min-width: 140px;
  }
}

/* ----------------------------------------------------------
   12. FEATURE GRID
   ---------------------------------------------------------- */
.features {
  background: var(--gradient-surface);
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.feature-card {
  position: relative;
  padding: var(--space-xl);
}

.feature-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-lg);
  font-size: var(--fs-xl);
}

.feature-card__icon--focus {
  background-color: rgba(31, 150, 207, 0.1);
  color: var(--color-primary);
}

.feature-card__icon--learn {
  background-color: rgba(99, 102, 241, 0.1);
  color: var(--color-secondary);
}

.feature-card__icon--quest {
  background-color: rgba(217, 119, 6, 0.1);
  color: var(--color-amber);
}

.feature-card__icon--social {
  background-color: rgba(21, 128, 61, 0.1);
  color: var(--color-green);
}

.feature-card__icon--parent {
  background-color: rgba(99, 102, 241, 0.1);
  color: var(--color-secondary);
}

.feature-card__icon--profile {
  background-color: rgba(31, 150, 207, 0.1);
  color: var(--color-primary);
}

.feature-card__title {
  font-family: var(--font-heading);
  font-size: var(--fs-lg);
  font-weight: var(--fw-bold);
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
}

.feature-card__text {
  font-size: var(--fs-base);
  color: var(--color-text-secondary);
  line-height: var(--lh-normal);
}

.feature-card__tag {
  display: inline-block;
  margin-top: var(--space-md);
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--fs-xs);
  font-weight: var(--fw-bold);
  color: var(--color-primary);
  background-color: var(--color-surface-container);
  border-radius: var(--radius-xs);
}

@media (max-width: 1099px) {
  .features__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 719px) {
  .features__grid {
    grid-template-columns: 1fr;
  }
}

/* ----------------------------------------------------------
   13. SCIENCE SECTION
   ---------------------------------------------------------- */
.science {
  position: relative;
}

.science__card {
  background: var(--gradient-dark);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  position: relative;
  overflow: hidden;
}

.science__card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 80% 20%, rgba(31, 150, 207, 0.08) 0%, transparent 50%);
  pointer-events: none;
}

.science__header {
  text-align: center;
  margin-bottom: var(--space-2xl);
  position: relative;
  z-index: 1;
}

.science__header .text-section-title {
  color: var(--color-text-on-dark);
}

.science__header .text-section-subtitle {
  color: var(--color-text-on-dark-secondary);
  margin-inline: auto;
}

.science__stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  position: relative;
  z-index: 1;
}

.science__stat {
  background-color: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  text-align: center;
  transition: background-color var(--transition-base), border-color var(--transition-base);
}

.science__stat:hover {
  background-color: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.15);
}

.science__stat-value {
  font-family: var(--font-heading);
  font-size: var(--fs-2xl);
  font-weight: var(--fw-extra-bold);
  color: var(--color-text-on-dark);
  margin-bottom: var(--space-xs);
}

.science__stat-value--primary {
  color: var(--color-primary);
}

.science__stat-value--secondary {
  color: var(--color-secondary);
}

.science__stat-value--amber {
  color: var(--color-amber);
}

.science__stat-value--green {
  color: var(--color-green);
}

.science__stat-label {
  font-size: var(--fs-sm);
  color: var(--color-text-on-dark-secondary);
  line-height: var(--lh-snug);
}

.science__source {
  text-align: center;
  margin-top: var(--space-lg);
  font-size: var(--fs-xs);
  color: var(--color-text-on-dark-secondary);
  opacity: 0.6;
  position: relative;
  z-index: 1;
}

@media (max-width: 1099px) {
  .science__stats {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 719px) {
  .science__card {
    padding: var(--space-xl) var(--space-lg);
    border-radius: var(--radius-lg);
  }

  .science__stats {
    grid-template-columns: 1fr;
  }
}

/* ----------------------------------------------------------
   14. HOW IT WORKS
   ---------------------------------------------------------- */
.how-it-works__steps {
  display: flex;
  gap: var(--space-xl);
  position: relative;
}

/* Connecting line behind steps */
.how-it-works__steps::before {
  content: '';
  position: absolute;
  top: 36px;
  left: calc(36px + var(--space-xl));
  right: calc(36px + var(--space-xl));
  height: 2px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  opacity: 0.3;
}

.step {
  flex: 1;
  text-align: center;
  position: relative;
}

.step__number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: var(--gradient-cta);
  color: var(--color-text-on-primary);
  font-family: var(--font-heading);
  font-size: var(--fs-xl);
  font-weight: var(--fw-extra-bold);
  margin: 0 auto var(--space-lg);
  position: relative;
  z-index: 1;
  box-shadow: var(--shadow-glow-primary);
}

.step__title {
  font-family: var(--font-heading);
  font-size: var(--fs-lg);
  font-weight: var(--fw-bold);
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
}

.step__text {
  font-size: var(--fs-base);
  color: var(--color-text-secondary);
  line-height: var(--lh-normal);
  max-width: 300px;
  margin-inline: auto;
}

.step__icon {
  font-size: var(--fs-2xl);
  margin-bottom: var(--space-sm);
}

@media (max-width: 719px) {
  .how-it-works__steps {
    flex-direction: column;
    gap: var(--space-xl);
    align-items: flex-start;
    padding-left: var(--space-2xl);
  }

  /* Vertical connecting line */
  .how-it-works__steps::before {
    top: 36px;
    bottom: 36px;
    left: 35px;
    right: auto;
    width: 2px;
    height: auto;
  }

  .step {
    text-align: left;
    display: flex;
    gap: var(--space-lg);
    align-items: flex-start;
  }

  .step__number {
    flex-shrink: 0;
    width: 56px;
    height: 56px;
    font-size: var(--fs-lg);
    margin: 0;
  }

  .step__content {
    flex: 1;
  }

  .step__text {
    margin-inline: 0;
    max-width: none;
  }
}

/* ----------------------------------------------------------
   15. TRUST SIGNALS
   ---------------------------------------------------------- */
.trust {
  background: var(--gradient-surface);
}

.trust__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

.trust-card {
  text-align: center;
  padding: var(--space-xl);
}

.trust-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  margin: 0 auto var(--space-md);
  font-size: var(--fs-xl);
}

.trust-card__icon--shield {
  background-color: rgba(21, 128, 61, 0.1);
  color: var(--color-green);
}

.trust-card__icon--lock {
  background-color: rgba(31, 150, 207, 0.1);
  color: var(--color-primary);
}

.trust-card__icon--star {
  background-color: rgba(217, 119, 6, 0.1);
  color: var(--color-amber);
}

.trust-card__icon--heart {
  background-color: rgba(99, 102, 241, 0.1);
  color: var(--color-secondary);
}

.trust-card__title {
  font-family: var(--font-heading);
  font-size: var(--fs-base);
  font-weight: var(--fw-bold);
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
}

.trust-card__text {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-normal);
}

@media (max-width: 1099px) {
  .trust__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 719px) {
  .trust__grid {
    grid-template-columns: 1fr;
  }
}

/* ----------------------------------------------------------
   16. DOWNLOAD CTA
   ---------------------------------------------------------- */
.download-cta {
  position: relative;
}

.download-cta__card {
  background: var(--gradient-cta);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  overflow: hidden;
  position: relative;
}

.download-cta__card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 90% 50%, rgba(255, 255, 255, 0.08) 0%, transparent 50%);
  pointer-events: none;
}

.download-cta__inner {
  display: flex;
  align-items: center;
  gap: var(--space-2xl);
  position: relative;
  z-index: 1;
}

.download-cta__content {
  flex: 1;
}

.download-cta__title {
  font-family: var(--font-heading);
  font-size: var(--fs-3xl);
  font-weight: var(--fw-extra-bold);
  color: var(--color-text-on-primary);
  margin-bottom: var(--space-md);
}

.download-cta__text {
  font-size: var(--fs-md);
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: var(--space-xl);
  max-width: 480px;
  line-height: var(--lh-normal);
}

.download-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.download-cta__image {
  flex: 0 0 auto;
  max-width: 300px;
}

.download-cta__image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
}

@media (max-width: 719px) {
  .download-cta__card {
    padding: var(--space-xl) var(--space-lg);
    border-radius: var(--radius-lg);
  }

  .download-cta__inner {
    flex-direction: column;
    text-align: center;
  }

  .download-cta__title {
    font-size: var(--fs-2xl);
  }

  .download-cta__text {
    margin-inline: auto;
  }

  .download-cta__actions {
    justify-content: center;
  }

  .download-cta__image {
    max-width: 240px;
  }
}

/* ----------------------------------------------------------
   17. STORE BADGES (pill buttons)
   ---------------------------------------------------------- */
.store-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  min-height: var(--touch-target);
  padding: 12px var(--space-lg);
  background-color: rgba(0, 0, 0, 0.85);
  color: #FFFFFF;
  border-radius: var(--radius-pill);
  font-family: var(--font-heading);
  font-size: var(--fs-sm);
  font-weight: var(--fw-bold);
  transition:
    background-color var(--transition-fast),
    transform var(--transition-fast),
    box-shadow var(--transition-fast);
  text-decoration: none;
}

.store-badge:hover {
  background-color: rgba(0, 0, 0, 0.95);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.store-badge:active {
  transform: scale(0.97);
}

.store-badge__icon {
  font-size: var(--fs-lg);
  line-height: 1;
}

.store-badge__text-small {
  font-size: var(--fs-xs);
  font-weight: var(--fw-regular);
  opacity: 0.8;
  display: block;
  line-height: 1;
}

.store-badge__text-large {
  display: block;
  line-height: 1.2;
}

.store-badge--light {
  background-color: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.25);
}

.store-badge--light:hover {
  background-color: rgba(255, 255, 255, 0.25);
}

@media (prefers-color-scheme: dark) {
  .store-badge {
    background-color: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.15);
  }

  .store-badge:hover {
    background-color: rgba(255, 255, 255, 0.2);
  }
}

/* ----------------------------------------------------------
   18. FOOTER
   ---------------------------------------------------------- */
.footer {
  background: var(--gradient-dark);
  color: var(--color-text-on-dark);
  padding-block: var(--space-2xl);
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  gap: var(--space-2xl);
}

.footer__brand {
  flex: 0 0 auto;
  max-width: 360px;
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-heading);
  font-size: var(--fs-xl);
  font-weight: var(--fw-extra-bold);
  color: var(--color-text-on-dark);
  margin-bottom: var(--space-md);
}

.footer__logo-img {
  height: 32px;
  width: auto;
}

.footer__tagline {
  font-size: var(--fs-sm);
  color: var(--color-text-on-dark-secondary);
  line-height: var(--lh-normal);
  margin-bottom: var(--space-lg);
}

.footer__social {
  display: flex;
  gap: var(--space-md);
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--touch-target);
  height: var(--touch-target);
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.06);
  color: var(--color-text-on-dark-secondary);
  font-size: var(--fs-lg);
  transition:
    background-color var(--transition-fast),
    color var(--transition-fast);
}

.footer__social-link:hover {
  background-color: rgba(255, 255, 255, 0.12);
  color: var(--color-text-on-dark);
}

.footer__links {
  display: flex;
  gap: var(--space-2xl);
}

.footer__links-group {
  min-width: 140px;
}

.footer__links-title {
  font-family: var(--font-heading);
  font-size: var(--fs-sm);
  font-weight: var(--fw-bold);
  color: var(--color-text-on-dark);
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  letter-spacing: var(--ls-eyebrow);
}

.footer__links-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer__link {
  font-size: var(--fs-sm);
  color: var(--color-text-on-dark-secondary);
  min-height: var(--touch-target);
  display: inline-flex;
  align-items: center;
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: var(--color-text-on-dark);
}

.footer__bottom {
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer__copyright {
  font-size: var(--fs-xs);
  color: var(--color-text-on-dark-secondary);
  opacity: 0.7;
}

.footer__legal {
  display: flex;
  gap: var(--space-lg);
}

.footer__legal-link {
  font-size: var(--fs-xs);
  color: var(--color-text-on-dark-secondary);
  opacity: 0.7;
  transition: opacity var(--transition-fast);
}

.footer__legal-link:hover {
  opacity: 1;
}

@media (max-width: 719px) {
  .footer__inner {
    flex-direction: column;
  }

  .footer__brand {
    max-width: 100%;
  }

  .footer__links {
    flex-direction: column;
    gap: var(--space-xl);
  }

  .footer__bottom {
    flex-direction: column;
    text-align: center;
  }
}

/* ----------------------------------------------------------
   19. SCROLL ANIMATIONS
   Driven by IntersectionObserver adding classes.
   ---------------------------------------------------------- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

.fade-in--visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in--delay-1 { transition-delay: 100ms; }
.fade-in--delay-2 { transition-delay: 200ms; }
.fade-in--delay-3 { transition-delay: 300ms; }
.fade-in--delay-4 { transition-delay: 400ms; }
.fade-in--delay-5 { transition-delay: 500ms; }
.fade-in--delay-6 { transition-delay: 600ms; }

.fade-in-left {
  opacity: 0;
  transform: translateX(-24px);
  transition:
    opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

.fade-in-left--visible {
  opacity: 1;
  transform: translateX(0);
}

.fade-in-right {
  opacity: 0;
  transform: translateX(24px);
  transition:
    opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

.fade-in-right--visible {
  opacity: 1;
  transform: translateX(0);
}

.scale-in {
  opacity: 0;
  transform: scale(0.95);
  transition:
    opacity 0.6s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

.scale-in--visible {
  opacity: 1;
  transform: scale(1);
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
  .fade-in,
  .fade-in-left,
  .fade-in-right,
  .scale-in {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ----------------------------------------------------------
   20. MISC / UTILITY
   ---------------------------------------------------------- */

/* Gradient text helper */
.gradient-text {
  background: var(--gradient-cta);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Divider */
.divider {
  width: 100%;
  height: 1px;
  background-color: var(--color-border);
  border: none;
}

/* Selection color */
::selection {
  background-color: rgba(31, 150, 207, 0.2);
  color: var(--color-text-primary);
}

/* Focus visible for accessibility */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-xs);
}

/* Smooth scroll anchor offset for sticky header */
[id] {
  scroll-margin-top: calc(var(--header-height) + var(--space-lg));
}

/* Skip link */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  z-index: 200;
  padding: var(--space-sm) var(--space-md);
  background-color: var(--color-primary);
  color: var(--color-text-on-primary);
  border-radius: var(--radius-sm);
  font-weight: var(--fw-bold);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: var(--space-md);
}