/* ==========================================================================
   NeuroAlert — FTF-AI Industries
   Medical AI Breast Cancer Detection Product Website
   Dark theme · Purple accents · Mobile-first responsive
   ========================================================================== */

/* --------------------------------------------------------------------------
   Cascade Layers — order of specificity
   -------------------------------------------------------------------------- */
@layer reset, tokens, base, layout, components, sections, utilities, responsive;

/* --------------------------------------------------------------------------
   @layer reset — Minimal modern reset
   -------------------------------------------------------------------------- */
@layer reset {
  *,
  *::before,
  *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }

  html {
    scroll-behavior: smooth;
    color-scheme: dark;
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
  }

  body {
    min-block-size: 100dvh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
  }

  img,
  picture,
  video,
  canvas,
  svg {
    display: block;
    max-inline-size: 100%;
    block-size: auto;
  }

  input,
  button,
  textarea,
  select {
    font: inherit;
    color: inherit;
  }

  button {
    cursor: pointer;
    border: none;
    background: none;
  }

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

  ul,
  ol {
    list-style: none;
  }

  h1, h2, h3, h4, h5, h6 {
    overflow-wrap: break-word;
    text-wrap: balance;
  }

  p {
    overflow-wrap: break-word;
    text-wrap: pretty;
  }
}

/* --------------------------------------------------------------------------
   @layer tokens — Design tokens as CSS custom properties
   -------------------------------------------------------------------------- */
@layer tokens {
  :root {
    /* ── Colors: Background ─────────────────────────────────────────────── */
    --color-bg-deep:       #0a0a0f;
    --color-bg-card:       #111118;
    --color-bg-elevated:   #1a1a25;

    /* ── Colors: Primary (Violet) ───────────────────────────────────────── */
    --color-primary:       #8b5cf6;
    --color-primary-light: #a78bfa;
    --color-primary-dark:  #7c3aed;

    /* ── Colors: Accent glow ────────────────────────────────────────────── */
    --color-accent-bright: #c084fc;
    --color-accent-pink:   #e879f9;

    /* ── Colors: Text ───────────────────────────────────────────────────── */
    --color-text-heading:  #ffffff;
    --color-text-body:     #e2e8f0;
    --color-text-muted:    #94a3b8;
    --color-text-subtle:   #64748b;

    /* ── Colors: Border ─────────────────────────────────────────────────── */
    --color-border-purple: rgba(139, 92, 246, 0.2);
    --color-border-subtle: rgba(255, 255, 255, 0.06);

    /* ── Colors: Status ─────────────────────────────────────────────────── */
    --color-success:       #22c55e;
    --color-warning:       #f59e0b;

    /* ── Gradients ──────────────────────────────────────────────────────── */
    --gradient-primary:    linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent-pink) 100%);
    --gradient-primary-oklch: linear-gradient(135deg, oklch(0.55 0.25 285) 0%, oklch(0.7 0.28 320) 100%);
    --gradient-text:       linear-gradient(135deg, var(--color-primary-light), var(--color-accent-pink));
    --gradient-text-oklch: linear-gradient(135deg, oklch(0.72 0.18 285), oklch(0.7 0.28 320));
    --gradient-glow:       radial-gradient(ellipse at 50% 0%, rgba(139, 92, 246, 0.15) 0%, transparent 70%);
    --gradient-hero-bg:    radial-gradient(ellipse at 30% 50%, rgba(139, 92, 246, 0.08) 0%, transparent 60%),
                           radial-gradient(ellipse at 70% 20%, rgba(232, 121, 249, 0.05) 0%, transparent 50%);

    /* ── Typography ─────────────────────────────────────────────────────── */
    --font-heading:   'Outfit', system-ui, sans-serif;
    --font-body:      'Inter', system-ui, sans-serif;

    --text-hero:      clamp(2rem, 1rem + 5vw, 4rem);
    --text-section:   clamp(1.5rem, 1rem + 3vw, 2.5rem);
    --text-lg:        clamp(1.125rem, 0.9rem + 1vw, 1.375rem);
    --text-base:      clamp(0.9375rem, 0.875rem + 0.25vw, 1rem);
    --text-sm:        clamp(0.8125rem, 0.75rem + 0.25vw, 0.875rem);
    --text-xs:        0.75rem;

    --leading-tight:  1.2;
    --leading-snug:   1.4;
    --leading-normal: 1.6;

    /* ── Spacing ────────────────────────────────────────────────────────── */
    --section-padding-block:  clamp(3rem, 8vw, 7rem);
    --section-padding-inline: clamp(1rem, 5vw, 6rem);
    --container-max:          1280px;

    --space-2xs: 0.25rem;
    --space-xs:  0.5rem;
    --space-sm:  0.75rem;
    --space-md:  1rem;
    --space-lg:  1.5rem;
    --space-xl:  2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* ── Borders & Radii ────────────────────────────────────────────────── */
    --radius-sm:   0.375rem;
    --radius-md:   0.5rem;
    --radius-lg:   0.75rem;
    --radius-xl:   1rem;
    --radius-2xl:  1.5rem;
    --radius-pill: 100vmax;

    /* ── Shadows & Effects ──────────────────────────────────────────────── */
    --shadow-card:    0 4px 24px rgba(0, 0, 0, 0.3);
    --shadow-glow:    0 0 30px rgba(139, 92, 246, 0.15);
    --shadow-glow-lg: 0 0 60px rgba(139, 92, 246, 0.2);
    --shadow-btn:     0 4px 15px rgba(139, 92, 246, 0.3);
    --shadow-btn-hover: 0 8px 30px rgba(139, 92, 246, 0.45);

    --glass-bg:      rgba(17, 17, 24, 0.6);
    --glass-bg-heavy: rgba(17, 17, 24, 0.85);
    --glass-blur:    blur(20px);

    /* ── Transitions ────────────────────────────────────────────────────── */
    --ease-out-expo:  cubic-bezier(0.16, 1, 0.3, 1);
    --ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);
    --duration-fast:  150ms;
    --duration-base:  250ms;
    --duration-slow:  400ms;
    --duration-reveal: 700ms;

    /* ── Z-index scale ──────────────────────────────────────────────────── */
    --z-behind:  -1;
    --z-base:    1;
    --z-dropdown: 100;
    --z-sticky:  500;
    --z-navbar:  1000;
    --z-modal:   2000;
    --z-toast:   3000;
  }
}

/* --------------------------------------------------------------------------
   @layer base — Global base styles
   -------------------------------------------------------------------------- */
@layer base {
  body {
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    color: var(--color-text-body);
    background-color: var(--color-bg-deep);
  }

  h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    color: var(--color-text-heading);
    line-height: var(--leading-tight);
  }

  a {
    transition: color var(--duration-base) var(--ease-out-quart);
  }

  ::selection {
    background-color: rgba(139, 92, 246, 0.3);
    color: var(--color-text-heading);
  }

  :focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
    border-radius: var(--radius-sm);
  }
}

/* --------------------------------------------------------------------------
   @layer layout — Container & structural helpers
   -------------------------------------------------------------------------- */
@layer layout {
  .container {
    max-inline-size: var(--container-max);
    margin-inline: auto;
    padding-inline: var(--section-padding-inline);
  }

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

/* --------------------------------------------------------------------------
   @layer components — Reusable UI components
   -------------------------------------------------------------------------- */
@layer components {

  /* ── Buttons ────────────────────────────────────────────────────────── */
  .btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
    padding: 0.875rem 2rem;
    font-family: var(--font-heading);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text-heading);
    background: var(--gradient-primary);
    background: var(--gradient-primary-oklch);
    border: none;
    border-radius: var(--radius-pill);
    cursor: pointer;
    transition:
      transform var(--duration-base) var(--ease-out-expo),
      box-shadow var(--duration-base) var(--ease-out-expo),
      filter var(--duration-base) var(--ease-out-expo);
    box-shadow: var(--shadow-btn);
    white-space: nowrap;

    &:hover {
      transform: translateY(-2px) scale(1.02);
      box-shadow: var(--shadow-btn-hover);
      filter: brightness(1.1);
    }

    &:active {
      transform: translateY(0) scale(0.98);
      box-shadow: var(--shadow-btn);
    }
  }

  .btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
    padding: 0.875rem 2rem;
    font-family: var(--font-heading);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-primary-light);
    background: transparent;
    border: 1.5px solid var(--color-border-purple);
    border-radius: var(--radius-pill);
    cursor: pointer;
    transition:
      background-color var(--duration-base) var(--ease-out-quart),
      color var(--duration-base) var(--ease-out-quart),
      border-color var(--duration-base) var(--ease-out-quart),
      transform var(--duration-base) var(--ease-out-expo);
    white-space: nowrap;

    &:hover {
      background-color: rgba(139, 92, 246, 0.1);
      border-color: var(--color-primary);
      color: var(--color-text-heading);
      transform: translateY(-2px);
    }

    &:active {
      transform: translateY(0);
      background-color: rgba(139, 92, 246, 0.15);
    }
  }

  /* ── Section typography ─────────────────────────────────────────────── */
  .section-subtitle {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-heading);
    font-size: var(--text-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--color-primary-light);
    margin-block-end: var(--space-md);
  }

  .section-title {
    font-size: var(--text-section);
    font-weight: 800;
    line-height: var(--leading-tight);
    color: var(--color-text-heading);
    margin-block-end: var(--space-lg);
  }

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

  /* ── Scroll reveal ──────────────────────────────────────────────────── */
  .reveal {
    opacity: 0;
    transform: translateY(30px);
    transition:
      opacity var(--duration-reveal) var(--ease-out-expo),
      transform var(--duration-reveal) var(--ease-out-expo);

    &.active {
      opacity: 1;
      transform: translateY(0);
    }
  }

  /* Stagger children reveals */
  .reveal-stagger {
    & > * {
      opacity: 0;
      transform: translateY(20px);
      transition:
        opacity var(--duration-reveal) var(--ease-out-expo),
        transform var(--duration-reveal) var(--ease-out-expo);
    }

    &.active > * {
      opacity: 1;
      transform: translateY(0);
    }

    &.active > *:nth-child(1) { transition-delay: 0ms; }
    &.active > *:nth-child(2) { transition-delay: 100ms; }
    &.active > *:nth-child(3) { transition-delay: 200ms; }
    &.active > *:nth-child(4) { transition-delay: 300ms; }
    &.active > *:nth-child(5) { transition-delay: 400ms; }
    &.active > *:nth-child(6) { transition-delay: 500ms; }
  }
}

/* --------------------------------------------------------------------------
   @layer sections — Section-specific styles
   -------------------------------------------------------------------------- */
@layer sections {

  /* ========================================================================
     1. NAVBAR
     ======================================================================== */
  .navbar {
    position: fixed;
    inset-block-start: 0;
    inset-inline: 0;
    z-index: var(--z-navbar);
    padding-block: var(--space-md);
    padding-inline: var(--section-padding-inline);
    background: rgba(10, 10, 15, 0.4);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-block-end: 1px solid var(--color-border-subtle);
    transition:
      background-color var(--duration-slow) var(--ease-out-quart),
      padding var(--duration-slow) var(--ease-out-quart);

    &.scrolled {
      background: var(--glass-bg-heavy);
      padding-block: var(--space-sm);
      box-shadow: 0 4px 30px rgba(0, 0, 0, 0.4);
    }

    /* Disable glass properties when mobile menu is active to avoid containing block issues for position: fixed */
    &:has(.nav-links.active) {
      background: transparent !important;
      backdrop-filter: none !important;
      -webkit-backdrop-filter: none !important;
      border-color: transparent !important;

      & .navbar-logo {
        position: relative;
        z-index: calc(var(--z-navbar) + 1);
      }
    }
  }

  .navbar-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-inline-size: var(--container-max);
    margin-inline: auto;
  }

  .navbar-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: clamp(1.1rem, 1rem + 0.5vw, 1.35rem);
    color: var(--color-text-heading);
    text-decoration: none;
    flex-shrink: 0;

    & img {
      block-size: 2rem;
      inline-size: auto;
    }
  }

  .nav-links {
    display: none;
    gap: var(--space-xl);
    align-items: center;

    & a {
      font-size: var(--text-sm);
      font-weight: 500;
      color: var(--color-text-muted);
      transition: color var(--duration-base) var(--ease-out-quart);
      position: relative;

      &::after {
        content: '';
        position: absolute;
        inset-block-end: -4px;
        inset-inline-start: 0;
        inline-size: 0;
        block-size: 2px;
        background: var(--gradient-primary);
        border-radius: var(--radius-pill);
        transition: inline-size var(--duration-base) var(--ease-out-expo);
      }

      &:hover {
        color: var(--color-text-heading);

        &::after {
          inline-size: 100%;
        }
      }

      &.active {
        color: var(--color-primary-light);

        &::after {
          inline-size: 100%;
        }
      }
    }
  }

  .nav-cta {
    display: none;
    padding: 0.625rem 1.5rem;
    font-size: var(--text-sm);
  }

  .nav-toggle {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 6px;
    inline-size: 2.5rem;
    block-size: 2.5rem;
    padding: 0;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.15) !important;
    border-radius: var(--radius-md);
    cursor: pointer;
    z-index: calc(var(--z-navbar) + 1);
    transition: background-color var(--duration-base), border-color var(--duration-base);
    outline: none;
    -webkit-tap-highlight-color: transparent;

    & span {
      display: block;
      inline-size: 20px;
      block-size: 2px;
      background-color: var(--color-text-heading);
      border-radius: var(--radius-pill);
      transition:
        transform var(--duration-base) var(--ease-out-expo),
        opacity var(--duration-fast);
    }

    &.active {
      background: rgba(255, 255, 255, 0.08);
      border-color: rgba(255, 255, 255, 0.3) !important;

      & span:nth-child(1) {
        transform: rotate(45deg) translate(4px, 4px);
      }
      & span:nth-child(2) {
        opacity: 0;
      }
      & span:nth-child(3) {
        transform: rotate(-45deg) translate(4px, -4px);
      }
    }
  }

  /* Mobile nav overlay */
  .nav-mobile-overlay {
    position: fixed;
    inset: 0;
    z-index: calc(var(--z-navbar) - 1);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-xl);
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    opacity: 0;
    visibility: hidden;
    transition:
      opacity var(--duration-slow) var(--ease-out-quart),
      visibility var(--duration-slow);

    &.open {
      opacity: 1;
      visibility: visible;
    }

    & a {
      font-family: var(--font-heading);
      font-size: var(--text-lg);
      font-weight: 600;
      color: var(--color-text-body);
      transition: color var(--duration-base);

      &:hover {
        color: var(--color-primary-light);
      }
    }
  }

  /* ========================================================================
     2. HERO
     ======================================================================== */
  .hero {
    position: relative;
    min-block-size: 100dvh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--space-3xl);
    padding-block-start: calc(6rem + var(--space-xl));
    padding-block-end: var(--space-2xl);
    padding-inline: var(--section-padding-inline);
    overflow: hidden;

    /* Subtle background glow */
    &::before {
      content: '';
      position: absolute;
      inset: 0;
      background: var(--gradient-hero-bg);
      z-index: var(--z-behind);
      pointer-events: none;
    }
  }

  .hero-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-3xl);
    max-inline-size: var(--container-max);
    margin-inline: auto;
    inline-size: 100%;
  }

  .hero-content {
    text-align: center;
    max-inline-size: 640px;
  }

  .hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-lg);
    margin-block-end: var(--space-xl);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.05em;
    color: var(--color-primary-light);
    background: rgba(139, 92, 246, 0.08);
    border: 1px solid var(--color-border-purple);
    border-radius: var(--radius-pill);
    animation: badge-pulse 3s ease-in-out infinite;
  }

  @keyframes badge-pulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(139, 92, 246, 0.15); }
    50%      { box-shadow: 0 0 20px 2px rgba(139, 92, 246, 0.1); }
  }

  .hero-title {
    font-size: var(--text-hero);
    font-weight: 800;
    line-height: var(--leading-tight);
    margin-block-end: var(--space-lg);
    letter-spacing: -0.02em;
  }

  .hero-subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-muted);
    line-height: var(--leading-snug);
    margin-block-end: var(--space-2xl);
    max-inline-size: 540px;
    margin-inline: auto;
  }

  .hero-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    inline-size: 100%;
    max-inline-size: 320px;
    margin-inline: auto;
    margin-block-end: var(--space-2xl);

    & .btn-primary,
    & .btn-secondary {
      display: inline-flex;
      justify-content: center;
      inline-size: 100%;
    }
  }

  .hero-mockup {
    max-inline-size: 100%;
    flex-shrink: 0;
    position: relative;

    & img {
      inline-size: 100%;
      max-inline-size: 480px;
      block-size: auto;
      border-radius: var(--radius-xl);
      box-shadow: var(--shadow-glow-lg);
    }

    /* Decorative glow behind mockup */
    &::before {
      content: '';
      position: absolute;
      inset: -10%;
      background: radial-gradient(circle, rgba(139, 92, 246, 0.12) 0%, transparent 70%);
      z-index: var(--z-behind);
      filter: blur(40px);
      pointer-events: none;
    }
  }

  .hero-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
    inline-size: 100%;
    max-inline-size: 640px;
    margin-inline: auto;
  }

  .stat-card {
    padding: var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-lg);
    text-align: center;
    transition:
      border-color var(--duration-base) var(--ease-out-quart),
      box-shadow var(--duration-base) var(--ease-out-quart);

    &:hover {
      border-color: var(--color-border-purple);
      box-shadow: var(--shadow-glow);
    }
  }

  .stat-value {
    font-family: var(--font-heading);
    font-size: clamp(1.5rem, 1rem + 2vw, 2rem);
    font-weight: 800;
    color: var(--color-text-heading);
    line-height: var(--leading-tight);
  }

  .stat-label {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    margin-block-start: var(--space-2xs);
  }

  /* ========================================================================
     3. FEATURES
     ======================================================================== */
  .features {
    padding-block: var(--section-padding-block);
    padding-inline: var(--section-padding-inline);
    position: relative;

    /* Soft top glow */
    &::before {
      content: '';
      position: absolute;
      inset-block-start: 0;
      inset-inline-start: 50%;
      translate: -50% 0;
      inline-size: 60%;
      block-size: 1px;
      background: linear-gradient(90deg, transparent, var(--color-border-purple), transparent);
    }
  }

  .features-header {
    text-align: center;
    max-inline-size: 640px;
    margin-inline: auto;
    margin-block-end: var(--space-3xl);
  }

  .features-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
    max-inline-size: var(--container-max);
    margin-inline: auto;
  }

  .feature-card {
    position: relative;
    padding: var(--space-xl);
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-xl);
    transition:
      transform var(--duration-slow) var(--ease-out-expo),
      border-color var(--duration-base) var(--ease-out-quart),
      box-shadow var(--duration-base) var(--ease-out-quart);
    overflow: hidden;

    /* Subtle inner glow on hover */
    &::after {
      content: '';
      position: absolute;
      inset: 0;
      background: radial-gradient(circle at 50% 0%, rgba(139, 92, 246, 0.06), transparent 60%);
      opacity: 0;
      transition: opacity var(--duration-slow);
      pointer-events: none;
    }

    &:hover {
      transform: translateY(-4px);
      border-color: var(--color-border-purple);
      box-shadow: var(--shadow-glow);

      &::after {
        opacity: 1;
      }
    }
  }

  .feature-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    inline-size: 3rem;
    block-size: 3rem;
    margin-block-end: var(--space-lg);
    background: rgba(139, 92, 246, 0.1);
    border: 1px solid var(--color-border-purple);
    border-radius: var(--radius-lg);
    font-size: 1.25rem;
    color: var(--color-primary-light);
    transition: background-color var(--duration-base);

    .feature-card:hover & {
      background: rgba(139, 92, 246, 0.18);
    }
  }

  .feature-title {
    font-size: clamp(1.1rem, 1rem + 0.5vw, 1.25rem);
    font-weight: 700;
    margin-block-end: var(--space-sm);
  }

  .feature-description {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    line-height: var(--leading-normal);
  }

  /* ========================================================================
     3b. PRIVACY & SECURITY SECTION
     ======================================================================== */
  .privacy-section {
    padding-block: var(--section-padding-block);
    padding-inline: var(--section-padding-inline);
    position: relative;
    overflow: hidden;
  }

  .privacy-inner {
    max-inline-size: var(--container-max);
    margin-inline: auto;
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-3xl);
    align-items: center;
  }

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

  .privacy-text {
    font-size: var(--text-base);
    color: var(--color-text-muted);
    line-height: var(--leading-normal);
    margin-block-end: var(--space-lg);
  }

  .security-benefits {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
  }

  .benefit-item {
    display: flex;
    align-items: flex-start;
    gap: var(--space-md);
  }

  .benefit-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    inline-size: 2.5rem;
    block-size: 2.5rem;
    background: rgba(139, 92, 246, 0.1);
    border: 1px solid var(--color-border-purple);
    border-radius: var(--radius-lg);
    color: var(--color-primary-light);
    flex-shrink: 0;
  }

  .benefit-detail h4 {
    font-size: var(--text-base);
    font-weight: 700;
    color: var(--color-text-heading);
    margin-block-end: var(--space-xs);
  }

  .benefit-detail p {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    line-height: var(--leading-normal);
  }

  .privacy-visual {
    display: flex;
    justify-content: center;
    position: relative;
  }

  .shield-card {
    position: relative;
    inline-size: 100%;
    max-inline-size: 380px;
    padding: var(--space-2xl) var(--space-xl);
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-2xl);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--space-lg);
    box-shadow: 0 20px 40px -15px rgba(0, 0, 0, 0.5);
    overflow: hidden;
  }

  .shield-glow {
    position: absolute;
    inset-block-start: -50px;
    inline-size: 200px;
    block-size: 200px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.15) 0%, transparent 70%);
    pointer-events: none;
  }

  .shield-icon-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    inline-size: 120px;
    block-size: 120px;
    background: rgba(139, 92, 246, 0.05);
    border: 1px solid rgba(139, 92, 246, 0.2);
    border-radius: 50%;
    box-shadow: 0 0 30px rgba(139, 92, 246, 0.1);
  }

  .shield-svg {
    filter: drop-shadow(0 0 8px rgba(139, 92, 246, 0.3));
  }

  .shield-badge {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.3);
    color: #34d399;
    font-size: var(--text-xs);
    font-weight: 600;
    padding: var(--space-xs) var(--space-md);
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }

  .shield-stats {
    display: flex;
    align-items: center;
    justify-content: space-around;
    inline-size: 100%;
    margin-block-start: var(--space-md);
  }

  .shield-stat {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
  }

  .shield-stat .stat-num {
    font-family: var(--font-heading);
    font-size: var(--text-2xl);
    font-weight: 800;
    color: var(--color-text-heading);
  }

  .shield-stat .stat-lbl {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
  }

  .shield-divider {
    inline-size: 1px;
    block-size: 40px;
    background: var(--color-border-subtle);
  }

  /* ========================================================================
     4. INTERACTIVE DEMO SECTION
     ======================================================================== */
  .demo-section {
    padding-block: var(--section-padding-block);
    padding-inline: var(--section-padding-inline);
    position: relative;
    overflow: hidden;
  }

  .demo-inner {
    max-inline-size: var(--container-max);
    margin-inline: auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-3xl);
  }

  .demo-header {
    text-align: center;
    max-inline-size: 680px;
    margin-inline: auto;
  }

  .demo-subtitle-text {
    font-size: var(--text-base);
    color: var(--color-text-muted);
    line-height: var(--leading-normal);
    margin-block-start: var(--space-md);
  }

  .demo-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-3xl);
    align-items: center;
  }

  /* Step selector list on the left */
  .demo-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
  }

  .demo-step-card {
    display: flex;
    align-items: flex-start;
    gap: var(--space-lg);
    padding: var(--space-xl);
    background: rgba(255, 255, 255, 0.01);
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-xl);
    cursor: pointer;
    transition:
      background-color var(--duration-slow) var(--ease-out-quart),
      border-color var(--duration-slow) var(--ease-out-quart),
      transform var(--duration-slow) var(--ease-out-quart),
      box-shadow var(--duration-slow) var(--ease-out-quart);
    position: relative;
    overflow: hidden;

    &:hover {
      background: rgba(255, 255, 255, 0.03);
      border-color: rgba(139, 92, 246, 0.3);
      transform: translateY(-2px);
    }

    &.active {
      background: rgba(139, 92, 246, 0.05);
      border-color: var(--color-primary);
      box-shadow: var(--shadow-glow);

      & .step-number {
        color: var(--color-primary-light);
        text-shadow: 0 0 10px rgba(139, 92, 246, 0.5);
      }

      & .step-title {
        color: var(--color-text-heading);
      }

      & .step-description {
        color: var(--color-text-body);
      }
    }
  }

  /* Step progressive fill line */
  .step-progress-bar {
    position: absolute;
    inset-block-start: 0;
    inset-inline-start: 0;
    inline-size: 100%;
    block-size: 3px;
    background: transparent;
  }

  .step-progress-fill {
    inline-size: 0;
    block-size: 100%;
    background: var(--gradient-primary);
  }

  .demo-step-card.active .step-progress-fill {
    inline-size: 100%;
    transition: inline-size 6000ms linear; /* 6s autoplay interval */
  }

  /* Reset transitions when step is clicked or changed */
  .demo-step-card.active.paused .step-progress-fill {
    inline-size: 100% !important;
    transition: none !important;
  }

  .step-number {
    font-family: var(--font-heading);
    font-size: var(--text-2xl);
    font-weight: 800;
    color: var(--color-text-subtle);
    line-height: 1;
    transition: color var(--duration-base);
  }

  .step-content {
    flex: 1;
  }

  .step-title {
    font-family: var(--font-heading);
    font-size: var(--text-base);
    font-weight: 700;
    color: var(--color-text-heading);
    margin-block-end: var(--space-xs);
    transition: color var(--duration-base);
  }

  .step-description {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    line-height: var(--leading-normal);
    transition: color var(--duration-base);
  }

  /* Screen Device mockup on the right */
  .demo-preview {
    display: flex;
    justify-content: center;
    position: relative;
  }

  .device-mockup {
    inline-size: 100%;
    max-inline-size: 720px;
    background: #06060a;
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.7);
    display: flex;
    flex-direction: column;
    position: relative;

    &::before {
      content: '';
      position: absolute;
      inset: 0;
      border-radius: inherit;
      padding: 1px;
      background: linear-gradient(
        180deg,
        rgba(255, 255, 255, 0.1) 0%,
        rgba(139, 92, 246, 0.2) 100%
      );
      -webkit-mask:
        linear-gradient(#fff 0 0) content-box,
        linear-gradient(#fff 0 0);
      -webkit-mask-composite: xor;
      mask:
        linear-gradient(#fff 0 0) content-box,
        linear-gradient(#fff 0 0);
      mask-composite: exclude;
      pointer-events: none;
    }
  }

  .device-header {
    background: #0b0b12;
    padding: var(--space-sm) var(--space-md);
    border-block-end: 1px solid var(--color-border-subtle);
    display: flex;
    align-items: center;
    gap: var(--space-md);
  }

  .device-buttons {
    display: flex;
    gap: 6px;

    & span {
      display: block;
      inline-size: 10px;
      block-size: 10px;
      border-radius: 50%;
    }
  }

  .device-dot-red { background-color: #ef4444; }
  .device-dot-yellow { background-color: #f59e0b; }
  .device-dot-green { background-color: #10b981; }

  .device-title {
    font-size: var(--text-xs);
    color: var(--color-text-subtle);
    font-family: var(--font-heading);
    font-weight: 500;
    text-align: center;
    flex: 1;
    margin-inline-end: 42px; /* balance out the buttons spacing */
  }

  .device-body {
    position: relative;
    aspect-ratio: 16 / 10;
    overflow: hidden;
    background: #000;
  }

  .demo-image-wrapper {
    position: relative;
    inline-size: 100%;
    block-size: 100%;
  }

  .demo-img {
    position: absolute;
    inset: 0;
    inline-size: 100%;
    block-size: 100%;
    object-fit: cover;
    opacity: 0;
    scale: 1.05;
    transition:
      opacity var(--duration-slow) var(--ease-out-quart),
      scale var(--duration-slow) var(--ease-out-quart);
    z-index: 1;

    &.active {
      opacity: 1;
      scale: 1;
      z-index: 2;
    }
  }

  /* ========================================================================
     5. DOWNLOAD CTA
     ======================================================================== */
  .download-cta {
    padding-inline: var(--section-padding-inline);
    padding-block: var(--space-3xl);
  }

  .download-cta-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-lg);
    max-inline-size: var(--container-max);
    margin-inline: auto;
    padding: var(--space-xl) var(--space-xl);
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: var(--radius-2xl);
    text-align: center;
    position: relative;
    overflow: hidden;

    /* Purple gradient border (simulated) */
    &::before {
      content: '';
      position: absolute;
      inset: 0;
      border-radius: inherit;
      padding: 1px;
      background: linear-gradient(
        135deg,
        var(--color-primary) 0%,
        var(--color-accent-pink) 50%,
        var(--color-primary-dark) 100%
      );
      -webkit-mask:
        linear-gradient(#fff 0 0) content-box,
        linear-gradient(#fff 0 0);
      -webkit-mask-composite: xor;
      mask:
        linear-gradient(#fff 0 0) content-box,
        linear-gradient(#fff 0 0);
      mask-composite: exclude;
      pointer-events: none;
    }

    /* Inner glow */
    &::after {
      content: '';
      position: absolute;
      inset-block-start: 0;
      inset-inline-start: 50%;
      translate: -50% 0;
      inline-size: 80%;
      block-size: 50%;
      background: radial-gradient(ellipse, rgba(139, 92, 246, 0.08), transparent 70%);
      pointer-events: none;
    }
  }

  .download-cta-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    inline-size: 3.5rem;
    block-size: 3.5rem;
    background: rgba(139, 92, 246, 0.12);
    border: 1px solid var(--color-border-purple);
    border-radius: var(--radius-lg);
    font-size: 1.5rem;
    color: var(--color-primary-light);
    position: relative;
    z-index: var(--z-base);
  }

  .download-cta-text {
    position: relative;
    z-index: var(--z-base);
  }

  .download-cta-title {
    font-size: clamp(1.25rem, 1rem + 1.5vw, 1.75rem);
    font-weight: 700;
    margin-block-end: var(--space-xs);
  }

  .download-cta-description {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
  }

  .download-cta .btn-primary {
    position: relative;
    z-index: var(--z-base);
  }

  /* ========================================================================
     6. FOOTER
     ======================================================================== */
  .footer {
    padding-block-start: var(--section-padding-block);
    padding-block-end: var(--space-xl);
    padding-inline: var(--section-padding-inline);
    border-block-start: 1px solid var(--color-border-subtle);
    background: var(--color-bg-card);
  }

  .footer-inner {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
    max-inline-size: var(--container-max);
    margin-inline: auto;
    padding-block-end: var(--space-2xl);
    border-block-end: 1px solid var(--color-border-subtle);
  }

  .footer-brand {
    max-inline-size: 320px;
  }

  .footer-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.2rem;
    color: var(--color-text-heading);
    margin-block-end: var(--space-md);

    & img {
      block-size: 1.75rem;
      inline-size: auto;
    }
  }

  .footer-brand-description {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    line-height: var(--leading-normal);
    margin-block-end: var(--space-lg);
  }

  .social-links {
    display: flex;
    gap: var(--space-sm);
  }

  .social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    inline-size: 2.25rem;
    block-size: 2.25rem;
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-md);
    color: var(--color-text-muted);
    font-size: 1rem;
    transition:
      color var(--duration-base),
      border-color var(--duration-base),
      background-color var(--duration-base);

    &:hover {
      color: var(--color-primary-light);
      border-color: var(--color-border-purple);
      background-color: rgba(139, 92, 246, 0.08);
    }
  }

  .footer-column {
    & h4 {
      font-size: var(--text-sm);
      font-weight: 700;
      color: var(--color-text-heading);
      margin-block-end: var(--space-lg);
      text-transform: uppercase;
      letter-spacing: 0.08em;
    }

    & ul {
      display: flex;
      flex-direction: column;
      gap: var(--space-sm);
    }

    & a {
      font-size: var(--text-sm);
      color: var(--color-text-muted);
      transition: color var(--duration-base);

      &:hover {
        color: var(--color-primary-light);
      }
    }
  }

  .footer-contact-item {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: var(--text-sm);
    color: var(--color-text-muted);

    & span:first-child {
      color: var(--color-primary-light);
      flex-shrink: 0;
    }
  }

  .footer-bottom {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    align-items: center;
    max-inline-size: var(--container-max);
    margin-inline: auto;
    padding-block-start: var(--space-xl);
    text-align: center;
  }

  .footer-copyright {
    font-size: var(--text-xs);
    color: var(--color-text-subtle);
  }

  .footer-legal {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-md);
    justify-content: center;

    & a {
      font-size: var(--text-xs);
      color: var(--color-text-subtle);
      transition: color var(--duration-base);

      &:hover {
        color: var(--color-text-muted);
      }
    }
  }
}

/* --------------------------------------------------------------------------
   Additional sections — About, mobile nav, brand, extras
   -------------------------------------------------------------------------- */
@layer sections {

  /* ── Mobile nav overlay (via JS .active on .nav-links) ────────────── */
  @media (max-width: 1023px) {
    .nav-links.active {
      display: flex;
      flex-direction: column;
      position: fixed;
      inset: 0;
      z-index: calc(var(--z-navbar) - 1);
      align-items: center;
      justify-content: center;
      gap: var(--space-xl);
      background: rgba(10, 10, 15, 0.95);
      backdrop-filter: var(--glass-blur);
      -webkit-backdrop-filter: var(--glass-blur);

      & a {
        font-family: var(--font-heading);
        font-size: var(--text-lg);
        font-weight: 600;
        color: var(--color-text-body);

        &:hover {
          color: var(--color-primary-light);
        }

        &::after {
          display: none;
        }
      }
    }
  }

  /* ── Navbar brand text ─────────────────────────────────────────────── */
  .navbar-brand {
    display: flex;
    flex-direction: column;
    line-height: 1.1;
  }

  .brand-name {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--color-text-heading);
  }

  .brand-tagline {
    font-size: 0.65rem;
    color: var(--color-text-subtle);
    letter-spacing: 0.03em;
  }

  /* ── Badge dot ─────────────────────────────────────────────────────── */
  .badge-dot {
    display: inline-block;
    inline-size: 6px;
    block-size: 6px;
    border-radius: 50%;
    background: var(--color-primary);
    animation: dot-blink 2s ease-in-out infinite;
  }

  @keyframes dot-blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.3; }
  }

  /* ── Typing cursor on hero badge ───────────────────────────────────── */
  .hero-badge.typing-cursor::after {
    content: '|';
    display: inline-block;
    color: var(--color-primary-light);
    animation: cursor-blink 1s step-end infinite;
    margin-inline-start: 2px;
  }

  @keyframes cursor-blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
  }

  /* ── Stat card icon ────────────────────────────────────────────────── */
  .stat-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-block-end: var(--space-sm);
    color: var(--color-primary-light);
  }

  .stat-value {
    display: block;
  }

  .stat-label {
    display: block;
  }

  /* ========================================================================
     7. ABOUT / STATS
     ======================================================================== */
  .about {
    padding-block: var(--section-padding-block);
    padding-inline: var(--section-padding-inline);
    position: relative;

    &::before {
      content: '';
      position: absolute;
      inset-block-start: 0;
      inset-inline-start: 50%;
      translate: -50% 0;
      inline-size: 60%;
      block-size: 1px;
      background: linear-gradient(90deg, transparent, var(--color-border-purple), transparent);
    }
  }

  .about-inner {
    max-inline-size: var(--container-max);
    margin-inline: auto;
  }

  .about-stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-lg);
    margin-block-end: var(--space-3xl);
  }

  .about-stat-card {
    text-align: center;
    padding: var(--space-xl) var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-xl);
    transition:
      border-color var(--duration-base) var(--ease-out-quart),
      box-shadow var(--duration-base) var(--ease-out-quart);

    &:hover {
      border-color: var(--color-border-purple);
      box-shadow: var(--shadow-glow);
    }
  }

  .about-stat-number {
    display: block;
    font-family: var(--font-heading);
    font-size: clamp(2rem, 1.5rem + 3vw, 3.5rem);
    font-weight: 800;
    background: var(--gradient-text);
    background: var(--gradient-text-oklch);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
    line-height: 1;
    margin-block-end: var(--space-sm);
  }

  .about-stat-label {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
  }

  .about-text {
    max-inline-size: 680px;
    margin-inline: auto;
    text-align: center;
    font-size: var(--text-lg);
    color: var(--color-text-muted);
    line-height: var(--leading-normal);

    & strong {
      color: var(--color-text-heading);
    }
  }

  /* ── Reveal direction variants ─────────────────────────────────────── */
  .reveal[data-reveal="left"] {
    transform: translateX(-30px);

    &.active {
      transform: translateX(0);
    }
  }

  .reveal[data-reveal="right"] {
    transform: translateX(30px);

    &.active {
      transform: translateX(0);
    }
  }

  .reveal[data-reveal="fade"] {
    transform: none;
  }

  /* ── Download compat text ──────────────────────────────────────────── */
  .download-compat {
    font-size: var(--text-xs);
    color: var(--color-text-subtle);
    position: relative;
    z-index: var(--z-base);
  }

  /* ── Clinical Partners section ─────────────────────────────────────── */
  .partners {
    padding-block: var(--space-xl);
    padding-inline: var(--section-padding-inline);
    background: rgba(10, 10, 12, 0.3);
    border-block: 1px solid var(--color-border-subtle);
    overflow: hidden;
    position: relative;
  }

  .partners-inner {
    max-inline-size: var(--container-max);
    margin-inline: auto;
    text-align: center;
  }

  .partners-title {
    font-size: var(--text-xs);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
    margin-block-end: var(--space-lg);
    font-weight: 600;
  }

  .partners-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-sm);
    justify-content: center;
    align-items: center;
  }

  .partner-card {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md);
    background: var(--glass-bg);
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-lg);
    transition: 
      transform var(--duration-slow) var(--ease-out-expo), 
      border-color var(--duration-base) var(--ease-out-quart),
      box-shadow var(--duration-base) var(--ease-out-quart);
    position: relative;

    &:hover {
      transform: translateY(-4px) scale(1.02);
      border-color: var(--color-border-purple);
      box-shadow: 0 10px 25px -10px rgba(139, 92, 246, 0.25);
    }
  }

  .partner-icon {
    font-size: var(--text-lg);
  }

  .partner-name {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-body);
  }

  /* ── Download explanation modal ────────────────────────────────────── */
  .modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(10, 10, 12, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--duration-base) ease;
    padding: var(--space-md);

    &.active {
      opacity: 1;
      pointer-events: auto;
    }
  }

  .modal-content {
    background: var(--glass-bg-heavy);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--color-border-purple);
    border-radius: var(--radius-2xl);
    padding: var(--space-2xl);
    max-inline-size: 500px;
    inline-size: 100%;
    position: relative;
    box-shadow: var(--shadow-glow-lg);
    transform: scale(0.95);
    transition: transform var(--duration-base) var(--ease-out-expo);
    text-align: center;

    .modal-overlay.active & {
      transform: scale(1);
    }
  }

  .modal-close {
    position: absolute;
    inset-block-start: var(--space-md);
    inset-inline-end: var(--space-md);
    background: none;
    border: none;
    font-size: var(--text-2xl);
    color: var(--color-text-muted);
    cursor: pointer;
    line-height: 1;
    transition: color var(--duration-base);

    &:hover {
      color: var(--color-text-heading);
    }
  }



  .modal-title {
    font-family: var(--font-heading);
    font-size: var(--text-lg);
    color: var(--color-text-heading);
    margin-block-end: var(--space-md);
    letter-spacing: -0.01em;
    font-weight: 700;
  }

  .modal-text {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    line-height: var(--leading-relaxed);
    margin-block-end: var(--space-md);

    & strong {
      color: var(--color-text-heading);
    }
  }

  .modal-list {
    list-style: none;
    padding: 0;
    margin-block-end: var(--space-lg);
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-xs);
    text-align: start;

    & li {
      font-size: var(--text-xs);
      color: var(--color-text-body);
      background: rgba(139, 92, 246, 0.06);
      border: 1px solid var(--color-border-subtle);
      padding: var(--space-sm) var(--space-md);
      border-radius: var(--radius-md);
    }
  }

  .modal-text.footer-note {
    font-size: var(--text-xs);
    border-block-start: 1px solid var(--color-border-subtle);
    padding-block-start: var(--space-md);
    margin-block-end: var(--space-lg);
  }

  .modal-buttons {
    display: flex;
    justify-content: center;
  }

  /* ── Brand tagline mobile responsiveness ────────────────────────────── */
  @media (max-width: 479px) {
    .brand-tagline {
      display: none !important;
    }
  }
}

/* --------------------------------------------------------------------------
   @layer utilities — Utility helpers
   -------------------------------------------------------------------------- */
@layer utilities {
  .visually-hidden {
    position: absolute;
    inline-size: 1px;
    block-size: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
  }

  .text-gradient {
    background: var(--gradient-text);
    background: var(--gradient-text-oklch);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
  }

  .glass {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
  }
}

/* --------------------------------------------------------------------------
   @layer responsive — Breakpoints (mobile-first)
   -------------------------------------------------------------------------- */
@layer responsive {

  /* ── 480px — Small tablets ────────────────────────────────────────────── */
  @media (min-width: 480px) {
    .hero-stats {
      grid-template-columns: repeat(4, 1fr);
    }

    .download-cta-inner {
      padding: var(--space-2xl);
    }

    .footer-inner {
      grid-template-columns: repeat(2, 1fr);
    }

    .about-stats-grid {
      grid-template-columns: repeat(4, 1fr);
    }

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

  /* ── 640px — Large mobile / small tablet ───────────────────────────── */
  @media (min-width: 640px) {
    .hero-buttons {
      flex-direction: row;
      justify-content: center;
      max-inline-size: none;

      & .btn-primary,
      & .btn-secondary {
        inline-size: auto;
      }
    }
  }

  /* ── 768px — Tablets ──────────────────────────────────────────────────── */
  @media (min-width: 768px) {
    .features-grid {
      grid-template-columns: repeat(2, 1fr);
    }

    .partners-grid {
      grid-template-columns: repeat(4, 1fr);
    }

    .download-cta-inner {
      flex-direction: row;
      text-align: start;
      padding: var(--space-2xl) var(--space-3xl);

      & .download-cta-text {
        flex: 1;
      }
    }

    .footer-inner {
      grid-template-columns: repeat(2, 1fr);
      gap: var(--space-3xl);
    }

    .footer-bottom {
      flex-direction: row;
      justify-content: space-between;
    }
  }

  /* ── 1024px — Desktop ─────────────────────────────────────────────────── */
  @media (min-width: 1024px) {

    /* Navbar: show desktop nav, hide toggle */
    .nav-links {
      display: flex;
    }

    .nav-cta {
      display: inline-flex;
    }

    .nav-toggle {
      display: none;
    }

    /* Hero: side-by-side */
    .hero-inner {
      flex-direction: row;
      align-items: center;
      justify-content: space-between;
    }

    .hero-content {
      text-align: start;
      max-inline-size: 560px;
      flex: 1;
    }

    .hero-subtitle {
      margin-inline: 0;
    }

    .hero-buttons {
      justify-content: flex-start;
    }

    .hero-mockup {
      flex: 0 0 auto;
      max-inline-size: 420px;

      & img {
        max-inline-size: 420px;
      }
    }

    .hero-stats {
      position: static;
      translate: none;
      max-inline-size: 800px;
      grid-template-columns: repeat(4, 1fr);
      inline-size: 100%;
      margin-block-start: var(--space-lg);
    }

    /* Privacy: side-by-side */
    .privacy-inner {
      grid-template-columns: 1.2fr 1fr;
      gap: var(--space-3xl);
    }

    /* Demo: side-by-side */
    .demo-grid {
      grid-template-columns: 1fr 1.3fr;
      gap: var(--space-3xl);
    }

    /* Footer: 4 columns */
    .footer-inner {
      grid-template-columns: 1.5fr repeat(3, 1fr);
    }
  }

  /* ── 1280px — Large desktop ───────────────────────────────────────────── */
  @media (min-width: 1280px) {
    .hero-mockup {
      max-inline-size: 480px;

      & img {
        max-inline-size: 480px;
      }
    }

    .hero-stats {
      max-inline-size: 920px;
    }

    .features-grid {
      gap: var(--space-xl);
    }
  }

  /* ── Language Switcher ────────────────────────────────────────────────── */
  .lang-en {
    display: none;
  }

  body.lang-en-active .lang-fr {
    display: none;
  }

  body.lang-en-active .lang-en {
    display: inline;
  }

  /* Block level element overrides for active language */
  body.lang-en-active p.lang-en,
  body.lang-en-active div.lang-en,
  body.lang-en-active h1.lang-en,
  body.lang-en-active h2.lang-en,
  body.lang-en-active h3.lang-en,
  body.lang-en-active h4.lang-en,
  body.lang-en-active section.lang-en {
    display: block;
  }

  body.lang-en-active flex.lang-en {
    display: flex;
  }

  .lang-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 6px 12px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-md);
    color: var(--color-text-subtle);
    font-size: var(--text-xs);
    font-weight: 700;
    cursor: pointer;
    transition:
      background-color var(--duration-base) var(--ease-out-quart),
      border-color var(--duration-base) var(--ease-out-quart),
      color var(--duration-base) var(--ease-out-quart);
    margin-inline-start: var(--space-md);
    line-height: 1;
    height: 34px;
  }

  .lang-toggle:hover {
    background: rgba(139, 92, 246, 0.1);
    border-color: var(--color-primary-light);
    color: var(--color-text-heading);
  }

  .mobile-lang-toggle {
    display: none;
  }

  @media (max-width: 1023px) {
    .navbar > .navbar-inner > .lang-toggle {
      display: none;
    }

    .nav-links .mobile-lang-toggle {
      display: inline-flex;
      margin-block-start: var(--space-md);
      margin-inline-start: 0;
      width: fit-content;
    }
  }

  /* ── System Status Indicator ────────────────────────────────────────── */
  .system-status {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    margin-block-start: var(--space-md);
    font-size: var(--text-xs);
    color: var(--color-text-muted);
  }

  .status-dot {
    inline-size: 8px;
    block-size: 8px;
    border-radius: 50%;
    background-color: #10b981; /* green-500 */
    box-shadow: 0 0 8px #10b981;
    animation: status-pulse 2s infinite ease-in-out;
  }

  @keyframes status-pulse {
    0%, 100% {
      opacity: 0.5;
      transform: scale(0.8);
    }
    50% {
      opacity: 1;
      transform: scale(1.2);
      box-shadow: 0 0 12px #10b981;
    }
  }

  /* ========================================================================
     4b. FAQ SECTION
     ======================================================================== */
  .faq-section {
    padding-block: var(--section-padding-block);
    padding-inline: var(--section-padding-inline);
    position: relative;
    overflow: hidden;
  }

  .faq-inner {
    max-inline-size: 800px;
    margin-inline: auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-2xl);
  }

  .faq-header {
    text-align: center;
  }

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

  .faq-item {
    background: var(--glass-bg);
    border: 1px solid var(--color-border-subtle);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: 
      border-color var(--duration-base) var(--ease-out-quart),
      box-shadow var(--duration-base) var(--ease-out-quart);
  }

  .faq-item:hover {
    border-color: rgba(139, 92, 246, 0.3);
  }

  .faq-item.open {
    border-color: var(--color-primary-light);
    box-shadow: 0 10px 30px -15px rgba(139, 92, 246, 0.2);
  }

  .faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    inline-size: 100%;
    padding: var(--space-lg) var(--space-xl);
    background: transparent;
    border: none;
    text-align: start;
    font-family: var(--font-heading);
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-text-heading);
    cursor: pointer;
    gap: var(--space-md);
  }

  .faq-arrow {
    display: flex;
    align-items: center;
    justify-content: center;
    inline-size: 1.5rem;
    block-size: 1.5rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--color-border-subtle);
    border-radius: 50%;
    color: var(--color-text-muted);
    transition: 
      transform var(--duration-base) var(--ease-out-quart),
      background-color var(--duration-base),
      color var(--duration-base);
    flex-shrink: 0;
  }

  .faq-item.open .faq-arrow {
    transform: rotate(180deg);
    background: rgba(139, 92, 246, 0.1);
    color: var(--color-primary-light);
    border-color: rgba(139, 92, 246, 0.3);
  }

  .faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--duration-slow) var(--ease-out-expo);
  }

  .faq-answer-content {
    padding: 0 var(--space-xl) var(--space-lg) var(--space-xl);
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    line-height: var(--leading-normal);
  }

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

    .reveal {
      opacity: 1;
      transform: none;
    }

    .reveal-stagger > * {
      opacity: 1;
      transform: none;
    }
  }
}