/* ─── DESIGN TOKENS ──────────────────────────────────────────────────────── */
:root {
  --bg-body:         #080c14;
  --bg-surface:      #0d1117;
  --bg-card:         #111827;
  --bg-card-hover:   #151f2e;

  --border-card:     rgba(255, 255, 255, 0.07);
  --border-divider:  rgba(255, 255, 255, 0.06);
  --border-subtle:   rgba(255, 255, 255, 0.10);

  --text-primary:    #f1f5f9;
  --text-secondary:  #64748b;
  --text-muted:      #475569;

  --accent:          #6366f1;
  --accent-hover:    #818cf8;
  --accent-gradient: linear-gradient(135deg, #6366f1, #8b5cf6);
  --accent-glow:     0 0 24px rgba(99, 102, 241, 0.35);
  --accent-glow-lg:  0 0 48px rgba(99, 102, 241, 0.25);

  --danger:          #f97316;
  --danger-border:   rgba(249, 115, 22, 0.25);

  --section-padding: 100px 20px;
  --content-width:   1040px;
  --nav-height:      72px;

  --radius-card:     14px;
  --radius-btn:      8px;
  --radius-pill:     100px;

  --transition-base: all 0.25s ease;
  --transition-slow: all 0.4s ease;
}

/* ─── RESET + BASE ────────────────────────────────────────────────────────── */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

ul {
  list-style: none;
  padding: 0;
}

/* ─── TYPOGRAPHY ──────────────────────────────────────────────────────────── */
h1 {
  font-size: clamp(2.6rem, 6vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  text-align: center;
  margin-bottom: 16px;
  color: var(--text-primary);
}

h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 10px;
}

p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.7;
}

/* ─── SECTION BASE ────────────────────────────────────────────────────────── */
section {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--section-padding);
}

/* Full-bleed sections */
.not-for,
.contact {
  max-width: 100%;
  background-color: var(--bg-surface);
  padding: var(--section-padding);
}

.not-for > *,
.contact > * {
  max-width: var(--content-width);
  margin-left: auto;
  margin-right: auto;
}

/* ─── NAVBAR ──────────────────────────────────────────────────────────────── */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 8%;
  height: var(--nav-height);
  background: rgba(8, 12, 20, 0.85);
  border-bottom: 1px solid var(--border-divider);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.nav-logo {
  font-size: 1.4rem;
  letter-spacing: -0.01em;
  cursor: default;
  user-select: none;
}

.logo-light {
  font-weight: 300;
  color: var(--text-primary);
}

.logo-bold {
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  gap: 32px;
  align-items: center;
}

.nav-links a {
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-secondary);
  transition: var(--transition-base);
}

.nav-links a:hover {
  color: var(--text-primary);
}

.cta {
  background: var(--accent-gradient);
  color: #fff;
  padding: 9px 20px;
  border-radius: var(--radius-btn);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: var(--transition-base);
  box-shadow: var(--accent-glow);
}

.cta:hover {
  opacity: 0.88;
  box-shadow: var(--accent-glow-lg);
  transform: translateY(-1px);
}

.nav-links a.cta {
  color: #fff;
}

.nav-mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}

.nav-mobile-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition-base);
}

/* ─── HERO ────────────────────────────────────────────────────────────────── */
.hero {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 90vh;
  text-align: center;
  padding: 80px 20px;
  max-width: 100%;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(99, 102, 241, 0.12) 0%, transparent 70%),
    var(--bg-body);
}

.hero-inner {
  max-width: 820px;
  margin: auto;
  position: relative;
  z-index: 1;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 28px;
}

.eyebrow::before,
.eyebrow::after {
  content: '';
  display: block;
  width: 32px;
  height: 1px;
  background: var(--accent);
  opacity: 0.5;
}

.hero-sub {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-secondary);
  max-width: 600px;
  margin: 20px auto 0;
  font-weight: 300;
}

.trust-line {
  margin-top: 18px;
  font-size: 0.82rem;
  color: var(--text-muted);
  font-style: italic;
}

.trust-line span {
  display: none;
}

.hero-buttons {
  display: flex;
  gap: 14px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 36px;
}

/* ─── BUTTONS ─────────────────────────────────────────────────────────────── */
.primary-btn {
  display: inline-block;
  background: var(--accent-gradient);
  color: #fff;
  padding: 14px 30px;
  border-radius: var(--radius-btn);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  transition: var(--transition-base);
  box-shadow: var(--accent-glow);
}

.primary-btn:hover {
  opacity: 0.88;
  transform: translateY(-2px);
  box-shadow: var(--accent-glow-lg);
}

.secondary-btn {
  display: inline-block;
  padding: 14px 30px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-btn);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 500;
  background: transparent;
  transition: var(--transition-base);
}

.secondary-btn:hover {
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.04);
}

/* ─── PROBLEMS ────────────────────────────────────────────────────────────── */
.problems {
  text-align: center;
}

.problems-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-top: 48px;
}

.problem-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-card);
  padding: 28px 24px;
  text-align: left;
  transition: var(--transition-base);
}

.problem-card:hover {
  border-left-color: var(--accent-hover);
  background: var(--bg-card-hover);
  transform: translateY(-3px);
}

.problem-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ─── SERVICES ────────────────────────────────────────────────────────────── */
.services {
  text-align: center;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  margin-top: 48px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-card);
  padding: 32px 28px;
  text-align: left;
  transition: var(--transition-slow);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: var(--transition-base);
}

.card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(99, 102, 241, 0.25);
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.4), var(--accent-glow);
}

.card:hover::before {
  opacity: 1;
}

.card-number {
  display: block;
  font-size: 2.5rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 18px;
}

/* ─── PROCESS ─────────────────────────────────────────────────────────────── */
.process {
  text-align: center;
}

.steps {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
  margin-top: 56px;
  flex-wrap: wrap;
}

.step {
  flex: 1;
  min-width: 160px;
  max-width: 220px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 8px 16px;
  background: transparent;
}

.step-number {
  font-size: 3rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 12px;
}

.step-divider {
  width: 40px;
  height: 2px;
  background: var(--accent);
  opacity: 0.5;
  margin: 0 auto 16px;
  border-radius: 2px;
}

.step-content strong {
  display: block;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.step-content p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.step-arrow {
  display: flex;
  align-items: center;
  align-self: flex-start;
  margin-top: 20px;
  font-size: 1.4rem;
  color: var(--accent);
  opacity: 0.5;
  flex: 0 0 auto;
  padding: 0 4px;
}

/* ─── ENGAGEMENT MODEL ────────────────────────────────────────────────────── */
.model {
  text-align: center;
}

.model-card {
  background: var(--bg-card);
  border: 1px solid rgba(99, 102, 241, 0.2);
  border-radius: 18px;
  padding: 48px 40px;
  max-width: 680px;
  margin: 48px auto 0;
  position: relative;
  overflow: hidden;
}

.model-card::after {
  content: '';
  position: absolute;
  top: -60px;
  right: -60px;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, rgba(99, 102, 241, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

.model-intro {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 36px;
}

.model-specs {
  border-top: 1px solid var(--border-divider);
  border-bottom: 1px solid var(--border-divider);
  padding: 12px 0;
  margin-bottom: 36px;
}

.model-spec-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--border-divider);
}

.model-spec-row:last-child {
  border-bottom: none;
}

.spec-label {
  font-size: 0.82rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.spec-value {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* ─── NETWORK ─────────────────────────────────────────────────────────────── */
.network {
  text-align: center;
}

.network-intro {
  max-width: 560px;
  margin: 0 auto 36px;
  font-size: 1rem;
  color: var(--text-secondary);
}

.network-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-top: 8px;
}

.pill {
  display: inline-block;
  padding: 10px 20px;
  border: 1px solid rgba(99, 102, 241, 0.35);
  border-radius: var(--radius-pill);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: rgba(99, 102, 241, 0.05);
  transition: var(--transition-base);
  cursor: default;
}

.pill:hover {
  border-color: var(--accent);
  color: var(--text-primary);
  background: rgba(99, 102, 241, 0.12);
  box-shadow: 0 0 12px rgba(99, 102, 241, 0.2);
}

/* ─── ABOUT + STATS ───────────────────────────────────────────────────────── */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-text h2 {
  text-align: left;
  margin-bottom: 20px;
}

.about-text p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.stats-block {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.stat-item {
  text-align: center;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-card);
  padding: 28px 16px;
}

.stat-number {
  display: block;
  font-size: 2.8rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 8px;
}

.stat-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

/* ─── CASE STUDIES ────────────────────────────────────────────────────────── */
.case-studies {
  text-align: center;
}

.cs-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--accent);
  margin-bottom: 16px;
}

.cs-eyebrow::before,
.cs-eyebrow::after {
  content: '';
  display: block;
  width: 24px;
  height: 1px;
  background: var(--accent);
  opacity: 0.5;
}

.cs-intro {
  max-width: 580px;
  margin: 0 auto 56px;
  color: var(--text-secondary);
  font-size: 1rem;
}

.cs-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  text-align: left;
}

.cs-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-card);
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  position: relative;
  overflow: hidden;
  transition: var(--transition-slow);
}

.cs-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: var(--transition-base);
}

.cs-card:hover {
  background: var(--bg-card-hover);
  border-color: rgba(99, 102, 241, 0.25);
  transform: translateY(-4px);
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.4), var(--accent-glow);
}

.cs-card:hover::before {
  opacity: 1;
}

.cs-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

.cs-category {
  display: inline-block;
  padding: 5px 12px;
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: var(--radius-pill);
  font-size: 0.68rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-hover);
}

.cs-location {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
}

.cs-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.4;
  margin-bottom: 0;
}

.cs-block {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.cs-block-label {
  display: inline-block;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
}

.cs-block p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin: 0;
}

.cs-block p strong {
  color: var(--text-primary);
  font-weight: 600;
}

.cs-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  padding: 20px 0;
  border-top: 1px solid var(--border-divider);
  border-bottom: 1px solid var(--border-divider);
  margin-top: auto;
}

.cs-metric {
  text-align: center;
}

.cs-metric-value {
  display: block;
  font-size: 1.45rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin-bottom: 6px;
}

.cs-metric-label {
  display: block;
  font-size: 0.68rem;
  color: var(--text-muted);
  font-weight: 500;
  line-height: 1.35;
}

.cs-impact {
  font-size: 0.88rem;
  color: var(--text-secondary);
  font-style: italic;
  line-height: 1.6;
  margin: 0;
}

/* ─── NOT FOR ─────────────────────────────────────────────────────────────── */
.not-for h2 {
  margin-bottom: 48px;
}

.notfor-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.notfor-card {
  background: rgba(249, 115, 22, 0.05);
  border: 1px solid var(--danger-border);
  border-left: 3px solid var(--danger);
  border-radius: var(--radius-card);
  padding: 24px 22px;
  transition: var(--transition-base);
}

.notfor-card:hover {
  background: rgba(249, 115, 22, 0.09);
  transform: translateY(-3px);
}

.notfor-card p {
  font-size: 0.93rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ─── CONTACT ─────────────────────────────────────────────────────────────── */
.contact {
  text-align: center;
  padding: 120px 20px;
}

.contact h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: 32px;
}

.contact-trust {
  margin-top: 20px;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-style: italic;
}

/* ─── FOOTER ──────────────────────────────────────────────────────────────── */
footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border-divider);
  padding: 0 8%;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 32px 0;
  border-bottom: 1px solid var(--border-divider);
}

.footer-nav {
  display: flex;
  gap: 28px;
}

.footer-nav a {
  font-size: 0.78rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  transition: var(--transition-base);
}

.footer-nav a:hover {
  color: var(--text-primary);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 0;
}

.footer-bottom span,
.footer-bottom a {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-bottom a:hover {
  color: var(--text-secondary);
}

.footer-legal {
  display: flex;
  align-items: center;
  gap: 10px;
}

.footer-dot {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-link-btn {
  background: none;
  border: none;
  padding: 0;
  font-size: 0.82rem;
  color: var(--text-muted);
  cursor: pointer;
  font-family: inherit;
  transition: var(--transition-base);
}

.footer-link-btn:hover {
  color: var(--text-secondary);
}

/* ─── COOKIE BANNER ───────────────────────────────────────────────────────── */
.cookie-banner {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-card);
  padding: 16px 24px;
  max-width: 640px;
  width: calc(100% - 48px);
  z-index: 200;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.5);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.cookie-banner.hidden {
  opacity: 0;
  transform: translateX(-50%) translateY(16px);
  pointer-events: none;
}

.cookie-banner p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.5;
  flex: 1;
}

.cookie-accept {
  flex-shrink: 0;
  background: var(--accent-gradient);
  color: #fff;
  border: none;
  border-radius: var(--radius-btn);
  padding: 8px 20px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-base);
  box-shadow: var(--accent-glow);
}

.cookie-accept:hover {
  opacity: 0.88;
}

/* ─── PRIVACY MODAL ───────────────────────────────────────────────────────── */
.privacy-modal {
  max-width: 640px;
  max-height: 80vh;
  overflow-y: auto;
}

.privacy-body {
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.privacy-body h3 {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 6px;
}

.privacy-body p {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin: 0;
}

.privacy-body a {
  color: var(--accent-hover);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ─── SECTION REVEAL ANIMATIONS ──────────────────────────────────────────── */
.section-reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.section-reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.problems-grid .problem-card,
.cards .card,
.notfor-grid .notfor-card,
.stats-block .stat-item,
.cs-grid .cs-card {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.is-visible .problems-grid .problem-card,
.is-visible .cards .card,
.is-visible .notfor-grid .notfor-card,
.is-visible .stats-block .stat-item,
.is-visible .cs-grid .cs-card {
  opacity: 1;
  transform: translateY(0);
}

.is-visible .problems-grid .problem-card:nth-child(1),
.is-visible .cards .card:nth-child(1),
.is-visible .notfor-grid .notfor-card:nth-child(1),
.is-visible .stats-block .stat-item:nth-child(1),
.is-visible .cs-grid .cs-card:nth-child(1) { transition-delay: 0.05s; }

.is-visible .problems-grid .problem-card:nth-child(2),
.is-visible .cards .card:nth-child(2),
.is-visible .notfor-grid .notfor-card:nth-child(2),
.is-visible .stats-block .stat-item:nth-child(2),
.is-visible .cs-grid .cs-card:nth-child(2) { transition-delay: 0.12s; }

.is-visible .problems-grid .problem-card:nth-child(3),
.is-visible .cards .card:nth-child(3),
.is-visible .notfor-grid .notfor-card:nth-child(3),
.is-visible .stats-block .stat-item:nth-child(3),
.is-visible .cs-grid .cs-card:nth-child(3) { transition-delay: 0.19s; }

.is-visible .problems-grid .problem-card:nth-child(4),
.is-visible .notfor-grid .notfor-card:nth-child(4),
.is-visible .cs-grid .cs-card:nth-child(4) { transition-delay: 0.26s; }

/* ─── RESPONSIVE: 1024px ──────────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .about-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about-text h2 {
    text-align: center;
  }
}

/* ─── RESPONSIVE: 768px ───────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    flex-direction: column;
    gap: 20px;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(8, 12, 20, 0.97);
    padding: 24px 8%;
    border-bottom: 1px solid var(--border-divider);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
  }

  .nav-links a {
    font-size: 0.9rem;
  }

  body.nav-open .nav-links {
    display: flex;
  }

  body.nav-open .nav-mobile-toggle span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
  }

  body.nav-open .nav-mobile-toggle span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
  }

  body.nav-open .nav-mobile-toggle span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
  }

  .nav-mobile-toggle {
    display: flex;
  }

  .navbar > .cta {
    display: none;
  }

  .steps {
    flex-direction: column;
    align-items: center;
  }

  .step {
    max-width: 100%;
    width: 100%;
  }

  .step-arrow {
    transform: rotate(90deg);
    margin: 4px 0;
  }

  .model-card {
    padding: 32px 24px;
  }

  .footer-top {
    flex-direction: column;
    gap: 20px;
    text-align: center;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 10px;
    text-align: center;
  }

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

/* ─── RESPONSIVE: 480px ───────────────────────────────────────────────────── */
@media (max-width: 480px) {
  :root {
    --section-padding: 72px 16px;
  }

  .navbar {
    padding: 0 5%;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .primary-btn,
  .secondary-btn {
    width: 100%;
    text-align: center;
  }

  .stats-block {
    grid-template-columns: 1fr;
    gap: 16px;
  }

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

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

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

  .cs-metrics {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .footer-nav {
    flex-direction: column;
    align-items: center;
    gap: 14px;
  }
}

/* ─── THEME TOGGLE BUTTON ─────────────────────────────────────────────────── */
.theme-toggle {
  background: none;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-btn);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  transition: var(--transition-base);
  flex-shrink: 0;
}

.theme-toggle:hover {
  color: var(--text-primary);
  border-color: var(--accent);
}

.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }

body.light .theme-toggle .icon-sun { display: block; }
body.light .theme-toggle .icon-moon { display: none; }

/* ─── LIGHT MODE ──────────────────────────────────────────────────────────── */
body.light {
  --bg-body:         #f8fafc;
  --bg-surface:      #f1f5f9;
  --bg-card:         #ffffff;
  --bg-card-hover:   #f8fafc;

  --border-card:     rgba(0, 0, 0, 0.08);
  --border-divider:  rgba(0, 0, 0, 0.07);
  --border-subtle:   rgba(0, 0, 0, 0.15);

  --text-primary:    #0f172a;
  --text-secondary:  #475569;
  --text-muted:      #94a3b8;

  --accent-glow:     0 0 24px rgba(99, 102, 241, 0.15);
  --accent-glow-lg:  0 0 48px rgba(99, 102, 241, 0.12);
}

body.light .navbar {
  background: rgba(248, 250, 252, 0.88);
}

body.light .nav-links {
  background: rgba(248, 250, 252, 0.97);
}

body.light .nav-mobile-toggle span {
  background: var(--text-primary);
}

body.light .hero {
  background:
    radial-gradient(ellipse 80% 60% at 50% 0%, rgba(99, 102, 241, 0.07) 0%, transparent 70%),
    var(--bg-body);
}

body.light footer {
  background: var(--bg-surface);
}

body.light .card {
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
}

body.light .card:hover {
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1), var(--accent-glow);
}

body.light .notfor-card {
  background: rgba(249, 115, 22, 0.04);
}

body.light .model-card {
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.06);
}

/* ─── BOOKING MODAL ───────────────────────────────────────────────────────── */
.booking-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.72);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.booking-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.booking-modal {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 18px;
  padding: 40px;
  width: 100%;
  max-width: 560px;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
  transform: translateY(24px);
  transition: transform 0.3s ease;
}

.booking-overlay.is-open .booking-modal {
  transform: translateY(0);
}

.booking-close {
  position: absolute;
  top: 14px;
  right: 16px;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  padding: 4px 8px;
  transition: color 0.2s;
}

.booking-close:hover {
  color: var(--text-primary);
}

.booking-modal > h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
  padding-right: 32px;
}

.booking-sub {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 28px !important;
}

.booking-form {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-muted);
}

.form-group label span {
  text-transform: none;
  font-weight: 400;
  letter-spacing: 0;
  opacity: 0.7;
}

.form-group input,
.form-group select,
.form-group textarea {
  background: var(--bg-body);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-btn);
  color: var(--text-primary);
  font-family: 'Inter', sans-serif;
  font-size: 0.9rem;
  padding: 10px 14px;
  transition: border-color 0.2s;
  outline: none;
  width: 100%;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--accent);
}

.form-group select {
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
  cursor: pointer;
}

.form-group textarea {
  resize: vertical;
  min-height: 88px;
}

.form-group input[type="date"],
.form-group input[type="time"] {
  color-scheme: dark;
}

body.light .form-group input[type="date"],
body.light .form-group input[type="time"] {
  color-scheme: light;
}

.booking-submit {
  width: 100%;
  text-align: center;
  padding: 14px;
  font-size: 0.95rem;
  cursor: pointer;
  border: none;
  margin-top: 4px;
}

.booking-submit:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none !important;
}

.booking-error {
  color: var(--danger);
  font-size: 0.85rem;
  text-align: center;
  min-height: 20px;
}

.booking-success {
  display: none;
  text-align: center;
  padding: 32px 20px;
}

.success-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: rgba(99, 102, 241, 0.12);
  color: var(--accent);
  font-size: 1.6rem;
  margin-bottom: 18px;
}

.booking-success h3 {
  font-size: 1.25rem;
  margin-bottom: 10px;
}

.booking-success p {
  font-size: 0.92rem;
  color: var(--text-secondary);
}

@media (max-width: 480px) {
  .booking-modal {
    padding: 28px 20px;
  }

  .form-row {
    grid-template-columns: 1fr;
  }
}