:root {
  --bg: #07070d;
  --bg-alt: #0c0c17;
  --surface: #12121f;
  --surface-2: #171728;
  --border: rgba(255, 255, 255, 0.08);
  --text: #eef0fb;
  --text-dim: #9a9db3;
  --accent: #8b7bff;
  --accent-2: #4fd6ff;
  --accent-gradient: linear-gradient(135deg, #8b7bff 0%, #4fd6ff 100%);
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
  --radius: 20px;
  --font-body: 'Manrope', system-ui, sans-serif;
  --font-heading: 'Sora', system-ui, sans-serif;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.65;
  overflow-x: hidden;
}

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

.container {
  width: 100%;
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

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

h1, h2, h3 {
  font-family: var(--font-heading);
  line-height: 1.2;
  margin: 0 0 16px;
}

p { color: var(--text-dim); margin: 0 0 16px; }

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

/* Progress bar */
.progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 3px;
  width: 0%;
  background: var(--accent-gradient);
  z-index: 999;
  transition: width 0.1s ease-out;
}

/* Background glows */
.bg-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.35;
  z-index: 0;
  pointer-events: none;
}
.bg-glow-1 {
  width: 500px; height: 500px;
  background: #6a5cff;
  top: -150px; left: -100px;
}
.bg-glow-2 {
  width: 600px; height: 600px;
  background: #2fb9ff;
  bottom: 10%; right: -200px;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(14px);
  background: rgba(7, 7, 13, 0.7);
  border-bottom: 1px solid var(--border);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.15rem;
}
.logo__icon {
  font-size: 1.4rem;
}

.nav {
  display: flex;
  gap: 32px;
}
.nav a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-dim);
  transition: color 0.2s;
  position: relative;
}
.nav a:hover { color: var(--text); }

.burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.burger span {
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: 0.25s;
}

/* Hero */
.hero {
  position: relative;
  padding: 90px 0 60px;
  overflow: hidden;
}
.hero__inner {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 48px;
  align-items: center;
}

.badge {
  display: inline-block;
  padding: 7px 16px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--accent-2);
  margin-bottom: 22px;
}

.hero h1 {
  font-size: clamp(2.1rem, 4.4vw, 3.2rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.hero__lead {
  font-size: 1.08rem;
  max-width: 540px;
}

.hero__actions {
  display: flex;
  gap: 14px;
  margin: 28px 0 40px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 28px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
  border: 1px solid transparent;
  cursor: pointer;
}
.btn--primary {
  background: var(--accent-gradient);
  color: #07070d;
  box-shadow: 0 10px 30px rgba(139, 123, 255, 0.35);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 14px 36px rgba(139, 123, 255, 0.5); }
.btn--ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}
.btn--ghost:hover { border-color: var(--accent); color: var(--accent-2); }

.hero__stats {
  display: flex;
  gap: 36px;
  flex-wrap: wrap;
}
.stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.stat strong {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat span {
  font-size: 0.82rem;
  color: var(--text-dim);
}

.hero__media {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}
.hero__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  aspect-ratio: 4/3;
}
.hero__media-glow {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 60%, rgba(7,7,13,0.6) 100%);
}

.scroll-hint {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  margin: 60px auto 0;
  width: fit-content;
  color: var(--text-dim);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}
.scroll-hint__line {
  width: 1px;
  height: 40px;
  background: linear-gradient(180deg, var(--accent), transparent);
  animation: scrollPulse 1.8s ease-in-out infinite;
}
@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 1; }
}

/* TOC */
.toc {
  position: relative;
  z-index: 1;
  padding: 30px 0;
  margin: 30px auto 0;
}
.toc__label {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.78rem;
  color: var(--accent-2);
  font-weight: 700;
  margin-bottom: 18px;
}
.toc__list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px 40px;
  list-style: none;
  padding: 0;
  margin: 0;
  border-top: 1px solid var(--border);
  padding-top: 20px;
}
.toc__list a {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text);
  transition: color 0.2s;
  display: inline-block;
}
.toc__list a:hover { color: var(--accent-2); }

/* Sections */
.section {
  position: relative;
  z-index: 1;
  padding: 90px 0;
}
.section--alt {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section__header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 44px;
}
.section__header h2 { margin: 0; }

.section__number {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--accent);
  border: 1px solid var(--border);
  padding: 6px 14px;
  border-radius: 999px;
  width: fit-content;
  height: fit-content;
}

.section__grid {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 20px;
}
.section__grid--reverse .section__content { max-width: 720px; }

.section__content h2 {
  font-size: clamp(1.7rem, 3vw, 2.3rem);
}
.section__content p {
  font-size: 1.02rem;
  max-width: 720px;
}

.quote {
  border-left: 3px solid var(--accent);
  padding: 6px 0 6px 24px;
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-style: italic;
  color: var(--text);
  margin-top: 28px;
  max-width: 640px;
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: 30px;
  border-left: 2px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 40px;
}
.timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 24px;
  align-items: start;
}
.timeline__item::before {
  content: '';
  position: absolute;
  left: -36.5px;
  top: 4px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--accent-gradient);
  box-shadow: 0 0 0 4px rgba(139, 123, 255, 0.15);
}
.timeline__year {
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--accent-2);
  font-size: 1.05rem;
}
.timeline__content h3 { margin-bottom: 6px; font-size: 1.1rem; }
.timeline__content p { margin: 0; font-size: 0.95rem; }

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 32px;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 26px;
  transition: transform 0.25s ease, border-color 0.25s ease;
}
.card:hover {
  transform: translateY(-6px);
  border-color: var(--accent);
}
.card__icon { font-size: 1.8rem; margin-bottom: 14px; }
.card h3 { font-size: 1.05rem; margin-bottom: 8px; }
.card p { font-size: 0.92rem; margin: 0; }

/* Tiles (types of AI) */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.tile {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  position: relative;
  overflow: hidden;
}
.tile::after {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--accent-gradient);
  opacity: 0;
  transition: opacity 0.3s;
  z-index: -1;
}
.tile__badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 5px 12px;
  border-radius: 999px;
  background: rgba(79, 214, 255, 0.12);
  color: var(--accent-2);
  margin-bottom: 16px;
}
.tile__badge--soon {
  background: rgba(255, 190, 90, 0.12);
  color: #ffbe5a;
}
.tile__badge--future {
  background: rgba(255, 100, 130, 0.12);
  color: #ff88a3;
}
.tile h3 { font-size: 1.15rem; margin-bottom: 10px; }
.tile p { font-size: 0.92rem; margin: 0; }

/* Feature grid */
.grid-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feature {
  padding: 24px 0;
  border-top: 1px solid var(--border);
}
.feature__icon {
  font-size: 1.6rem;
  margin-bottom: 12px;
}
.feature h3 { font-size: 1.05rem; margin-bottom: 8px; }
.feature p { font-size: 0.92rem; margin: 0; }

/* Checklist */
.checklist {
  list-style: none;
  padding: 0;
  margin: 24px 0 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 560px;
}
.checklist li {
  position: relative;
  padding-left: 30px;
  font-size: 0.98rem;
  color: var(--text);
}
.checklist li::before {
  content: '✓';
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent-2);
  font-weight: 700;
}

/* CTA section */
.section--cta {
  text-align: center;
  background: radial-gradient(ellipse at center, rgba(139,123,255,0.12), transparent 70%);
}
.section--cta .section__number { margin: 0 auto 20px; }
.section--cta h2 { font-size: clamp(1.8rem, 3.4vw, 2.6rem); }
.cta__lead {
  max-width: 700px;
  margin: 0 auto 30px;
  font-size: 1.05rem;
}
.cta__box {
  max-width: 600px;
  margin: 0 auto;
  padding: 24px 30px;
  border-radius: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
}
.cta__box p { margin: 0; color: var(--text); font-weight: 600; }

/* Footer */
.footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
}
.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}
.footer p { margin: 0; font-size: 0.85rem; }
.back-to-top {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent-2);
  transition: opacity 0.2s;
}
.back-to-top:hover { opacity: 0.7; }

/* Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 900px) {
  .hero__inner { grid-template-columns: 1fr; }
  .hero__media { order: -1; }
  .toc__list { grid-template-columns: 1fr; }
  .section__grid { grid-template-columns: 1fr; }
  .section__number { margin-bottom: 4px; }
  .cards, .grid-3, .grid-features { grid-template-columns: 1fr; }
  .timeline__item { grid-template-columns: 90px 1fr; }
}

@media (max-width: 720px) {
  .nav { 
    position: fixed;
    top: 76px; left: 0; right: 0;
    flex-direction: column;
    background: rgba(7,7,13,0.97);
    padding: 20px 24px 30px;
    gap: 18px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-130%);
    transition: transform 0.3s ease;
  }
  .nav.is-open { transform: translateY(0); }
  .burger { display: flex; }
  .footer__inner { flex-direction: column; text-align: center; }
}