/* ============ reset ============ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

/* ============ tokens ============ */
:root {
  --bg-0: #070708;
  --bg-1: #0d0d10;
  --bg-2: #14141a;
  --line: rgba(255,255,255,0.08);
  --line-strong: rgba(255,255,255,0.14);
  --text: #e8e8ee;
  --text-dim: #8a8a95;
  --text-dim-2: #5a5a66;
  --accent: #7cff6b;
  --accent-2: #00e0ff;
  --accent-3: #b48cff;
  --warn: #f5c56f;
  --green: #7cff6b;
  --yellow: #f5c56f;
  --gray: #5a5a66;
  --font-sans: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-0);
  color: var(--text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ============ bg effects ============ */
.noise {
  position: fixed; inset: 0;
  pointer-events: none;
  opacity: 0.035;
  z-index: 1;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.grid-bg {
  position: fixed; inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse at 50% 0%, black 30%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at 50% 0%, black 30%, transparent 70%);
  opacity: 0.6;
}

main { position: relative; z-index: 2; }

/* ============ nav ============ */
.nav {
  position: sticky; top: 0; z-index: 100;
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  background: rgba(7, 7, 8, 0.65);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 1280px; margin: 0 auto;
  padding: 18px 32px;
  display: flex; justify-content: space-between; align-items: center;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  color: var(--text); text-decoration: none;
  font-weight: 700; font-size: 18px;
  font-family: var(--font-mono);
}
.brand-dot {
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 12px var(--accent);
  animation: pulse 2s infinite;
}
.brand-accent { color: var(--accent); }
.nav nav { display: flex; gap: 28px; }
.nav nav a {
  color: var(--text-dim);
  text-decoration: none;
  font-size: 14px;
  font-family: var(--font-mono);
  transition: color .2s;
}
.nav nav a:hover { color: var(--text); }

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}

/* ============ hero ============ */
.hero {
  min-height: calc(100vh - 70px);
  display: flex; align-items: center; justify-content: center;
  padding: 80px 32px;
  position: relative;
}
.hero-inner { max-width: 1000px; text-align: center; }

.hero-tag {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 8px 16px;
  border: 1px solid var(--line-strong);
  border-radius: 100px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
  margin-bottom: 40px;
  background: rgba(255,255,255,0.02);
}
.dot-live {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
  animation: pulse 1.5s infinite;
}

.hero h1 {
  font-size: clamp(40px, 6.5vw, 84px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 32px;
}

.gradient-text {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 50%, var(--accent-3) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  background-size: 200% auto;
  animation: shimmer 6s linear infinite;
}
@keyframes shimmer {
  to { background-position: 200% center; }
}

.hero-sub {
  font-size: clamp(16px, 1.4vw, 19px);
  color: var(--text-dim);
  max-width: 720px;
  margin: 0 auto 48px;
  line-height: 1.7;
}

.hero-cta { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.btn {
  padding: 14px 28px;
  border-radius: 100px;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: all .2s;
  display: inline-flex; align-items: center; gap: 8px;
  cursor: pointer;
  border: 1px solid transparent;
}
.btn-primary {
  background: var(--accent);
  color: var(--bg-0);
  box-shadow: 0 0 0 0 var(--accent);
}
.btn-primary:hover {
  box-shadow: 0 0 24px rgba(124,255,107,0.45);
  transform: translateY(-2px);
}
.btn-ghost {
  color: var(--text);
  border-color: var(--line-strong);
}
.btn-ghost:hover {
  border-color: var(--text);
  background: rgba(255,255,255,0.03);
}

.scroll-hint {
  position: absolute;
  bottom: 32px; left: 50%; transform: translateX(-50%);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim-2);
  animation: bob 2s ease-in-out infinite;
}
@keyframes bob {
  0%, 100% { transform: translate(-50%, 0); }
  50% { transform: translate(-50%, 8px); }
}

/* ============ stats ============ */
.stats {
  max-width: 1280px;
  margin: 40px auto;
  padding: 48px 32px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}
.stat { text-align: center; }
.stat-num {
  font-family: var(--font-mono);
  font-size: clamp(40px, 4vw, 64px);
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  letter-spacing: -0.02em;
}
.stat-label {
  margin-top: 12px;
  font-size: 13px;
  color: var(--text-dim);
  font-family: var(--font-mono);
}
@media (max-width: 720px) {
  .stats { grid-template-columns: repeat(2, 1fr); }
}

/* ============ sections ============ */
.section {
  max-width: 1280px;
  margin: 0 auto;
  padding: 120px 32px;
}
.section-head { margin-bottom: 64px; max-width: 800px; }
.section-kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 12px;
  display: block;
}
.section h2 {
  font-size: clamp(32px, 3.5vw, 48px);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 16px;
}
.section-sub {
  color: var(--text-dim);
  font-size: 16px;
  line-height: 1.7;
}

/* ============ timeline ============ */
.timeline {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 24px;
}

.card {
  background: var(--bg-1);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 28px;
  position: relative;
  transition: all .25s;
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 3px; height: 100%;
  background: var(--gray);
  transition: width .25s;
}
.card-green::before { background: var(--green); }
.card-yellow::before { background: var(--yellow); }
.card-gray::before { background: var(--gray); }
.card:hover {
  border-color: var(--line-strong);
  transform: translateY(-4px);
}
.card:hover::before { width: 6px; }

.card-head {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: 16px;
}
.chip {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 5px 10px;
  border-radius: 100px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--line);
  color: var(--text-dim);
}
.card-green .chip { color: var(--green); border-color: rgba(124,255,107,0.25); }
.card-yellow .chip { color: var(--yellow); border-color: rgba(245,197,111,0.25); }
.card-gray .chip { color: var(--text-dim-2); }

.card-date {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim-2);
}
.card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
  line-height: 1.35;
}
.card p {
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 18px;
}
.card-tags {
  display: flex; flex-wrap: wrap; gap: 6px;
}
.card-tags span {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 3px 10px;
  background: var(--bg-2);
  border-radius: 100px;
  color: var(--text-dim);
}

/* ============ lessons ============ */
.lessons {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 20px;
}
.lesson {
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: linear-gradient(180deg, var(--bg-1) 0%, var(--bg-0) 100%);
  position: relative;
  transition: all .25s;
}
.lesson:hover {
  border-color: rgba(124,255,107,0.3);
  box-shadow: 0 0 0 1px rgba(124,255,107,0.08), 0 12px 40px rgba(0,0,0,0.3);
}
.lesson-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 16px;
  opacity: 0.7;
}
.lesson h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}
.lesson p {
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.65;
}

/* ============ stack ============ */
.section-stack { padding-bottom: 80px; }
.stack-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 16px;
}
.stack-item {
  display: flex; align-items: center; gap: 16px;
  padding: 20px 24px;
  background: var(--bg-1);
  border: 1px solid var(--line);
  border-radius: 12px;
  transition: all .2s;
}
.stack-item:hover {
  border-color: var(--line-strong);
  background: var(--bg-2);
}
.stack-icon {
  width: 44px; height: 44px;
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
  background: var(--bg-2);
  border-radius: 10px;
  flex-shrink: 0;
}
.stack-item strong {
  display: block;
  font-size: 15px;
  margin-bottom: 2px;
}
.stack-item span {
  display: block;
  font-size: 13px;
  color: var(--text-dim);
}

/* ============ footer ============ */
footer {
  border-top: 1px solid var(--line);
  padding: 60px 32px;
  margin-top: 80px;
  position: relative; z-index: 2;
}
.footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 32px;
  flex-wrap: wrap;
}
.footer-brand {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}
footer p {
  color: var(--text-dim);
  font-size: 14px;
  max-width: 400px;
}
.footer-meta { text-align: right; font-family: var(--font-mono); font-size: 13px; }
.footer-meta p { margin-bottom: 6px; }
.footer-meta code {
  color: var(--accent);
  background: var(--bg-2);
  padding: 3px 8px;
  border-radius: 6px;
  font-size: 12px;
}

@media (max-width: 720px) {
  .nav-inner { padding: 16px 20px; }
  .nav nav { gap: 16px; }
  .section { padding: 80px 20px; }
  .hero { padding: 60px 20px; }
  .stats { padding: 32px 20px; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
  .footer-meta { text-align: left; }
}

/* ============ scroll reveal ============ */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .6s, transform .6s;
}
.reveal.in {
  opacity: 1;
  transform: translateY(0);
}