/* Base
   ============================================ */
:root {
  --bg: #0A0A0B;
  --surface: #111113;
  --surface2: #1A1A1D;
  --border: #2A2A2E;
  --text: #FAFAF9;
  --text-muted: #A1A1AA;
  --accent: #7C3AED;
  --accent-bright: #8B5CF6;
  --accent-dim: rgba(124, 58, 237, 0.15);
  --green: #22C55E;
  --amber: #F59E0B;
  --font-display: 'Syne', sans-serif;
  --font-body: 'Figtree', sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Navigation
   ============================================ */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 48px;
  border-bottom: 1px solid var(--border);
}

.nav-brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  color: var(--text);
}

.nav-tagline {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 500;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.nav-cta {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-bright);
  border: 1px solid var(--accent);
  padding: 8px 18px;
  border-radius: 8px;
  text-decoration: none;
  transition: all 0.15s;
  background: var(--accent-dim);
}

.nav-cta:hover {
  background: var(--accent);
  color: #fff;
}

/* Hero
   ============================================ */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
  padding: 80px 48px 100px;
  border-bottom: 1px solid var(--border);
}

.hero-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-bright);
  border: 1px solid var(--accent);
  padding: 4px 12px;
  border-radius: 20px;
  margin-bottom: 24px;
}

.hero-headline {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 4vw, 3.4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 24px;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 460px;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  align-items: center;
  gap: 32px;
}

.stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.stat-number {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 800;
  color: var(--text);
  line-height: 1;
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border);
}

/* Agent Window
   ============================================ */
.hero-visual {
  display: flex;
  justify-content: flex-end;
}

.agent-window {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  width: 100%;
  max-width: 420px;
  overflow: hidden;
  box-shadow: 0 32px 64px rgba(0,0,0,0.4);
}

.agent-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 20px;
  background: var(--surface2);
  border-bottom: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}

.agent-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--text-muted);
}

.agent-dot.active {
  background: var(--green);
  box-shadow: 0 0 6px var(--green);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.agent-body {
  padding: 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.agent-line {
  display: grid;
  grid-template-columns: 44px 60px 1fr;
  align-items: center;
  gap: 10px;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.agent-line.highlight {
  color: var(--text);
}

.agent-ts {
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
}

.agent-tag {
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 2px 8px;
  border-radius: 4px;
}

.agent-tag.research { background: rgba(59,130,246,0.15); color: #60A5FA; }
.agent-tag.write   { background: rgba(168,85,247,0.15); color: #A78BFA; }
.agent-tag.send    { background: rgba(34,197,94,0.15);  color: #4ADE80; }

/* How It Works
   ============================================ */
.howitworks {
  padding: 80px 48px;
  border-bottom: 1px solid var(--border);
}

.section-header {
  margin-bottom: 56px;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-bright);
  margin-bottom: 12px;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.steps {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: start;
  gap: 0;
}

.step {
  padding: 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
}

.step-number {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--accent);
  margin-bottom: 16px;
  line-height: 1;
}

.step-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.step-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.step-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 24px;
  padding-top: 48px;
}

.step-arrow::before {
  content: '';
  display: block;
  width: 32px;
  height: 2px;
  background: var(--border);
  position: relative;
}

/* Features
   ============================================ */
.features {
  padding: 80px 48px;
  border-bottom: 1px solid var(--border);
}

.features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.feature-card {
  padding: 36px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
}

.feature-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--accent-dim);
  border: 1px solid var(--accent);
  margin-bottom: 20px;
}

.feature-card h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Differentiation band
   ============================================ */
.differentiation {
  padding: 80px 48px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.diff-headline {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 24px;
}

.diff-sub {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 540px;
  margin-bottom: 48px;
  line-height: 1.7;
}

.diff-contrast {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  max-width: 700px;
}

.contrast-item {
  padding: 24px;
  border-radius: 12px;
  border: 1px solid var(--border);
}

.contrast-item.wrong {
  background: rgba(239,68,68,0.05);
  border-color: rgba(239,68,68,0.2);
}

.contrast-item.right {
  background: rgba(34,197,94,0.05);
  border-color: rgba(34,197,94,0.2);
}

.contrast-label {
  display: block;
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}

.wrong .contrast-label { color: #F87171; }
.right .contrast-label { color: #4ADE80; }

.contrast-item span:last-child {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Closing
   ============================================ */
.closing {
  padding: 100px 48px;
  border-bottom: 1px solid var(--border);
}

.closing-inner {
  max-width: 680px;
}

.closing-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-bright);
  margin-bottom: 20px;
}

.closing-headline {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 24px;
}

.closing-sub {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 520px;
}

/* Footer
   ============================================ */
.footer {
  padding: 40px 48px;
  display: flex;
  align-items: center;
  gap: 24px;
}

.footer-brand {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1rem;
  letter-spacing: -0.02em;
}

.footer-note {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Responsive
   ============================================ */
@media (max-width: 768px) {
  .nav { padding: 20px 24px; }
  .hero { grid-template-columns: 1fr; padding: 48px 24px; gap: 48px; }
  .hero-visual { justify-content: flex-start; }
  .agent-window { max-width: 100%; }
  .steps { grid-template-columns: 1fr; gap: 16px; }
  .step-arrow { display: none; }
  .features-grid { grid-template-columns: 1fr; }
  .diff-contrast { grid-template-columns: 1fr; }
  .howitworks, .features, .differentiation, .closing { padding: 60px 24px; }
  .footer { flex-direction: column; align-items: flex-start; padding: 32px 24px; }
  .hero-stats { flex-wrap: wrap; gap: 24px; }
}