/* ── Theme: ProofLayer — scholarly dark, amber accents ── */

:root {
  --bg-deep:      #0c1318;
  --bg-surface:   #111c24;
  --bg-card:      #162030;
  --border:       #1e3040;
  --text-primary: #e8e6df;
  --text-muted:   #7a8fa6;
  --text-dim:     #3d5a70;
  --accent:       #f5c842;
  --accent-dim:   rgba(245,200,66,0.12);
  --accent-glow:  rgba(245,200,66,0.06);
  --blue-mid:     #7a9abf;
  --blue-dim:     #4a6a8a;
}

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

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

body {
  background: var(--bg-deep);
  color: var(--text-primary);
  font-family: 'IBM Plex Sans', system-ui, sans-serif;
  font-weight: 300;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ── Navbar ── */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(12, 19, 24, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
}
.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 1.1rem;
}
.logo-bracket { color: var(--accent); font-weight: 300; }
.logo-text { color: var(--text-primary); font-weight: 500; margin: 0 1px; }
.nav-links { display: flex; align-items: center; gap: 1.5rem; }
.nav-status {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.75rem;
  color: var(--accent);
  background: var(--accent-dim);
  border: 1px solid rgba(245,200,66,0.2);
  border-radius: 20px;
  padding: 0.2rem 0.7rem;
}
.status-dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: pulse-dot 2s ease-in-out infinite;
}
@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

/* ── Hero ── */
.hero {
  min-height: calc(100vh - 56px);
  display: flex;
  align-items: center;
  padding: 6rem 2rem 4rem;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background:
    radial-gradient(ellipse 60% 50% at 20% 40%, rgba(245,200,66,0.04) 0%, transparent 70%),
    radial-gradient(ellipse 40% 60% at 80% 70%, rgba(122,154,191,0.05) 0%, transparent 60%);
  pointer-events: none;
}
.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
  width: 100%;
  position: relative;
}
.hero-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.75rem;
  color: var(--blue-mid);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
}
.hero-headline {
  font-family: 'IBM Plex Mono', monospace;
  font-size: clamp(3.5rem, 8vw, 7rem);
  font-weight: 300;
  line-height: 1.05;
  color: var(--text-primary);
  margin-bottom: 2rem;
  letter-spacing: -0.02em;
}
.hero-headline em {
  font-style: italic;
  color: var(--accent);
}
.hero-sub {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 520px;
  line-height: 1.7;
  margin-bottom: 3rem;
}
.hero-dag {
  margin: 2rem 0 0.5rem;
}
.dag-svg {
  width: 100%;
  max-width: 560px;
  height: auto;
}
.hero-caption {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.05em;
}

/* ── Proof Structure ── */
.proof-structure {
  padding: 6rem 2rem;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.proof-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.proof-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.75rem;
  color: var(--accent);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
}
.proof-headline {
  font-family: 'IBM Plex Mono', monospace;
  font-size: clamp(1.8rem, 4vw, 3.2rem);
  font-weight: 300;
  color: var(--text-primary);
  line-height: 1.2;
  margin-bottom: 1.5rem;
}
.proof-body {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 560px;
  line-height: 1.75;
  margin-bottom: 3rem;
}
.proof-diagram {
  position: relative;
}
.pd-row {
  display: flex;
  align-items: center;
  gap: 0;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.pd-node {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.75rem 1rem;
  text-align: center;
  min-width: 110px;
}
.pd-node-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}
.pd-node-sub {
  font-size: 0.72rem;
  color: var(--text-dim);
}
.pd-theorem { border-color: rgba(245,200,66,0.3); }
.pd-proof { border-color: var(--blue-mid); }
.pd-verified { border-color: rgba(245,200,66,0.3); background: var(--accent-glow); }
.pd-forked { border-color: var(--accent); background: var(--accent-dim); }
.pd-arrow {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 1.2rem;
  color: var(--text-dim);
  flex-shrink: 0;
}

/* ── Features ── */
.features {
  padding: 6rem 2rem;
  background: var(--bg-deep);
}
.features-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5px;
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}
.feature-card {
  background: var(--bg-surface);
  padding: 2rem;
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  transition: background 0.2s ease;
}
.feature-card:hover {
  background: var(--bg-card);
}
.feature-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-dim);
  border: 1px solid rgba(245,200,66,0.15);
  border-radius: 8px;
  margin-bottom: 1.2rem;
}
.feature-title {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 0.6rem;
}
.feature-desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ── Vision ── */
.vision {
  padding: 6rem 2rem;
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.vision-inner {
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}
.vision-label {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.75rem;
  color: var(--blue-mid);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 2.5rem;
}
.vision-quote {
  font-family: 'IBM Plex Mono', monospace;
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 300;
  font-style: italic;
  color: var(--text-primary);
  line-height: 1.6;
  margin-bottom: 1.5rem;
  position: relative;
  padding: 0 2rem;
}
.vision-quote::before {
  content: '\201C';
  position: absolute;
  left: 0;
  top: -0.3rem;
  font-size: 3rem;
  color: var(--accent);
  opacity: 0.3;
  font-family: Georgia, serif;
}
.vision-sub {
  font-size: 1rem;
  color: var(--text-muted);
  margin-bottom: 3rem;
  line-height: 1.7;
}
.vision-badges {
  display: flex;
  justify-content: center;
  gap: 3rem;
  flex-wrap: wrap;
}
.v-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.3rem;
}
.v-badge-num {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 2rem;
  font-weight: 300;
  color: var(--accent);
}
.v-badge-text {
  font-size: 0.8rem;
  color: var(--text-dim);
  text-align: center;
  max-width: 120px;
}

/* ── Closing ── */
.closing {
  padding: 6rem 2rem 8rem;
  background: var(--bg-deep);
}
.closing-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.closing-headline {
  font-family: 'IBM Plex Mono', monospace;
  font-size: clamp(1.5rem, 3.5vw, 2.8rem);
  font-weight: 300;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 1.5rem;
}
.closing-body {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 500px;
  line-height: 1.75;
  margin-bottom: 3rem;
}
.closing-pulse {
  display: flex;
  align-items: center;
  gap: 1rem;
  position: relative;
  display: inline-flex;
  align-items: center;
}
.pulse-ring {
  width: 16px; height: 16px;
  border-radius: 50%;
  border: 1.5px solid var(--accent);
  position: absolute;
  left: 0;
  animation: ring-expand 2s ease-out infinite;
}
@keyframes ring-expand {
  0% { transform: scale(1); opacity: 0.8; }
  100% { transform: scale(2.5); opacity: 0; }
}
.pulse-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--accent);
  position: relative;
  z-index: 1;
}
.pulse-text {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.85rem;
  color: var(--accent);
  padding-left: 2rem;
}

/* ── Footer ── */
.footer {
  padding: 2rem;
  border-top: 1px solid var(--border);
  background: var(--bg-surface);
}
.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-logo {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.9rem;
  color: var(--text-primary);
}
.footer-tagline {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-left: 0.75rem;
}
.footer-meta {
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.72rem;
  color: var(--text-dim);
}

/* ── Responsive ── */
@media (max-width: 600px) {
  .hero { padding: 4rem 1.25rem 3rem; }
  .features-grid { grid-template-columns: 1fr; }
  .proof-diagram .pd-row { flex-direction: column; align-items: flex-start; }
  .pd-arrow { display: none; }
  .vision-badges { gap: 1.5rem; }
  .footer-inner { flex-direction: column; }
}