/* ═══════════════════════════════════════════════════════════
   Epistemea — Landing Page Styles
   Aurora theme: dark backgrounds, cyan/blue/purple accents
   ═══════════════════════════════════════════════════════════ */

/* ── Reset & Tokens ────────────────────────────────────── */
:root {
  --bg-0: #050B10;
  --bg-1: #07131A;
  --surface-0: #0A1D24;
  --surface-1: #0D2630;
  --surface-2: #103543;
  --border: rgba(120, 255, 245, 0.10);
  --border-strong: rgba(120, 255, 245, 0.20);
  --text-0: #EAF2F2;
  --text-1: rgba(234, 242, 242, 0.72);
  --text-2: rgba(234, 242, 242, 0.48);
  --accent-0: #2AFADF;
  --accent-1: #26C6FF;
  --accent-2: #7C3AED;
  --danger: #FB7185;
  --success: #34D399;
  --font: "Space Grotesk", "SF Pro Display", "Helvetica Neue", system-ui, -apple-system, sans-serif;
  --max-w: 1120px;
  --max-w-narrow: 720px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font);
  background: var(--bg-0);
  color: var(--text-1);
  line-height: 1.6;
  letter-spacing: -0.005em;
  font-weight: 400;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

/* ── Utility ───────────────────────────────────────────── */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 1.5rem; }
.narrow    { max-width: var(--max-w-narrow); }
.center    { text-align: center; }

.gradient-text {
  background: linear-gradient(90deg, var(--accent-0), var(--accent-1), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.lead {
  font-size: 1.125rem;
  color: var(--text-1);
  line-height: 1.7;
}

/* ── Nav ───────────────────────────────────────────────── */
#nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(5, 11, 16, 0.75);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s;
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 3.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
}

.nav-logo { height: 1.75rem; width: 1.75rem; object-fit: contain; }
.nav-wordmark { height: 1.25rem; width: auto; object-fit: contain; }

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-1);
  transition: color 0.2s;
  letter-spacing: 0.01em;
}
.nav-links a:hover { color: var(--accent-0); }

/* ── Hero ──────────────────────────────────────────────── */
#hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

#network-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.35;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 45%, transparent 0%, var(--bg-0) 100%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 700px;
  padding: 2rem 1.5rem;
}

.hero-tag {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent-0);
  margin-bottom: 1.25rem;
}

#hero h1 {
  font-size: clamp(2.25rem, 5.5vw, 3.75rem);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
  color: var(--text-0);
}

.hero-sub {
  font-size: 1.125rem;
  color: var(--text-1);
  line-height: 1.7;
  max-width: 560px;
  margin: 0 auto 2.5rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 0.75rem;
  background: linear-gradient(90deg, var(--accent-0), var(--accent-1));
  color: var(--bg-0);
  transition: opacity 0.2s, transform 0.15s;
  box-shadow: 0 0 0 1px rgba(38,198,255,0.25), 0 0 22px rgba(38,198,255,0.18);
}
.btn-primary:hover { opacity: 0.92; transform: translateY(-1px); }
.btn-primary:active { transform: scale(0.98); }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 0.75rem;
  border: 1px solid var(--border-strong);
  color: var(--text-0);
  transition: background 0.2s, border-color 0.2s, transform 0.15s;
}
.btn-ghost:hover { background: var(--surface-0); border-color: var(--accent-1); }
.btn-ghost:active { transform: scale(0.98); }

/* ── Sections ──────────────────────────────────────────── */
.section {
  padding: 6rem 0;
}

.section-alt {
  background: var(--bg-1);
}

.section-tag {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-0);
  margin-bottom: 0.75rem;
}

.section h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  color: var(--text-0);
}

.section .lead {
  margin-bottom: 0;
}

/* ── Cards ─────────────────────────────────────────────── */
.card-grid {
  display: grid;
  gap: 1.25rem;
  margin-top: 3rem;
}
.card-grid.two  { grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
.card-grid.three { 
  grid-template-columns: repeat(3, 1fr);
  max-width: 920px;
  margin-left: auto;
  margin-right: auto;
}

.card {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  padding: 2rem;
  transition: border-color 0.25s, background 0.25s;
}
.card:hover {
  border-color: var(--border-strong);
  background: var(--surface-0);
}

.card-compact { padding: 1.5rem; }

.card-icon {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
}

.card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-0);
}

.card h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.375rem;
  color: var(--text-0);
}

.card p {
  font-size: 0.9375rem;
  color: var(--text-1);
  line-height: 1.65;
}

/* ── Steps ─────────────────────────────────────────────── */
.steps {
  margin-top: 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.step {
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  padding: 2rem;
  transition: border-color 0.25s, background 0.25s;
}
.step:hover {
  border-color: var(--border-strong);
  background: var(--surface-0);
}

.step-num {
  flex-shrink: 0;
  width: 2.5rem;
  height: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.625rem;
  font-size: 0.8125rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-0), var(--accent-1));
  color: var(--bg-0);
}

.step-body h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.375rem;
  color: var(--text-0);
}

.step-body p {
  font-size: 0.9375rem;
  color: var(--text-1);
  line-height: 1.65;
}

/* ── Comparison ────────────────────────────────────────── */
.comparison {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 3rem;
}

.comparison-single {
  background: transparent;
  border: none;
  border-radius: 0.375rem;
  padding: 2.5rem;
  margin-top: 3rem;
}

.comparison-col {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  padding: 2rem;
}

.comparison-good {
  border-color: rgba(42, 250, 223, 0.2);
}

.comparison-single h4,
.comparison-col h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.comparison-single ul,
.comparison-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.comparison-single li,
.comparison-col li {
  font-size: 0.9375rem;
  color: var(--text-1);
  line-height: 1.55;
  padding-left: 1.25rem;
  position: relative;
}

.comparison-single li::before,
.comparison-col li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
}

.comparison-single li::before,
.comparison-good li::before { background: var(--accent-0); }
.comparison-neutral li::before { background: var(--text-2); }

/* ── VS Box ────────────────────────────────────────────── */
.vs-box {
  display: flex;
  align-items: stretch;
  gap: 0;
  margin-top: 2.5rem;
  border-radius: 1rem;
  overflow: hidden;
  border: 1px solid var(--border);
}

.vs-item {
  flex: 1;
  padding: 2rem;
  background: transparent;
}

.vs-item:first-child { border-right: 1px solid var(--border); }

.vs-label {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
  color: var(--text-2);
}

.vs-label.gradient-text { color: unset; -webkit-text-fill-color: unset; }

.vs-item p {
  font-size: 0.9375rem;
  color: var(--text-1);
  line-height: 1.65;
}

.vs-item p em {
  font-style: normal;
  font-weight: 600;
  color: var(--text-0);
}

.vs-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  flex-shrink: 0;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-2);
  background: var(--surface-1);
  border-left: 1px solid var(--border);
  border-right: 1px solid var(--border);
}

/* ── Architecture Grid ─────────────────────────────────── */
.arch-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 1.25rem;
  margin-top: 3rem;
}

.arch-item {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  padding: 1.75rem;
  transition: border-color 0.25s, background 0.25s;
}
.arch-item:hover {
  border-color: var(--border-strong);
  background: var(--surface-0);
}

.arch-num {
  width: 1.75rem;
  height: 1.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.375rem;
  font-size: 0.75rem;
  font-weight: 700;
  background: var(--surface-2);
  color: var(--accent-0);
  margin-bottom: 1rem;
}

.arch-item h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-0);
}

.arch-item p {
  font-size: 0.875rem;
  color: var(--text-1);
  line-height: 1.65;
}

/* ── Tech Stack Bar ────────────────────────────────────── */
.stack-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.625rem;
  justify-content: center;
}

.stack-bar span {
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.375rem 0.875rem;
  border-radius: 0.25rem;
  border: 1px solid var(--border-strong);
  color: var(--text-1);
  background: transparent;
}

/* ── Foundations ────────────────────────────────────────── */
.foundations {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
  margin-top: 2.5rem;
}

.foundations span {
  font-size: 0.875rem;
  font-weight: 500;
  padding: 0.625rem 1.25rem;
  border-radius: 0.25rem;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-1);
  transition: border-color 0.2s, background 0.2s;
}
.foundations span:hover { border-color: var(--accent-1); background: var(--surface-0); }

.foundation-novel {
  text-align: center;
  font-size: 0.9375rem;
  color: var(--text-1);
  margin-top: 2rem;
  line-height: 1.65;
}

/* ── Footer ────────────────────────────────────────────── */
footer {
  padding: 4rem 0 3rem;
  border-top: 1px solid var(--border);
  background: var(--bg-1);
}

.footer-logo {
  width: 2rem;
  height: 2rem;
  margin: 0 auto 1rem;
  opacity: 0.6;
}

.footer-text {
  font-size: 0.9375rem;
  color: var(--text-1);
  line-height: 1.65;
  max-width: 520px;
  margin: 0 auto 1.5rem;
}

.footer-copy {
  font-size: 0.75rem;
  color: var(--text-2);
}

/* ── Scroll Reveal ─────────────────────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── Responsive ────────────────────────────────────────── */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .section { padding: 4rem 0; }
  .comparison { grid-template-columns: 1fr; }
  .card-grid.three { grid-template-columns: 1fr; }
  .vs-box { flex-direction: column; }
  .vs-divider {
    width: 100%;
    height: 2.5rem;
    border-left: 0;
    border-right: 0;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
  }
  .vs-item:first-child { border-right: 0; }
  .step { flex-direction: column; gap: 1rem; }
}

@media (max-width: 480px) {
  #hero h1 { font-size: 1.75rem; }
  .hero-sub { font-size: 1rem; }
  .card { padding: 1.25rem; }
  .step { padding: 1.25rem; }
}