/* =========================================
   ExecutionOS Landing Page
   AI education content engine
   ========================================= */

/* --- Variables --- */
:root {
  --green-deep: #1B4D3E;
  --green-mid: #2A6B54;
  --green-light: #3D8B6E;
  --amber: #E8956A;
  --amber-light: #F0B08A;
  --amber-dark: #C47A50;
  --cream: #FBF8F4;
  --cream-warm: #F5F0E8;
  --ink: #0D0D0D;
  --ink-soft: #3A3A3A;
  --ink-muted: #6B6B6B;
  --border: rgba(27,77,62,0.15);
}

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

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

body {
  font-family: 'Manrope', system-ui, sans-serif;
  background: var(--cream);
  color: var(--ink);
  line-height: 1.6;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: 'Fraunces', Georgia, serif;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

/* --- Navigation --- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 48px;
  background: rgba(251,248,244,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.topbar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: 'Fraunces', serif;
  font-size: 18px;
  font-weight: 600;
  color: var(--green-deep);
  letter-spacing: -0.01em;
}

.logo-mark svg { display: block; }

.topbar-tagline {
  font-size: 12px;
  color: var(--ink-muted);
  letter-spacing: 0.03em;
  text-transform: uppercase;
  font-weight: 500;
}

/* --- Hero --- */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: calc(100vh - 65px);
  background: var(--cream);
  overflow: hidden;
}

.hero-left {
  padding: 80px 64px 80px 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  max-width: 580px;
}

.hero-eyebrow {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--amber-dark);
  font-weight: 600;
  margin-bottom: 20px;
}

.hero-headline {
  font-size: clamp(40px, 5vw, 60px);
  font-weight: 600;
  color: var(--green-deep);
  margin-bottom: 28px;
  line-height: 1.08;
}

.hero-headline em {
  font-style: italic;
  color: var(--amber-dark);
  font-weight: 300;
}

.hero-lede {
  font-size: 17px;
  color: var(--ink-soft);
  line-height: 1.7;
  max-width: 460px;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  align-items: center;
  gap: 0;
}

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

.stat-num {
  font-family: 'Fraunces', serif;
  font-size: 32px;
  font-weight: 600;
  color: var(--green-deep);
  line-height: 1;
}

.stat-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-muted);
  font-weight: 500;
}

.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--border);
  margin: 0 32px;
}

/* Hero right - circuit visualization */
.hero-right {
  position: relative;
  background: var(--cream-warm);
  overflow: hidden;
}

.circuit-bg {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.circuit-grid {
  width: 100%;
  height: 100%;
  position: relative;
}

.circuit-svg {
  width: 100%;
  height: 100%;
}

.stage-labels {
  position: absolute;
  right: 48px;
  top: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-around;
  padding: 10% 0;
}

.stage-label {
  font-family: 'Manrope', sans-serif;
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--green-deep);
  opacity: 0.5;
  text-align: right;
  position: absolute;
  right: 0;
}

.stage-label-accent { color: var(--amber-dark); opacity: 0.8; }

/* --- Sections common --- */
.section-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--amber-dark);
  font-weight: 600;
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(28px, 3.5vw, 44px);
  font-weight: 600;
  color: var(--green-deep);
  margin-bottom: 16px;
}

.section-sub {
  font-size: 16px;
  color: var(--ink-soft);
  line-height: 1.7;
  max-width: 560px;
}

/* --- Systems --- */
.systems {
  background: var(--green-deep);
  padding: 100px 48px;
}

.systems-header {
  margin-bottom: 64px;
}

.systems .section-label { color: var(--amber-light); }
.systems .section-title { color: var(--cream); }
.systems .section-sub { color: rgba(251,248,244,0.6); }

.systems-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.system-card {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 16px;
  padding: 36px 32px;
  transition: background 0.3s ease;
}

.system-card:hover {
  background: rgba(255,255,255,0.1);
}

.system-icon {
  margin-bottom: 24px;
}

.system-title {
  font-family: 'Fraunces', serif;
  font-size: 22px;
  font-weight: 600;
  color: var(--cream);
  margin-bottom: 12px;
}

.system-desc {
  font-size: 14px;
  color: rgba(251,248,244,0.65);
  line-height: 1.65;
  margin-bottom: 20px;
}

.system-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.system-features li {
  font-size: 13px;
  color: rgba(251,248,244,0.5);
  padding-left: 16px;
  position: relative;
}

.system-features li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 6px;
  background: var(--amber);
  border-radius: 50%;
}

/* --- Principles --- */
.principles {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  background: var(--cream);
}

.principles-left {
  padding: 100px 48px 100px 48px;
  border-right: 1px solid var(--border);
}

.principles-left .section-title { margin-bottom: 12px; }
.principles-left .section-sub { margin-bottom: 48px; }

.principle-list {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.principle {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.principle-num {
  font-family: 'Fraunces', serif;
  font-size: 13px;
  font-weight: 400;
  color: var(--amber);
  opacity: 0.7;
  flex-shrink: 0;
  margin-top: 4px;
}

.principle-body h4 {
  font-family: 'Manrope', sans-serif;
  font-size: 15px;
  font-weight: 600;
  color: var(--green-deep);
  margin-bottom: 6px;
}

.principle-body p {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
}

.principles-right {
  padding: 100px 48px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  justify-content: center;
}

.metric-card {
  background: var(--cream-warm);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px 28px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.metric-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink-muted);
  font-weight: 600;
}

.metric-value {
  font-family: 'Fraunces', serif;
  font-size: 28px;
  font-weight: 600;
  color: var(--green-deep);
  line-height: 1;
}

.metric-note {
  font-size: 12px;
  color: var(--ink-muted);
  line-height: 1.5;
}

/* --- Pipeline --- */
.pipeline {
  background: var(--cream-warm);
  padding: 100px 48px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.pipeline-header {
  margin-bottom: 64px;
}

.pipeline-stages {
  display: flex;
  align-items: stretch;
  gap: 0;
  overflow-x: auto;
  padding-bottom: 8px;
}

.stage {
  flex: 1;
  min-width: 140px;
  background: var(--cream);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px 20px;
  position: relative;
}

.stage-connector {
  display: flex;
  align-items: center;
  padding: 0 4px;
  flex-shrink: 0;
}

.stage-num {
  font-family: 'Fraunces', serif;
  font-size: 13px;
  color: var(--amber);
  opacity: 0.6;
  margin-bottom: 12px;
}

.stage-num--accent { color: var(--amber-dark); opacity: 1; }

.stage-name {
  font-family: 'Manrope', sans-serif;
  font-size: 15px;
  font-weight: 700;
  color: var(--green-deep);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.stage-desc {
  font-size: 12px;
  color: var(--ink-muted);
  line-height: 1.6;
}

/* --- Closing --- */
.closing {
  background: var(--green-deep);
  padding: 100px 48px;
  text-align: center;
}

.closing-inner {
  max-width: 720px;
  margin: 0 auto;
}

.closing-label {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--amber-light);
  font-weight: 600;
  margin-bottom: 24px;
}

.closing-headline {
  font-family: 'Fraunces', serif;
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 300;
  font-style: italic;
  color: var(--cream);
  line-height: 1.25;
  margin-bottom: 32px;
}

.closing-body {
  font-size: 16px;
  color: rgba(251,248,244,0.6);
  line-height: 1.75;
  max-width: 600px;
  margin: 0 auto;
}

/* --- Footer --- */
.site-footer {
  background: var(--ink);
  padding: 40px 48px;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: 'Fraunces', serif;
  font-size: 16px;
  font-weight: 600;
  color: var(--cream);
  margin-bottom: 4px;
}

.footer-note {
  font-size: 13px;
  color: rgba(251,248,244,0.4);
}

.footer-copy {
  font-size: 12px;
  color: rgba(251,248,244,0.25);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .hero { grid-template-columns: 1fr; }
  .hero-right { display: none; }
  .hero-left { max-width: 100%; padding: 60px 32px 60px 32px; }
  .systems-grid { grid-template-columns: 1fr; }
  .principles { grid-template-columns: 1fr; }
  .principles-left { border-right: none; border-bottom: 1px solid var(--border); padding: 60px 32px; }
  .principles-right { padding: 60px 32px; }
  .topbar { padding: 14px 32px; }
}

@media (max-width: 768px) {
  .hero-left { padding: 48px 24px; }
  .hero-headline { font-size: 36px; }
  .systems { padding: 64px 24px; }
  .principles-left { padding: 64px 24px; }
  .principles-right { padding: 64px 24px; }
  .pipeline { padding: 64px 24px; }
  .closing { padding: 64px 24px; }
  .site-footer { padding: 32px 24px; }
  .stage-connector { display: none; }
  .pipeline-stages { gap: 12px; }
  .stage { min-width: 120px; }
}

/* --- Scrollbar --- */
::-webkit-scrollbar { height: 4px; width: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--green-light); border-radius: 2px; }

/* --- Selection --- */
::selection { background: var(--amber); color: var(--cream); }