/* ============================
   ARC — Theme CSS
   ============================ */

:root {
  --bg: #0A0A0F;
  --surface: #111118;
  --surface-2: #18181F;
  --border: #1F1F2A;
  --text: #E8E8EE;
  --text-muted: #7A7A90;
  --accent: #F5A623;
  --accent-dim: rgba(245, 166, 35, 0.12);
  --amber-glow: rgba(245, 166, 35, 0.08);
  --red: #FF4D4D;
  --green: #34D399;
}

*, *::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: 'DM Sans', sans-serif;
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ---- Typography ---- */
h1, h2, h3, h4 { font-family: 'Syne', sans-serif; line-height: 1.15; }

/* ---- Nav ---- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1140px; margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex; align-items: center; gap: 12px;
}
.wordmark {
  font-family: 'Syne', sans-serif;
  font-weight: 800; font-size: 1.25rem;
  color: var(--accent);
  letter-spacing: -0.02em;
}
.nav-tag {
  font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--text-muted);
  padding: 3px 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
}

/* ---- Section commons ---- */
.section-inner { max-width: 1140px; margin: 0 auto; padding: 0 24px; }
.section-eyebrow {
  font-size: 0.7rem; letter-spacing: 0.15em; text-transform: uppercase;
  color: var(--accent); font-weight: 500; margin-bottom: 16px;
}
.section-title {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700; color: var(--text);
  margin-bottom: 40px;
  line-height: 1.2;
}

/* ---- Hero ---- */
.hero {
  padding: 140px 0 80px;
  background: radial-gradient(ellipse 80% 50% at 50% 0%, rgba(245,166,35,0.06) 0%, transparent 70%);
}
.hero-inner {
  max-width: 1140px; margin: 0 auto; padding: 0 24px;
  display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center;
}
.hero-copy {}
.hero-eyebrow {
  font-size: 0.75rem; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--accent); font-weight: 500; margin-bottom: 20px;
}
.hero-headline {
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  font-weight: 800; color: var(--text);
  margin-bottom: 24px; line-height: 1.1;
  letter-spacing: -0.02em;
}
.hero-sub {
  font-size: 1.05rem; color: var(--text-muted); line-height: 1.7;
  max-width: 440px;
}

/* Routing diagram */
.hero-routing { display: flex; flex-direction: column; gap: 24px; }
.routing-diagram {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
  position: relative;
}
.routing-input { display: flex; justify-content: center; margin-bottom: 28px; }
.input-badge {
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: 8px; padding: 10px 16px; display: flex;
  flex-direction: column; gap: 4px; align-items: center;
}
.input-label { font-size: 0.65rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-muted); }
.input-text { font-size: 0.8rem; color: var(--accent); font-style: italic; }

.routing-lines {
  display: flex; justify-content: center; gap: 80px;
  margin-bottom: 20px; position: relative;
}
.routing-lines::before {
  content: ''; position: absolute; top: -16px; left: 50%; transform: translateX(-50%);
  width: 2px; height: 16px; background: var(--border);
}
.line {
  width: 1px; height: 28px;
  background: linear-gradient(to bottom, var(--border), var(--accent));
  position: relative;
}
.line::after {
  content: ''; position: absolute; bottom: -1px; left: 50%; transform: translateX(-50%);
  border-left: 5px solid transparent; border-right: 5px solid transparent;
  border-top: 6px solid var(--accent);
}

.routing-outputs { display: flex; justify-content: space-between; gap: 12px; }
.output-node {
  flex: 1; display: flex; flex-direction: column; align-items: center;
  gap: 6px; padding: 14px 8px;
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: 10px; text-align: center;
}
.node-icon {
  width: 28px; height: 28px; border-radius: 50%;
  border: 2px solid;
}
.node-icon.mini { border-color: var(--green); background: rgba(52,211,153,0.15); }
.node-icon.standard { border-color: var(--accent); background: var(--accent-dim); }
.node-icon.premium { border-color: #A78BFA; background: rgba(167,139,250,0.15); }
.node-name { font-size: 0.72rem; font-weight: 600; color: var(--text); font-family: 'Syne', sans-serif; }
.node-cost { font-size: 0.62rem; color: var(--text-muted); }
.node-tag {
  font-size: 0.58rem; letter-spacing: 0.08em; text-transform: uppercase;
  padding: 2px 6px; border-radius: 3px; font-weight: 500;
}
.tag-simple { color: var(--green); background: rgba(52,211,153,0.1); }
.tag-standard { color: var(--accent); background: var(--accent-dim); }
.tag-complex { color: #A78BFA; background: rgba(167,139,250,0.1); }

.routing-stats { display: flex; gap: 16px; }
.stat {
  flex: 1; background: var(--surface); border: 1px solid var(--border);
  border-radius: 10px; padding: 14px 16px; display: flex;
  flex-direction: column; gap: 4px;
}
.stat-val { font-family: 'Syne', sans-serif; font-size: 1.4rem; font-weight: 700; color: var(--accent); }
.stat-label { font-size: 0.7rem; color: var(--text-muted); line-height: 1.4; }

/* ---- Flow section ---- */
.flow-section { padding: 100px 0; border-top: 1px solid var(--border); }
.flow-steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 48px; }
.flow-step {}
.step-num {
  font-family: 'Syne', sans-serif; font-size: 0.75rem; font-weight: 700;
  color: var(--accent); letter-spacing: 0.05em; margin-bottom: 16px;
}
.step-content h3 {
  font-size: 1.15rem; font-weight: 700; color: var(--text); margin-bottom: 10px;
}
.step-content p { font-size: 0.9rem; color: var(--text-muted); line-height: 1.7; }

/* ---- Features section ---- */
.features-section { padding: 100px 0; background: var(--surface); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: 14px; padding: 28px;
  transition: border-color 0.2s;
}
.feature-card:hover { border-color: rgba(245,166,35,0.3); }
.feature-icon {
  width: 40px; height: 40px; border-radius: 10px;
  background: var(--accent-dim);
  border: 1px solid rgba(245,166,35,0.25);
  margin-bottom: 18px;
  position: relative;
}
.feature-icon::after {
  content: ''; position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%);
  width: 18px; height: 18px;
  border: 2px solid var(--accent);
  border-radius: 50%;
}
.feature-card h3 { font-size: 1rem; font-weight: 700; color: var(--text); margin-bottom: 10px; }
.feature-card p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.65; }

/* ---- Economics section ---- */
.economics-section { padding: 100px 0; }
.economics-content { max-width: 760px; }
.economics-title { max-width: 600px; }
.economics-body { font-size: 1rem; color: var(--text-muted); line-height: 1.8; margin-bottom: 48px; max-width: 620px; }
.economics-comparison { display: flex; gap: 32px; margin-bottom: 20px; }
.comp-col { flex: 1; }
.comp-label { font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 10px; }
.comp-bar { height: 48px; border-radius: 8px; margin-bottom: 10px; }
.bar-red { background: linear-gradient(to right, var(--red), #FF7A7A); opacity: 0.8; }
.bar-amber { background: linear-gradient(to right, var(--accent), #FFD280); opacity: 0.8; }
.comp-cost { font-family: 'Syne', sans-serif; font-size: 1.1rem; font-weight: 700; color: var(--text); margin-bottom: 4px; }
.comp-note { font-size: 0.75rem; color: var(--text-muted); }
.economics-footnote { font-size: 0.75rem; color: var(--text-muted); font-style: italic; }

/* ---- Closing ---- */
.closing-section {
  padding: 100px 0;
  background: radial-gradient(ellipse 60% 60% at 50% 100%, rgba(245,166,35,0.05) 0%, transparent 70%);
  border-top: 1px solid var(--border);
}
.closing-title { max-width: 640px; }
.closing-body { font-size: 1rem; color: var(--text-muted); line-height: 1.8; max-width: 620px; margin-bottom: 48px; }
.closing-statement {
  border-left: 3px solid var(--accent);
  padding-left: 28px; max-width: 540px;
}
.closing-statement p {
  font-family: 'Syne', sans-serif; font-size: 1.2rem; font-weight: 600;
  color: var(--text); line-height: 1.5;
}

/* ---- Footer ---- */
.footer {
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
}
.footer-inner {
  max-width: 1140px; margin: 0 auto; padding: 0 24px;
  display: flex; justify-content: space-between; align-items: flex-start; gap: 40px;
  margin-bottom: 40px;
}
.footer-brand .wordmark { font-size: 1.5rem; display: block; margin-bottom: 8px; }
.footer-brand p { font-size: 0.85rem; color: var(--text-muted); }
.footer-links { display: flex; gap: 24px; flex-wrap: wrap; align-items: center; }
.footer-links span { font-size: 0.75rem; color: var(--text-muted); }
.footer-bottom { max-width: 1140px; margin: 0 auto; padding: 0 24px; border-top: 1px solid var(--border); padding-top: 24px; }
.footer-bottom p { font-size: 0.75rem; color: var(--text-muted); }

/* ---- Responsive ---- */
@media (max-width: 768px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero-routing { order: -1; }
  .flow-steps { grid-template-columns: 1fr; gap: 32px; }
  .features-grid { grid-template-columns: 1fr; }
  .economics-comparison { flex-direction: column; gap: 20px; }
  .footer-inner { flex-direction: column; }
  .footer-links { flex-wrap: wrap; }
  .routing-outputs { gap: 8px; }
  .routing-lines { gap: 40px; }
}
@media (max-width: 480px) {
  .hero { padding: 120px 0 60px; }
  .routing-outputs { flex-direction: column; align-items: center; }
}