:root {
  --bg-main: #05070a;
  --bg-alt: #0b1018;
  --bg-card: #111827;
  --bg-chip: #141b2b;

  --text-main: #f9fafb;
  --text-soft: #cbd5f5;
  --text-muted: #9ca3af;
  --accent: #38bdf8;
  --accent-soft: rgba(56, 189, 248, 0.16);
  --danger: #f97373;

  --border-soft: #1f2937;

  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 999px;

  --shadow-soft: 0 18px 45px rgba(0, 0, 0, 0.55);

  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text",
    "Inter", "Segoe UI", sans-serif;
}

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

html,
body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  color: var(--text-main);
  background: radial-gradient(circle at top, #020617 0, #020617 45%, #020617 100%);
}

/* Layout */

.page {
  max-width: 1120px;
  margin: 0 auto;
  padding: 96px 16px 64px;
}

/* Topbar */

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  background: linear-gradient(to right, rgba(15, 23, 42, 0.96), rgba(15, 23, 42, 0.9));
  border-bottom: 1px solid rgba(148, 163, 184, 0.15);
}

.topbar-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: radial-gradient(circle at 30% 0, var(--accent), #0ea5e9);
  color: #020617;
  font-weight: 700;
  font-size: 0.85rem;
}

.brand-text {
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-size: 0.83rem;
  color: var(--text-soft);
}

.nav {
  display: flex;
  align-items: center;
  gap: 16px;
}

.nav-link {
  text-decoration: none;
  font-size: 0.9rem;
  color: var(--text-muted);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease, background 0.15s ease, transform 0.12s ease;
}

.nav-link:hover {
  color: var(--text-main);
  background: rgba(148, 163, 184, 0.18);
  transform: translateY(-1px);
}

.nav-cta {
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid rgba(56, 189, 248, 0.4);
}

.nav-cta:hover {
  background: rgba(56, 189, 248, 0.24);
}

/* Hero */

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: 32px;
  align-items: center;
  margin-top: 32px;
}

.hero-main h1 {
  font-size: clamp(2.45rem, 3vw, 3rem);
  line-height: 1.1;
  margin-bottom: 14px;
}

.accent {
  color: var(--accent);
}

.hero-text {
  color: var(--text-soft);
  font-size: 0.98rem;
  max-width: 34rem;
}

.hero-actions {
  display: flex;
  gap: 12px;
  margin: 20px 0 10px;
  flex-wrap: wrap;
}

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

/* Hero diagram */

.hero-card {
  background: radial-gradient(circle at top left, rgba(56, 189, 248, 0.24), #020617);
  border-radius: var(--radius-lg);
  padding: 18px 18px 16px;
  border: 1px solid rgba(148, 163, 184, 0.2);
  box-shadow: var(--shadow-soft);
}

.hero-diagram {
  position: relative;
  border-radius: 14px;
  border: 1px solid rgba(148, 163, 184, 0.32);
  background: radial-gradient(circle at 0 0, rgba(56, 189, 248, 0.18), #020617);
  height: 220px;
  margin-bottom: 12px;
  overflow: hidden;
}

/* simple pseudo arrows */

.arrow {
  position: absolute;
  font-size: 0.7rem;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  background: rgba(15, 23, 42, 0.86);
  border: 1px solid rgba(56, 189, 248, 0.5);
  color: var(--accent);
}

.arrow-in {
  left: 10px;
  bottom: 22px;
}

.arrow-out-back {
  right: 12px;
  bottom: 40px;
}

.arrow-out-top {
  right: 28px;
  top: 10px;
}

.hero-label {
  position: absolute;
  font-size: 0.7rem;
  color: var(--text-soft);
  background: rgba(15, 23, 42, 0.7);
  padding: 3px 7px;
  border-radius: 999px;
}

.hero-label-front {
  left: 16px;
  bottom: 70px;
}

.hero-label-cpu {
  right: 40px;
  bottom: 110px;
}

.diagram-caption {
  font-size: 0.8rem;
  color: var(--text-soft);
}

/* Generic */

.section {
  margin-top: 72px;
}

.section-alt {
  background: radial-gradient(circle at top, #020617, #020617 40%, #020617 100%);
  padding: 40px 20px 36px;
  margin: 72px -20px 0;
  border-top: 1px solid rgba(148, 163, 184, 0.16);
  border-bottom: 1px solid rgba(148, 163, 184, 0.16);
}

.section-header {
  max-width: 640px;
  margin-bottom: 28px;
}

.section-header h2 {
  margin: 0 0 8px;
  font-size: 1.4rem;
}

.section-header p {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.95rem;
}

/* Grid & cards */

.grid {
  display: grid;
  gap: 18px;
}

.grid.two {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.grid.three {
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 18px 18px 16px;
  border: 1px solid rgba(148, 163, 184, 0.22);
}

.card.mini {
  padding: 16px 16px 14px;
}

.card h3 {
  margin-top: 0;
  margin-bottom: 8px;
  font-size: 1.02rem;
}

.card p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--text-soft);
}

.list {
  margin: 8px 0 0;
  padding-left: 18px;
  color: var(--text-soft);
  font-size: 0.9rem;
}

.list li + li {
  margin-top: 4px;
}

/* CTA panel */

.cta-panel {
  margin-top: 36px;
  padding: 18px 18px 16px;
  border-radius: var(--radius-md);
  border: 1px dashed rgba(56, 189, 248, 0.5);
  background: rgba(15, 23, 42, 0.85);
}

.cta-panel h3 {
  margin: 0 0 6px;
}

.cta-panel p {
  margin: 0 0 12px;
  font-size: 0.9rem;
  color: var(--text-soft);
}

/* Buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background 0.15s ease, color 0.15s ease, transform 0.1s ease,
    box-shadow 0.15s ease, border-color 0.15s ease;
}

.btn.primary {
  background: linear-gradient(to right, #22d3ee, #0ea5e9);
  color: #020617;
  box-shadow: 0 12px 30px rgba(56, 189, 248, 0.4);
}

.btn.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 15px 40px rgba(56, 189, 248, 0.6);
}

.btn.ghost {
  background: transparent;
  color: var(--text-soft);
  border-color: rgba(148, 163, 184, 0.5);
}

.btn.ghost:hover {
  background: rgba(15, 23, 42, 0.9);
  color: var(--text-main);
}

/* Footer */

.site-footer {
  border-top: 1px solid rgba(148, 163, 184, 0.16);
  background: #020617;
}

.footer-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 18px 16px 22px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 16px;
}

.footer-nav {
  display: flex;
  gap: 14px;
  font-size: 0.86rem;
}

.footer-nav a {
  color: var(--text-muted);
  text-decoration: none;
}

.footer-nav a:hover {
  color: var(--text-main);
}

.footer-meta {
  width: 100%;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Secondary pages */

.page-narrow {
  max-width: 720px;
  margin: 0 auto;
  padding: 96px 16px 64px;
}

.page-title {
  font-size: 1.6rem;
  margin-bottom: 8px;
}

.page-lead {
  color: var(--text-soft);
  margin-bottom: 24px;
  font-size: 0.95rem;
}

.text-block h2 {
  font-size: 1.15rem;
  margin-top: 24px;
  margin-bottom: 6px;
}

.text-block p,
.text-block li {
  font-size: 0.92rem;
  color: var(--text-soft);
}

.text-block ul {
  padding-left: 18px;
}

/* Form */

.form-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 18px 18px 16px;
  border: 1px solid rgba(148, 163, 184, 0.22);
  max-width: 520px;
}

.form-grid {
  display: grid;
  gap: 12px 18px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

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

.field label {
  font-size: 0.84rem;
  color: var(--text-soft);
}

.field input,
.field select,
.field textarea {
  border-radius: 10px;
  border: 1px solid rgba(148, 163, 184, 0.4);
  padding: 8px 9px;
  background: #020617;
  color: var(--text-main);
  font-size: 0.9rem;
}

.field textarea {
  min-height: 96px;
  resize: vertical;
}

.field small {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.form-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-top: 14px;
}

.form-footer p {
  margin: 0;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* FAQ */

.faq-list {
  margin-top: 18px;
}

.faq-item + .faq-item {
  margin-top: 12px;
  border-top: 1px solid rgba(148, 163, 184, 0.18);
  padding-top: 12px;
}

.faq-q {
  font-weight: 500;
  font-size: 0.95rem;
}

.faq-a {
  font-size: 0.9rem;
  color: var(--text-soft);
}

/* Responsive */

@media (max-width: 800px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .hero-card {
    order: -1;
  }
}

@media (max-width: 640px) {
  .nav {
    display: none; /* simple for v1, no mobile nav logic yet */
  }

  .page,
  .page-narrow {
    padding-top: 80px;
  }
}