:root {
  --bg: #050816;
  --bg-alt: #0b1020;
  --surface: #0f172a;
  --surface-alt: #111827;
  --border-subtle: rgba(148, 163, 184, 0.25);
  --text: #e5e7eb;
  --text-muted: #9ca3af;
  --accent: #3b82f6;
  --accent-soft: rgba(59, 130, 246, 0.16);
  --accent-strong: #2563eb;
  --danger: #f97373;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --shadow-soft: 0 18px 45px rgba(15, 23, 42, 0.65);
  --shadow-card: 0 16px 35px rgba(15, 23, 42, 0.6);
  --max-width: 1100px;
}

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

html, body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at top left, #111827 0, #020617 45%, #000 100%);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

/* Layout */

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 80px 0;
}

.section.alt {
  background: radial-gradient(circle at top right, #111827 0, #020617 60%);
}

.section.emphasis {
  background: linear-gradient(135deg, #0f172a, #020617);
}

.section-inner {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.section-intro {
  max-width: 620px;
  color: var(--text-muted);
  margin-bottom: 24px;
}

/* Header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(16px);
  background: radial-gradient(circle at top left, rgba(15, 23, 42, 0.95), rgba(15, 23, 42, 0.95));
  border-bottom: 1px solid rgba(148, 163, 184, 0.35);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-size: 14px;
}

.logo-mark {
  width: 28px;
  height: 28px;
  border-radius: 999px;
  background: radial-gradient(circle at 30% 10%, #60a5fa, #1d4ed8);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: white;
  box-shadow: 0 0 0 1px rgba(191, 219, 254, 0.4);
}

.logo-text {
  color: #e5e7eb;
}

.nav {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 14px;
}

.nav a {
  padding: 6px 8px;
  border-radius: 999px;
  color: var(--text-muted);
  transition: color 0.15s ease, background-color 0.15s ease, transform 0.1s ease;
}

.nav a:hover {
  color: #e5e7eb;
  background: rgba(15, 23, 42, 0.9);
  transform: translateY(-1px);
}

.nav-cta {
  border: 1px solid rgba(129, 140, 248, 0.6);
  color: #e5e7eb;
}

/* Hero */

.hero {
  padding: 72px 0 64px;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: 40px;
  align-items: stretch;
}

.hero-text h1 {
  font-size: clamp(32px, 4vw, 40px);
  line-height: 1.15;
  margin: 0 0 18px;
}

.hero-subtitle {
  margin: 0 0 24px;
  color: var(--text-muted);
  max-width: 640px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 18px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 9px 18px;
  font-size: 14px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #f9fafb;
  box-shadow: 0 12px 30px rgba(37, 99, 235, 0.5);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 40px rgba(37, 99, 235, 0.6);
}

.btn-ghost {
  border-color: rgba(148, 163, 184, 0.5);
  color: var(--text-muted);
  background: rgba(15, 23, 42, 0.5);
}

.btn-ghost:hover {
  color: #e5e7eb;
  border-color: rgba(209, 213, 219, 0.7);
  background: rgba(17, 24, 39, 0.9);
}

.btn-full {
  width: 100%;
  justify-content: center;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 8px;
}

.tag {
  font-size: 11px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.9);
  border: 1px solid rgba(148, 163, 184, 0.4);
  color: var(--text-muted);
}

.hero-card {
  border-radius: var(--radius-xl);
  padding: 22px 22px 20px;
  background:
    radial-gradient(circle at 0 0, rgba(96, 165, 250, 0.18), transparent 55%),
    radial-gradient(circle at 100% 0, rgba(129, 140, 248, 0.18), transparent 55%),
    linear-gradient(145deg, #020617, #020617);
  border: 1px solid rgba(148, 163, 184, 0.4);
  box-shadow: var(--shadow-soft);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.hero-card h2 {
  font-size: 18px;
  margin: 0;
}

.hero-list {
  margin: 0;
  padding-left: 18px;
  color: var(--text-muted);
  font-size: 14px;
}

.hero-badge {
  margin-top: 4px;
  padding: 10px 12px;
  border-radius: 14px;
  border: 1px dashed rgba(148, 163, 184, 0.6);
  font-size: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  background: rgba(15, 23, 42, 0.8);
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: #22c55e;
  box-shadow: 0 0 0 4px rgba(34, 197, 94, 0.25);
}

/* Two-column section */

.two-col {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: 32px;
  align-items: flex-start;
}

/* Typography */

h2 {
  font-size: 26px;
  margin: 0 0 12px;
}

h3 {
  font-size: 18px;
  margin: 0 0 8px;
}

p {
  margin: 0 0 12px;
  color: var(--text-muted);
}

/* Cards & boxes */

.highlight-box,
.architecture-card,
.card,
.contact-card {
  border-radius: var(--radius-lg);
  padding: 18px 18px 16px;
  background: rgba(15, 23, 42, 0.96);
  border: 1px solid rgba(148, 163, 184, 0.45);
  box-shadow: var(--shadow-card);
  font-size: 14px;
}

.highlight-box ul,
.architecture-card ol {
  margin: 8px 0 0;
  padding-left: 18px;
  color: var(--text-muted);
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.card p {
  font-size: 14px;
}

/* Chips */

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
}

.chip {
  font-size: 12px;
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.6);
  background: rgba(15, 23, 42, 0.9);
  color: var(--text-muted);
}

/* Emphasis section */

.emphasis .cards-grid .card {
  background: rgba(15, 23, 42, 0.96);
}

.solution-note {
  margin-top: 24px;
  padding: 14px 16px;
  border-radius: 16px;
  background: rgba(15, 23, 42, 0.96);
  border: 1px dashed rgba(148, 163, 184, 0.6);
  font-size: 13px;
  color: var(--text-muted);
}

/* Contact */

.contact-section {
  background: radial-gradient(circle at bottom right, #111827 0, #020617 60%);
}

.contact-card {
  max-width: 360px;
}

.contact-list {
  list-style: none;
  padding: 0;
  margin: 8px 0 16px;
  font-size: 14px;
}

.contact-list li {
  margin-bottom: 6px;
}

.contact-list a {
  color: var(--accent);
}

/* Footer */

.site-footer {
  border-top: 1px solid rgba(148, 163, 184, 0.35);
  background: #020617;
  padding: 14px 0;
  font-size: 12px;
  color: var(--text-muted);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-note {
  opacity: 0.8;
}

/* Responsive */

@media (max-width: 900px) {
  .hero-inner,
  .two-col {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero {
    padding-top: 56px;
  }

  .cards-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .header-inner {
    gap: 12px;
  }

  .nav {
    gap: 10px;
    font-size: 13px;
  }
}

@media (max-width: 640px) {
  .site-header {
    position: static;
  }

  .hero-inner {
    gap: 28px;
  }

  .cards-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-inner {
    flex-direction: column;
    gap: 6px;
    align-items: flex-start;
  }
}