:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --soft: #eef3f8;
  --text: #142033;
  --muted: #5d6b7d;
  --line: #d8e0ea;
  --primary: #2563eb;
  --primary-dark: #1e40af;
  --accent: #0f766e;
  --shadow: 0 18px 45px rgba(20, 32, 51, 0.10);
  --radius: 18px;
  --max: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
}

a {
  color: inherit;
}

img,
video {
  max-width: 100%;
}

.container {
  width: min(100% - 40px, var(--max));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(247, 248, 251, 0.9);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.nav {
  min-height: 72px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
}

.brand {
  font-weight: 800;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 18px;
  color: var(--muted);
  font-size: 0.95rem;
}

.nav-links a {
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--primary);
}

.hero {
  padding: 92px 0 72px;
  background:
    radial-gradient(circle at 20% 10%, rgba(37, 99, 235, 0.16), transparent 34%),
    radial-gradient(circle at 90% 20%, rgba(15, 118, 110, 0.12), transparent 30%);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(300px, 0.75fr);
  gap: 36px;
  align-items: center;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  line-height: 1.15;
  letter-spacing: -0.035em;
}

h1 {
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 5rem);
}

h2 {
  margin: 0 0 16px;
  font-size: clamp(1.8rem, 3.5vw, 3rem);
}

h3 {
  margin: 0 0 12px;
  font-size: 1.2rem;
}

.subtitle {
  max-width: 760px;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.25rem);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 12px 18px;
  border-radius: 999px;
  font-weight: 800;
  text-decoration: none;
  border: 1px solid transparent;
  transition: 0.18s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  color: white;
  background: var(--primary);
  box-shadow: 0 12px 26px rgba(37, 99, 235, 0.28);
}

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-secondary {
  color: white;
  background: var(--accent);
}

.btn-outline {
  color: var(--text);
  border-color: var(--line);
  background: rgba(255, 255, 255, 0.8);
}

.hero-card,
.card,
.logic-box {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.hero-card {
  padding: 28px;
}

.hero-card dl {
  margin: 0;
  display: grid;
  gap: 16px;
}

.hero-card div {
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.hero-card dt {
  color: var(--muted);
  font-size: 0.86rem;
}

.hero-card dd {
  margin: 4px 0 0;
  font-weight: 800;
}

.section {
  padding: 76px 0;
}

.muted {
  background: var(--soft);
}

.two-column {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 42px;
  align-items: start;
}

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

.cards.three {
  grid-template-columns: repeat(3, 1fr);
}

.cards.four {
  grid-template-columns: repeat(4, 1fr);
}

.card,
.logic-box {
  padding: 24px;
}

.card p,
.logic-box p {
  color: var(--muted);
}

.logic-box {
  margin-top: 22px;
}

code {
  padding: 0.15em 0.35em;
  border-radius: 6px;
  background: #e8eef7;
  color: #1e3a8a;
}

pre {
  overflow-x: auto;
  padding: 22px;
  border-radius: 14px;
  background: #101827;
  color: #dbeafe;
  box-shadow: var(--shadow);
}

pre code {
  background: transparent;
  color: inherit;
}

.inline-link {
  color: var(--primary);
  font-weight: 800;
  text-decoration: none;
}

.inline-link:hover {
  text-decoration: underline;
}

.gallery {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
}

.gallery figure {
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.gallery img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: #dbeafe;
}

.gallery figcaption {
  padding: 14px 16px;
  color: var(--muted);
  font-weight: 700;
}

.demo-video {
  width: 100%;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: #000;
  box-shadow: var(--shadow);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.tags span {
  padding: 10px 14px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--line);
  font-weight: 800;
  color: var(--muted);
}

.id-summary {
  padding-top: 42px;
}

.footer {
  padding: 32px 0;
  color: #e5e7eb;
  background: #111827;
}

.footer-grid {
  display: flex;
  justify-content: space-between;
  gap: 20px;
}

.footer a {
  color: #bfdbfe;
  text-decoration: none;
  margin-left: 18px;
}

.footer a:hover {
  text-decoration: underline;
}

@media (max-width: 900px) {
  .hero-grid,
  .two-column,
  .cards.three,
  .cards.four,
  .gallery {
    grid-template-columns: 1fr;
  }

  .nav {
    align-items: flex-start;
    flex-direction: column;
    padding: 16px 0;
  }

  .nav-links {
    flex-wrap: wrap;
  }
}

@media (max-width: 560px) {
  .container {
    width: min(100% - 28px, var(--max));
  }

  .cta-row,
  .footer-grid {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  h1 {
    font-size: 2.35rem;
  }

  .section {
    padding: 54px 0;
  }

  .footer a {
    margin-left: 0;
    margin-right: 18px;
  }
}