:root {
  --bg: #04040e;
  --surface: #0c1024;
  --border: rgba(0, 170, 255, 0.22);
  --text: #e8eef8;
  --muted: #8a9bb5;
  --accent: #00d4ff;
  --accent-dim: #0077aa;
  --gold: #ffc84d;
  --max: 720px;
  --radius: 14px;
  --font: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background:
    radial-gradient(ellipse 80% 50% at 50% -10%, rgba(0, 120, 200, 0.18), transparent),
    radial-gradient(ellipse 60% 40% at 100% 100%, rgba(80, 40, 180, 0.12), transparent),
    var(--bg);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: rgba(8, 12, 28, 0.85);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.site-header__logo {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
}

.site-header__brand {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  color: var(--text);
  text-decoration: none;
}

.site-header__brand:hover {
  text-decoration: none;
  color: var(--accent);
}

.site-header__nav {
  margin-left: auto;
  display: flex;
  gap: 1.25rem;
  font-size: 0.92rem;
}

.site-header__nav a {
  color: var(--muted);
}

.site-header__nav a:hover,
.site-header__nav a[aria-current="page"] {
  color: var(--accent);
}

main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

.hero {
  text-align: center;
  padding: 2.5rem 0 2rem;
}

.hero__logo {
  width: 120px;
  height: 120px;
  margin: 0 auto 1.25rem;
  filter: drop-shadow(0 8px 24px rgba(0, 180, 255, 0.25));
}

.hero h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.75rem, 5vw, 2.25rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.hero p {
  margin: 0;
  color: var(--muted);
  max-width: 36ch;
  margin-inline: auto;
}

.card-grid {
  display: grid;
  gap: 1rem;
  margin-top: 2rem;
}

@media (min-width: 540px) {
  .card-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.card {
  display: block;
  padding: 1.35rem 1.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  color: inherit;
  text-decoration: none;
  transition: border-color 0.2s, transform 0.2s;
}

.card:hover {
  text-decoration: none;
  border-color: var(--accent);
  transform: translateY(-2px);
}

.card h2 {
  margin: 0 0 0.35rem;
  font-size: 1.1rem;
  color: var(--accent);
}

.card p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--muted);
}

.doc h1 {
  margin: 0 0 0.25rem;
  font-size: clamp(1.6rem, 4vw, 2rem);
  font-weight: 800;
}

.doc .meta {
  color: var(--muted);
  font-size: 0.9rem;
  margin-bottom: 2rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
}

.doc h2 {
  margin: 2rem 0 0.75rem;
  font-size: 1.15rem;
  color: var(--accent);
}

.doc h3 {
  margin: 1.25rem 0 0.5rem;
  font-size: 1rem;
}

.doc p,
.doc li {
  color: #c8d4e8;
}

.doc ul {
  padding-left: 1.25rem;
}

.doc li {
  margin-bottom: 0.4rem;
}

.doc strong {
  color: var(--text);
}

.site-footer {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1.5rem 1.25rem 2.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.88rem;
  color: var(--muted);
  text-align: center;
}