:root {
  --bg: #0b1020;
  --bg-soft: #111831;
  --card: #151d39;
  --text: #e8ecf7;
  --muted: #aeb8d0;
  --line: rgba(255, 255, 255, 0.08);
  --accent: #6ea8ff;
  --accent-2: #8b7cff;
  --max: 1180px;
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background:
    radial-gradient(circle at top, rgba(110, 168, 255, 0.18), transparent 28%),
    linear-gradient(180deg, #08101f 0%, #0b1020 100%);
  color: var(--text);
  line-height: 1.6;
}

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

a:hover {
  text-decoration: underline;
}

.container {
  width: min(var(--max), calc(100% - 2rem));
  margin: 0 auto;
}

.hero {
  padding: 56px 0 28px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0));
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.85rem;
}

.hero h1 {
  margin: 0;
  font-size: clamp(2rem, 5vw, 3.2rem);
  line-height: 1.1;
}

.subtitle {
  max-width: 720px;
  color: var(--muted);
  margin: 14px 0 24px;
}

.top-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.top-nav a {
  padding: 10px 14px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--text);
  font-size: 0.95rem;
}

.layout {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 24px;
  padding: 28px 0 56px;
}

.sidebar {
  position: relative;
}

.sidebar-card {
  position: sticky;
  top: 24px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  backdrop-filter: blur(8px);
}

.sidebar-card h2 {
  margin-top: 0;
  font-size: 1.1rem;
}

.sidebar-card ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.sidebar-card li + li {
  margin-top: 10px;
}

.sidebar-card a {
  color: var(--muted);
}

.sidebar-card a:hover {
  color: var(--text);
}

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

.card {
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  backdrop-filter: blur(8px);
  box-shadow: 0 10px 28px rgba(0,0,0,0.18);
}

.card h2 {
  margin-top: 0;
  font-size: 1.3rem;
}

.card p:last-child,
.card ul:last-child {
  margin-bottom: 0;
}

.card ul {
  padding-left: 18px;
}

.scroll-top {
  position: fixed;
  right: 18px;
  bottom: 18px;
  width: 46px;
  height: 46px;
  border: 0;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: 0 10px 20px rgba(0,0,0,0.25);
  display: none;
}

.scroll-top.show {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

@media (max-width: 920px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .sidebar-card {
    position: static;
  }
}

@media (max-width: 640px) {
  .hero {
    padding-top: 40px;
  }

  .card,
  .sidebar-card {
    padding: 18px;
  }

  .top-nav {
    gap: 8px;
  }

  .top-nav a {
    font-size: 0.9rem;
    padding: 9px 12px;
  }
}