:root {
  --bg: #070b14;
  --bg-elevated: #0f1624;
  --bg-soft: #121a2b;
  --text: #e8eef9;
  --text-muted: #9aabc4;
  --accent: #3de0ff;
  --accent-soft: rgba(61, 224, 255, 0.14);
  --border: rgba(148, 175, 210, 0.18);
  --warning: #ffb454;
  --warning-bg: rgba(255, 180, 84, 0.1);
  --danger: #ff7b8a;
  --radius: 16px;
  --max: 820px;
  --font: "Avenir Next", "Segoe UI", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(ellipse 90% 55% at 50% -10%, rgba(61, 224, 255, 0.18), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 20%, rgba(80, 120, 255, 0.08), transparent 50%),
    var(--bg);
  line-height: 1.65;
}

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

a:hover {
  text-decoration: underline;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  background: rgba(7, 11, 20, 0.82);
  border-bottom: 1px solid var(--border);
}

.header-inner,
.page,
.footer-inner {
  width: min(100% - 2rem, var(--max));
  margin: 0 auto;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.9rem 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--text);
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-mark {
  width: 1.7rem;
  height: 1.7rem;
  border-radius: 0.55rem;
  background: linear-gradient(145deg, #3de0ff, #4f7cff);
  box-shadow: 0 0 18px rgba(61, 224, 255, 0.35);
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.nav a {
  display: inline-flex;
  align-items: center;
  padding: 0.45rem 0.8rem;
  border-radius: 999px;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  text-decoration: none;
  font-size: 0.92rem;
}

.nav a:hover,
.nav a[aria-current="page"] {
  color: var(--text);
  background: var(--accent-soft);
  border-color: rgba(61, 224, 255, 0.28);
  text-decoration: none;
}

.page {
  padding: 2.2rem 0 3.5rem;
}

.hero {
  margin-bottom: 1.8rem;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 0.75rem;
  padding: 0.28rem 0.7rem;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

h1 {
  margin: 0 0 0.7rem;
  font-size: clamp(1.85rem, 4vw, 2.55rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.lede,
.meta {
  color: var(--text-muted);
  margin: 0;
}

.meta {
  margin-top: 0.85rem;
  font-size: 0.95rem;
}

.card-grid {
  display: grid;
  gap: 1rem;
  margin: 1.8rem 0 0.5rem;
}

@media (min-width: 720px) {
  .card-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.card {
  display: block;
  padding: 1.25rem 1.3rem;
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(18, 26, 43, 0.95), rgba(15, 22, 36, 0.95));
  border: 1px solid var(--border);
  color: inherit;
  text-decoration: none;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

.card:hover {
  border-color: rgba(61, 224, 255, 0.45);
  transform: translateY(-2px);
  text-decoration: none;
}

.card h2 {
  margin: 0 0 0.45rem;
  font-size: 1.2rem;
}

.card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.toc {
  margin: 1.5rem 0 2rem;
  padding: 1rem 1.15rem;
  border-radius: var(--radius);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
}

.toc h2 {
  margin: 0 0 0.65rem;
  font-size: 1rem;
}

.toc ol {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--text-muted);
}

.toc a {
  color: var(--text-muted);
}

.toc a:hover {
  color: var(--accent);
}

article section {
  margin: 0 0 1.75rem;
  padding: 1.25rem 1.3rem;
  border-radius: var(--radius);
  background: rgba(15, 22, 36, 0.72);
  border: 1px solid var(--border);
}

article h2 {
  margin: 0 0 0.7rem;
  font-size: 1.2rem;
}

article h3 {
  margin: 1.1rem 0 0.45rem;
  font-size: 1.02rem;
}

article p,
article li {
  color: var(--text-muted);
}

article ul,
article ol {
  margin: 0.4rem 0 0.2rem;
  padding-left: 1.2rem;
}

article li + li {
  margin-top: 0.35rem;
}

.safety {
  border-color: rgba(255, 180, 84, 0.35);
  background: linear-gradient(180deg, var(--warning-bg), rgba(15, 22, 36, 0.85));
}

.safety h2 {
  color: var(--warning);
}

.note {
  margin-top: 0.9rem;
  padding: 0.8rem 0.95rem;
  border-radius: 12px;
  background: rgba(255, 123, 138, 0.08);
  border: 1px solid rgba(255, 123, 138, 0.25);
  color: #ffc2ca;
  font-size: 0.95rem;
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.4rem 0 2rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  justify-content: space-between;
}

@media (max-width: 640px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .nav {
    width: 100%;
  }

  .nav a {
    flex: 1 1 auto;
    justify-content: center;
  }
}