:root {
  --bg: #0b0f19;
  --card: #121a2b;
  --text: #e7ecff;
  --muted: #a7b0d6;
  --line: rgba(231,236,255,0.12);
  --btn: #2b66ff;
  --btn2: rgba(231,236,255,0.08);
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
  --radius: 14px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --sans: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Arial, sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--sans);
  background: radial-gradient(900px 600px at 20% 0%, rgba(43,102,255,0.22), transparent 60%),
              radial-gradient(900px 600px at 90% 10%, rgba(255,255,255,0.10), transparent 60%),
              var(--bg);
  color: var(--text);
}

.wrap { max-width: 980px; margin: 0 auto; padding: 18px; }
.header {
  display: flex; align-items: center; justify-content: space-between;
  gap: 18px; position: sticky; top: 0; backdrop-filter: blur(10px);
  background: rgba(11,15,25,0.65); border-bottom: 1px solid var(--line);
  z-index: 2;
}
.brand { display: flex; gap: 12px; align-items: center; }
.logo {
  width: 44px; height: 44px; display: grid; place-items: center;
  border-radius: 12px; background: rgba(43,102,255,0.22);
  border: 1px solid var(--line); font-size: 20px;
}
h1 { margin: 0; font-size: 18px; }
.muted { color: var(--muted); }
.nav { display: flex; gap: 14px; flex-wrap: wrap; justify-content: flex-end; }
.nav a { color: var(--muted); text-decoration: none; font-size: 14px; }
.nav a:hover { color: var(--text); }

.card {
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.02));
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  border-radius: var(--radius);
  padding: 18px;
  margin: 18px 0;
}
h2 { margin: 0 0 10px; font-size: 20px; }
h3 { margin: 18px 0 8px; font-size: 16px; }

.video {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
  background: #000;
  margin: 12px 0;
  aspect-ratio: 16 / 9;
}
.video iframe { width: 100%; height: 100%; border: 0; }

.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.space-between { justify-content: space-between; width: 100%; }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 12px; border-radius: 12px;
  background: var(--btn); color: white; text-decoration: none;
  border: 1px solid rgba(255,255,255,0.12);
  font-weight: 600; font-size: 14px;
}
.btn:hover { filter: brightness(1.05); }
.btn.ghost { background: var(--btn2); color: var(--text); border: 1px solid var(--line); }
.btn.tiny { padding: 6px 10px; font-size: 12px; border-radius: 10px; }

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 12px;
}
@media (max-width: 720px) { .grid { grid-template-columns: 1fr; } }

.tile {
  display: block;
  padding: 14px;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: rgba(231,236,255,0.03);
  text-decoration: none;
  color: var(--text);
}
.tile strong { display: block; margin-bottom: 6px; }
.tile:hover { background: rgba(231,236,255,0.06); }

.table { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; margin-top: 10px; }
.trow { display: grid; grid-template-columns: 1.2fr 1fr 1.2fr 1.6fr; gap: 10px; padding: 10px 12px; border-top: 1px solid var(--line); }
.trow:first-child { border-top: 0; }
.thead { background: rgba(231,236,255,0.05); font-weight: 700; }

.mono { font-family: var(--mono); }
.box { padding: 12px; border-radius: var(--radius); border: 1px solid var(--line); background: rgba(0,0,0,0.25); }

.code {
  font-family: var(--mono);
  background: rgba(0,0,0,0.28);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px;
  overflow-x: auto;
}

.hint { margin-top: 10px; color: var(--muted); font-size: 13px; }

.footer { padding-bottom: 40px; }
.footer a { color: var(--muted); text-decoration: none; }
.footer a:hover { color: var(--text); }
.hidden { display: none; }