:root {
  --bg: #000000;
  --ink: #e9ebf4;
  --muted: #a6acc4;
  --purple: #a78bfa;
  --blue: #7aa2ff;
  --green: #6fe7b7;
  --gold: #e9bb5f;
  --card: rgba(10, 10, 10, 0.85);
  --line: rgba(233, 235, 244, 0.08);
  --border: rgba(122, 162, 255, 0.2);
  --danger: #f87171;
  --font-display: "Playfair Display", Georgia, serif;
  --font-body: "Inter", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

* { box-sizing: border-box; }
html, body {
  margin: 0; min-height: 100%;
  background: var(--bg); color: var(--ink); font-family: var(--font-body);
}

/* ---- Atmosphere: pure black void, stars only, no other colouring ---- */
.stars {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image:
    radial-gradient(1px 1px at 6% 18%, rgba(201,206,223,0.48) 50%, transparent 51%),
    radial-gradient(1px 1px at 16% 44%, rgba(201,206,223,0.32) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 24% 70%, rgba(201,206,223,0.6) 50%, transparent 51%),
    radial-gradient(1px 1px at 33% 15%, rgba(201,206,223,0.36) 50%, transparent 51%),
    radial-gradient(2px 2px at 40% 55%, rgba(201,206,223,0.62) 50%, transparent 51%),
    radial-gradient(1px 1px at 49% 88%, rgba(201,206,223,0.4) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 57% 27%, rgba(201,206,223,0.54) 50%, transparent 51%),
    radial-gradient(1px 1px at 64% 63%, rgba(201,206,223,0.3) 50%, transparent 51%),
    radial-gradient(1px 1px at 71% 9%, rgba(201,206,223,0.58) 50%, transparent 51%),
    radial-gradient(2px 2px at 80% 47%, rgba(201,206,223,0.42) 50%, transparent 51%),
    radial-gradient(1px 1px at 88% 78%, rgba(201,206,223,0.52) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 94% 22%, rgba(201,206,223,0.36) 50%, transparent 51%),
    radial-gradient(1px 1px at 3% 60%, rgba(201,206,223,0.46) 50%, transparent 51%),
    radial-gradient(1px 1px at 11% 92%, rgba(201,206,223,0.28) 50%, transparent 51%),
    radial-gradient(2px 2px at 20% 33%, rgba(201,206,223,0.63) 50%, transparent 51%),
    radial-gradient(1px 1px at 29% 5%, rgba(201,206,223,0.34) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 36% 80%, rgba(201,206,223,0.49) 50%, transparent 51%),
    radial-gradient(1px 1px at 44% 40%, rgba(201,206,223,0.4) 50%, transparent 51%),
    radial-gradient(1px 1px at 53% 68%, rgba(201,206,223,0.56) 50%, transparent 51%),
    radial-gradient(2px 2px at 61% 12%, rgba(201,206,223,0.36) 50%, transparent 51%),
    radial-gradient(1px 1px at 68% 84%, rgba(201,206,223,0.6) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 76% 30%, rgba(201,206,223,0.32) 50%, transparent 51%),
    radial-gradient(1px 1px at 83% 58%, rgba(201,206,223,0.48) 50%, transparent 51%),
    radial-gradient(1px 1px at 91% 8%, rgba(201,206,223,0.4) 50%, transparent 51%),
    radial-gradient(1.5px 1.5px at 97% 72%, rgba(201,206,223,0.54) 50%, transparent 51%),
    radial-gradient(5px 5px at 15% 27%, rgba(201,206,223,0.73) 0%, rgba(201,206,223,0.25) 45%, transparent 72%),
    radial-gradient(6px 6px at 48% 63%, rgba(201,206,223,0.66) 0%, rgba(201,206,223,0.22) 45%, transparent 72%),
    radial-gradient(5px 5px at 72% 18%, rgba(201,206,223,0.7) 0%, rgba(201,206,223,0.24) 45%, transparent 72%),
    radial-gradient(6px 6px at 90% 50%, rgba(201,206,223,0.64) 0%, rgba(201,206,223,0.22) 45%, transparent 72%),
    radial-gradient(5px 5px at 30% 90%, rgba(201,206,223,0.71) 0%, rgba(201,206,223,0.24) 45%, transparent 72%);
}
@media (prefers-reduced-motion: no-preference) {
  .stars { animation: twinkle 7.5s ease-in-out infinite; }
}
@keyframes twinkle { 0%, 100% { opacity: .72; } 50% { opacity: 1; } }

.top {
  display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center;
  gap: 1rem; padding: 1rem 1.25rem; border-bottom: 1px solid var(--line);
}
.brand { display: flex; gap: 0.75rem; align-items: center; }
.brand h1 { margin: 0; font-family: var(--font-display); font-weight: 600; font-size: 1.25rem; letter-spacing: 0.01em; }
.sub { margin: 0; color: var(--muted); font-size: 0.8rem; }
.mark {
  width: 34px; height: 34px; border-radius: 50%;
  background: conic-gradient(from 200deg, var(--purple), var(--blue), var(--gold), var(--purple));
  box-shadow: 0 0 20px rgba(167, 139, 250, 0.4);
}
.meta { display: flex; flex-wrap: wrap; gap: 0.4rem; align-items: center; }
.pill {
  font-size: 0.7rem; padding: 0.25rem 0.55rem; border-radius: 999px;
  border: 1px solid var(--border); color: var(--blue);
}
.pill.gold { color: var(--gold); border-color: rgba(233, 187, 95, 0.4); }
.pill.muted { color: var(--muted); }

.nav {
  display: flex; flex-wrap: wrap; gap: 0.35rem;
  padding: 0.55rem 1.25rem; border-bottom: 1px solid var(--line);
  background: rgba(0, 0, 0, 0.4);
}
.nav-btn {
  background: transparent; border: 1px solid transparent; color: var(--muted);
  padding: 0.4rem 0.75rem; border-radius: 8px; cursor: pointer; font-size: 0.85rem; font-family: var(--font-body);
}
.nav-btn:hover { color: var(--ink); border-color: var(--border); }
.nav-btn.active {
  color: #050208; background: var(--purple); border-color: var(--purple); font-weight: 600;
}

main { padding: 1.25rem; max-width: 920px; margin: 0 auto; }
.panel { display: none; }
.panel.active { display: block; animation: fade 0.2s ease; }
@keyframes fade {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: none; }
}
.panel-head {
  display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center;
  gap: 0.75rem; margin-bottom: 0.75rem;
}
.panel-head h2 { margin: 0; font-family: var(--font-display); font-weight: 600; font-size: 1.15rem; }

.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 14px; padding: 1.1rem 1.2rem; margin-bottom: 0.75rem;
}
.hero h2 { margin-top: 0; font-family: var(--font-display); font-weight: 600; font-size: 1.3rem; }
.stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0.5rem; margin: 1rem 0;
}
.stats .n { display: block; font-size: 1.35rem; color: var(--blue); font-weight: 700; }
.stats .l { font-size: 0.7rem; color: var(--muted); }
@media (max-width: 600px) { .stats { grid-template-columns: 1fr 1fr; } }

.row { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; }
.btn {
  display: inline-block; text-decoration: none;
  background: rgba(122, 162, 255, 0.1); border: 1px solid var(--border);
  color: var(--ink); padding: 0.45rem 0.9rem; border-radius: 8px;
  cursor: pointer; font-size: 0.85rem; font-family: var(--font-body);
}
.btn:hover { border-color: var(--blue); }
.btn.primary { background: var(--purple); color: #050208; border-color: var(--purple); font-weight: 600; }
.btn.danger { border-color: rgba(248, 113, 113, 0.5); color: var(--danger); }

label {
  display: block; margin: 0.6rem 0; font-size: 0.85rem; color: var(--muted);
}
label select, label input {
  display: block; margin-top: 0.25rem; width: min(100%, 280px);
  background: var(--bg); border: 1px solid var(--border); color: var(--ink);
  padding: 0.4rem 0.55rem; border-radius: 8px; font-family: var(--font-body);
}
.chk { display: inline-flex; align-items: center; gap: 0.35rem; color: var(--muted); font-size: 0.85rem; }

#twinCanvas {
  width: 100%; height: auto; border-radius: 12px;
  border: 1px solid var(--border); background: var(--bg); display: block;
}

.table { width: 100%; border-collapse: collapse; font-size: 0.85rem; }
.table th, .table td {
  text-align: left; padding: 0.5rem 0.45rem;
  border-bottom: 1px solid var(--line);
}
.table th { color: var(--muted); font-weight: 500; }

.code {
  background: var(--bg); border: 1px solid var(--border); border-radius: 8px;
  padding: 0.75rem; font-size: 0.78rem; overflow: auto; color: var(--green);
  font-family: var(--font-mono);
}
.mono { font-family: var(--font-mono); }
.muted { color: var(--muted); font-size: 0.85rem; }
.journey { color: var(--ink); line-height: 1.7; padding-left: 1.2rem; }

.foot {
  text-align: center; padding: 1.5rem; color: var(--muted); font-size: 0.8rem;
  border-top: 1px solid var(--line); margin-top: 2rem;
}
.foot a { color: var(--blue); }

.toast {
  position: fixed; bottom: 1.25rem; left: 50%; transform: translateX(-50%) translateY(20px);
  background: #0a0a0a; border: 1px solid var(--blue); color: var(--ink);
  padding: 0.55rem 1rem; border-radius: 10px; opacity: 0; pointer-events: none;
  transition: opacity 0.2s, transform 0.2s; z-index: 50; font-size: 0.85rem;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }