:root {
  --bg: #09090b;
  --panel: #111114;
  --line: #2b2b31;
  --text: #f4f4f5;
  --muted: #a1a1aa;
  --violet: #8b5cf6;
  --cyan: #22d3ee;
  --green: #34d399;
  --amber: #fbbf24;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--text);
}

body {
  font-family:
    Inter,
    ui-sans-serif,
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
}

button {
  font: inherit;
}

.shell {
  display: flex;
  max-width: 1180px;
  min-height: 100vh;
  margin: 0 auto;
  padding: 24px;
  flex-direction: column;
  gap: 20px;
}

header {
  display: grid;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
  grid-template-columns: 1fr auto;
  gap: 18px;
  align-items: end;
}

h1 {
  margin: 0 0 8px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2rem, 5vw, 3.7rem);
  font-weight: 500;
  letter-spacing: -0.04em;
}

header p {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.proof {
  color: var(--green);
  font:
    600 0.78rem ui-monospace,
    SFMono-Regular,
    Menlo,
    monospace;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  white-space: nowrap;
}

.layout {
  display: grid;
  min-height: 620px;
  flex: 1;
  grid-template-columns: 250px minmax(0, 1fr);
  gap: 18px;
}

nav {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.tab {
  padding: 14px;
  border: 1px solid transparent;
  border-radius: 12px;
  background: transparent;
  color: var(--muted);
  text-align: left;
  cursor: pointer;
  transition: 0.18s ease;
}

.tab strong {
  display: block;
  margin-bottom: 4px;
  color: inherit;
}

.tab small {
  display: block;
  line-height: 1.35;
}

.tab:hover {
  background: #ffffff08;
  color: var(--text);
}

.tab.active {
  border-color: #8b5cf666;
  background: #8b5cf618;
  color: #ddd6fe;
}

.note {
  padding: 14px;
  margin-top: auto;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #ffffff04;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.5;
}

.note strong {
  color: var(--cyan);
}

main {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 18px;
  background:
    radial-gradient(circle at 70% 20%, #312e811e, transparent 38%), var(--panel);
}

.view {
  display: none;
  min-height: 620px;
  padding: 28px;
}

.view.active {
  display: flex;
  flex-direction: column;
}

.view h2 {
  margin: 0 0 7px;
  font:
    500 1.45rem Georgia,
    serif;
}

.lede {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.viz {
  display: flex;
  min-height: 390px;
  margin-top: 18px;
  flex: 1;
  align-items: center;
  justify-content: center;
}

svg {
  width: 100%;
  height: 100%;
  max-height: 500px;
  overflow: visible;
}

.equation {
  overflow-x: auto;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #09090b99;
  color: #e4e4e7;
  font:
    clamp(0.76rem, 1.6vw, 1rem) / 1.8 ui-monospace,
    SFMono-Regular,
    Menlo,
    monospace;
}

.equation b {
  color: var(--cyan);
}

.cards {
  display: grid;
  width: 100%;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.card {
  min-width: 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #09090b99;
}

.card h3 {
  margin: 0 0 8px;
  font-size: 0.95rem;
}

.matrix {
  overflow-x: auto;
  margin: 10px 0;
  color: #d4d4d8;
  font:
    0.73rem/1.5 ui-monospace,
    monospace;
  white-space: pre;
}

.det {
  display: inline-flex;
  padding: 4px 8px;
  border: 1px solid #34d39955;
  border-radius: 999px;
  color: var(--green);
  font:
    700 0.72rem ui-monospace,
    monospace;
}

.mini {
  width: 100%;
  height: 180px;
}

.facts {
  display: grid;
  width: 100%;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.fact {
  padding: 4px 0 4px 16px;
  border-left: 2px solid var(--violet);
}

.fact h3 {
  margin: 0 0 6px;
  font-size: 1rem;
}

.fact p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.warning {
  padding: 14px;
  margin-top: 20px;
  border: 1px solid #fbbf2440;
  border-radius: 12px;
  background: #fbbf240b;
  color: #fde68a;
  line-height: 1.5;
}

@media (max-width: 800px) {
  .shell {
    padding: 14px;
  }

  header {
    grid-template-columns: 1fr;
  }

  .proof {
    white-space: normal;
  }

  .layout {
    min-height: 0;
    grid-template-columns: 1fr;
  }

  nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .note {
    margin-top: 0;
    grid-column: 1 / -1;
  }

  .view {
    min-height: 680px;
    padding: 18px;
  }

  .cards,
  .facts {
    grid-template-columns: 1fr;
  }
}