/* Widget suite — color-first flashcard study tools (2D only; no 3D) */
:root {
  --bg: #0f172a;
  --bg-elevated: #111827;
  --surface: #1a2438;
  --surface2: #22304a;
  --surface3: #2c3d5c;
  --border: #334155;
  --border-soft: #2a3548;
  --text: #f1f5f9;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --accent-dim: #0ea5e9;
  --accent-glow: rgba(56, 189, 248, 0.22);
  --accent-soft: rgba(14, 165, 233, 0.14);
  --good: #22c55e;
  --good-bright: #4ade80;
  --good-dim: rgba(34, 197, 94, 0.16);
  --warn: #fbbf24;
  --warn-dim: rgba(251, 191, 36, 0.16);
  --bad: #f87171;
  --bad-dim: rgba(248, 113, 113, 0.16);
  --hot: #fb923c;
  --coral: #fb7185;
  --gold: #facc15;
  --purple: #a78bfa;
  --amber: #f59e0b;
  --teal: #2dd4bf;
  /* Domain families */
  --d1: #38bdf8;
  --d1-deep: #0284c7;
  --d1-soft: rgba(56, 189, 248, 0.14);
  --d1-strip: #0ea5e9;
  --d1-pastel: #bae6fd;
  --d2: #2dd4bf;
  --d2-deep: #0d9488;
  --d2-soft: rgba(45, 212, 191, 0.14);
  --d2-strip: #14b8a6;
  --d2-pastel: #99f6e4;
  --d3: #a78bfa;
  --d3-deep: #7c3aed;
  --d3-soft: rgba(167, 139, 250, 0.14);
  --d3-strip: #8b5cf6;
  --d3-pastel: #ddd6fe;
  --d3-amber: #fbbf24;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow: 0 8px 28px rgba(0, 0, 0, 0.35);
  --shadow-soft: 0 2px 12px rgba(0, 0, 0, 0.22);
  --font: "Segoe UI", system-ui, -apple-system, sans-serif;
  --mono: ui-monospace, "Cascadia Code", "SF Mono", Consolas, monospace;
  --focus: 0 0 0 3px var(--accent-glow);
}

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

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  background:
    radial-gradient(1100px 560px at 8% -8%, rgba(14, 165, 233, 0.12), transparent 55%),
    radial-gradient(900px 480px at 92% 0%, rgba(167, 139, 250, 0.1), transparent 50%),
    radial-gradient(700px 400px at 50% 100%, rgba(45, 212, 191, 0.06), transparent 55%),
    var(--bg);
  color: var(--text);
  font-family: var(--font);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

/* Domain-tinted page glow */
body.domain-d1 {
  background:
    radial-gradient(1100px 560px at 10% -10%, rgba(14, 165, 233, 0.18), transparent 55%),
    radial-gradient(700px 400px at 90% 20%, rgba(56, 189, 248, 0.08), transparent 50%),
    var(--bg);
}
body.domain-d2 {
  background:
    radial-gradient(1100px 560px at 10% -10%, rgba(20, 184, 166, 0.18), transparent 55%),
    radial-gradient(700px 400px at 90% 20%, rgba(45, 212, 191, 0.08), transparent 50%),
    var(--bg);
}
body.domain-d3 {
  background:
    radial-gradient(1100px 560px at 10% -10%, rgba(139, 92, 246, 0.18), transparent 55%),
    radial-gradient(700px 400px at 90% 30%, rgba(251, 191, 36, 0.08), transparent 50%),
    var(--bg);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; color: #7dd3fc; }
body.domain-d2 a { color: var(--teal); }
body.domain-d2 a:hover { color: #5eead4; }
body.domain-d3 a { color: #c4b5fd; }
body.domain-d3 a:hover { color: #ddd6fe; }

.app {
  max-width: 1040px;
  margin: 0 auto;
  padding: 1.35rem 1.35rem 3.5rem;
}
@media (max-width: 640px) {
  .app { padding: 1rem 0.9rem 2.75rem; }
}

/* ——— Header ——— */
header.app-header {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.85rem;
  margin-bottom: 1.15rem;
  padding-bottom: 1.1rem;
  border-bottom: 3px solid var(--border);
}
body.domain-d1 header.app-header { border-bottom-color: var(--d1-deep); }
body.domain-d2 header.app-header { border-bottom-color: var(--d2-deep); }
body.domain-d3 header.app-header { border-bottom-color: var(--d3-deep); }

header h1 {
  margin: 0;
  font-size: clamp(1.35rem, 2.6vw, 1.7rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
}

header .sub {
  color: var(--muted);
  font-size: 0.92rem;
  margin: 0.35rem 0 0;
  max-width: 42rem;
}

.header-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  align-items: center;
  justify-content: flex-end;
}

/* ——— Badges ——— */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.28rem 0.65rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 650;
  letter-spacing: 0.02em;
  background: #0c4a6e;
  color: #7dd3fc;
  border: 1px solid #0284c7;
  white-space: nowrap;
}
.badge.year {
  background: #14532d;
  color: #86efac;
  border-color: #22c55e;
}
.badge.hot {
  background: #7c2d12;
  color: #fed7aa;
  border-color: #ea580c;
}
.badge.new {
  background: #164e63;
  color: #a5f3fc;
  border-color: #0891b2;
}
.badge.d1 {
  background: #0c4a6e;
  color: #bae6fd;
  border-color: #0ea5e9;
}
.badge.d2 {
  background: #134e4a;
  color: #99f6e4;
  border-color: #14b8a6;
}
.badge.d3 {
  background: #4c1d95;
  color: #ddd6fe;
  border-color: #8b5cf6;
}
/* legacy — hide if any remain */
.badge.viz3d { display: none !important; }

/* Semantic chips */
.chip {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.22rem 0.6rem;
  border-radius: 999px;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  border: 1px solid transparent;
}
.chip-trap {
  background: #7c2d12;
  color: #ffedd5;
  border-color: #fb923c;
}
.chip-answer, .chip-total {
  background: #14532d;
  color: #bbf7d0;
  border-color: #22c55e;
}
.chip-gold {
  background: #713f12;
  color: #fef08a;
  border-color: #facc15;
}
.chip-watch {
  background: #713f12;
  color: #fef9c3;
  border-color: #fbbf24;
}
.chip-safe {
  background: #14532d;
  color: #bbf7d0;
  border-color: #4ade80;
}
.chip-danger {
  background: #7f1d1d;
  color: #fecaca;
  border-color: #f87171;
}

/* ——— Page intro (colored flashcard) ——— */
.page-intro {
  margin: 0 0 1.15rem;
  padding: 1.05rem 1.2rem 1.05rem 1.15rem;
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.2), rgba(167, 139, 250, 0.12));
  border: 1px solid rgba(56, 189, 248, 0.45);
  border-left: 5px solid var(--accent);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
}
body.domain-d1 .page-intro {
  background: linear-gradient(135deg, rgba(14, 165, 233, 0.22), rgba(56, 189, 248, 0.08));
  border-color: rgba(14, 165, 233, 0.5);
  border-left-color: var(--d1);
}
body.domain-d2 .page-intro {
  background: linear-gradient(135deg, rgba(20, 184, 166, 0.22), rgba(45, 212, 191, 0.08));
  border-color: rgba(20, 184, 166, 0.5);
  border-left-color: var(--d2);
}
body.domain-d3 .page-intro {
  background: linear-gradient(135deg, rgba(139, 92, 246, 0.22), rgba(251, 191, 36, 0.1));
  border-color: rgba(139, 92, 246, 0.5);
  border-left-color: var(--d3);
}
.page-intro .eyebrow {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin: 0 0 0.35rem;
}
body.domain-d2 .page-intro .eyebrow { color: var(--teal); }
body.domain-d3 .page-intro .eyebrow { color: #c4b5fd; }
.page-intro p {
  margin: 0;
  font-size: 1.02rem;
  color: var(--text);
  line-height: 1.5;
}
.page-intro .hint {
  margin-top: 0.45rem;
  font-size: 0.88rem;
  color: var(--muted);
}

/* ——— Cards ——— */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
  margin-bottom: 1.1rem;
  box-shadow: var(--shadow-soft);
  border-top: 3px solid var(--border);
}
body.domain-d1 .card { border-top-color: rgba(14, 165, 233, 0.55); }
body.domain-d2 .card { border-top-color: rgba(20, 184, 166, 0.55); }
body.domain-d3 .card { border-top-color: rgba(139, 92, 246, 0.55); }
.card h2 {
  margin: 0 0 0.35rem;
  font-size: 1.12rem;
  font-weight: 700;
  letter-spacing: -0.01em;
}
.card h2 + .section-lead,
.card .section-lead {
  margin: 0 0 0.9rem;
  color: var(--muted);
  font-size: 0.9rem;
}
.card h3 {
  margin: 1.15rem 0 0.55rem;
  font-size: 0.95rem;
  color: var(--accent);
  font-weight: 650;
}
body.domain-d2 .card h3 { color: var(--teal); }
body.domain-d3 .card h3 { color: #c4b5fd; }
.card > h3:first-child { margin-top: 0; }

.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
.mono { font-family: var(--mono); }

/* ——— Flashcard teaching beats ——— */
.fc {
  margin: 0.75rem 0;
  padding: 0.85rem 1rem 0.85rem 1.05rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  border-left: 5px solid var(--border);
  font-size: 0.9rem;
  line-height: 1.45;
}
.fc-rule {
  border-left-color: var(--accent);
  background: rgba(56, 189, 248, 0.12);
  border-color: rgba(56, 189, 248, 0.35);
}
.fc-example {
  border-left-color: var(--purple);
  background: rgba(167, 139, 250, 0.12);
  border-color: rgba(167, 139, 250, 0.35);
}
.fc-trap, .trap {
  margin-top: 1.1rem;
  padding: 0.95rem 1.1rem 0.95rem 1.15rem;
  border-radius: var(--radius-sm);
  border: 1px solid #ea580c;
  border-left: 5px solid #fb923c;
  background: linear-gradient(135deg, rgba(234, 88, 12, 0.22), rgba(251, 113, 133, 0.12));
  font-size: 0.9rem;
  box-shadow: inset 0 0 0 1px rgba(251, 146, 60, 0.12);
}
.fc-trap strong, .trap strong {
  color: #fdba74;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.fc-trap strong::before, .trap strong::before {
  content: "⚠";
  font-size: 0.95em;
}
.fc-result {
  border-left-color: var(--good-bright);
  background: linear-gradient(135deg, rgba(34, 197, 94, 0.18), rgba(250, 204, 21, 0.1));
  border-color: rgba(34, 197, 94, 0.4);
}
.fc-watch {
  border-left-color: var(--warn);
  background: rgba(251, 191, 36, 0.14);
  border-color: rgba(251, 191, 36, 0.4);
  color: #fef3c7;
}
.fc-safe {
  border-left-color: var(--good);
  background: var(--good-dim);
  border-color: rgba(34, 197, 94, 0.4);
}
.fc-danger {
  border-left-color: var(--bad);
  background: var(--bad-dim);
  border-color: rgba(248, 113, 113, 0.4);
}
.fc .fc-label {
  display: block;
  font-size: 0.68rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  margin-bottom: 0.3rem;
  opacity: 0.9;
}
.fc-rule .fc-label { color: #7dd3fc; }
.fc-example .fc-label { color: #c4b5fd; }
.fc-result .fc-label { color: #86efac; }
.fc-watch .fc-label { color: #fde68a; }
.fc-safe .fc-label { color: #86efac; }
.fc-danger .fc-label { color: #fca5a5; }
.fc-trap .fc-label { color: #fdba74; }

.callout {
  margin: 0.75rem 0;
  padding: 0.85rem 1rem 0.85rem 1.05rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  border-left: 5px solid var(--border);
  background: var(--surface2);
  font-size: 0.9rem;
}
.callout.info {
  border-left-color: var(--accent);
  border-color: rgba(56, 189, 248, 0.35);
  background: var(--accent-soft);
}
.callout.good {
  border-left-color: var(--good);
  border-color: rgba(74, 222, 128, 0.35);
  background: var(--good-dim);
}
.callout.warn {
  border-left-color: var(--warn);
  border-color: rgba(251, 191, 36, 0.4);
  background: var(--warn-dim);
}
.callout.danger {
  border-left-color: var(--bad);
  border-color: rgba(248, 113, 113, 0.4);
  background: var(--bad-dim);
}

/* ——— Buttons ——— */
.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-top: 0.95rem;
}

button, .btn {
  appearance: none;
  border: 1px solid var(--border);
  background: var(--surface2);
  color: var(--text);
  font: inherit;
  font-size: 0.92rem;
  padding: 0.58rem 1.05rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: border-color 0.12s, background 0.12s, box-shadow 0.12s;
}
button:hover, .btn:hover {
  border-color: var(--accent);
  text-decoration: none;
  background: var(--surface3);
}
button:focus-visible, .btn:focus-visible, .field input:focus-visible, .field select:focus-visible {
  outline: none;
  box-shadow: var(--focus);
  border-color: var(--accent);
}
button.primary {
  background: linear-gradient(180deg, #38bdf8, #0ea5e9);
  border-color: #7dd3fc;
  color: #0b1220;
  font-weight: 700;
}
body.domain-d2 button.primary {
  background: linear-gradient(180deg, #2dd4bf, #0d9488);
  border-color: #99f6e4;
}
body.domain-d3 button.primary {
  background: linear-gradient(180deg, #a78bfa, #7c3aed);
  border-color: #ddd6fe;
  color: #1e1035;
}
button.primary:hover { filter: brightness(1.06); }
button.ghost, .btn.ghost { background: transparent; }
button.active-toggle {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: #7dd3fc;
  box-shadow: inset 0 0 0 1px rgba(56, 189, 248, 0.25);
}
body.domain-d2 button.active-toggle {
  background: var(--d2-soft);
  border-color: var(--d2);
  color: #99f6e4;
}
body.domain-d3 button.active-toggle {
  background: var(--d3-soft);
  border-color: var(--d3);
  color: #ddd6fe;
}

/* ——— Fields ——— */
.field-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.95rem 1rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.field > span, .field > label {
  font-size: 0.8rem;
  color: var(--muted);
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.3;
}
.field input[type="number"],
.field input[type="text"],
.field select,
.field textarea {
  padding: 0.7rem 0.85rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text);
  font: inherit;
  font-family: var(--mono);
  font-size: 1rem;
  width: 100%;
  transition: border-color 0.12s, box-shadow 0.12s;
}
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: var(--focus);
}
.field input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  height: 1.4rem;
}
body.domain-d2 .field input[type="range"] { accent-color: var(--d2); }
body.domain-d3 .field input[type="range"] { accent-color: var(--d3); }
.field .hint {
  font-size: 0.75rem;
  color: var(--muted);
  font-weight: 400;
}

.check-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.check-list label {
  display: flex;
  gap: 0.7rem;
  align-items: flex-start;
  padding: 0.75rem 0.95rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-left: 4px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: border-color 0.12s, background 0.12s;
}
.check-list label:hover { border-color: var(--accent); background: var(--surface3); }
.check-list input { margin-top: 0.25rem; accent-color: var(--accent); width: 1.05rem; height: 1.05rem; }

/* ——— Progressive step rail (colorful) ——— */
.step-rail {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin: 0.75rem 0 1rem;
  position: relative;
}
.step-rail::before {
  content: "";
  position: absolute;
  left: 1.55rem;
  top: 1.4rem;
  bottom: 1.4rem;
  width: 3px;
  background: linear-gradient(180deg, var(--good-bright), var(--accent), var(--border));
  opacity: 0.55;
  z-index: 0;
  border-radius: 2px;
}
.step {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.85rem;
  align-items: center;
  padding: 0.8rem 1rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-left: 4px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 0.55rem;
  position: relative;
  z-index: 1;
  transition: border-color 0.15s, background 0.15s, opacity 0.15s;
}
.step .n {
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--surface3);
  color: var(--muted);
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.78rem;
  font-weight: 700;
  flex-shrink: 0;
}
.step .label { font-size: 0.92rem; }
.step .amt {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 0.98rem;
  white-space: nowrap;
}
.step.up .amt { color: var(--good-bright); }
.step.down .amt { color: var(--bad); }
.step.neutral .amt { color: var(--warn); }
.step.done {
  border-color: rgba(34, 197, 94, 0.45);
  border-left-color: var(--good);
  background: var(--good-dim);
}
.step.done .n {
  background: #166534;
  border-color: var(--good-bright);
  color: #bbf7d0;
}
.step.current {
  border-color: var(--accent);
  border-left-color: var(--accent);
  background: rgba(56, 189, 248, 0.18);
  box-shadow: 0 0 0 1px rgba(56, 189, 248, 0.28);
}
.step.current .n {
  background: #0369a1;
  border-color: #7dd3fc;
  color: #e0f2fe;
}
.step.upcoming {
  opacity: 0.5;
  border-left-color: #64748b;
  background: rgba(100, 116, 139, 0.12);
}
.step.result {
  border-color: rgba(250, 204, 21, 0.5);
  border-left-color: var(--gold);
  background: linear-gradient(135deg, rgba(34, 197, 94, 0.16), rgba(250, 204, 21, 0.14));
}
.step.result .n {
  background: #854d0e;
  border-color: var(--gold);
  color: #fef08a;
}
.step.danger-step {
  border-left-color: var(--bad);
  border-color: rgba(248, 113, 113, 0.45);
  background: var(--bad-dim);
}
.step.safe-step {
  border-left-color: var(--good);
  border-color: rgba(34, 197, 94, 0.45);
  background: var(--good-dim);
}

/* ——— Meters ——— */
.meter-wrap { margin: 0.55rem 0; }
.meter-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--muted);
  margin-bottom: 0.3rem;
  gap: 0.5rem;
}
.meter {
  height: 14px;
  background: #0f172a;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
}
.meter > span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--accent-dim), var(--accent));
  border-radius: 7px;
  transition: width 0.35s ease;
  min-width: 0;
}
.meter.good > span { background: linear-gradient(90deg, #16a34a, var(--good-bright)); }
.meter.warn > span { background: linear-gradient(90deg, #d97706, var(--warn)); }
.meter.bad > span { background: linear-gradient(90deg, #dc2626, var(--bad)); }
.meter.purple > span { background: linear-gradient(90deg, #7c3aed, var(--purple)); }
.meter.teal > span { background: linear-gradient(90deg, #0d9488, var(--teal)); }

/* ——— Hero pills / running total ——— */
.hero-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 0.75rem;
  margin: 0.85rem 0 1rem;
}
.hero-stat {
  background: linear-gradient(160deg, var(--surface2), var(--bg-elevated));
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 1rem 1.15rem;
  text-align: center;
  box-shadow: var(--shadow-soft);
}
.hero-stat .label {
  font-size: 0.72rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 650;
}
.hero-stat .value {
  font-size: clamp(1.4rem, 3.5vw, 1.8rem);
  font-weight: 800;
  font-family: var(--mono);
  margin-top: 0.3rem;
  letter-spacing: -0.02em;
  line-height: 1.15;
}
.hero-stat .value.good { color: var(--good-bright); }
.hero-stat .value.bad { color: var(--bad); }
.hero-stat .value.warn { color: var(--warn); }
.hero-stat .value.accent { color: var(--accent); }
.hero-stat .value.gold { color: var(--gold); }
.hero-stat .sublabel {
  font-size: 0.75rem;
  color: var(--muted);
  margin-top: 0.25rem;
}
.hero-stat.pill-blue {
  background: linear-gradient(160deg, rgba(14, 165, 233, 0.28), rgba(14, 165, 233, 0.08));
  border-color: rgba(56, 189, 248, 0.55);
}
.hero-stat.pill-green {
  background: linear-gradient(160deg, rgba(34, 197, 94, 0.28), rgba(34, 197, 94, 0.08));
  border-color: rgba(74, 222, 128, 0.55);
}
.hero-stat.pill-gold {
  background: linear-gradient(160deg, rgba(250, 204, 21, 0.28), rgba(250, 204, 21, 0.08));
  border-color: rgba(250, 204, 21, 0.55);
}
.hero-stat.pill-coral {
  background: linear-gradient(160deg, rgba(251, 113, 133, 0.28), rgba(251, 146, 60, 0.1));
  border-color: rgba(251, 113, 133, 0.55);
}
.hero-stat.pill-purple {
  background: linear-gradient(160deg, rgba(167, 139, 250, 0.28), rgba(167, 139, 250, 0.08));
  border-color: rgba(167, 139, 250, 0.55);
}
.hero-stat.pill-teal {
  background: linear-gradient(160deg, rgba(45, 212, 191, 0.28), rgba(45, 212, 191, 0.08));
  border-color: rgba(45, 212, 191, 0.55);
}

.running-total {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin: 0.85rem 0;
  padding: 0.95rem 1.15rem;
  border-radius: var(--radius);
  border: 2px solid rgba(34, 197, 94, 0.55);
  background: linear-gradient(90deg, rgba(34, 197, 94, 0.2), rgba(250, 204, 21, 0.14));
  box-shadow: var(--shadow-soft);
}
.running-total .rt-label {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: #86efac;
}
.running-total .rt-value {
  font-family: var(--mono);
  font-size: 1.55rem;
  font-weight: 800;
  color: var(--gold);
}
.running-total .rt-note {
  flex: 1 1 100%;
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.65rem;
  margin: 0.75rem 0;
}
.stat {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.85rem;
}
.stat .label {
  font-size: 0.72rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
}
.stat .value {
  font-size: 1.12rem;
  font-weight: 700;
  font-family: var(--mono);
  margin-top: 0.15rem;
}
.stat .value.good { color: var(--good-bright); }
.stat .value.bad { color: var(--bad); }
.stat .value.warn { color: var(--warn); }
.stat .hint {
  font-size: 0.72rem;
  color: var(--muted);
  margin-top: 0.2rem;
}

/* ——— Tree / flow ——— */
.tree-node {
  margin: 0.45rem 0 0.45rem 0.35rem;
  padding: 0.75rem 0.95rem;
  border-left: 4px solid var(--border);
  background: var(--surface2);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.tree-node.active {
  border-left-color: var(--accent);
  background: var(--accent-soft);
}
.tree-node.leaf-good { border-left-color: var(--good); background: var(--good-dim); }
.tree-node.leaf-bad { border-left-color: var(--bad); background: var(--bad-dim); }
.tree-node.leaf-warn { border-left-color: var(--warn); background: var(--warn-dim); }

.flow-row {
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
  gap: 0.45rem;
  margin: 0.85rem 0;
}
.flow-box {
  flex: 1 1 120px;
  min-width: 100px;
  padding: 0.75rem 0.85rem;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  text-align: center;
  font-size: 0.85rem;
}
.flow-box strong { display: block; font-size: 0.95rem; margin-bottom: 0.2rem; }
.flow-box.active {
  border-color: var(--accent);
  background: var(--accent-soft);
  box-shadow: 0 0 0 1px rgba(56, 189, 248, 0.2);
}
.flow-box.good { border-top-color: var(--good); border-color: rgba(74, 222, 128, 0.45); background: var(--good-dim); }
.flow-box.warn { border-top-color: var(--warn); background: var(--warn-dim); }
.flow-box.danger { border-top-color: var(--bad); background: var(--bad-dim); }
.flow-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  font-size: 1.25rem;
  font-weight: 700;
  flex: 0 0 auto;
  padding: 0 0.15rem;
  opacity: 0.85;
}
@media (max-width: 640px) {
  .flow-arrow { transform: rotate(90deg); width: 100%; padding: 0.15rem 0; }
}

.toggle-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin: 0.55rem 0;
}

.compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}
@media (max-width: 640px) {
  .compare-grid { grid-template-columns: 1fr; }
  .step { grid-template-columns: auto 1fr; }
  .step .amt { grid-column: 2; }
  .step-rail::before { left: 1.35rem; }
}

/* ——— Chart / viz panels ——— */
.viz-panel {
  margin: 0.85rem 0 0.5rem;
  padding: 0.85rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}
.viz-panel .viz-title {
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin: 0 0 0.55rem 0.15rem;
}
.chart-box {
  width: 100%;
  min-height: 280px;
}
.chart-box.tall { min-height: 380px; }
.chart-box.short { min-height: 220px; }

/* Inventory tank (COGS) */
.tank {
  position: relative;
  height: 180px;
  max-width: 160px;
  margin: 0.5rem auto;
  border: 2px solid var(--border);
  border-radius: 12px 12px 8px 8px;
  background: #0f172a;
  overflow: hidden;
}
.tank-fill {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  background: linear-gradient(180deg, #38bdf8, #0369a1);
  transition: height 0.4s ease;
  opacity: 0.85;
}
.tank-label {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 1;
  font-family: var(--mono);
  font-weight: 700;
  text-shadow: 0 1px 4px #000;
  pointer-events: none;
}
.tank-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.25rem;
  margin: 0.75rem 0;
}
.tank-cap {
  text-align: center;
  font-size: 0.8rem;
  color: var(--muted);
}

/* Stacked composition bars */
.stack-bar {
  display: flex;
  height: 28px;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: #0f172a;
  margin: 0.5rem 0;
}
.stack-bar > span {
  display: block;
  height: 100%;
  transition: width 0.35s ease;
  min-width: 0;
}
.legend-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.1rem;
  margin: 0.45rem 0 0.75rem;
  font-size: 0.8rem;
  color: var(--muted);
}
.legend-row i {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  margin-right: 0.35rem;
  vertical-align: middle;
}

/* Assumptions = watch-out yellow */
.assumptions {
  margin: 0.75rem 0;
  padding: 0.7rem 0.95rem 0.7rem 1.05rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(251, 191, 36, 0.55);
  border-left: 5px solid var(--warn);
  background: rgba(251, 191, 36, 0.14);
  font-size: 0.82rem;
  color: #fef3c7;
}
.assumptions strong { color: var(--warn); }

/* ——— Catalog — flashcard board ——— */
.catalog-intro {
  margin: 0 0 1.25rem;
  padding: 1.1rem 1.25rem;
  border-radius: var(--radius);
  border: 1px solid rgba(56, 189, 248, 0.4);
  border-left: 5px solid var(--accent);
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.16), rgba(167, 139, 250, 0.12), rgba(45, 212, 191, 0.08));
}
.catalog-intro h2 { margin: 0 0 0.4rem; font-size: 1.1rem; }
.catalog-intro p { margin: 0; color: var(--muted); font-size: 0.92rem; }

.catalog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 0.95rem;
}
.catalog-card {
  display: block;
  padding: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: inherit;
  transition: border-color 0.15s, transform 0.12s, box-shadow 0.15s;
  box-shadow: var(--shadow-soft);
  position: relative;
  overflow: hidden;
}
.catalog-card .card-strip {
  height: 8px;
  width: 100%;
  background: var(--accent);
}
.catalog-card.d1 .card-strip { background: linear-gradient(90deg, #0284c7, #38bdf8, #7dd3fc); }
.catalog-card.d2 .card-strip { background: linear-gradient(90deg, #0d9488, #2dd4bf, #5eead4); }
.catalog-card.d3 .card-strip { background: linear-gradient(90deg, #7c3aed, #a78bfa, #fbbf24); }
.catalog-card.featured .card-strip {
  height: 10px;
  background: linear-gradient(90deg, #0ea5e9, #2dd4bf, #a78bfa, #fbbf24);
}
.catalog-card .card-body {
  padding: 0.95rem 1.1rem 1.1rem;
}
.catalog-card:hover {
  border-color: var(--accent);
  text-decoration: none;
  transform: translateY(-3px);
  box-shadow: var(--shadow);
}
.catalog-card.d1:hover { border-color: var(--d1); }
.catalog-card.d2:hover { border-color: var(--d2); }
.catalog-card.d3:hover { border-color: var(--d3); }
.catalog-card .tag-id {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--accent);
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
}
.catalog-card.d1 .tag-id { color: #7dd3fc; }
.catalog-card.d2 .tag-id { color: #5eead4; }
.catalog-card.d3 .tag-id { color: #c4b5fd; }
.catalog-card .title {
  font-weight: 700;
  margin: 0.4rem 0 0.3rem;
  font-size: 1rem;
  letter-spacing: -0.01em;
}
.catalog-card .blurb {
  font-size: 0.82rem;
  color: var(--muted);
  margin: 0;
  line-height: 1.4;
}
.catalog-card .card-icon {
  font-size: 1.45rem;
  margin-bottom: 0.2rem;
  line-height: 1;
}
.catalog-card.featured {
  border-color: rgba(45, 212, 191, 0.45);
  background: linear-gradient(160deg, var(--surface), rgba(14, 165, 233, 0.12), rgba(167, 139, 250, 0.1));
}

.domain-head {
  margin: 1.75rem 0 0.85rem;
  padding: 0.55rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 1.05rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  border: 1px solid var(--border);
  border-left: 5px solid var(--border);
  background: var(--surface2);
}
.domain-head.d1 {
  border-left-color: var(--d1);
  background: var(--d1-soft);
  color: #bae6fd;
}
.domain-head.d2 {
  border-left-color: var(--d2);
  background: var(--d2-soft);
  color: #99f6e4;
}
.domain-head.d3 {
  border-left-color: var(--d3);
  background: var(--d3-soft);
  color: #ddd6fe;
}
.domain-head.featured {
  border-left-color: var(--gold);
  background: linear-gradient(90deg, rgba(250, 204, 21, 0.14), rgba(56, 189, 248, 0.1));
  color: #fef08a;
}

footer.site-footer {
  margin-top: 2.25rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.8rem;
}
.disclaimer {
  font-size: 0.78rem;
  color: var(--muted);
  margin-top: 0.85rem;
  line-height: 1.45;
}

code {
  font-family: var(--mono);
  font-size: 0.85em;
  color: var(--accent);
}
.hidden { display: none !important; }

.output-box {
  background: #0b1220;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  font-family: var(--mono);
  font-size: 0.82rem;
  white-space: pre-wrap;
  color: #cbd5e1;
  margin-top: 0.75rem;
}

/* Plotly modebar tweak on dark */
.js-plotly-plot .plotly .modebar { top: 4px !important; }