/* Xenia–Helly is a local teaching instrument. Its geometry is rendered from
   current-page input only; the stylesheet contains no imported asset. */

.helly-page {
  --helly-ink: #24392f;
  --helly-green: #3f7a5b;
  --helly-mint: #a8d7bd;
  --helly-gold: #c28a32;
  --helly-coral: #d3644e;
  --helly-violet: #7a68ac;
  /* Stroke/fill accents stay vivid. Small text variants mix toward the active
     theme ink and clear WCAG AA against both dawn and night surfaces. */
  --helly-green-text: color-mix(in srgb, var(--helly-green) 60%, var(--text));
  --helly-gold-text: color-mix(in srgb, var(--helly-gold) 60%, var(--text));
  --helly-coral-text: color-mix(in srgb, var(--helly-coral) 60%, var(--text));
  --helly-violet-text: color-mix(in srgb, var(--helly-violet) 60%, var(--text));
  background:
    radial-gradient(circle at 8% 12%, color-mix(in srgb, var(--helly-mint) 18%, transparent), transparent 30rem),
    radial-gradient(circle at 92% 24%, color-mix(in srgb, var(--helly-gold) 12%, transparent), transparent 27rem),
    var(--bg);
}

.helly-shell {
  width: min(1180px, calc(100% - 2rem));
  margin: 0 auto;
  padding: calc(var(--nav-height) + 2.5rem) 0 5rem;
}

.helly-hero {
  position: relative;
  isolation: isolate;
  padding: clamp(2rem, 7vw, 5.6rem) clamp(1rem, 5vw, 4rem) 3.5rem;
  overflow: hidden;
  border: 1px solid var(--border-bright);
  border-radius: clamp(1.2rem, 3vw, 2.4rem);
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--surface) 92%, var(--helly-mint)), var(--surface));
  box-shadow: var(--shadow-card);
}

.helly-hero::before,
.helly-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  border: 1px solid color-mix(in srgb, var(--helly-green) 35%, transparent);
  border-radius: 50%;
}

.helly-hero::before {
  width: 26rem;
  height: 26rem;
  right: -7rem;
  top: -12rem;
}

.helly-hero::after {
  width: 18rem;
  height: 18rem;
  right: 5rem;
  top: -8rem;
  border-color: color-mix(in srgb, var(--helly-gold) 45%, transparent);
}

.helly-eyebrow,
.helly-kicker,
.outcome-code,
.helly-chip,
.helly-label {
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

.helly-eyebrow,
.helly-kicker,
.helly-label { color: var(--helly-green-text); }

.helly-hero h1 {
  max-width: 15ch;
  margin: 0.6rem 0 1rem;
  font-family: var(--serif);
  font-size: clamp(3rem, 8vw, 6.6rem);
  font-weight: 500;
  line-height: 0.92;
  letter-spacing: -0.045em;
}

.helly-hero h1 em {
  color: var(--helly-green-text);
  font-weight: 500;
}

.helly-lede {
  max-width: 63ch;
  color: var(--text-muted);
  font-size: clamp(1.02rem, 2vw, 1.22rem);
  line-height: 1.7;
}

.helly-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

.helly-chip {
  padding: 0.42rem 0.7rem;
  border: 1px solid color-mix(in srgb, var(--helly-green) 38%, var(--border));
  border-radius: 999px;
  color: var(--text-muted);
  background: color-mix(in srgb, var(--surface) 86%, transparent);
}

.helly-doctrine {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 1rem;
  align-items: start;
  margin: 1.2rem 0 3rem;
  padding: 1.1rem 1.3rem;
  border-left: 4px solid var(--helly-green);
  border-radius: 0 var(--r-lg) var(--r-lg) 0;
  background: color-mix(in srgb, var(--helly-mint) 11%, var(--surface));
}

.helly-doctrine .mark {
  color: var(--helly-green-text);
  font-family: var(--serif);
  font-size: 2rem;
  line-height: 1;
}

.helly-doctrine p { margin: 0; line-height: 1.6; }

.helly-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(300px, 0.88fr);
  gap: 1.25rem;
  align-items: start;
}

.helly-lab,
.helly-explainer,
.helly-section,
.helly-wake,
.helly-challenge-gate {
  border: 1px solid var(--border);
  border-radius: var(--r-xl);
  background: var(--surface);
  box-shadow: var(--shadow-card);
}

.helly-lab { overflow: hidden; }

.helly-lab-head,
.helly-section,
.helly-wake,
.helly-challenge-gate { padding: clamp(1.25rem, 3vw, 2.2rem); }

.helly-lab-head h2,
.helly-section h2,
.helly-wake h2,
.helly-challenge-gate h2 {
  margin: 0.35rem 0 0.7rem;
  font-family: var(--serif);
  font-size: clamp(1.7rem, 4vw, 2.6rem);
  line-height: 1.05;
}

.helly-muted,
.helly-lab-head > p,
.helly-section > p,
.helly-wake > p,
.helly-challenge-gate > p {
  color: var(--text-muted);
  line-height: 1.65;
}

.helly-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 1rem 0;
}

.helly-button {
  min-height: 2.55rem;
  padding: 0.62rem 0.9rem;
  border: 1px solid var(--border-bright);
  border-radius: 999px;
  color: var(--text);
  background: var(--surface-raised, var(--surface));
  font: 600 0.78rem var(--sans);
  cursor: pointer;
}

.helly-button:hover,
.helly-button:focus-visible {
  border-color: var(--helly-green);
  outline: none;
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--helly-mint) 30%, transparent);
}

.helly-button.primary {
  color: #fff;
  border-color: var(--helly-green);
  background: var(--helly-green);
}

.helly-input {
  width: 100%;
  min-height: 11rem;
  resize: vertical;
  padding: 0.9rem;
  border: 1px solid var(--border-bright);
  border-radius: var(--r-lg);
  color: var(--text);
  background: color-mix(in srgb, var(--surface) 88%, var(--bg));
  font: 0.78rem/1.65 var(--mono);
}

.helly-input:focus {
  border-color: var(--helly-green);
  outline: 3px solid color-mix(in srgb, var(--helly-mint) 32%, transparent);
}

.helly-format {
  display: block;
  margin: 0.45rem 0 0.9rem;
  color: var(--text-dim);
  font: 0.7rem/1.5 var(--mono);
}

.helly-action-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-top: 0.9rem;
}

.helly-local-note { color: var(--text-dim); font-size: 0.75rem; }

.helly-plot-wrap {
  margin: 0;
  padding: 1rem;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg) 75%, var(--surface));
}

.helly-plot {
  display: block;
  width: 100%;
  height: auto;
  min-height: 280px;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--surface);
}

.helly-plot .grid-line { stroke: var(--border); stroke-width: 1; }
.helly-plot .axis { stroke: var(--text-dim); stroke-width: 1.5; }
.helly-plot .feasible-region {
  fill: color-mix(in srgb, var(--helly-mint) 48%, transparent);
  stroke: var(--helly-green);
  stroke-width: 2;
}
.helly-plot .constraint-line {
  stroke: var(--helly-violet);
  stroke-width: 2.4;
  opacity: 0.82;
}
.helly-plot .witness-line { stroke: var(--helly-coral); stroke-width: 4; opacity: 1; }
.helly-plot .witness-point {
  fill: var(--helly-gold-text);
  stroke: var(--surface);
  stroke-width: 3;
}

.helly-plot-wrap figcaption {
  margin-top: 0.55rem;
  color: var(--text-dim);
  font-size: 0.72rem;
}

.helly-result {
  margin: 1rem;
  padding: 1rem 1.1rem;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: color-mix(in srgb, var(--surface) 88%, var(--bg));
}

.helly-result h3 { margin: 0.3rem 0 0.6rem; font-size: 1.1rem; }
.helly-result p,
.helly-result li { color: var(--text-muted); font-size: 0.86rem; line-height: 1.6; }
.helly-result ul { padding-left: 1.2rem; }
.helly-result .outcome-code { margin: 0; color: var(--helly-green-text); }
.helly-result.outcome-no_common_ground_witnessed .outcome-code,
.helly-result.outcome-model_not_applicable .outcome-code { color: var(--helly-coral-text); }
.result-boundary { padding-top: 0.6rem; border-top: 1px solid var(--border); }

.helly-normalized-wrap { padding: 0 1rem 1rem; }
.helly-normalized-wrap h3 { font-size: 0.82rem; }
.helly-normalized {
  display: grid;
  gap: 0.45rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.helly-normalized li {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.55rem 0.65rem;
  border-radius: 0.5rem;
  background: color-mix(in srgb, var(--bg) 55%, transparent);
  font-size: 0.73rem;
}
.helly-normalized code { color: var(--helly-violet-text); }

.helly-explainer {
  position: sticky;
  top: calc(var(--nav-height) + 1rem);
  padding: 1.4rem;
}

.helly-explainer h2 {
  margin: 0.25rem 0 0.8rem;
  font-family: var(--serif);
  font-size: 2rem;
}

.helly-formula {
  margin: 1rem 0;
  padding: 1rem;
  overflow-x: auto;
  border: 1px solid color-mix(in srgb, var(--helly-green) 35%, var(--border));
  border-radius: var(--r-lg);
  color: var(--helly-ink);
  background: color-mix(in srgb, var(--helly-mint) 20%, #fff);
  font: 600 0.92rem/1.6 var(--mono);
}

.helly-explainer ol,
.helly-explainer ul { padding-left: 1.2rem; }
.helly-explainer li { margin: 0.65rem 0; color: var(--text-muted); line-height: 1.55; }
.helly-explainer strong { color: var(--text); }

.helly-outcomes {
  display: grid;
  gap: 0.55rem;
  margin: 1rem 0;
}

.helly-outcomes code {
  display: block;
  padding: 0.55rem 0.65rem;
  border-left: 3px solid var(--helly-green);
  color: var(--text);
  background: color-mix(in srgb, var(--helly-mint) 10%, transparent);
  font-size: 0.72rem;
}

.helly-section,
.helly-wake,
.helly-challenge-gate { margin-top: 1.25rem; }

.helly-three,
.helly-four,
.helly-two {
  display: grid;
  gap: 0.8rem;
  margin-top: 1rem;
}
.helly-three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.helly-four { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.helly-two { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.helly-card {
  padding: 1.05rem;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: color-mix(in srgb, var(--surface) 90%, var(--bg));
}
.helly-card .number {
  color: var(--helly-gold-text);
  font: 700 0.68rem var(--mono);
  letter-spacing: 0.1em;
}
.helly-card h3 { margin: 0.4rem 0; font-size: 1rem; }
.helly-card p { margin: 0; color: var(--text-muted); font-size: 0.84rem; line-height: 1.55; }

.helly-counterexample {
  margin-top: 1rem;
  padding: 1rem;
  border: 1px solid color-mix(in srgb, var(--helly-coral) 45%, var(--border));
  border-radius: var(--r-lg);
  background: color-mix(in srgb, var(--helly-coral) 7%, var(--surface));
}
.helly-counterexample code { color: var(--helly-coral-text); }

.helly-gate-columns {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 1rem;
  align-items: stretch;
  margin-top: 1.2rem;
}
.helly-gate-column {
  padding: 1.1rem;
  border-radius: var(--r-lg);
  background: color-mix(in srgb, var(--helly-mint) 10%, var(--surface));
}
.helly-gate-column.pedestal {
  background: color-mix(in srgb, var(--helly-coral) 7%, var(--surface));
}
.helly-gate-column h3 { margin-top: 0; }
.helly-gate-column li { margin: 0.55rem 0; color: var(--text-muted); line-height: 1.5; }
.helly-gate-or { align-self: center; color: var(--text-dim); font: 700 0.68rem var(--mono); }

.helly-subtraction {
  margin: 1.2rem 0 0;
  padding: 1rem 1.2rem;
  border: 1px solid var(--helly-gold);
  border-radius: var(--r-lg);
  color: var(--text);
  font: 500 clamp(1.05rem, 2vw, 1.3rem)/1.5 var(--serif);
  background: color-mix(in srgb, var(--helly-gold) 8%, var(--surface));
}

.helly-questions {
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
  counter-reset: helly-question;
}
.helly-questions li {
  counter-increment: helly-question;
  display: grid;
  grid-template-columns: 2.2rem 1fr;
  gap: 0.7rem;
  padding: 0.8rem 0;
  border-bottom: 1px solid var(--border);
  color: var(--text-muted);
  line-height: 1.55;
}
.helly-questions li::before {
  content: counter(helly-question, decimal-leading-zero);
  color: var(--helly-green-text);
  font: 700 0.72rem var(--mono);
}

.helly-wake-flow {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.55rem;
  margin-top: 1rem;
}
.helly-wake-step {
  position: relative;
  padding: 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: color-mix(in srgb, var(--surface) 90%, var(--bg));
}
.helly-wake-step:not(:last-child)::after {
  content: "→";
  position: absolute;
  right: -0.48rem;
  top: 50%;
  z-index: 1;
  color: var(--helly-green);
  font-weight: 800;
}
.helly-wake-step strong { display: block; margin-bottom: 0.35rem; }
.helly-wake-step span { color: var(--text-muted); font-size: 0.78rem; line-height: 1.45; }

.helly-boundary-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}
.helly-boundary-list li {
  padding: 0.45rem 0.65rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text-muted);
  font: 0.7rem var(--mono);
}

.helly-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
  margin-top: 1.2rem;
}
.helly-links a { font-size: 0.82rem; }

@media (max-width: 920px) {
  .helly-grid { grid-template-columns: 1fr; }
  .helly-explainer { position: static; }
  .helly-four { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .helly-three { grid-template-columns: 1fr; }
  .helly-wake-flow { grid-template-columns: repeat(2, 1fr); }
  .helly-wake-step:nth-child(2)::after { display: none; }
}

@media (max-width: 640px) {
  .helly-shell { width: min(100% - 1rem, 1180px); padding-top: calc(var(--nav-height) + 1rem); }
  .helly-hero { padding: 2rem 1rem; }
  .helly-hero::before,
  .helly-hero::after { opacity: 0.45; }
  .helly-doctrine { grid-template-columns: 1fr; }
  .helly-doctrine .mark { display: none; }
  .helly-two,
  .helly-four,
  .helly-wake-flow { grid-template-columns: 1fr; }
  .helly-wake-step::after { display: none; }
  .helly-gate-columns { grid-template-columns: 1fr; }
  .helly-gate-or { text-align: center; }
  .helly-action-row { align-items: stretch; }
  .helly-button.primary { width: 100%; }
  nav.topnav .nav-actions a:not(.nav-cta):not(.nav-essential):not(.active) { display: none; }
  .brand-tail { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .helly-page *,
  .helly-page *::before,
  .helly-page *::after { scroll-behavior: auto !important; transition: none !important; }
}