/* =========================================================================
   Stochastic Cascade Systems — Tools design system
   Matched to the main site: deep navy ground, signal-cyan accent,
   violet secondary. Dark-only (single visual world), Space Grotesk /
   Inter / JetBrains Mono.
   ========================================================================= */

/* ---- Tokens (dark-only, matched to stochasticcascadesystems.com) ------- */
:root {
  /* neutrals — deep navy instrument panel */
  --bg:        #0a0e14;
  --surface:   #131a26;   /* cards / panels          (site --bg-card)  */
  --surface-2: #0e131c;   /* readout inset / display (site --bg-alt)   */
  --border:    #1f2937;   /* site --line      */
  --border-2:  #172030;   /* site --line-soft */

  /* ink */
  --ink:   #e8edf4;
  --ink-2: #a6b3c4;
  --ink-3: #6b7a8f;

  /* accents (site palette) */
  --accent:      #38e1c4;  /* signal cyan/teal — data / primary */
  --accent-ink:  #04120f;  /* text on cyan */
  --accent-hover:#5fe9d1;
  --accent-soft: rgba(56, 225, 196, 0.14);   /* site --accent-glow */
  --accent-dim:  #1d9b86;
  --energy:      #8b7cf6;   /* violet — secondary / dose / threshold */
  --energy-soft: rgba(139, 124, 246, 0.15);

  /* semantic status */
  --good: #38e1c4;
  --warn: #8b7cf6;
  --crit: #ff6b6b;         /* site --danger */
  --crit-soft: rgba(255, 107, 107, 0.13);

  /* chart ink */
  --grid: #172030;
  --axis: #2b3648;

  --shadow: 0 1px 2px rgba(0,0,0,.35), 0 14px 34px -14px rgba(0,0,0,.6);
  --radius: 14px;
  --radius-sm: 9px;

  --font-display: "Space Grotesk", system-ui, -apple-system, Segoe UI, sans-serif;
  --font-sans:    "Inter", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  --font-mono:    "JetBrains Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

/* ---- Base ------------------------------------------------------------- */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; text-underline-offset: 2px; }
h1, h2, h3 { font-family: var(--font-display); text-wrap: balance; line-height: 1.15; margin: 0; letter-spacing: -0.02em; font-weight: 600; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-3);
  font-weight: 500;
}
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* ---- Top bar ---------------------------------------------------------- */
.topbar {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: saturate(1.4) blur(8px);
  border-bottom: 1px solid var(--border-2);
}
.topbar .wrap { display: flex; align-items: center; gap: 20px; height: 60px; }
.brand { display: flex; flex-direction: column; line-height: 1.05; gap: 2px; }
.brand b { font-family: var(--font-display); font-weight: 600; font-size: 0.95rem; letter-spacing: -0.01em; }
.brand span { font-family: var(--font-mono); font-size: 0.6rem; letter-spacing: 0.18em; color: var(--ink-3); text-transform: uppercase; }
.brand, .brand:hover { color: var(--ink); text-decoration: none; }
.nav { margin-left: auto; display: flex; align-items: center; gap: 6px; }
.nav a {
  color: var(--ink-2); font-size: 0.88rem; font-weight: 500;
  padding: 7px 11px; border-radius: 8px;
}
.nav a:hover { color: var(--ink); background: var(--accent-soft); text-decoration: none; }
.nav a.cta { color: var(--accent-ink); background: var(--accent); }
.nav a.cta:hover { background: var(--accent-hover); color: var(--accent-ink); }
.theme-btn {
  display: inline-grid; place-items: center; width: 34px; height: 34px;
  border: 1px solid var(--border); border-radius: 8px; background: var(--surface);
  color: var(--ink-2); cursor: pointer; padding: 0;
}
.theme-btn:hover { color: var(--ink); border-color: var(--accent); }
.theme-btn svg { width: 17px; height: 17px; }

/* ---- Chips / labels --------------------------------------------------- */
.chip {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: var(--font-mono); font-size: 0.72rem; font-weight: 500;
  letter-spacing: 0.04em; padding: 4px 10px; border-radius: 999px;
  border: 1px solid var(--border);
}
.chip .dot { width: 7px; height: 7px; border-radius: 50%; background: currentColor; }
.chip.illustrative { color: var(--warn); background: var(--energy-soft); border-color: color-mix(in srgb, var(--warn) 35%, var(--border)); }
.chip.model { color: var(--accent); background: var(--accent-soft); border-color: color-mix(in srgb, var(--accent) 30%, var(--border)); }

/* ---- Page header ------------------------------------------------------ */
.page-head { padding: 40px 0 8px; }
.page-head .kicker { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 14px; }
.page-head h1 { font-size: clamp(1.7rem, 3.6vw, 2.5rem); font-weight: 700; }
.page-head .dek { color: var(--ink-2); font-size: 1.05rem; max-width: 64ch; margin-top: 12px; }
.breadcrumb { font-family: var(--font-mono); font-size: 0.75rem; color: var(--ink-3); margin-bottom: 18px; }
.breadcrumb a { color: var(--ink-3); }
.breadcrumb a:hover { color: var(--accent); }

/* ---- Instrument layout ------------------------------------------------ */
.instrument { display: grid; grid-template-columns: 370px 1fr; gap: 22px; align-items: start; margin: 26px 0; }
@media (max-width: 900px) { .instrument { grid-template-columns: 1fr; } }

.panel {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.panel-head {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 14px 18px; border-bottom: 1px solid var(--border-2);
}
.panel-head h2 { font-size: 0.82rem; font-family: var(--font-mono); text-transform: uppercase; letter-spacing: 0.12em; color: var(--ink-3); font-weight: 600; }
.panel-body { padding: 18px; }

/* controls */
.field { margin-bottom: 18px; }
.field:last-child { margin-bottom: 4px; }
.field > label { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; margin-bottom: 8px; }
.field .lab { font-size: 0.9rem; font-weight: 500; color: var(--ink); }
.field .unit { font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-3); }
.control-row { display: flex; align-items: center; gap: 12px; }
input[type="range"] {
  -webkit-appearance: none; appearance: none; height: 4px; flex: 1;
  background: var(--border); border-radius: 999px; outline-offset: 6px;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none; width: 17px; height: 17px; border-radius: 50%;
  background: var(--accent); border: 2px solid var(--surface); box-shadow: 0 0 0 1px var(--accent); cursor: pointer;
}
input[type="range"]::-moz-range-thumb {
  width: 17px; height: 17px; border-radius: 50%; background: var(--accent);
  border: 2px solid var(--surface); box-shadow: 0 0 0 1px var(--accent); cursor: pointer;
}
input[type="number"], select {
  width: 92px; font-family: var(--font-mono); font-variant-numeric: tabular-nums;
  font-size: 0.9rem; padding: 7px 9px; text-align: right;
  background: var(--surface-2); color: var(--ink);
  border: 1px solid var(--border); border-radius: var(--radius-sm);
}
select { width: 100%; text-align: left; }
input[type="number"]:focus, select:focus { border-color: var(--accent); outline: none; }
.presets { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 10px; }
.preset {
  font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-2);
  background: var(--surface-2); border: 1px solid var(--border); border-radius: 999px;
  padding: 5px 11px; cursor: pointer;
}
.preset:hover { border-color: var(--accent); color: var(--accent); }
.hint { font-size: 0.78rem; color: var(--ink-3); margin-top: 8px; line-height: 1.5; }

/* readout / instrument display */
.readout { background: var(--surface-2); }
.readout .panel-body { padding: 0; }
.primary-metric { padding: 22px 20px 18px; border-bottom: 1px solid var(--border-2); }
.primary-metric .m-label { font-family: var(--font-mono); font-size: 0.74rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-3); }
.primary-metric .m-value {
  font-family: var(--font-mono); font-weight: 600; font-variant-numeric: tabular-nums;
  font-size: clamp(2rem, 5vw, 2.9rem); line-height: 1.05; margin-top: 8px; color: var(--ink);
  letter-spacing: -0.01em; word-break: break-word;
}
.primary-metric .m-value .u { font-size: 0.42em; color: var(--ink-3); font-weight: 500; margin-left: 8px; letter-spacing: 0; }
.primary-metric .m-sub { font-size: 0.84rem; color: var(--ink-2); margin-top: 8px; }
.primary-metric.accent .m-value { color: var(--accent); }
.primary-metric.energy .m-value { color: var(--energy); }
.primary-metric.crit .m-value { color: var(--crit); }
.primary-metric.good .m-value { color: var(--good); }

.metric-list { padding: 6px 20px 18px; }
.metric-list .row {
  display: flex; align-items: baseline; justify-content: space-between; gap: 14px;
  padding: 9px 0; border-bottom: 1px dashed var(--border-2);
}
.metric-list .row:last-child { border-bottom: none; }
.metric-list .k { font-size: 0.86rem; color: var(--ink-2); }
.metric-list .k small { display: block; color: var(--ink-3); font-size: 0.72rem; }
.metric-list .v { font-family: var(--font-mono); font-variant-numeric: tabular-nums; font-size: 0.95rem; color: var(--ink); text-align: right; white-space: nowrap; }
.metric-list .v.accent { color: var(--accent); }
.metric-list .v.energy { color: var(--energy); }
.metric-list .v.crit { color: var(--crit); }

/* viz */
.viz { margin-top: 22px; }
.viz .panel-body { padding: 16px 12px 12px; }
.chart { width: 100%; display: block; }
.chart text { font-family: var(--font-mono); fill: var(--ink-3); }
.legend { display: flex; flex-wrap: wrap; gap: 16px; padding: 4px 8px 6px; font-family: var(--font-mono); font-size: 0.74rem; color: var(--ink-2); }
.legend .li { display: inline-flex; align-items: center; gap: 7px; }
.legend .sw { width: 16px; height: 3px; border-radius: 2px; background: var(--accent); }
.legend .sw.dash { background: repeating-linear-gradient(90deg, var(--ink-3) 0 4px, transparent 4px 7px); }
.legend .sw.crit { background: var(--crit); }
.legend .sw.energy { background: var(--energy); }
.strip-wrap { margin-top: 6px; padding: 0 8px; }
.strip-wrap canvas { width: 100%; height: auto; display: block; border-radius: 6px; image-rendering: pixelated; }
.strip-label { font-family: var(--font-mono); font-size: 0.68rem; color: var(--ink-3); margin: 8px 2px 2px; text-transform: uppercase; letter-spacing: 0.08em; }

/* interpretation callout */
.callout {
  display: flex; gap: 12px; padding: 14px 16px; border-radius: var(--radius-sm);
  background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 22%, var(--border));
  font-size: 0.9rem; color: var(--ink-2); margin: 2px 0 0;
}
.callout.crit { background: var(--crit-soft); border-color: color-mix(in srgb, var(--crit) 30%, var(--border)); }
.callout b { color: var(--ink); font-weight: 600; }
.callout .ico { flex: none; margin-top: 1px; color: var(--accent); }
.callout.crit .ico { color: var(--crit); }

/* methods / prose */
.prose { max-width: 68ch; }
.prose h2 { font-size: 1.15rem; margin: 30px 0 10px; }
.prose h3 { font-size: 0.98rem; margin: 22px 0 6px; }
.prose p { color: var(--ink-2); margin: 10px 0; }
.prose ul { color: var(--ink-2); padding-left: 20px; }
.prose li { margin: 6px 0; }
.prose code, .formula {
  font-family: var(--font-mono); font-size: 0.86em;
  background: var(--surface-2); border: 1px solid var(--border-2); border-radius: 6px; padding: 1px 6px;
}
.formula { display: block; padding: 12px 14px; margin: 12px 0; overflow-x: auto; color: var(--ink); font-size: 0.9rem; }
details.methods { border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); margin: 24px 0; }
details.methods > summary {
  cursor: pointer; padding: 15px 18px; font-weight: 600; font-size: 0.92rem; list-style: none;
  display: flex; align-items: center; gap: 10px;
}
details.methods > summary::-webkit-details-marker { display: none; }
details.methods > summary .caret { transition: transform .18s ease; color: var(--ink-3); }
details.methods[open] > summary .caret { transform: rotate(90deg); }
details.methods .methods-body { padding: 2px 18px 18px; border-top: 1px solid var(--border-2); }

/* ---- Hub -------------------------------------------------------------- */
.hero { padding: 52px 0 26px; }
.hero h1 { font-size: clamp(2rem, 5vw, 3.15rem); font-weight: 700; max-width: 18ch; }
.hero .dek { color: var(--ink-2); font-size: 1.12rem; max-width: 60ch; margin-top: 18px; }
.hero .actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 26px; }
.btn {
  display: inline-flex; align-items: center; gap: 9px; font-weight: 600; font-size: 0.92rem;
  padding: 11px 18px; border-radius: 10px; border: 1px solid transparent; cursor: pointer;
}
.btn.primary { background: var(--accent); color: var(--accent-ink); box-shadow: 0 4px 20px rgba(56,225,196,.22); }
.btn.primary:hover { background: var(--accent-hover); color: var(--accent-ink); text-decoration: none; transform: translateY(-2px); box-shadow: 0 8px 28px rgba(56,225,196,.36); }
.btn { transition: transform .15s ease, box-shadow .2s ease, background .2s ease, border-color .2s ease; }
.btn.ghost { background: var(--surface); color: var(--ink); border-color: var(--border); }
.btn.ghost:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

.flow-note { display: flex; gap: 10px; align-items: center; margin-top: 22px; font-family: var(--font-mono); font-size: 0.78rem; color: var(--ink-3); flex-wrap: wrap; }
.flow-note b { color: var(--accent); font-weight: 600; }
.flow-note .arw { color: var(--border); }

.section { padding: 30px 0; }
.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin-bottom: 20px; flex-wrap: wrap; }
.section-head h2 { font-size: 1.35rem; font-weight: 700; }
.section-head p { color: var(--ink-3); font-size: 0.9rem; }

.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(248px, 1fr)); gap: 18px; }
@media (max-width: 860px) { .card-grid { grid-template-columns: 1fr; } }
.tool-card {
  display: flex; flex-direction: column; background: var(--surface);
  border: 1px solid var(--border); border-radius: var(--radius); padding: 20px;
  box-shadow: var(--shadow); position: relative; overflow: hidden;
}
.tool-card:hover { border-color: var(--accent); text-decoration: none; }
.tool-card .idx { font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-3); letter-spacing: 0.1em; }
.tool-card .tc-mini { height: 66px; margin: 12px -4px 14px; }
.tool-card h3 { font-size: 1.12rem; font-weight: 600; color: var(--ink); }
.tool-card p { color: var(--ink-2); font-size: 0.9rem; margin: 8px 0 0; flex: 1; }
.tool-card .kw { margin-top: 14px; font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-3); }
.tool-card .go { margin-top: 14px; display: inline-flex; align-items: center; gap: 6px; font-weight: 600; font-size: 0.86rem; color: var(--accent); }

.ladder { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
@media (max-width: 860px) { .ladder { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .ladder { grid-template-columns: 1fr; } }
.rung { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 16px; }
.rung .t { font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-3); }
.rung .h { font-weight: 600; font-size: 0.98rem; margin: 8px 0 6px; }
.rung.free .t { color: var(--accent); }
.rung.paid .t { color: var(--energy); }
.rung p { font-size: 0.84rem; color: var(--ink-2); margin: 0; }

/* email capture */
.capture { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow); }
.capture h3 { font-size: 1.2rem; font-weight: 700; }
.capture p { color: var(--ink-2); font-size: 0.92rem; margin: 8px 0 16px; max-width: 54ch; }
.capture form { display: flex; gap: 10px; flex-wrap: wrap; }
.capture input[type="email"] {
  flex: 1; min-width: 220px; text-align: left; width: auto;
  font-family: var(--font-sans); font-size: 0.95rem; padding: 11px 13px;
  background: var(--surface-2); border: 1px solid var(--border); border-radius: 10px; color: var(--ink);
}
.capture input[type="email"]:focus { border-color: var(--accent); outline: none; }
.capture .ok { color: var(--good); font-size: 0.88rem; margin-top: 12px; }

/* ---- Footer ----------------------------------------------------------- */
.site-foot { border-top: 1px solid var(--border-2); margin-top: 40px; padding: 34px 0; }
.foot-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 26px; }
@media (max-width: 720px) { .foot-grid { grid-template-columns: 1fr; gap: 22px; } }
.foot-grid h4 { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); margin: 0 0 12px; font-weight: 600; }
.foot-grid a { display: block; color: var(--ink-2); font-size: 0.9rem; padding: 4px 0; }
.foot-grid a:hover { color: var(--accent); text-decoration: none; }
.foot-grid p { color: var(--ink-3); font-size: 0.85rem; margin: 0; }
.foot-legal { margin-top: 26px; padding-top: 18px; border-top: 1px solid var(--border-2); font-size: 0.8rem; color: var(--ink-3); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

.disclaimer-bar {
  background: var(--energy-soft); border: 1px solid color-mix(in srgb, var(--warn) 30%, var(--border));
  border-radius: var(--radius-sm); padding: 12px 15px; margin: 20px 0;
  font-size: 0.85rem; color: var(--ink-2); display: flex; gap: 10px; align-items: flex-start;
}
.disclaimer-bar .ico { color: var(--warn); flex: none; margin-top: 1px; }
.disclaimer-bar b { color: var(--ink); }

@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }

/* ---- Articles (research explainers) ----------------------------------- */
.article { max-width: 720px; margin: 0 auto; }
.article-head { padding: 8px 0 6px; }
.article-head .kicker { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; margin-bottom: 16px; }
.article-head h1 { font-size: clamp(1.9rem, 4vw, 2.7rem); font-weight: 700; line-height: 1.1; }
.byline { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; margin-top: 18px; font-family: var(--font-mono); font-size: 0.75rem; color: var(--ink-3); }
.byline .sep { color: var(--border); }
.article-body { margin-top: 12px; }
.article-body > p, .article-body > ul, .article-body > ol { font-size: 1.05rem; line-height: 1.75; color: var(--ink-2); margin: 16px 0; }
.article-body > ul, .article-body > ol { padding-left: 22px; }
.article-body > p.lead { font-size: 1.22rem; line-height: 1.6; color: var(--ink); margin: 18px 0 24px; }
.article-body h2 { font-size: 1.5rem; margin: 42px 0 8px; }
.article-body h3 { font-size: 1.1rem; margin: 28px 0 2px; }
.article-body strong { color: var(--ink); font-weight: 600; }
.article-body em { color: var(--ink); }
figure.fig { margin: 30px 0; }
figure.fig .figbox { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 16px 10px; }
figure.fig svg { width: 100%; height: auto; display: block; }
figure.fig svg text { font-family: var(--font-mono); fill: var(--ink-3); }
figure.fig figcaption { font-size: 0.82rem; color: var(--ink-3); margin-top: 12px; text-align: center; line-height: 1.5; }
.keybox { border-left: 3px solid var(--accent); background: var(--surface); border-radius: var(--radius-sm); padding: 16px 20px; margin: 28px 0; }
.keybox .kb-label { font-family: var(--font-mono); font-size: 0.7rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent); }
.keybox p { margin: 6px 0 0; color: var(--ink); font-size: 1rem; line-height: 1.6; }
.trybox { display: flex; align-items: center; justify-content: space-between; gap: 20px; flex-wrap: wrap;
          background: linear-gradient(160deg, var(--surface), var(--surface-2)); border: 1px solid var(--accent-dim);
          border-radius: var(--radius); padding: 22px 24px; margin: 34px 0; box-shadow: 0 0 30px var(--accent-soft); }
.trybox .tb-t { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--accent); }
.trybox h3 { font-size: 1.18rem; margin: 6px 0 4px; }
.trybox p { color: var(--ink-2); font-size: 0.9rem; margin: 0; max-width: 46ch; }
.related-articles { border-top: 1px solid var(--border-2); margin-top: 42px; padding-top: 22px; }
.related-articles h4 { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--ink-3); margin: 0 0 12px; }
.related-articles a { display: inline-block; color: var(--ink); border: 1px solid var(--border); border-radius: 100px; padding: 7px 14px; margin: 0 8px 8px 0; font-size: 0.86rem; }
.related-articles a:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

/* hub research list */
.art-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 14px; }
.art-card { display: block; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 20px; box-shadow: var(--shadow); }
.art-card:hover { border-color: var(--accent); text-decoration: none; }
.art-card .rl { font-family: var(--font-mono); font-size: 0.68rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); }
.art-card h3 { font-size: 1.02rem; margin: 8px 0 4px; color: var(--ink); }
.art-card p { color: var(--ink-3); font-size: 0.85rem; margin: 0; }