/* Solidified Sky — base stylesheet.
   Design system: "living cell in the dark" — a dark forest-green depth where
   photons, electrons and molecules glow. Sibling to Valence's dark-lab look.

   ALL theming via :root custom properties. Never hardcode a color in a rule.

   THE MOLECULE COLOR LAW (the single most important rule on the site — this is
   pedagogy, not decoration). Every molecule has ONE fixed color used
   EVERYWHERE it appears — in canvas particles, in prose, in legends, in
   equations. If a visual shows CO2 it is red; H2O is blue; O2 is orange.
   JS mirrors these exact values in scripts/tokens.js — keep the two in sync. */

:root {
  /* ---- backgrounds, darkest to lightest ---- */
  --bg-deep: #04100b;      /* near-black forest green — the void inside a cell */
  --bg-surface: #08170f;
  --bg-elevated: #0e2016;
  --bg-hover: #143020;

  /* ---- text ---- */
  --text-primary: #e8f2ea;
  --text-secondary: #a6bcae;
  --text-muted: #6a8377;

  /* ---- primary accents ---- */
  --accent: #4ade80;       /* chlorophyll green — links, primary glow */
  --accent-2: #ffd54a;     /* sunlight gold — secondary */

  /* ================= THE MOLECULE COLOR LAW ================= */
  --co2:     #f87171;      /* carbon dioxide — red */
  --h2o:     #60a5fa;      /* water — blue */
  --o2:      #fb923c;      /* oxygen — orange */
  --atp:     #fbbf24;      /* ATP energy carrier — yellow */
  --nadph:   #a78bfa;      /* NADPH electron carrier — violet */
  --sugar:   #d8a15e;      /* glucose / G3P — warm brown */
  --photon:  #ffe066;      /* light — gold */
  --electron:#38e0d0;      /* excited electron — cyan */
  --proton:  #f5b8d0;      /* H+ proton — pale pink */
  --chloro:  #4ade80;      /* chlorophyll — green */
  --rubisco: #5eead4;      /* the enzyme rubisco — teal */
  /* ========================================================= */

  /* ---- semantic (callouts, states) ---- */
  --blue: #60a5fa;
  --green: #4ade80;
  --purple: #a78bfa;
  --amber: #fbbf24;
  --rose: #fb7185;

  /* ---- rules ---- */
  --rule: rgba(150, 200, 170, 0.12);
  --rule-strong: rgba(150, 200, 170, 0.26);

  /* ---- fonts ---- */
  --display: "Space Grotesk", system-ui, sans-serif;
  --sans: "Inter", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;

  /* ---- layout ---- */
  --sidebar-w: 260px;
  --content-max: 760px;
  --stage-max: 900px;
}

/* ---------- reset / base ---------- */

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg-deep);
  color: var(--text-primary);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: rgba(74, 222, 128, 0.26); }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

strong { color: var(--text-primary); }

/* ---------- molecule-colored inline text ---------- */
/* Use these to color a molecule's NAME in prose so it matches its particle. */
.m-co2     { color: var(--co2); }
.m-h2o     { color: var(--h2o); }
.m-o2      { color: var(--o2); }
.m-atp     { color: var(--atp); }
.m-nadph   { color: var(--nadph); }
.m-sugar   { color: var(--sugar); }
.m-photon  { color: var(--photon); }
.m-electron{ color: var(--electron); }
.m-chloro  { color: var(--chloro); }
.m-rubisco { color: var(--rubisco); }
.m-co2, .m-h2o, .m-o2, .m-atp, .m-nadph, .m-sugar,
.m-photon, .m-electron, .m-chloro, .m-rubisco { font-weight: 600; }

/* little inline swatch dot, e.g. a legend chip */
.swatch {
  display: inline-block;
  width: 9px; height: 9px;
  border-radius: 99px;
  vertical-align: 1px;
  margin-right: 5px;
  box-shadow: 0 0 8px currentColor;
  background: currentColor;
}

/* ---------- progress bar ---------- */

.progress-bar {
  position: fixed;
  top: 0; left: 0;
  height: 2px;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 10px var(--accent);
  z-index: 100;
}

/* ---------- typography ---------- */

article p { margin: 14px 0; color: var(--text-secondary); }
article p strong, article li strong { color: var(--text-primary); }
article ul, article ol { margin: 14px 0 14px 26px; color: var(--text-secondary); }
article li { margin: 6px 0; }
article hr { border: none; border-top: 1px solid var(--rule); margin: 40px 0; }

article table {
  border-collapse: collapse;
  width: 100%;
  margin: 20px 0;
  font-size: 15px;
}
article th {
  font-family: var(--mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  text-align: left;
  padding: 8px 12px;
  border-bottom: 1px solid var(--rule-strong);
}
article td {
  padding: 8px 12px;
  border-bottom: 1px solid var(--rule);
  color: var(--text-secondary);
  vertical-align: top;
}

/* ---------- callouts ---------- */

.callout {
  margin: 24px 0;
  padding: 18px 22px;
  border-radius: 12px;
  border: 1px solid var(--rule);
  border-left: 3px solid var(--text-muted);
  background: var(--bg-surface);
}
.callout p { margin: 6px 0 0; }
.callout p:first-of-type { margin-top: 0; }

.callout-label {
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  margin-bottom: 8px;
  color: var(--text-muted);
}

.callout.definition { border-left-color: var(--blue); background: color-mix(in srgb, var(--blue) 6%, var(--bg-surface)); }
.callout.definition .callout-label { color: var(--blue); }
.callout.insight { border-left-color: var(--green); background: color-mix(in srgb, var(--green) 6%, var(--bg-surface)); }
.callout.insight .callout-label { color: var(--green); }
.callout.example { border-left-color: var(--amber); background: color-mix(in srgb, var(--amber) 6%, var(--bg-surface)); }
.callout.example .callout-label { color: var(--amber); }
/* the load-bearing accuracy warnings (O2 comes from water, not CO2) */
.callout.warn { border-left-color: var(--rose); background: color-mix(in srgb, var(--rose) 7%, var(--bg-surface)); }
.callout.warn .callout-label { color: var(--rose); }

/* ---------- collapsible deep-dives ---------- */

details.collapsible {
  margin: 24px 0;
  border: 1px solid var(--rule);
  border-radius: 12px;
  background: var(--bg-surface);
}
details.collapsible summary {
  cursor: pointer;
  padding: 14px 20px;
  font-weight: 600;
  color: var(--text-primary);
  list-style: none;
}
details.collapsible summary::-webkit-details-marker { display: none; }
details.collapsible summary::before {
  content: "+";
  font-family: var(--mono);
  color: var(--accent);
  margin-right: 10px;
}
details.collapsible[open] summary::before { content: "\2212"; }
.collapsible-content { padding: 0 20px 18px; color: var(--text-secondary); }
.collapsible-content p { margin: 10px 0; }

/* ---------- inline glossary popups ---------- */
/* A term the reader can click for a first-principles aside + external link. */
.gloss {
  border-bottom: 1px dashed var(--accent);
  cursor: help;
  color: var(--text-primary);
}
.gloss-pop {
  position: absolute;
  max-width: 300px;
  padding: 14px 16px;
  background: var(--bg-elevated);
  border: 1px solid var(--rule-strong);
  border-radius: 12px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.6), 0 0 24px -10px var(--accent);
  font-size: 14px;
  line-height: 1.55;
  color: var(--text-secondary);
  z-index: 200;
}
.gloss-pop h5 {
  font-family: var(--display);
  font-size: 14.5px;
  color: var(--text-primary);
  margin-bottom: 6px;
}
.gloss-pop a { font-family: var(--mono); font-size: 12.5px; }

/* ---------- interactive panels (shared with Valence's language) ---------- */

.interactive {
  margin: 34px 0;
  padding: 24px 26px 22px;
  background: var(--bg-surface);
  border: 1px solid var(--rule-strong);
  border-radius: 16px;
  box-shadow: 0 0 50px -24px rgba(74, 222, 128, 0.4),
              inset 0 1px 0 rgba(255, 255, 255, 0.03);
}

.interactive-label {
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--accent);
  margin-bottom: 8px;
}
.interactive-label::before {
  content: "";
  display: inline-block;
  width: 7px; height: 7px;
  border-radius: 99px;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
  margin-right: 8px;
  vertical-align: 1px;
}

.interactive-title {
  font-family: var(--display);
  font-size: 19px;
  font-weight: 600;
  margin: 0 0 4px;
}

.interactive-hint {
  font-size: 14.5px;
  color: var(--text-muted);
  margin: 0 0 16px;
}

.interactive-stage {
  position: relative;
  width: 100%;
  display: flex;
  justify-content: center;
  margin: 8px 0 14px;
}
.interactive-stage canvas,
.interactive-stage svg {
  display: block;
  max-width: 100%;
  border-radius: 12px;
}

.interactive-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 26px;
  align-items: center;
  padding-top: 14px;
  border-top: 1px solid var(--rule);
}

.control-group { display: flex; flex-direction: column; gap: 6px; min-width: 150px; }
.control-group.row { flex-direction: row; align-items: center; gap: 10px; min-width: 0; }

.control-label {
  font-family: var(--mono);
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}
.control-value { color: var(--text-primary); font-family: var(--mono); font-size: 13px; }

.interactive-readout {
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 13.5px;
  color: var(--text-secondary);
  min-height: 1.4em;
}

/* live numeric counters (day/night station, output meters) */
.readout-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 22px;
  margin-top: 12px;
}
.readout-stat { display: flex; flex-direction: column; gap: 2px; }
.readout-stat .rv {
  font-family: var(--mono);
  font-size: 22px;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}
.readout-stat .rl {
  font-family: var(--mono);
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}

/* ---------- sliders ---------- */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 200px;
  height: 4px;
  border-radius: 99px;
  background: var(--bg-hover);
  outline: none;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px; height: 16px;
  border-radius: 99px;
  background: var(--accent);
  border: 2px solid var(--bg-deep);
  box-shadow: 0 0 10px var(--accent);
}
input[type="range"]::-moz-range-thumb {
  width: 14px; height: 14px;
  border-radius: 99px;
  background: var(--accent);
  border: 2px solid var(--bg-deep);
  box-shadow: 0 0 10px var(--accent);
}

/* ---------- buttons ---------- */
.btn {
  font-family: var(--mono);
  font-size: 13px;
  padding: 8px 16px;
  border-radius: 9px;
  border: 1px solid var(--rule-strong);
  background: var(--bg-elevated);
  color: var(--text-primary);
  cursor: pointer;
  transition: border-color 0.15s, box-shadow 0.15s, background 0.15s;
}
.btn:hover { border-color: var(--accent); }
.btn.primary {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 14%, var(--bg-elevated));
  box-shadow: 0 0 18px -6px var(--accent);
}
.btn:disabled { opacity: 0.4; cursor: default; }
.btn:disabled:hover { border-color: var(--rule-strong); }

/* ---------- segmented toggles ---------- */
.seg-toggle {
  display: inline-flex;
  border: 1px solid var(--rule-strong);
  border-radius: 10px;
  overflow: hidden;
}
.seg-btn {
  font-family: var(--mono);
  font-size: 12.5px;
  padding: 7px 14px;
  background: transparent;
  border: none;
  border-right: 1px solid var(--rule);
  color: var(--text-secondary);
  cursor: pointer;
}
.seg-btn:last-child { border-right: none; }
.seg-btn[aria-pressed="true"] {
  background: color-mix(in srgb, var(--accent) 16%, transparent);
  color: var(--accent);
}

/* ---------- footer ---------- */

.site-footer {
  margin: 90px auto 0;
  max-width: var(--content-max);
  padding: 24px 0 40px;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--text-muted);
}
.site-footer a { color: var(--text-secondary); }