/* The spark in a neuron (web/spark). Uses the shell tokens (--cme-*) when the shell is loaded, with its own fallbacks. */
:root {
  --sp-page: var(--cme-page, #eef3f2); --sp-panel: var(--cme-panel, #f7faf9); --sp-raised: var(--cme-raised, #ffffff);
  --sp-ink: var(--cme-ink, #13201e); --sp-muted: var(--cme-muted, #4c5e5b); --sp-line: var(--cme-line-soft, #cad5d2);
  --sp-accent: var(--cme-accent, #0b7469); --sp-on-accent: var(--cme-on-accent, #ffffff);
  --sp-na: #c46a00; --sp-k: #6d3fd6; --sp-volt: #0b7469; --sp-stim: #b3261e; --sp-o: #d0261b; --sp-chain: #b07a12;
  --sp-stage: #f2f6f8; --sp-membrane: #e7cf9a; --sp-tail: #c8b07a; --sp-protein: #8aa7b8; --sp-grid: rgba(20, 40, 50, 0.12);
  --sp-font-ui: var(--cme-font-ui, "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif);
  --sp-font-data: var(--cme-font-data, "IBM Plex Mono", ui-monospace, Menlo, Consolas, monospace);
  --sp-font-name: var(--cme-font-name, "Source Serif 4", Georgia, serif);
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --sp-page: var(--cme-page, #0e1514); --sp-panel: var(--cme-panel, #141e1d); --sp-raised: var(--cme-raised, #1b2826);
    --sp-ink: var(--cme-ink, #e4eeeb); --sp-muted: var(--cme-muted, #9db0ac); --sp-line: var(--cme-line-soft, #283a38);
    --sp-accent: var(--cme-accent, #39b9ab); --sp-on-accent: var(--cme-on-accent, #04201c);
    --sp-na: #ffb547; --sp-k: #b79bff; --sp-volt: #4fe0cf; --sp-stim: #ff8a80; --sp-o: #ff6b5e; --sp-chain: #e2b04a;
    --sp-stage: #0a1418; --sp-membrane: #5b4a28; --sp-tail: #3f3420; --sp-protein: #4b6878; --sp-grid: rgba(200, 230, 240, 0.12);
  }
}
:root[data-theme="dark"] {
  --sp-page: var(--cme-page, #0e1514); --sp-panel: var(--cme-panel, #141e1d); --sp-raised: var(--cme-raised, #1b2826);
  --sp-ink: var(--cme-ink, #e4eeeb); --sp-muted: var(--cme-muted, #9db0ac); --sp-line: var(--cme-line-soft, #283a38);
  --sp-accent: var(--cme-accent, #39b9ab); --sp-on-accent: var(--cme-on-accent, #04201c);
  --sp-na: #ffb547; --sp-k: #b79bff; --sp-volt: #4fe0cf; --sp-stim: #ff8a80; --sp-o: #ff6b5e; --sp-chain: #e2b04a;
  --sp-stage: #0a1418; --sp-membrane: #5b4a28; --sp-tail: #3f3420; --sp-protein: #4b6878; --sp-grid: rgba(200, 230, 240, 0.12);
}
* { box-sizing: border-box; }
html, body { margin: 0; }
body { background: var(--sp-page); color: var(--sp-ink); font-family: var(--sp-font-ui); font-size: 16px; line-height: 1.55; -webkit-font-smoothing: antialiased; }
body.cme-shell main.sp { padding-top: calc(var(--cme-bar-h, 52px) + var(--cme-top, 0px) + 8px); padding-bottom: calc(var(--cme-dock-h, 0px) + 24px); }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
[hidden] { display: none !important; }
a { color: var(--sp-accent); }
:focus-visible { outline: 3px solid var(--sp-accent); outline-offset: 2px; }
main.sp { max-width: 1180px; margin: 0 auto; padding: 16px 16px 40px; }
.sp-hero { padding: 12px 0 8px; }
.sp-eyebrow { font-size: 13px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--sp-accent); margin: 0 0 4px; }
.sp-hero h1 { font-family: var(--sp-font-name); font-size: clamp(30px, 6vw, 46px); line-height: 1.1; margin: 0 0 10px; font-weight: 600; }
.sp-lede { font-size: 18px; max-width: 62ch; margin: 0 0 12px; }
.sp-note { font-size: 14.5px; color: var(--sp-muted); max-width: 72ch; margin: 0 0 12px; }
.sp-tag { display: inline-block; font-size: 12px; font-weight: 700; padding: 1px 8px; border-radius: 999px; background: var(--sp-accent); color: var(--sp-on-accent); margin-right: 6px; vertical-align: 1px; }
.sp-tag.illus { background: #e8b100; color: #1c1600; }
.sp-jump { display: flex; flex-wrap: wrap; gap: 8px; margin: 8px 0 4px; padding: 0; list-style: none; }
.sp-jump a { display: inline-block; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--sp-line); background: var(--sp-panel); text-decoration: none; color: var(--sp-ink); font-size: 14px; }
section.sp-sec { margin: 28px 0; padding: 18px; border-radius: 14px; background: var(--sp-panel); border: 1px solid var(--sp-line); scroll-margin-top: 70px; }
section.sp-sec h2 { font-family: var(--sp-font-name); font-size: clamp(24px, 4vw, 30px); margin: 0 0 6px; font-weight: 600; line-height: 1.2; }
section.sp-sec h3 { font-size: 17px; margin: 18px 0 6px; }
.sp-intro { max-width: 70ch; margin: 0 0 14px; }
.sp-grid2 { display: grid; grid-template-columns: 1fr; gap: 14px; }
@media (min-width: 900px) { .sp-grid2 { grid-template-columns: 1.05fr 1fr; } }
.sp-stage { position: relative; border-radius: 12px; overflow: hidden; background: var(--sp-stage); border: 1px solid var(--sp-line); }
.sp-stage canvas { display: block; width: 100%; height: 100%; }
.sp-membrane { aspect-ratio: 16 / 11; }
.sp-trace { aspect-ratio: 16 / 11; }
@media (max-width: 600px) { .sp-membrane { aspect-ratio: 4 / 3.6; } .sp-trace { aspect-ratio: 4 / 3.4; } }
.sp-controls { display: flex; flex-wrap: wrap; gap: 10px 14px; align-items: center; margin: 14px 0 8px; }
.sp-btn { min-height: 44px; padding: 8px 18px; border-radius: 999px; border: 1px solid var(--sp-line); background: var(--sp-raised); color: var(--sp-ink); font: inherit; font-size: 15px; font-weight: 500; cursor: pointer; }
.sp-btn.primary { background: var(--sp-accent); color: var(--sp-on-accent); border-color: transparent; font-weight: 700; font-size: 16px; padding: 8px 24px; }
.sp-btn[aria-pressed="true"] { outline: 2px solid var(--sp-accent); }
.sp-field { display: flex; flex-direction: column; gap: 2px; min-width: 200px; flex: 1 1 220px; }
.sp-field label, .sp-field .sp-lab { font-size: 13.5px; font-weight: 600; }
.sp-field output, .sp-val { font-family: var(--sp-font-data); font-size: 14px; }
.sp-field small { color: var(--sp-muted); font-size: 13px; }
input[type="range"] { width: 100%; min-height: 32px; accent-color: var(--sp-accent); }
select { min-height: 40px; font: inherit; font-size: 15px; padding: 4px 8px; border-radius: 8px; border: 1px solid var(--sp-line); background: var(--sp-raised); color: var(--sp-ink); }
.sp-readout { font-family: var(--sp-font-data); font-size: 14px; display: flex; flex-wrap: wrap; gap: 6px 18px; padding: 10px 12px; border-radius: 10px; background: var(--sp-raised); border: 1px solid var(--sp-line); }
.sp-readout b { font-family: var(--sp-font-ui); font-weight: 600; margin-right: 4px; }
.sp-said { min-height: 1.5em; font-weight: 600; margin: 8px 0; }
.sp-phase { margin-top: 12px; padding: 12px 14px; border-radius: 10px; background: var(--sp-raised); border-left: 5px solid var(--sp-accent); }
.sp-phase h3 { margin: 0 0 4px; }
.sp-phase p { margin: 0; }
.sp-gates { display: grid; gap: 6px; margin: 10px 0 0; }
.sp-gate { display: grid; grid-template-columns: minmax(0, 1fr) 120px 48px; gap: 8px; align-items: center; font-size: 13.5px; }
.sp-bar { height: 10px; border-radius: 6px; background: var(--sp-line); overflow: hidden; }
.sp-bar i { display: block; height: 100%; width: 0; background: var(--sp-accent); }
.sp-bar.na i { background: var(--sp-na); } .sp-bar.k i { background: var(--sp-k); }
.sp-small { font-size: 13.5px; color: var(--sp-muted); }
.sp-steps { padding-left: 1.3em; }
.sp-steps li { margin: 8px 0; }
.sp-steps li.on { background: var(--sp-raised); border-radius: 8px; outline: 2px solid var(--sp-accent); outline-offset: 4px; }
.sp-cite { font-size: 0.75em; vertical-align: super; line-height: 0; margin-left: 2px; white-space: nowrap; }
.sp-cite a { text-decoration: none; }
details.sp-more { margin-top: 12px; }
details.sp-more summary { cursor: pointer; font-weight: 600; min-height: 32px; }
dl.sp-parts dt { font-weight: 600; margin-top: 8px; }
dl.sp-parts dd { margin: 2px 0 0 0; }
table.sp-table { border-collapse: collapse; margin: 6px 0 10px; font-size: 15px; width: 100%; max-width: 520px; }
.sp-table th, .sp-table td { text-align: left; padding: 6px 10px; border-bottom: 1px solid var(--sp-line); }
.sp-table td.num { font-family: var(--sp-font-data); text-align: right; }
.sp-table th.num { text-align: right; }
.sp-tablewrap { overflow-x: auto; }
.sp-scale { position: relative; height: 64px; margin: 18px 0 8px; }
.sp-scale .track { position: absolute; left: 0; right: 0; top: 28px; height: 8px; border-radius: 4px; background: linear-gradient(90deg, var(--sp-k), var(--sp-line) 50%, var(--sp-na)); }
.sp-scale .mk { position: absolute; top: 0; transform: translateX(-50%); font-size: 12.5px; text-align: center; white-space: nowrap; }
.sp-scale .mk::after { content: ""; display: block; width: 2px; height: 22px; margin: 2px auto 0; background: currentColor; }
.sp-scale .mk.v { top: 26px; color: var(--sp-ink); font-weight: 700; }
.sp-scale .mk.v::after { display: none; }
.sp-scale .mk.v::before { content: ""; display: block; width: 14px; height: 14px; margin: 0 auto 2px; border-radius: 50%; background: var(--sp-accent); border: 2px solid var(--sp-raised); }
.sp-formula { font-family: var(--sp-font-data); font-size: 14px; padding: 8px 10px; background: var(--sp-raised); border-radius: 8px; overflow-x: auto; white-space: nowrap; }
.sp-big { font-size: 20px; font-weight: 700; margin: 6px 0; }
.sp-race { aspect-ratio: 16 / 6; min-height: 200px; }
@media (max-width: 600px) { .sp-race { aspect-ratio: 4 / 3; } }
.sp-chan { aspect-ratio: 1 / 1; max-height: 640px; touch-action: none; cursor: grab; }
.sp-chan:active { cursor: grabbing; }
.sp-legend { display: flex; flex-wrap: wrap; gap: 6px 14px; font-size: 13px; margin: 8px 0; padding: 0; list-style: none; }
.sp-legend i { display: inline-block; width: 12px; height: 12px; border-radius: 50%; margin-right: 5px; vertical-align: -1px; }
.sp-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 12px; }
.sp-card { padding: 12px 14px; border-radius: 10px; background: var(--sp-raised); border: 1px solid var(--sp-line); }
.sp-card p { margin: 4px 0; }
.sp-card .myth { color: var(--sp-muted); }
.sp-card .myth b { color: var(--cme-bad, #b3261e); }
.sp-card .truth b { color: var(--cme-good, #1d7a3a); }
ol.sp-key li { margin: 8px 0; }
dl.sp-vocab { display: grid; grid-template-columns: 1fr; gap: 4px 16px; }
@media (min-width: 760px) { dl.sp-vocab { grid-template-columns: max-content 1fr; } }
dl.sp-vocab dt { font-weight: 700; }
dl.sp-vocab dd { margin: 0 0 8px; }
ul.sp-links { display: flex; flex-wrap: wrap; gap: 8px; padding: 0; list-style: none; }
ul.sp-links a { display: inline-flex; align-items: center; min-height: 44px; padding: 6px 14px; border-radius: 999px; border: 1px solid var(--sp-line); background: var(--sp-raised); text-decoration: none; color: var(--sp-ink); }
ol.sp-sources { font-size: 14px; padding-left: 1.6em; }
ol.sp-sources li { margin: 6px 0; scroll-margin-top: 80px; }
ol.sp-sources li:target { background: var(--sp-raised); outline: 2px solid var(--sp-accent); }
.sp-err { padding: 16px; }