/* Base styles for CeL lab tools: calm, clinical palette with automatic dark mode for the content area.
 * The CeL header and sidebar (assets/cel/cel-chrome.css) keep the brand colours. */
:root {
  --bg: #F5F8FA; --surface: #FFFFFF; --ink: #14304A; --ink2: #4E6478; --ink3: #8496A6;
  --grid: #E1E8EE; --point: #2F6E8E; --alert: #B8205F; --ok: #1F7A4D; --accent: #2F6E8E;
  --code-bg: #0F1A24; --code-ink: #D6E2EC;
  --radius: 12px; --shadow: 0 1px 2px rgba(20,48,74,.06), 0 8px 24px rgba(20,48,74,.06);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:#0F1A24; --surface:#152331; --ink:#E4ECF2; --ink2:#A7B8C6; --ink3:#6E8394;
    --grid:#22364A; --point:#7DB7D6; --alert:#FF6FA5; --ok:#6FD39A; --accent:#7DB7D6; --code-bg:#0A131B;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.25); color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg:#0F1A24; --surface:#152331; --ink:#E4ECF2; --ink2:#A7B8C6; --ink3:#6E8394;
  --grid:#22364A; --point:#7DB7D6; --alert:#FF6FA5; --ok:#6FD39A; --accent:#7DB7D6; --code-bg:#0A131B; color-scheme: dark;
}
* { box-sizing: border-box; }
html, body { margin: 0; background: var(--bg); color: var(--ink); }
body { font: 400 16px/1.5 "Source Sans 3", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; font-variant-numeric: tabular-nums; }
a { color: var(--point); }
h1, h2, h3 { margin: 0; line-height: 1.15; letter-spacing: -.01em; }
button, .btn { font: inherit; font-size: 14.5px; color: var(--ink); background: var(--surface); border: 1px solid var(--grid); border-radius: 8px;
  padding: 7px 13px; cursor: pointer; display: inline-flex; align-items: center; gap: 7px; text-decoration: none; white-space: nowrap; }
button:hover, .btn:hover { border-color: var(--ink3); }
.btn.primary { background: var(--ink); color: var(--surface); border-color: var(--ink); }
:focus-visible { outline: 2px solid var(--point); outline-offset: 2px; }
svg.i { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 1.9; stroke-linecap: round; stroke-linejoin: round; flex-shrink: 0; }
.wrap { max-width: 1180px; margin: 0 auto; padding: 0 16px; }
@media (min-width: 720px) { .wrap { padding: 0 28px; } }
.muted { color: var(--ink2); }

.hero { padding: 44px 0 26px; }
.eyebrow { font-size: 13px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--ink3); margin-bottom: 10px; }
.hero h1 { font-size: clamp(30px, 4.6vw, 46px); max-width: 860px; }
.hero p.lead { font-size: 18.5px; color: var(--ink2); max-width: 760px; margin: 14px 0 0; }
h2.sec { font-size: 22px; margin: 34px 0 14px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 16px; }
.card, .panel-card { background: var(--surface); border: 1px solid var(--grid); border-radius: var(--radius); box-shadow: var(--shadow); padding: 18px; }
.card { display: flex; flex-direction: column; gap: 10px; border-top: 4px solid var(--acc, var(--accent)); }
.tag { font-size: 12.5px; border: 1px solid var(--grid); border-radius: 999px; padding: 1px 9px; color: var(--ink2); }
.tabs { display: flex; gap: 2px; margin-top: 12px; overflow-x: auto; scrollbar-width: none; }
.tabs button { border: 0; border-bottom: 3px solid transparent; border-radius: 0; background: transparent; padding: 9px 14px; font-weight: 600; color: var(--ink2); }
.tabs button[aria-selected="true"] { color: var(--ink); border-bottom-color: var(--ink); }
.tbl { width: 100%; border-collapse: collapse; font-size: 14.5px; }
.tbl th { text-align: left; font-size: 12.5px; text-transform: uppercase; letter-spacing: .05em; color: var(--ink3); font-weight: 700; padding: 8px 14px; background: var(--bg); }
.tbl td { padding: 9px 14px; border-top: 1px solid var(--grid); vertical-align: top; }
.scroll { overflow-x: auto; }
pre.code { background: var(--code-bg); color: var(--code-ink); border-radius: var(--radius); padding: 16px 18px; overflow: auto; font: 12.5px/1.55 ui-monospace, SFMono-Regular, Menlo, monospace; }
.flag { font-weight: 700; color: var(--alert); }
.backlink { display: inline-flex; align-items: center; gap: 4px; margin-top: 14px; font-size: 14.5px; font-weight: 600; color: var(--ink2); text-decoration: none; }
.backlink:hover { color: var(--ink); }
footer.site { margin: 46px 0 0; padding: 22px 0 34px; border-top: 1px solid var(--grid); color: var(--ink2); font-size: 14px; }
footer.site p { margin: 0 0 6px; }