/* ==========================================================================
   GCSEs, explained — page-specific styles.
   Builds on the site's /style.css (variables --bg --fg --muted --accent --rule
   --code-bg; serif body, sans-serif headings, 38rem column). This file only
   adds the page's components — charts, mini-apps, cards, timeline, etc. —
   restyled to match the rest of the site: bordered, low-contrast, no shadows,
   one accent colour. Light/dark comes for free from /style.css.
   ========================================================================== */

:root {
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  /* Compatibility: a few inline style="" attributes in the markup still refer
     to the original design tokens. Alias them onto the site palette so nothing
     renders unstyled. */
  --indigo-600: var(--accent);
  --gold: var(--accent);
  --grade9: #3f6f5f;
  --grade4: #c08443;
  --grade1: #a8556a;
}

/* skip link */
.skip-link {
  position: absolute; left: 0.75rem; top: -3rem; z-index: 50;
  background: var(--accent); color: var(--bg); padding: 0.5rem 0.9rem;
  border-radius: 6px; font-family: var(--sans); font-size: 0.9rem;
  text-decoration: none; transition: top 0.15s ease;
}
.skip-link:focus { top: 0.75rem; }

/* ---- layout neutralisers ------------------------------------------------
   The page was authored for a wide multi-column layout; inside the site's
   38rem column everything collapses to a single column. */
.wrap { width: 100%; margin: 0; }
.section { padding: 1.5rem 0 0; }
.section.alt { background: transparent; }
.section-head { margin: 0 0 1rem; }
.grid { display: grid; gap: 1rem; }
.grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }

/* ---- page header (was the hero) ---------------------------------------- */
.page-head { margin: 0 0 1.75rem; }
.lede { color: var(--muted); font-size: 1.05rem; }
.hl { color: var(--accent); }
.eyebrow {
  display: inline-block; font-family: var(--sans); font-size: 0.78rem;
  font-weight: 600; letter-spacing: 0.02em; color: var(--muted); margin: 0 0 0.3rem;
}
.kicker { display: flex; align-items: center; gap: 0.6rem; margin: 0 0 0.3rem; }
.kicker .idx { font-family: var(--mono); font-size: 0.78rem; font-weight: 600; color: var(--accent); }
.kicker .eyebrow { margin: 0; }
.dek { color: var(--muted); margin: 0; }

.hero-stats { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.6rem; margin: 1.25rem 0 0; }
.hero-stats .stat { border: 1px solid var(--rule); border-radius: 6px; padding: 0.6rem 0.75rem; }
.hero-stats .num { font-family: var(--sans); font-weight: 700; font-size: 1.4rem; line-height: 1; }
.hero-stats .num .unit { font-size: 0.6em; color: var(--muted); }
.hero-stats .lbl { font-family: var(--sans); font-size: 0.8rem; color: var(--muted); margin-top: 0.25rem; }

/* ---- prose ------------------------------------------------------------- */
.prose p, .prose li { color: var(--fg); }
.prose strong { color: var(--fg); }
.read { max-width: 100%; }
.muted { color: var(--muted); }

/* ---- cards ------------------------------------------------------------- */
.card { border: 1px solid var(--rule); border-radius: 6px; padding: 1rem 1.1rem; margin: 0 0 1rem; }
.card.pad-lg { padding: 1.1rem 1.2rem; }
.card h3 { margin-top: 0; }

.fact { border: 1px solid var(--rule); border-radius: 6px; padding: 0.8rem 0.9rem; display: flex; flex-direction: column; gap: 0.3rem; }
.fact .ico { font-size: 1.3rem; line-height: 1; }
.fact .ft { font-family: var(--sans); font-weight: 600; }
.fact .fd { color: var(--muted); font-size: 0.9rem; margin: 0; }
.fact .src { margin-top: auto; font-family: var(--sans); font-size: 0.78rem; }
.fact .src a { color: var(--muted); }

.stat-tile { border: 1px solid var(--rule); border-radius: 6px; padding: 0.9rem 1rem; }
.stat-tile .big { font-family: var(--sans); font-weight: 700; font-size: 1.8rem; line-height: 1; color: var(--accent); }
.stat-tile.gold .big, .stat-tile.teal .big, .stat-tile.rose .big { color: var(--accent); }
.stat-tile .cap { color: var(--muted); font-size: 0.88rem; margin-top: 0.4rem; }

/* ---- charts ------------------------------------------------------------ */
.chart-card { border: 1px solid var(--rule); border-radius: 6px; padding: 0.9rem 1rem; margin: 0 0 1rem; }
.chart-card h3 { margin: 0 0 0.2rem; font-size: 1.05rem; }
.chart-desc { color: var(--muted); font-size: 0.9rem; margin: 0 0 0.75rem; }
.chart-holder { width: 100%; height: auto !important; }
.chart-holder.tall { height: auto !important; }

/* hand-rolled inline SVG charts — every value/label is drawn on the chart, so
   it reads at a glance with no hover. Structural colours follow the site vars
   (theme-aware); the series palette is set in JS and theme-neutral. */
.gx-svg { display: block; width: 100%; height: auto; font-family: var(--sans); }
.gx-svg text { font-family: var(--sans); }
.gx-base { stroke: var(--rule); stroke-width: 1; }
.gx-bar { fill: var(--accent); }
.gx-line { stroke: var(--accent); }
.gx-dot { fill: var(--accent); }
.gx-sep { stroke: var(--bg); stroke-width: 1.5; }
.gx-cat { fill: var(--muted); font-size: 11px; }
.gx-hcat { fill: var(--muted); font-size: 10.5px; }
.gx-val { fill: var(--fg); font-size: 11px; font-weight: 600; font-variant-numeric: tabular-nums; }
.gx-leg { fill: var(--muted); font-size: 11px; }
.gx-pieval { fill: #fff; font-size: 11px; font-weight: 700; }
.chart-foot { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.75rem; font-family: var(--sans); font-size: 0.78rem; color: var(--muted); }
.chart-foot a { color: var(--muted); }
.chart-note { margin-top: 0.75rem; padding: 0.6rem 0.8rem; background: var(--code-bg); border-left: 2px solid var(--accent); border-radius: 4px; font-size: 0.85rem; color: var(--muted); }

.legend { display: flex; flex-wrap: wrap; gap: 0.4rem 1rem; margin-top: 0.6rem; font-family: var(--sans); font-size: 0.82rem; color: var(--muted); }
.legend span { display: inline-flex; align-items: center; gap: 0.4rem; }
.legend i { width: 0.75rem; height: 0.75rem; border-radius: 3px; display: inline-block; }

/* ---- timeline ---------------------------------------------------------- */
.timeline { position: relative; }
.timeline::before { content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 2px; background: var(--rule); }
.tl-item { position: relative; padding: 0 0 1.1rem 1.75rem; }
.tl-item:last-child { padding-bottom: 0; }
.tl-dot { position: absolute; left: 0; top: 0.25rem; width: 16px; height: 16px; border-radius: 50%; background: var(--bg); border: 2px solid var(--accent); }
.tl-year { font-family: var(--mono); font-weight: 600; color: var(--accent); font-size: 0.85rem; }
.tl-event { font-family: var(--sans); font-weight: 600; margin: 0.1rem 0; }
.tl-detail { color: var(--muted); font-size: 0.9rem; margin: 0; }

/* ---- people ------------------------------------------------------------ */
.person { display: flex; gap: 0.8rem; align-items: flex-start; border: 1px solid var(--rule); border-radius: 6px; padding: 0.8rem 0.9rem; }
.person .av { width: 2.4rem; height: 2.4rem; border-radius: 6px; flex: none; display: grid; place-items: center; font-family: var(--sans); font-weight: 700; color: var(--bg); background: var(--accent); font-size: 0.95rem; }
.person .pn { font-family: var(--sans); font-weight: 600; }
.person .pr { font-family: var(--sans); font-size: 0.8rem; color: var(--accent); }
.person .pc { font-size: 0.88rem; color: var(--muted); margin: 0.25rem 0 0; }

/* ---- quotes ------------------------------------------------------------ */
.quote { border-left: 2px solid var(--accent); background: var(--code-bg); padding: 0.8rem 1rem; border-radius: 0 6px 6px 0; }
.quote blockquote { margin: 0; border: 0; padding: 0; color: var(--fg); font-size: 1.05rem; }
.quote cite { display: block; margin-top: 0.5rem; font-style: normal; font-family: var(--sans); font-size: 0.82rem; color: var(--muted); }
.quote cite a { color: var(--muted); }

/* ---- callouts ---------------------------------------------------------- */
.callout { display: flex; gap: 0.7rem; align-items: flex-start; border: 1px solid var(--rule); border-left-width: 2px; border-radius: 6px; padding: 0.8rem 1rem; background: var(--code-bg); }
.callout .ci { font-size: 1.15rem; flex: none; }
.callout p { margin: 0; font-size: 0.9rem; color: var(--muted); }
.callout strong { color: var(--fg); }
.callout.info { border-left-color: var(--accent); }
.callout.warn { border-left-color: #b07a2e; }

/* ---- mini-apps --------------------------------------------------------- */
.app { border: 1px solid var(--rule); border-radius: 6px; padding: 1.1rem 1.2rem; margin: 0 0 1rem; }
.app h3 { margin-top: 0; }
.app-sub { color: var(--muted); font-size: 0.92rem; margin-top: -0.2rem; }
.app-row { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: center; }

.field { display: flex; flex-direction: column; gap: 0.3rem; }
.field label { font-family: var(--sans); font-size: 0.82rem; color: var(--muted); }
select, input[type="text"], input[type="number"] {
  font: inherit; font-family: var(--sans); color: var(--fg); background: var(--bg);
  border: 1px solid var(--rule); border-radius: 6px; padding: 0.5rem 0.6rem;
}
select:focus, input:focus { border-color: var(--accent); outline: none; }

.chip-row { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.chip {
  font-family: var(--sans); border: 1px solid var(--rule); background: transparent;
  color: var(--fg); border-radius: 999px; padding: 0.35rem 0.75rem; font-size: 0.85rem;
  font-weight: 600; cursor: pointer;
}
.chip:hover { border-color: var(--accent); }
.chip[aria-pressed="true"], .chip.on { background: var(--accent); color: var(--bg); border-color: var(--accent); }

.range-wrap { display: flex; align-items: center; gap: 0.8rem; }
input[type="range"] { -webkit-appearance: none; appearance: none; height: 6px; border-radius: 999px; background: var(--rule); flex: 1; }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 20px; height: 20px; border-radius: 50%; background: var(--accent); border: 3px solid var(--bg); cursor: pointer; }
input[type="range"]::-moz-range-thumb { width: 18px; height: 18px; border-radius: 50%; background: var(--accent); border: 3px solid var(--bg); cursor: pointer; }

.gc-display { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 0.8rem; margin: 1rem 0; }
.gc-badge { display: grid; place-items: center; aspect-ratio: 1; width: 100%; max-width: 8rem; margin: 0 auto; border-radius: 8px; color: #fff; background: var(--accent); }
.gc-badge .g { font-family: var(--sans); font-weight: 700; font-size: 2.4rem; line-height: 1; }
.gc-badge .gt { font-family: var(--sans); font-size: 0.7rem; letter-spacing: 0.1em; opacity: 0.9; }
.gc-arrow { font-size: 1.3rem; color: var(--muted); text-align: center; }
.gc-meaning { text-align: center; font-size: 0.92rem; color: var(--muted); min-height: 2.6em; margin-top: 0.4rem; }

.result-panel { margin-top: 0.9rem; padding: 0.8rem 1rem; border: 1px solid var(--rule); border-radius: 6px; background: var(--code-bg); }
.result-panel.good { border-color: var(--accent); }
.result-big { font-family: var(--sans); font-size: 1.3rem; font-weight: 700; }

.meter { height: 10px; border-radius: 999px; background: var(--rule); overflow: hidden; }
.meter > i { display: block; height: 100%; background: var(--accent); transition: width 0.24s ease; }

.quiz-q { font-family: var(--sans); font-size: 1.05rem; font-weight: 600; margin-bottom: 0.8rem; }
.quiz-opts { display: grid; gap: 0.5rem; }
.quiz-opt {
  text-align: left; font: inherit; font-family: var(--sans); font-weight: 600;
  border: 1px solid var(--rule); background: transparent; color: var(--fg);
  border-radius: 6px; padding: 0.7rem 0.8rem; cursor: pointer; display: flex; gap: 0.6rem; align-items: center;
}
.quiz-opt:hover:not([disabled]) { border-color: var(--accent); }
.quiz-opt .mk { width: 1.5rem; height: 1.5rem; border-radius: 5px; border: 1px solid var(--rule); display: grid; place-items: center; font-size: 0.8rem; flex: none; }
.quiz-opt.correct { border-color: #0a8a3f; background: color-mix(in srgb, #0a8a3f 12%, transparent); }
.quiz-opt.wrong { border-color: #c0392b; background: color-mix(in srgb, #c0392b 12%, transparent); }
.quiz-progress { font-family: var(--sans); font-size: 0.82rem; color: var(--muted); font-weight: 600; }
.quiz-explain { margin-top: 0.75rem; font-size: 0.9rem; color: var(--muted); padding: 0.6rem 0.8rem; background: var(--code-bg); border-left: 2px solid var(--accent); border-radius: 4px; }

.planner-grid { display: grid; gap: 0.4rem; margin-top: 0.8rem; }
.planner-day { display: grid; grid-template-columns: 3.25rem 1fr; gap: 0.6rem; align-items: start; padding: 0.5rem 0.6rem; border: 1px solid var(--rule); border-radius: 6px; }
.planner-day .d { font-family: var(--sans); font-weight: 700; font-size: 0.85rem; color: var(--accent); }
.planner-day .s { font-size: 0.88rem; color: var(--muted); }
.pill { display: inline-block; font-family: var(--sans); font-size: 0.76rem; font-weight: 600; padding: 0.15rem 0.5rem; border-radius: 999px; background: var(--bg); border: 1px solid var(--rule); color: var(--fg); margin: 0 0.3rem 0.3rem 0; }

.countdown { display: flex; gap: 0.6rem; flex-wrap: wrap; }
.cd-unit { text-align: center; border: 1px solid var(--rule); border-radius: 6px; padding: 0.7rem 0.9rem; min-width: 4.5rem; }
.cd-unit .n { font-family: var(--sans); font-size: 1.7rem; font-weight: 700; line-height: 1; font-variant-numeric: tabular-nums; color: var(--accent); }
.cd-unit .u { font-family: var(--sans); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin-top: 0.35rem; }

/* ---- link lists & tags ------------------------------------------------- */
.linklist { columns: 2; column-gap: 1.4rem; }
.linklist a { break-inside: avoid; display: block; padding: 0.45rem 0; border-bottom: 1px solid var(--rule); text-decoration: none; color: var(--fg); font-family: var(--sans); font-weight: 600; font-size: 0.9rem; }
.linklist a:hover { color: var(--accent); }
.linklist a .host { display: block; font-weight: 400; font-size: 0.76rem; color: var(--muted); }
@media (max-width: 30rem) { .linklist { columns: 1; } }

.tagrow { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.tag { font-family: var(--sans); font-size: 0.78rem; font-weight: 600; color: var(--muted); background: var(--code-bg); border: 1px solid var(--rule); border-radius: 999px; padding: 0.25rem 0.6rem; text-decoration: none; }
a.tag:hover { color: var(--accent); border-color: var(--accent); }

/* Table of contents uses the shared .toc style from /style.css (a single
   bordered box with an "On this page" heading and a numbered list). */

/* ---- buttons (used by the mini-apps) ----------------------------------- */
.btn { display: inline-flex; align-items: center; gap: 0.4rem; cursor: pointer; font-family: var(--sans); font-weight: 600; font-size: 0.9rem; text-decoration: none; padding: 0.55rem 1rem; border-radius: 6px; border: 1px solid var(--accent); background: transparent; color: var(--accent); }
.btn-primary { background: var(--accent); color: var(--bg); }
.btn:hover { opacity: 0.88; }

/* ---- scroll-reveal: the site is static, so just show everything --------- */
.reveal { opacity: 1; transform: none; }

/* ---- footer (the page's original footer, toned down to the site style) -- */
.footer { background: transparent; color: var(--muted); border-top: 1px solid var(--rule); margin-top: 3rem; padding: 1.5rem 0 0; font-family: var(--sans); font-size: 0.85rem; }
.footer .wrap { max-width: 38rem; margin: 0 auto; padding: 0 1.25rem; }
.footer h4 { color: var(--fg); font-size: 0.9rem; margin: 0 0 0.5rem; }
.footer a { color: var(--muted); }
.footer .foot-grid { display: grid; grid-template-columns: 1fr; gap: 1.25rem; }
.footer ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 0.4rem; }
.footer .fine { margin-top: 1.25rem; padding-top: 1rem; border-top: 1px solid var(--rule); font-size: 0.8rem; }