/*
 * Explainers: full-screen interactive pages in knowledge/ (see ARCHITECTURE.md,
 * "Explainers"). Load after main.css, which supplies the theme tokens; this
 * file adds the app layout plus a few tokens of its own, mirrored in the same
 * three theme blocks main.css uses.
 *
 * Progressive enhancement: until js/explainer.js stamps html.xp-ready, the
 * page is an ordinary main.css article (every topic section in order), so it
 * still reads without JavaScript or WebGL. Everything app-shaped is scoped
 * under .xp-ready; elements that only make sense in the app carry .xp-only.
 */

/* ===== Tokens ===== */
:root {
  --xp-panel: rgba(255, 255, 255, 0.9);
  --xp-panel-solid: #ffffff;
  --xp-panel-border: rgba(0, 0, 0, 0.12);
  --xp-shadow: 0 4px 22px rgba(0, 0, 0, 0.14);
  --xp-ink-2: #52514e;          /* secondary text */
  --xp-ink-3: #686762;          /* muted labels; 5.5:1 on the panel */
  --xp-hover: rgba(0, 0, 0, 0.055);
  --xp-track: #e3e2dd;          /* slider tracks, meter backgrounds */
  --xp-grid: #e8e7e2;           /* chart gridlines */
  --xp-axis: #c3c2b7;           /* chart baselines */
  --xp-chart-bg: #ffffff;
  --xp-good: #0c7d0c;           /* status text colours, each paired with an icon */
  --xp-warn: #9a6500;
  --xp-serious: #c0440f;
  --xp-critical: #c62828;
  --xp-good-mark: #0ca30c;      /* status marks (dots, bars) */
  --xp-warn-mark: #fab219;
  --xp-serious-mark: #ec835a;
  --xp-critical-mark: #d03b3b;
  --xp-scrim: rgba(0, 0, 0, 0.28);
  --xp-drawer-w: min(470px, 44vw);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --xp-panel: rgba(22, 22, 22, 0.88);
    --xp-panel-solid: #181818;
    --xp-panel-border: rgba(255, 255, 255, 0.13);
    --xp-shadow: 0 4px 22px rgba(0, 0, 0, 0.55);
    --xp-ink-2: #c3c2b7;
    --xp-ink-3: #9c9a92;
    --xp-hover: rgba(255, 255, 255, 0.07);
    --xp-track: #3a3a37;
    --xp-grid: #2c2c2a;
    --xp-axis: #45453f;
    --xp-chart-bg: #1a1a1a;
    --xp-good: #3fcf3f;
    --xp-warn: #fab219;
    --xp-serious: #f08a60;
    --xp-critical: #ff7070;
    --xp-scrim: rgba(0, 0, 0, 0.45);
  }
}

:root[data-theme="dark"] {
  --xp-panel: rgba(22, 22, 22, 0.88);
  --xp-panel-solid: #181818;
  --xp-panel-border: rgba(255, 255, 255, 0.13);
  --xp-shadow: 0 4px 22px rgba(0, 0, 0, 0.55);
  --xp-ink-2: #c3c2b7;
  --xp-ink-3: #9c9a92;
  --xp-hover: rgba(255, 255, 255, 0.07);
  --xp-track: #3a3a37;
  --xp-grid: #2c2c2a;
  --xp-axis: #45453f;
  --xp-chart-bg: #1a1a1a;
  --xp-good: #3fcf3f;
  --xp-warn: #fab219;
  --xp-serious: #f08a60;
  --xp-critical: #ff7070;
  --xp-scrim: rgba(0, 0, 0, 0.45);
}

[hidden] { display: none !important; }

/* ===== Loading ===== */
/* Set by an inline head script while the model loads, so the article doesn't
   flash before the app takes over. */
html.xp-booting:not(.xp-ready) #xp-drawer { visibility: hidden; }
html.xp-booting:not(.xp-ready) body::before {
  content: "Loading the model\2026";
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text);
  opacity: 0.6;
}

/* ===== Article mode (no JS / no WebGL) ===== */
html:not(.xp-ready) .xp-only,
html:not(.xp-ready) [data-widget],
html:not(.xp-ready) [data-run] { display: none !important; }
html:not(.xp-ready) .xp-topic { margin-bottom: 2.4em; }
html:not(.xp-ready) .xp-topic > h2 { border-top: 1px solid var(--border); padding-top: 1em; }

/* ===== App mode ===== */
html.xp-ready,
html.xp-ready body {
  height: 100%;
  overflow: hidden;
  overscroll-behavior: none;
}

html.xp-ready body {
  margin: 0;
  max-width: none;
  padding: 0;
}

html.xp-ready .xp-article-only { display: none !important; }

.xp-stage {
  position: fixed;
  inset: 0;
  background: var(--bg);
  touch-action: none;           /* the 3D view owns drags and pinches */
}

.xp-stage canvas {
  display: block;
  width: 100%;
  height: 100%;
  outline: none;
}

/* Floating panels share one look. */
.xp-panel {
  background: var(--xp-panel);
  border: 1px solid var(--xp-panel-border);
  border-radius: 10px;
  box-shadow: var(--xp-shadow);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  color: var(--text);
}

/* ----- Top bar ----- */
.xp-topbar {
  position: fixed;
  top: 12px;
  left: 12px;
  right: 64px;                  /* leave room for the theme toggle */
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  pointer-events: none;
  z-index: 30;
  transition: right 0.28s ease;
}

.xp-topbar > * { pointer-events: auto; }

.xp-title {
  padding: 8px 14px 9px;
  max-width: 380px;
}

.xp-title .xp-home {
  font-size: 0.8em;
  display: inline-block;
  margin-bottom: 2px;
}

.xp-title h1 {
  font-size: 1.15em;
  line-height: 1.2;
  margin: 0;
}

.xp-title p {
  margin: 3px 0 0;
  font-size: 0.82em;
  color: var(--xp-ink-2);
  line-height: 1.35;
}

/* ----- Buttons and controls ----- */
.xp-btn {
  font: inherit;
  font-size: 0.86em;
  color: var(--text);
  background: var(--xp-panel);
  border: 1px solid var(--xp-panel-border);
  border-radius: 999px;
  padding: 6px 13px;
  cursor: pointer;
  line-height: 1.2;
  white-space: nowrap;
}

.xp-btn:hover { background: var(--xp-hover); border-color: var(--link); }
.xp-btn:focus-visible, .xp-chip:focus-visible, .xp-menu a:focus-visible { outline: 2px solid var(--link); outline-offset: 2px; }

.xp-btn.xp-primary {
  background: var(--link);
  border-color: var(--link);
  color: #ffffff;
}

.xp-btn.xp-primary:hover { background: var(--link-hover); }

.xp-btn[aria-expanded="true"] { border-color: var(--link); }

.xp-chip {
  font: inherit;
  font-size: 0.8em;
  color: var(--xp-ink-2);
  background: transparent;
  border: 1px solid var(--xp-panel-border);
  border-radius: 999px;
  padding: 3px 10px;
  cursor: pointer;
}

.xp-chip:hover { background: var(--xp-hover); }

.xp-chip[aria-pressed="true"] {
  color: var(--text);
  border-color: var(--link);
  background: var(--xp-hover);
}

.xp-field {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 0;
}

.xp-field > label,
.xp-field > .xp-field-label {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-size: 0.74em;
  color: var(--xp-ink-3);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.xp-field output,
.xp-field .xp-value {
  color: var(--text);
  text-transform: none;
  letter-spacing: 0;
  font-weight: bold;
  font-variant-numeric: tabular-nums;
}

.xp-ready input[type="range"] {
  width: 100%;
  margin: 2px 0;
  accent-color: var(--link);
  cursor: pointer;
}

.xp-ready select {
  font: inherit;
  font-size: 0.86em;
  color: var(--text);
  background: var(--xp-panel-solid);
  border: 1px solid var(--xp-panel-border);
  border-radius: 6px;
  padding: 5px 6px;
  max-width: 100%;
}

/* ----- Explore menu ----- */
.xp-menu {
  position: fixed;
  top: 64px;
  right: 12px;
  width: min(360px, calc(100vw - 24px));
  box-sizing: border-box;       /* the width includes padding, so it fits on phones */
  max-height: calc(100dvh - 90px);
  overflow-y: auto;
  padding: 10px 12px 14px;
  z-index: 60;
}

.xp-menu input[type="search"] {
  font: inherit;
  font-size: 0.9em;
  width: 100%;
  box-sizing: border-box;
  padding: 7px 10px;
  margin-bottom: 6px;
  color: var(--text);
  background: var(--xp-panel-solid);
  border: 1px solid var(--xp-panel-border);
  border-radius: 6px;
}

.xp-menu h3 {
  font-size: 0.72em;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--xp-ink-3);
  margin: 12px 0 4px;
}

.xp-menu ul { list-style: none; margin: 0; padding: 0; }
.xp-menu li { margin: 0; }

.xp-menu a {
  display: block;
  padding: 5px 8px;
  border-radius: 6px;
  color: var(--text);
  border-bottom: none;
  font-size: 0.92em;
}

.xp-menu a:hover { background: var(--xp-hover); }
.xp-menu a[aria-current="true"] { background: var(--xp-hover); color: var(--link); }

/* ----- Drawer: one topic at a time ----- */
html.xp-ready .xp-drawer {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: var(--xp-drawer-w);
  display: flex;
  flex-direction: column;
  background: var(--xp-panel-solid);
  border-left: 1px solid var(--xp-panel-border);
  box-shadow: var(--xp-shadow);
  transform: translateX(105%);
  transition: transform 0.28s ease;
  z-index: 50;
}

html.xp-ready.xp-drawer-open .xp-drawer { transform: translateX(0); }

.xp-drawer-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 64px 10px 16px; /* right padding clears the theme toggle */
  border-bottom: 1px solid var(--xp-panel-border);
  min-height: 40px;
}

.xp-crumb {
  flex: 1;
  font-size: 0.75em;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--xp-ink-3);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.xp-drawer-body {
  flex: 1;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 4px 18px 40px;
  line-height: 1.55;
}

.xp-drawer-body h2 { font-size: 1.35em; line-height: 1.25; margin: 0.6em 0 0.4em; }
.xp-drawer-body h3 { font-size: 1.05em; margin: 1.4em 0 0.4em; }
.xp-drawer-body h2:focus { outline: none; }

.xp-next {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  margin-top: 2em;
  padding-top: 1em;
  border-top: 1px solid var(--xp-panel-border);
  font-size: 0.92em;
}

/* Previous on the left, next on the right; long titles wrap within each half. */
.xp-next > * { max-width: 48%; }
.xp-next .xp-next-link { margin-left: auto; text-align: right; }

/* "← Contents" in the drawer header (added by js/explainer.js). */
.xp-contents { flex: none; }

/* ----- Topic furniture ----- */
.xp-lede { font-size: 1.04em; color: var(--xp-ink-2); }

.xp-stats {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(118px, 1fr));
  gap: 8px;
  margin: 1em 0 1.2em;
}

.xp-stat {
  border: 1px solid var(--xp-panel-border);
  border-radius: 8px;
  padding: 7px 10px 8px;
}

.xp-stat b {
  display: block;
  font-size: 1.15em;
  line-height: 1.25;
}

.xp-stat span {
  display: block;
  font-size: 0.76em;
  color: var(--xp-ink-3);
  line-height: 1.3;
}

.xp-figure {
  margin: 1.2em 0;
  border: 1px solid var(--xp-panel-border);
  border-radius: 8px;
  padding: 10px;
  background: var(--xp-chart-bg);
}

.xp-figure figcaption,
.xp-caption {
  text-align: left;
  font-size: 0.8em;
  color: var(--xp-ink-3);
  margin-top: 6px;
  line-height: 1.4;
}

.xp-figure canvas { display: block; width: 100%; }

.xp-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 8px;
  margin: 8px 0 2px;
}

.xp-note {
  font-size: 0.84em;
  color: var(--xp-ink-2);
  border-left: 3px solid var(--xp-panel-border);
  padding: 2px 0 2px 10px;
  margin: 1em 0;
}

.xp-drawer-body table,
.xp-topic table {
  border-collapse: collapse;
  font-size: 0.86em;
  margin: 1em 0;
  width: 100%;
}

.xp-drawer-body th,
.xp-drawer-body td,
.xp-topic th,
.xp-topic td {
  border: none;
  border-bottom: 1px solid var(--xp-panel-border);
  padding: 5px 6px;
  text-align: left;
  vertical-align: top;
}

.xp-drawer-body th { color: var(--xp-ink-3); font-weight: normal; font-size: 0.9em; }
.xp-num { text-align: right !important; font-variant-numeric: tabular-nums; white-space: nowrap; }

.xp-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 12px;
  font-size: 0.78em;
  color: var(--xp-ink-2);
  margin: 6px 0 2px;
}

.xp-legend span { display: inline-flex; align-items: center; gap: 5px; }

.xp-swatch {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 3px;
  flex: none;
}

/* Status: always an icon plus a word, never colour alone. */
.xp-status { font-weight: bold; white-space: nowrap; }
.xp-status::before { margin-right: 4px; }
.xp-status[data-level="0"] { color: var(--xp-good); }
.xp-status[data-level="0"]::before { content: "\25CF"; }
.xp-status[data-level="1"] { color: var(--xp-warn); }
.xp-status[data-level="1"]::before { content: "\25B2"; }
.xp-status[data-level="2"],
.xp-status[data-level="3"] { color: var(--xp-serious); }
.xp-status[data-level="2"]::before,
.xp-status[data-level="3"]::before { content: "\25B2"; }
.xp-status[data-level="4"],
.xp-status[data-level="5"] { color: var(--xp-critical); }
.xp-status[data-level="4"]::before,
.xp-status[data-level="5"]::before { content: "\2716"; }

/* ----- Story card (scenario captions) ----- */
.xp-story {
  position: fixed;
  left: 50%;
  bottom: 132px;
  transform: translateX(-50%);
  width: min(560px, calc(100vw - 24px));
  padding: 12px 14px 10px;
  z-index: 35;
  font-size: 0.92em;
  line-height: 1.45;
}

.xp-story-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
  font-size: 0.75em;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--xp-ink-3);
  margin-bottom: 4px;
}

.xp-story p { margin: 0 0 8px; }
.xp-story .xp-controls { margin: 0; justify-content: flex-end; }

/* ----- Dock (bottom controls) ----- */
.xp-dock {
  position: fixed;
  left: 12px;
  right: 12px;
  bottom: 12px;
  padding: 10px 14px;
  z-index: 30;
  display: grid;
  grid-template-columns: minmax(150px, 1.2fr) minmax(150px, 1.4fr) minmax(190px, 1.6fr) auto;
  gap: 10px 18px;
  align-items: end;
  transition: right 0.28s ease;
}

/* ----- 3D labels and tooltips ----- */
.xp-labels {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 10;
  overflow: hidden;
}

.xp-label {
  position: absolute;
  left: 0;
  top: 0;
  transform: translate(-50%, -100%);
  padding: 2px 8px 3px;
  border-radius: 6px;
  font-size: 0.72em;
  line-height: 1.25;
  white-space: nowrap;
  background: var(--xp-panel);
  border: 1px solid var(--xp-panel-border);
  color: var(--text);
  pointer-events: auto;
  cursor: pointer;
  text-align: center;
  will-change: transform;
}

.xp-label b { display: block; font-size: 1.05em; }
.xp-label small { color: var(--xp-ink-2); font-variant-numeric: tabular-nums; }
.xp-label[data-selected="true"] { border-color: var(--link); box-shadow: 0 0 0 2px var(--link); }
.xp-label:hover { border-color: var(--link); }

.xp-tip {
  position: fixed;
  z-index: 70;
  pointer-events: none;
  padding: 6px 9px;
  border-radius: 6px;
  font-size: 0.78em;
  line-height: 1.35;
  background: var(--tooltip-bg);
  color: var(--tooltip-text);
  max-width: 260px;
}

/* ----- Drawer open: keep the dock and story clear of it on wide screens ----- */
@media (min-width: 901px) {
  html.xp-ready.xp-drawer-open .xp-dock { right: calc(var(--xp-drawer-w) + 12px); }
  html.xp-ready.xp-drawer-open .xp-story { left: calc((100vw - var(--xp-drawer-w)) / 2); }
  html.xp-ready.xp-drawer-open .xp-menu { right: calc(var(--xp-drawer-w) + 12px); }
  /* Keep Explore visible beside the open drawer instead of under it. */
  html.xp-ready.xp-drawer-open .xp-topbar { right: calc(var(--xp-drawer-w) + 12px); }
}

/* ----- Theme toggle (built by theme.js) ----- */
html.xp-ready #theme-toggle {
  top: 12px;
  right: 12px;
  z-index: 80;
}

/* ===== Narrow screens: drawer becomes a bottom sheet ===== */
@media (max-width: 900px) {
  :root { --xp-drawer-w: 100vw; }

  html.xp-ready .xp-drawer {
    top: auto;
    left: 0;
    width: auto;
    height: min(78dvh, 720px);
    border-left: none;
    border-top: 1px solid var(--xp-panel-border);
    border-radius: 14px 14px 0 0;
    transform: translateY(105%);
  }

  html.xp-ready.xp-drawer-open .xp-drawer { transform: translateY(0); }
  .xp-drawer-head { padding-right: 12px; }
  html.xp-ready.xp-drawer-open #theme-toggle { display: none; }

  .xp-dock {
    grid-template-columns: 1fr 1fr;
    gap: 8px 12px;
    padding: 8px 12px 10px;
    left: 8px;
    right: 8px;
    bottom: 8px;
  }

  .xp-story { bottom: 172px; }
  .xp-title { max-width: 62vw; padding: 6px 10px 7px; }
  .xp-title p { display: none; }
}

@media (max-width: 520px) {
  .xp-title h1 { font-size: 1em; }
  .xp-story { font-size: 0.86em; }
}

@media (prefers-reduced-motion: reduce) {
  html.xp-ready .xp-drawer,
  .xp-topbar,
  .xp-dock { transition: none; }
}