/* Même palette et même structure que le Space gridworld-dp */
:root {
  --navy: #162a40;
  --cyan: #0096c8;
  --orange: #dc7832;
  --light: #e4f0f8;
  --grey: #e0e0e0;
  --ok: #288c5a;
  --ko: #b42828;
  --text: #162a40;
  --muted: #5b6b7c;
  --border: #c9d6e2;
  --bg: #f7fafc;
  --panel: #ffffff;
  /* tokens du thème (graphiques SVG compris) */
  --strong: #162a40;     /* onglet actif, crochets des matrices, points */
  --seg-on: #162a40;
  --on-accent: #fff;
  --btn-bg: #fff;
  --track: #e4f0f8;
  --plot-bg: #fff;       /* fond des graphiques, et halo des étiquettes */
  --grid: #e6edf3;
  --axis: #9fb0c0;
  --axis3: #b8c5d2;
  color-scheme: light;
}
:root[data-theme="dark"] {
  --cyan: #4fb6ea; --orange: #f09a5a; --ok: #4cc38a; --ko: #ef6b5b;
  --text: #e6edf3; --muted: #93a1b0; --border: #2c3a48; --bg: #10161d; --panel: #18212b;
  --strong: #e6edf3; --seg-on: #2a5576; --on-accent: #0d1b2a; --btn-bg: #18212b; --track: #243140;
  --plot-bg: #18212b; --grid: #243140; --axis: #5a6c7e; --axis3: #4a5c6e;
  color-scheme: dark;
}
/* sans JS : on suit le système */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --cyan: #4fb6ea; --orange: #f09a5a; --ok: #4cc38a; --ko: #ef6b5b;
    --text: #e6edf3; --muted: #93a1b0; --border: #2c3a48; --bg: #10161d; --panel: #18212b;
    --strong: #e6edf3; --seg-on: #2a5576; --on-accent: #0d1b2a; --btn-bg: #18212b; --track: #243140;
    --plot-bg: #18212b; --grid: #243140; --axis: #5a6c7e; --axis3: #4a5c6e;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; background: var(--bg); color: var(--text); }
body {
  font-family: "Fira Sans", "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 17px;
  line-height: 1.45;
}
code, pre, .mono { font-family: "Fira Mono", "SFMono-Regular", Menlo, Consolas, monospace; }

#banner {
  background: var(--navy); color: #fff;
  padding: 14px 24px 12px; border-bottom: 4px solid var(--orange);
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
}
#banner h1 { margin: 0; font-size: 1.6em; font-weight: 700; }
#banner p { margin: 2px 0 0; color: var(--light); font-size: 0.9em; }

/* Bouton clair / sombre, dans le bandeau */
.theme-toggle { width: 34px; height: 34px; padding: 0; display: inline-grid; place-items: center;
  border-radius: 999px; border: 1px solid rgba(255, 255, 255, 0.35); background: transparent;
  color: #fff; cursor: pointer; flex: none; }
.theme-toggle:hover { border-color: var(--orange); }
.theme-toggle:focus-visible { outline: 2px solid var(--orange); outline-offset: 2px; }
.theme-toggle svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 2;
  stroke-linecap: round; stroke-linejoin: round; }
/* l'icône montre le thème vers lequel on bascule */
:root[data-theme="dark"] .theme-toggle .i-moon, :root:not([data-theme="dark"]) .theme-toggle .i-sun { display: none; }

nav.tabs {
  display: flex; gap: 4px; flex-wrap: wrap;
  padding: 10px 24px 0; background: var(--bg); border-bottom: 1px solid var(--border);
}
nav.tabs button {
  font: inherit; font-weight: 600; color: var(--muted);
  background: none; border: none; border-bottom: 3px solid transparent;
  padding: 8px 14px; cursor: pointer;
}
nav.tabs button.active { color: var(--strong); border-bottom-color: var(--orange); }
nav.tabs button:hover { color: var(--strong); }

main.tab { display: none; grid-template-columns: minmax(0, 1fr) 340px; gap: 20px; padding: 18px 24px 32px; max-width: 1500px; margin: 0 auto; }
main.tab.active { display: grid; }

.panel { background: var(--panel); border: 1px solid var(--border); border-radius: 8px; padding: 14px 16px; }

.sidebar .panel + .panel { margin-top: 14px; }
.sidebar h3 { margin: 0 0 8px; font-size: 1em; }
.explain p { margin: 0; font-size: 0.95em; }

button, input { font: inherit; }
.seg { display: inline-flex; border: 1px solid var(--border); border-radius: 6px; overflow: hidden; }
.seg button { border: none; background: var(--btn-bg); padding: 5px 10px; cursor: pointer; color: var(--muted); font-size: 0.9em; }
.seg button + button { border-left: 1px solid var(--border); }
.seg button.on { background: var(--seg-on); color: #fff; }

.btn { border: 1px solid var(--border); background: var(--btn-bg); border-radius: 6px; padding: 6px 12px; cursor: pointer; }
.btn:hover { border-color: var(--cyan); }
.btn.primary { background: var(--cyan); border-color: var(--cyan); color: var(--on-accent); font-weight: 600; }
.btn.play { min-width: 9.5em; font-weight: 700; }
.slider { display: inline-flex; align-items: center; gap: 8px; font-size: 0.95em; }
.slider input { width: 150px; accent-color: var(--orange); }

.toolbar { display: flex; gap: 8px 12px; flex-wrap: wrap; align-items: center; margin: 0 0 10px; }
.check { display: inline-flex; align-items: center; gap: 6px; font-size: 0.95em; cursor: pointer; user-select: none; }
.check input { width: 18px; height: 18px; accent-color: var(--orange); margin: 0; }
.hint { color: var(--muted); font-size: 0.9em; margin: 8px 0 0; }
.toolbar .hint { margin: 0; }

figure.plot { margin: 0; background: var(--plot-bg); border: 1px solid var(--border); border-radius: 8px; padding: 6px; }
figure.plot svg {
  display: block; margin: 0 auto;
  width: 100%; height: auto; aspect-ratio: 1 / 1;
  max-width: max(300px, calc(100vh - 240px));
  touch-action: none; user-select: none; -webkit-user-select: none;
  cursor: crosshair;
}
figure.plot svg .pt { cursor: grab; }
figure.plot svg.dragging, figure.plot svg.dragging .pt { cursor: grabbing; }
figure.plot svg.del .pt { cursor: not-allowed; }
figure.plot figcaption { font-weight: 600; margin: 2px 4px 6px; }
figure.plot figcaption .sub { font-weight: 400; color: var(--muted); }
figure.plot .toolbar.under { margin: 6px 4px 2px; }
.plots { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); gap: 14px; align-items: start; }
.plots figure.plot svg { max-width: max(260px, calc(100vh - 320px)); }
#plot3 { cursor: grab; }
#plot3.dragging { cursor: grabbing; }
#plot2 { touch-action: auto; cursor: default; }
.bracket.c3 { grid-template-columns: auto auto auto; }
.eigtab { border-collapse: collapse; font-variant-numeric: tabular-nums; }
.eigtab th, .eigtab td { padding: 2px 10px; text-align: right; }
.eigtab th { font-family: "Fira Sans", system-ui, sans-serif; font-weight: 700; }
.eigtab tr:first-child th { border-bottom: 1px solid var(--border); }
.eigtab tr:nth-child(2) td { padding-bottom: 6px; }
.eigtab tr.u0 td { border-top: 1px solid var(--border); padding-top: 6px; }
.eigtab tr:not(:first-child) th { color: var(--muted); font-style: italic; }
.pc3 { color: var(--ko); }
.bar .b3 { background: var(--ko); opacity: 0.6; }

/* Panneau des résultats */
.stat { margin: 0 0 12px; }
.stat:last-child { margin-bottom: 0; }
.stat .lbl { font-size: 0.9em; color: var(--muted); margin-bottom: 3px; }
.num { font-family: "Fira Mono", Menlo, Consolas, monospace; font-variant-numeric: tabular-nums; }
.vec, .mat { display: inline-flex; align-items: center; gap: 8px; vertical-align: middle; }
.bracket {
  display: inline-grid; gap: 1px 14px; padding: 2px 8px;
  border-left: 2px solid var(--strong); border-right: 2px solid var(--strong); border-radius: 6px;
  text-align: right;
}
.bracket.c1 { grid-template-columns: auto; }
.bracket.c2 { grid-template-columns: auto auto; }
.eig { display: grid; grid-template-columns: auto 1fr; gap: 6px 10px; align-items: center; }
.eig .tag { font-weight: 700; }
.pc1 { color: var(--orange); }
.pc2 { color: var(--cyan); }
.bar { height: 12px; background: var(--track); border-radius: 6px; overflow: hidden; margin-top: 6px; display: flex; }
.bar span { display: block; height: 100%; }
.bar .b1 { background: var(--orange); }
.bar .b2 { background: var(--cyan); opacity: 0.55; }
.big { font-size: 1.6em; font-weight: 700; color: var(--orange); }
.note { font-size: 0.85em; color: var(--muted); margin: 4px 0 0; }
.warn { color: var(--orange); font-weight: 600; }

footer { text-align: center; color: var(--muted); font-size: 0.85em; padding: 0 16px 24px; }

@media (max-width: 1180px) {
  #tab-3d.active { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 980px) {
  main.tab.active { grid-template-columns: minmax(0, 1fr); }
  figure.plot svg { max-width: min(100%, 640px); }
}
@media (max-width: 820px) {
  main.tab { padding: 12px 16px 24px; }
  nav.tabs { padding: 8px 16px 0; }
  .plots { grid-template-columns: minmax(0, 1fr); }
  .plots figure.plot svg { max-width: min(100%, 560px); }
  #banner { padding: 12px 16px 10px; }
  #banner h1 { font-size: 1.35em; }
  body { font-size: 16px; }
}