/* Interactive NMPC demo (mpc-demo.html). Uses the palette in lab.css. */

.mpc-demo { margin: 36px 0 12px; }
.mpc-stage {
  position: relative; width: 100%; aspect-ratio: 16 / 8.6;
  background: transparent; border: 1px solid var(--rule); border-radius: 3px; overflow: hidden;
}
.mpc-stage canvas { display: block; width: 100%; height: 100%; touch-action: none; cursor: grab; }
.mpc-stage canvas.dragging { cursor: grabbing; }

.mpc-status {
  position: absolute; top: 12px; left: 14px; display: inline-flex; align-items: center; gap: 8px;
  font-size: 12.5px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--ink);
  background: rgba(250, 248, 244, .9); border: 1px solid var(--rule); border-radius: 999px; padding: 3px 12px 3px 10px;
  pointer-events: none;
}
.mpc-status .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--muted); transition: background .3s; }
.mpc-status[data-state="balancing"] .dot { background: #2f7d4f; }
.mpc-status[data-state="swinging"] .dot,
.mpc-status[data-state="recovering"] .dot { background: var(--warm); }
.mpc-status[data-state="off"] .dot { background: #9a958c; }

.mpc-hint {
  position: absolute; right: 14px; bottom: 12px; font-size: 13.5px; color: var(--muted);
  pointer-events: none; transition: opacity .6s var(--ease);
}
.mpc-hint.gone { opacity: 0; }

.mpc-chart { height: 74px; margin-top: 8px; border: 1px solid var(--rule); border-radius: 3px; background: transparent; }
.mpc-chart canvas { display: block; width: 100%; height: 100%; }

.mpc-toolbar { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 12px 24px; margin-top: 16px; }
.mpc-buttons { display: flex; flex-wrap: wrap; gap: 8px; }
.mpc-buttons button {
  font: inherit; font-size: 14.5px; font-weight: 600; color: var(--ink); background: #fff;
  border: 1px solid var(--rule); border-radius: 4px; padding: 6px 13px; cursor: pointer;
  transition: border-color .2s, color .2s, background .2s;
}
.mpc-buttons button:hover { border-color: var(--accent); color: var(--accent); }
.mpc-buttons button:active { background: var(--accent-soft); }
.mpc-buttons button[data-act="reset"] { color: #fff; background: var(--ink); border-color: var(--ink); }
.mpc-buttons button[data-act="reset"]:hover { background: var(--accent-deep); border-color: var(--accent-deep); color: #fff; }
.mpc-buttons button[data-act="shove"] { color: var(--warm); }
.mpc-buttons button[data-act="shove"]:hover { border-color: var(--warm); background: var(--warm-soft); }
.mpc-buttons button:focus-visible, .mpc-toggles input:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.mpc-toggles { display: flex; flex-wrap: wrap; gap: 6px 20px; font-size: 15px; color: var(--text); }
.mpc-toggles label { display: inline-flex; align-items: center; gap: 7px; cursor: pointer; user-select: none; }
.mpc-toggles input { accent-color: var(--accent); width: 15px; height: 15px; margin: 0; }

.mpc-readout {
  display: flex; flex-wrap: wrap; gap: 4px 26px; margin: 14px 0 0; font-size: 14.5px; color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.mpc-readout b { color: var(--ink); font-weight: 600; }
.mpc-readout #mpc-solve { display: inline-block; min-width: 2.2em; text-align: right; }
.mpc-readout #mpc-force { display: inline-block; min-width: 2.2em; text-align: right; }
.mpc-readout small { font-size: 13px; }

ol.mpc-loop { list-style: none; padding: 0; margin: 4px 0 22px; display: grid; gap: 14px; }
ol.mpc-loop li { display: grid; grid-template-columns: 34px minmax(0, 1fr); gap: 14px; align-items: start; }
ol.mpc-loop .n {
  width: 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
  font-family: var(--serif); font-weight: 600; font-size: 16px; color: var(--warm); background: var(--warm-soft);
}
ol.mpc-loop li div { padding-top: 2px; }

.mpc-math {
  margin: 4px 0 22px; padding: 16px 20px; background: var(--panel); border-left: 3px solid var(--warm);
  font-family: var(--serif); font-size: 17px; line-height: 1.9; color: var(--ink); overflow-x: auto;
}
.mpc-math .small { font-family: var(--sans); font-size: 14.5px; color: var(--text); line-height: 1.6; margin-top: 6px; }

.mpc-links { display: flex; flex-wrap: wrap; align-items: baseline; gap: 8px 24px; margin-top: 26px; font-size: 15.5px; }
.mpc-cta { font-weight: 600; color: var(--ink); }
.mpc-cta span { display: inline-block; color: var(--warm); transition: transform .3s var(--ease); }
.mpc-cta:hover span { transform: translateX(4px); }

/* teaching page: card linking to the demo */
.demo-card {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.25fr); gap: 20px 32px; align-items: center;
  padding: 0; border: 0; background: none; color: var(--text);
}
.demo-card:hover { text-decoration: none; color: var(--text); }
.demo-card:hover .dc-title { color: var(--accent); }
.demo-card:hover .dc-go span { transform: translateX(4px); }
.demo-card .dc-go span { display: inline-block; transition: transform .3s var(--ease); }
.demo-card:focus-visible { outline: 2px solid var(--accent); outline-offset: 6px; border-radius: 2px; }
.demo-card img { width: 100%; height: auto; display: block; }
.demo-card .dc-tag { margin: 0 0 6px; color: var(--warm); font-size: 12.5px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; }
.demo-card .dc-title { transition: color .2s; margin: 0 0 8px; font-family: var(--serif); font-size: 22px; font-weight: 600; color: var(--ink); line-height: 1.25; }
.demo-card .dc-text { margin: 0 0 10px; font-size: 15.5px; line-height: 1.55; }
.demo-card .dc-go { margin: 0; font-weight: 600; font-size: 15px; color: var(--accent); }

@media (max-width: 760px) {
  .mpc-stage { aspect-ratio: 4 / 3; }
  .mpc-hint { left: 14px; right: auto; font-size: 12.5px; }
  .demo-card { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) { .mpc-cta span, .mpc-hint { transition: none; } }

/* mathematics (KaTeX, served from demos/nmpc/katex) */
main .katex { font-size: 1.06em; }
main .katex-display { margin: 18px 0 22px; padding: 4px 0; overflow-x: auto; overflow-y: hidden; }
main .katex-display > .katex { font-size: 1.1em; }
main h3 + p, main h3 + .katex-display { margin-top: 0; }