/* Accumulator media uses the shared hardware gallery and portfolio theme. */
.acc-cad-placeholder { height: clamp(240px, 40vw, 360px); display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; border: 1px dashed var(--border); border-radius: 14px; background: var(--panel); color: var(--muted); text-align: center; padding: 20px; }
.acc-cad-placeholder svg { width: 180px; height: 128px; color: var(--accent); opacity: .65; }
.acc-cad-placeholder strong { color: var(--text); font-size: 17px; font-weight: 500; }
.acc-cad-placeholder span { font-size: 13px; }
.acc-pid { margin-top: 36px; }
.accumulator-page .acc-source { color: var(--muted); font-size: 13px; margin-top: 28px; }
.accumulator-page .pib-equation strong { line-height: 1.8; }

.acc-viewer { margin: 36px 0 0; }
.acc-viewer-heading { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 12px; margin-bottom: 18px; }
.acc-viewer-heading h3 { font-size: 22px; margin: 0; letter-spacing: -.02em; }
.acc-viewer-heading > span { color: var(--muted); font-size: 12px; }
.acc-stage { position: relative; height: clamp(300px, 44vw, 480px); border: 1px solid var(--border); border-radius: 14px; overflow: hidden; background: var(--panel); }
.acc-stage canvas { display: block; width: 100%; height: 100%; touch-action: none; cursor: grab; }
.acc-stage canvas:active { cursor: grabbing; }
.acc-stage > p { position: absolute; inset: 0; display: grid; place-content: center; text-align: center; padding: 24px; color: var(--muted); font-size: 14px; }
.acc-stage > p[hidden] { display: none; }
.acc-controls-row { display: flex; align-items: center; gap: 20px; margin: 12px 0 16px; border-bottom: 1px solid var(--border); }
.acc-toolbar { display: flex; flex: 1; min-width: 0; gap: 24px; overflow-x: auto; scrollbar-width: thin; }
.acc-toolbar button { flex-shrink: 0; padding: 14px 0; border: 0; border-bottom: 2px solid transparent; border-radius: 0; background: transparent; color: var(--muted); font: inherit; font-size: 15px; cursor: pointer; }
.acc-toolbar button[aria-pressed="true"] { color: var(--text); border-bottom-color: var(--accent); }
.acc-camera-controls { flex-shrink: 0; margin-left: auto; }
.acc-viewer button:hover { color: var(--text); background: var(--hover); }
.acc-viewer button:disabled { cursor: default; opacity: .5; }
.acc-viewer :is(canvas,button):focus-visible { outline: 2px solid var(--accent); outline-offset: -3px; }
.acc-viewer figcaption { font-size: 12px; color: var(--muted); line-height: 1.7; margin: 0; }
@media (max-width: 760px) { .acc-controls-row { gap: 12px; } .acc-toolbar { gap: 20px; } }

/* The design model reads as a single derivation, with space around each equation. */
.acc-model { margin: 30px 0; border: 1px solid var(--border); border-radius: 12px; background: var(--panel); overflow: hidden; }
.acc-model-heading { padding: 24px 28px; border-bottom: 1px solid var(--border); }
.acc-model-heading > span { color: var(--accent); font-size: 12px; font-weight: 500; }
.acc-model-heading p { margin: 8px 0 0; font-size: 20px; letter-spacing: -.02em; }
.acc-model-step { display: grid; grid-template-columns: minmax(150px, .8fr) minmax(0, 1.4fr); gap: 28px; padding: 30px 28px; border-bottom: 1px solid var(--border); }
.acc-model-label > span { font-size: 12px; color: var(--muted); }
.acc-model-label h3 { margin: 10px 0 0; font-size: 16px; line-height: 1.5; font-weight: 500; }
.acc-model-detail { min-width: 0; }
.acc-model-detail math { font-size: 25px; margin: 0 0 22px; padding: 6px 0; text-align: left; }
.acc-model-detail math + math { margin-top: -6px; }
.acc-model-detail p { margin: 0; font-size: 14px; line-height: 1.75; color: var(--muted); }
.acc-model-symbols { display: grid; grid-template-columns: 1fr 1fr; gap: 20px 28px; padding: 24px 28px; margin: 0; }
.acc-model-symbols div { min-width: 0; }
.acc-model-symbols dt { font-family: Georgia, serif; font-size: 16px; }
.acc-model-symbols dd { margin: 6px 0 0; color: var(--muted); font-size: 12px; line-height: 1.65; }
.acc-model-note { margin: 28px 0; padding-left: 20px; border-left: 2px solid var(--accent); }
.acc-model-note h3 { margin: 0 0 10px; font-size: 16px; font-weight: 500; }
.acc-model-note p { margin: 0; color: var(--muted); font-size: 14px; line-height: 1.75; }
@container (max-width: 650px) {
  .acc-model-step { grid-template-columns: 1fr; gap: 18px; padding: 24px 20px; }
  .acc-model-label { display: flex; align-items: baseline; gap: 12px; }
  .acc-model-label h3 { margin: 0; }
  .acc-model-heading, .acc-model-symbols { padding: 22px 20px; }
  .acc-model-detail math { font-size: 23px; }
}
@container (max-width: 360px) {
  .acc-model-symbols { grid-template-columns: 1fr; }
  .acc-model-detail math { font-size: 20px; }
  .acc-model-heading p { font-size: 18px; line-height: 1.6; }
}

.acc-pid-image { display: block; padding: 16px; background: #111; border: 1px solid var(--border); border-radius: 12px; overflow: hidden; }
.acc-pid-image img { display: block; width: 100%; height: auto; }
.acc-pid-image:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.acc-presentation-stage { aspect-ratio: 16 / 9; position: relative; display: grid; place-items: center; background: var(--panel); border: 1px solid var(--border); border-radius: 12px; overflow: hidden; }
.acc-presentation-placeholder { padding: 24px; text-align: center; color: var(--muted); }
.acc-presentation-placeholder span { display: block; font-size: 12px; letter-spacing: .04em; margin-bottom: 14px; }
.acc-presentation-placeholder strong { color: var(--text); font-size: 20px; font-weight: 500; }
.acc-presentation-placeholder p { font-size: 13px; margin: 12px 0 0; }
.acc-presentation-slide { position: absolute; width: 100%; height: 100%; object-fit: contain; }
.acc-presentation [hidden] { display: none; }
.acc-presentation-controls { display: flex; align-items: center; gap: 14px; margin-top: 14px; color: var(--muted); font-size: 13px; }
.acc-presentation-status { margin-right: auto; }
.acc-presentation-jump { display: flex; align-items: center; gap: 8px; }
.acc-presentation-jump input { width: 64px; padding: 7px; border: 1px solid var(--border); border-radius: 6px; background: var(--panel); color: var(--text); font: inherit; }
.acc-presentation button:disabled { opacity: .35; cursor: default; }
.acc-presentation :is(button,input,.acc-presentation-stage):focus-visible { outline: 2px solid var(--accent); outline-offset: -3px; }

.acc-slide-full { font-size: 13px; color: var(--accent); white-space: nowrap; }
@container (max-width: 420px) { .acc-presentation-controls { flex-wrap: wrap; gap: 10px; } .acc-presentation-controls .pib-arrows { margin-left: auto; } }