.pre-calculus-understand { width:100%; min-height:0; height:100%; display:block; overflow:hidden; }
.pre-calculus-understand__panel { height:100%; min-height:0; display:grid; grid-template-rows:auto minmax(0,1fr); gap:var(--space-3); }
.pre-calculus-understand__panel-header { display:flex; align-items:baseline; justify-content:space-between; gap:var(--space-4); }
.pre-calculus-understand__panel-header h3 { margin:0; font-size:var(--text-lg); }
.pre-calculus-understand__eyebrow { color:var(--mode-soft-text); font-size:var(--text-xs); font-weight:var(--weight-bold); letter-spacing:.04em; text-transform:uppercase; }
.pre-calculus-understand__panel-body { min-height:0; display:grid; gap:var(--space-3); align-content:start; overflow:auto; padding-right:2px; }
.pre-calculus-understand__graph-host { min-height:300px; }
.pre-calculus-understand__action-row,.pre-calculus-understand__choice-row { display:flex; flex-wrap:wrap; align-items:center; gap:var(--space-2); }
.pre-calculus-understand__action-row .diagram-primitives__slider { flex:1 1 260px; }
.pre-calculus-understand__button { min-height:var(--touch-target-min); padding:0 var(--space-3); border:1px solid var(--border-default); border-radius:var(--radius-md); background:var(--surface-base); color:var(--text-primary); font:inherit; font-weight:var(--weight-semibold); cursor:pointer; }
.pre-calculus-understand__button--primary,.pre-calculus-understand__button[aria-pressed="true"] { border-color:var(--mode-accent); background:var(--mode-soft); color:var(--mode-soft-text); }
.pre-calculus-understand__button:focus-visible,.pre-calculus-understand input:focus-visible { outline:3px solid var(--focus-ring); outline-offset:2px; }
.pre-calculus-understand__status,.pre-calculus-understand__takeaway { margin:0; padding:var(--space-3); border-radius:var(--radius-md); background:var(--mode-soft); color:var(--mode-soft-text); line-height:var(--leading-normal); }
.pre-calculus-understand__question { min-height:92px; display:grid; place-items:center; gap:var(--space-2); padding:var(--space-4); border:2px solid var(--mode-accent); border-radius:var(--radius-lg); background:var(--mode-soft); color:var(--mode-soft-text); text-align:center; font-size:clamp(1.05rem,2.2vw,1.45rem); }
.pre-calculus-understand__question strong { font-size:1.05em; }

.activity-stage__content[data-pre-calculus-understand-active="true"] { grid-template-columns:minmax(210px,.52fr) minmax(0,1.48fr); gap:var(--space-5); align-items:stretch; }
.activity-stage__content[data-pre-calculus-understand-active="true"] .activity-copy h2 { font-size:clamp(1.4rem,2.2vw,2rem); margin-bottom:var(--space-2); }
.activity-stage__content[data-pre-calculus-understand-active="true"] .activity-callout { margin-top:var(--space-3); padding:var(--space-3); }
.activity-stage__content[data-pre-calculus-understand-active="true"] .math-placeholder { min-height:0; height:100%; display:block; overflow:hidden; border:0; border-radius:0; background:transparent; }
.activity-stage__content[data-pre-calculus-understand-active="true"] .math-placeholder__grid,
.activity-stage__content[data-pre-calculus-understand-active="true"] .math-placeholder__formula,
.activity-stage__content[data-pre-calculus-understand-active="true"] .math-placeholder__caption { display:none; }

@media (max-width:900px) {
  .activity-stage__content[data-pre-calculus-understand-active="true"] { grid-template-columns:minmax(190px,.48fr) minmax(0,1.52fr); gap:var(--space-4); }
}
@media (max-width:680px) {
  .activity-stage__content[data-pre-calculus-understand-active="true"] { grid-template-columns:1fr; align-content:start; }
  .activity-stage__content[data-pre-calculus-understand-active="true"] .math-placeholder { min-height:390px; padding:0; }
  .pre-calculus-understand { min-height:390px; }
  .pre-calculus-understand__panel-header { align-items:flex-start; flex-direction:column-reverse; gap:var(--space-1); }
}