.concept-trigger{display:inline-block;vertical-align:baseline;margin-inline:5px;padding:0 9px;min-height:44px;font:normal .76rem var(--sans);color:var(--accent);border:1px solid var(--line);border-radius:999px;background:transparent;cursor:pointer}
.concept-trigger[hidden],.focus-exit[hidden]{display:none}
.concept-note{margin:10px 0 26px;padding:14px 18px;border-left:2px solid var(--accent);font-size:.95rem;line-height:1.7;background:var(--white)}
.concept-note p{margin:8px 0 0!important}.concept-note[hidden]{display:none}
.learning-example,.local-experiment{margin:18px 0 30px;border-block:1px solid var(--line);padding:8px 0;font-size:.95rem;line-height:1.7}
.local-experiment{width:min(740px,calc(100% - 40px));margin:24px auto 30px}
.learning-example summary,.local-experiment summary{min-height:44px;display:flex;align-items:center;gap:8px;cursor:pointer;color:var(--accent);list-style:none}
.learning-example summary::before,.local-experiment summary::before{content:'▸';transition:transform 180ms ease-out}
.learning-example[open]>summary::before,.local-experiment[open]>summary::before{transform:rotate(90deg)}
.learning-example summary::-webkit-details-marker,.local-experiment summary::-webkit-details-marker{display:none}
.learning-example small,.local-experiment .muted{color:var(--muted);font-size:.8rem}.learning-example a{text-decoration:underline}
.learning-example[open]>p,.local-experiment[open]>.scenario-body{animation:learning-reveal 180ms ease-out}
.local-experiment .quiet-control{display:block;width:100%;text-align:left;white-space:normal;margin:10px 0;min-height:44px}
.local-experiment .quiet-control[aria-pressed=true]{border-color:var(--accent);color:var(--accent)}
.local-experiment [data-experiment-explanation]{padding:8px 0;color:var(--ink)}
.reading-mode-entry{margin:20px 0}.focus-exit{margin-left:auto;font-size:.8rem;min-height:44px;padding:8px 12px;white-space:nowrap}
.reading-focus .topbar nav,.reading-focus .topbar .search-toggle,.reading-focus .topbar .menu-toggle,.reading-focus .brand-subtitle{display:none}
.reading-focus .breadcrumbs,.reading-focus .article-header .post-meta,.reading-focus .article-header time,.reading-focus .reading-mode-entry{visibility:hidden}
.reading-focus:not(.focus-at-end) .related,.reading-focus:not(.focus-at-end) .route-context{display:none}
.reading-focus .topbar .brand-area{flex-shrink:0}
[data-focus-end]{display:block;height:1px}
.concept-trigger:focus-visible,.learning-example summary:focus-visible,.local-experiment summary:focus-visible,.local-experiment button:focus-visible,.focus-exit:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
@keyframes learning-reveal{from{opacity:0;transform:translateY(-4px)}to{opacity:1;transform:none}}
@media(max-width:650px){.concept-note{padding:12px 14px}.reading-focus .topbar .wordmark{font-size:1.2rem}.focus-exit{max-width:160px}.learning-example,.local-experiment{font-size:.94rem}}
@media(prefers-reduced-motion:reduce){.learning-example summary::before,.local-experiment summary::before{transition:none}.learning-example[open]>p,.local-experiment[open]>.scenario-body{animation:none}}