.lesson-page { padding-block: clamp(34px, 6vw, 76px); }
.lesson-heading { margin-bottom: clamp(22px, 4vw, 38px); }
.lesson-heading > p:not(.kicker) { max-width: 65ch; margin-block: 12px 18px; color: var(--muted); }
.lesson-breadcrumb { display: flex; flex-wrap: wrap; align-items: center; gap: .65rem; margin-bottom: clamp(22px, 5vw, 44px); color: var(--muted); font-size: .875rem; }
.lesson-video { display: block; width: 100%; max-width: 820px; margin-top: 16px; border-radius: 12px; background: #0b1220; }
.lesson-page [id] { scroll-margin-top: 90px; }
.lesson-page details { margin-top: 17px; }
.lesson-page summary { color: var(--amber); font-weight: 700; cursor: pointer; }
.lesson-page details ul { padding-left: 21px; margin-bottom: 0; }
.lesson-page details li + li { margin-top: 8px; }
.lesson-page details p { color: var(--muted); margin-top: 10px; font-size: .92rem; }
.workspace { display: grid; grid-template-columns: minmax(0, 1.12fr) minmax(0, 1fr); gap: 18px; align-items: start; }
.section-intro { color: var(--muted); margin-top: 9px; }
.circuit { display: grid; grid-template-columns: 1fr clamp(26px, 9vw, 90px) 1fr; grid-template-rows: 78px 42px 78px; gap: 6px; margin: 22px 0 16px; }
.stop { background: #0d141e; color: var(--bone); border: 1px solid var(--border); border-radius: 10px; min-width: 0; padding: 6px 8px; display: grid; align-content: center; gap: 3px; text-align: left; }
.stop strong { font-size: clamp(.84rem, 2.7vw, 1.1rem); overflow-wrap: anywhere; }
.stop small { color: var(--muted); font-size: .7rem; line-height: 1.25; }
.stop[aria-pressed="true"] { background: var(--amber-deep); border-color: var(--amber); box-shadow: inset 3px 0 0 var(--amber); }
.stop:hover { border-color: var(--amber); }
.stop[data-stop="0"] { grid-area: 1 / 1; }
.stop[data-stop="1"] { grid-area: 1 / 3; }
.stop[data-stop="2"] { grid-area: 3 / 3; }
.stop[data-stop="3"] { grid-area: 3 / 1; }
.flow { display: grid; align-content: center; justify-items: center; color: var(--muted); text-align: center; line-height: 1.08; }
.flow b { font-size: 1.5rem; font-weight: 500; }
.flow small { font-size: .63rem; }
.flow[data-edge="0"] { grid-area: 1 / 2; color: var(--cool); }
.flow[data-edge="1"] { grid-area: 2 / 3; color: var(--warm); }
.flow[data-edge="2"] { grid-area: 3 / 2; color: var(--warm); }
.flow[data-edge="3"] { grid-area: 2 / 1; color: var(--cool); }
.flow.active b { color: var(--amber); animation: mark 1.15s ease-in-out infinite alternate; }
@keyframes mark { from { opacity: .72; } to { opacity: 1; transform: scale(1.15); } }
.detail { background: #0d141e; border: 1px solid var(--border); padding: 14px; border-radius: 10px; min-height: 145px; }
.detail h3 { margin-bottom: 8px; }
.detail p:last-child { color: var(--muted); }
.controls { margin-top: 12px; }
.controls .action { padding-inline: 11px; font-size: .9rem; }
.controls button:disabled { opacity: .55; cursor: default; }
.progress-label { margin-left: auto; color: var(--muted); font-variant-numeric: tabular-nums; font-size: .85rem; }
.quiz { min-height: 518px; }
.quiz-top { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; margin-top: 20px; }
.quiz-top p { color: var(--muted); font-size: .85rem; font-variant-numeric: tabular-nums; }
progress { display: block; height: 7px; width: 100%; margin: 8px 0 18px; border: none; border-radius: 20px; overflow: hidden; accent-color: var(--amber); background: var(--border); }
progress::-webkit-progress-bar { background: var(--border); }
progress::-webkit-progress-value { background: var(--amber); }
progress::-moz-progress-bar { background: var(--amber); }
.question { font-size: clamp(1.12rem, 2.7vw, 1.42rem); font-weight: 760; line-height: 1.28; margin-bottom: 14px; }
.answers { display: grid; gap: 8px; }
.answer { display: flex; text-align: left; align-items: center; gap: 10px; width: 100%; }
.answer .letter { flex: 0 0 24px; display: grid; place-items: center; height: 24px; border: 1px solid var(--border); border-radius: 5px; font-size: .77rem; color: var(--muted); }
.answer.correct { border-color: #68a889; color: var(--good); background: #132822; }
.answer.incorrect { border-color: #bb7773; color: var(--warm); background: #2b1d21; }
.answer[aria-disabled="true"] { cursor: default; }
.answer[aria-disabled="true"]:not(.correct):not(.incorrect) { color: var(--muted); }
.feedback { margin-top: 12px; border-left: 3px solid var(--amber); padding-left: 11px; color: var(--muted); }
.feedback strong { color: var(--bone); display: block; margin-bottom: 4px; }
.next { margin-top: 15px; }
.results { margin-top: 16px; }
.results h3 { font-size: 2.1rem; color: var(--amber); }
.results p { color: var(--muted); margin: 10px 0; }
.results ol { padding-left: 22px; }
.results li + li { margin-top: 7px; }
.sources { margin-top: 18px; }
.sources p { color: var(--muted); margin-top: 8px; }
.sources ul { padding-left: 20px; margin-bottom: 0; }
@media (max-width: 850px) { .workspace { grid-template-columns: 1fr; } .quiz { min-height: 0; } }
@media (max-width: 520px) { .circuit { grid-template-columns: 1fr 31px 1fr; } .flow[data-edge="0"] small, .flow[data-edge="2"] small { display: none; } }
@media (max-width: 345px) { .progress-label { margin-left: 0; } }
@media (prefers-reduced-motion: reduce) { .flow.active b { animation: none; } }