.series-param, .timeline-control { grid-column: 1 / -1; }
.series-param input { accent-color: #087c86; }
.series-param { color: #087c86; }
.scene-caption { line-height: 1.65; font-size: .82rem; color: #607783; margin: 8px 0 14px; }
.series-observation { margin-top: 14px; }
.series-readings { display: flex; flex-wrap: wrap; gap: 8px 18px; margin-top: 10px; font-weight: 750; color: #216846; }
.series-motion { margin-top: 12px; }
.collision-stages { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.collision-stages button { font-size: .875rem; min-height: 44px; }
.collision-stages button[aria-pressed="true"] { background: #e3f1fa; color: #12557f; border-color: #1676b7; box-shadow: inset 0 -3px #1676b7; }
.collision-stages button:focus-visible { outline: 3px solid #1676b7; outline-offset: 3px; }
.series-motion p { font-size: .82rem; color: #607783; }
.lesson-nav { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; padding-top: 24px; font-size: .9rem; }
.scene-text { font-family: "Yu Gothic", system-ui, sans-serif; font-size: 19px; font-weight: 700; }
.scene-small { font-size: 16px; font-weight: 500; }
.recipient-caption { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 10px 0; }
.recipient-caption span { border-radius: 10px; padding: 10px 12px; background: #f1f6fa; line-height: 1.5; font-size: .9rem; }
.timeline-labels { display: flex; justify-content: space-between; font-size: .76rem; color: #607783; }
@media(max-width:760px) { .recipient-caption { grid-template-columns: 1fr; gap: 6px; } }