.children-why{--why-ink:#303b47;--why-muted:#657482;--why-line:#dfe7ec;--why-paper:#fff;--why-soft:#f3f7f9;--why-blue:#336c96;margin:20px 0 24px;padding:16px 0;border-top:1px solid var(--why-line);border-bottom:1px solid var(--why-line);color:var(--why-ink);scroll-margin-top:90px}.children-why>header{height:auto;min-height:0;display:flex;align-items:center;justify-content:space-between;gap:12px}.children-why h2{font-size:var(--ui-section-title-size,15px);font-weight:500;line-height:24px;margin:2px 0}.children-why p{font-size:14px;line-height:1.7;margin:4px 0;color:var(--why-muted)}.why-eyebrow{font-size:12px;color:var(--why-blue)}.children-why button,.children-why a,.kids-why-dialog button{font:inherit;cursor:pointer;border:1px solid var(--why-line,#dfe7ec);background:var(--why-paper,#fff);color:inherit;border-radius:4px;min-height:36px;padding:6px 10px;box-shadow:none}.children-why button:hover,.kids-why-dialog button:hover{border-color:var(--why-blue,#336c96)}.children-why a:focus-visible,.children-why button:focus-visible,.children-why input:focus-visible,.kids-why-dialog button:focus-visible,.kids-why-dialog input:focus-visible{outline:2px solid #407eae;outline-offset:3px}.why-tools{display:flex;gap:10px;align-items:center;justify-content:space-between;border-bottom:1px solid var(--why-line);margin:12px 0 8px}.why-tools>div{display:flex;gap:8px;flex-wrap:wrap}.why-tools button{border:0;border-bottom:2px solid transparent;border-radius:0;padding:6px 2px;background:none;white-space:nowrap}.why-tools button[aria-pressed=true]{border-bottom-color:var(--why-blue);color:var(--why-blue)}.why-tools input{font:inherit;width:170px;max-width:100%;border:1px solid var(--why-line);border-radius:4px;padding:7px 8px;background:var(--why-paper);color:var(--why-ink)}.why-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.children-why .why-count{font-size:12px;margin:8px 0}.children-why .why-question{display:flex;align-items:center;gap:10px;text-align:left;min-width:0;padding:12px 10px;background:var(--why-paper);color:var(--why-ink)}.why-question>span:nth-child(2){min-width:0;flex:1}.why-question strong{display:block;font-size:14px;font-weight:500;line-height:1.6;margin:2px 0}.why-question small{color:var(--why-blue);font-size:12px}.why-question>span>span{display:block;font-size:12px;color:var(--why-muted);line-height:1.7}.why-question>b{font-weight:400;color:var(--why-blue)}.why-art{display:grid;place-items:center;flex:0 0 36px}.why-art svg{width:36px;height:36px}.why-empty{grid-column:1/-1}.why-sr{position:absolute;width:1px;height:1px;overflow:hidden;clip-path:inset(50%)}
dialog.kids-why-dialog{--why-ink:#303b47;--why-muted:#657482;--why-line:#dfe7ec;--why-paper:#fff;--why-soft:#f3f7f9;--why-blue:#336c96;border:1px solid var(--why-line);border-radius:4px;width:min(620px,calc(100vw - 24px));max-width:none;max-height:calc(100dvh - 36px);overflow:auto;background:var(--why-paper);color:var(--why-ink);padding:18px 20px;font-size:14px;line-height:1.75;box-sizing:border-box}dialog.kids-why-dialog::backdrop{background:#1323389c}.kids-why-dialog>header{height:auto;min-height:36px;position:static;display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:12px;color:var(--why-muted)}.kids-why-dialog>header button{font-size:22px;line-height:1;width:36px;padding:0}.kids-why-dialog h2{font-size:18px;font-weight:500;line-height:1.7;margin:10px 0 6px}.kids-why-dialog p{margin:6px 0;line-height:1.8}.why-guess{border:0;margin:14px 0 0;padding:0;display:grid;gap:6px}.why-guess legend{margin-bottom:6px;color:var(--why-blue)}.why-guess button{text-align:left;line-height:1.65}.why-feedback{min-height:24px;color:var(--why-blue);font-size:13px}.why-play{background:var(--why-soft);padding:10px 12px;border-radius:4px}.why-play svg{display:block;width:100%;height:190px;margin:0 auto}.why-play svg text{font:12px -apple-system,BlinkMacSystemFont,'PingFang SC',sans-serif;fill:var(--why-ink)}.why-play>[role=status],.why-play p{font-size:13px;color:var(--why-muted)}.why-play svg [data-why-rays]{transition:opacity .4s}.why-range{display:flex;align-items:center;gap:12px;flex-wrap:wrap}.why-range input{flex:1;min-width:130px;accent-color:var(--why-blue);height:30px}.why-demo-buttons{display:flex;gap:8px;flex-wrap:wrap}.why-demo-buttons button[aria-pressed=true]{border-color:var(--why-blue);color:var(--why-blue)}.why-reveal{margin-top:12px;background:var(--why-blue)!important;color:#fff!important}.why-answer{border-top:1px solid var(--why-line);margin-top:12px;padding-top:10px}.why-answer h3{font-size:15px;margin:2px 0;font-weight:500}.why-answer>p{font-size:15px}.why-answer .why-followup{font-size:13px;color:var(--why-muted)}.why-answer a{font-size:12px;color:var(--why-blue)}.kids-why-dialog>footer{font-size:14px;display:flex;gap:10px;align-items:center;justify-content:space-between;border-top:1px solid var(--why-line);padding-top:12px;margin-top:14px}.kids-why-dialog>footer>span{font-size:12px;color:var(--why-muted)}.why-bubble{width:150px;height:150px;margin:18px auto;border-radius:50%;background:radial-gradient(circle at 32% 24%,#fff9 0 5%,transparent 17%),repeating-conic-gradient(from 30deg,#88b8cfcc,#db9cadbb,#edcf94aa,#a6c5a9bb,#88b8cfcc);filter:hue-rotate(var(--bubble-hue,126deg));box-shadow:inset -12px -12px 22px #6b8ca633,inset 7px 7px 18px #fff8}
body.dark .children-why,body.dark .kids-why-dialog{--why-ink:#e5edf7;--why-muted:#adbed1;--why-line:#35506a;--why-paper:#122c43;--why-soft:#0d2339;--why-blue:#9ac8eb}.kids-why-dialog [hidden]{display:none!important}@media(max-width:650px){.children-why>header{align-items:flex-start}.children-why>header>button{font-size:12px;flex:none}.why-tools{align-items:stretch;flex-direction:column;padding-bottom:8px}.why-tools input{width:100%}.why-grid{grid-template-columns:1fr}.why-question{min-height:90px}dialog.kids-why-dialog{padding:14px;max-height:calc(100dvh - 20px)}.kids-why-dialog>footer{align-items:flex-start;flex-direction:column}.why-play svg{height:170px}}@media(prefers-reduced-motion:reduce){.why-play svg [data-why-rays]{transition:none}}
.why-day-bar{height:8px;background:var(--why-line);margin:4px 0 12px}.why-day-bar span{display:block;height:100%;background:#dcb35b}

.children-why a{text-decoration:none;box-sizing:border-box}.why-preview .why-grid{margin-top:14px}.why-zone-link{white-space:nowrap;flex-shrink:0;color:var(--why-blue)!important}.why-nav-link{display:flex;align-items:center;gap:9px;min-height:44px;padding:8px;text-decoration:none;color:inherit;font:inherit;box-sizing:border-box}.why-nav-link b{font-weight:500}.why-nav-link small{display:block;color:var(--muted);font-size:12px}.why-nav-link:focus-visible{outline:2px solid #72a4e4;outline-offset:2px}
body.why-page{margin:0;background:#f6f8fa;color:#303b47;font-family:-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif}.why-page.dark{background:#0c1729;color:#e5edf7}.why-page-header{display:flex;align-items:center;justify-content:space-between;gap:20px;padding:14px 24px;border-bottom:1px solid #8a9baa33}.why-page-header img{display:block;width:84px;height:auto}.why-page-header a{color:inherit;text-decoration:none;font-size:14px}.why-page main{width:min(1120px,calc(100% - 40px));margin:20px auto}.why-page .children-why{border:0;margin:0;padding:10px 0 28px}.why-page .children-why h1{font-size:22px;line-height:1.5;font-weight:500;margin:5px 0}.why-page .why-art{flex-basis:48px}.why-page .why-art svg{width:48px;height:48px}.why-page .why-grid{gap:12px}.why-page .why-question{min-height:116px}.why-page .why-tools{margin-top:22px}@media(min-width:1000px){.why-page .why-grid{grid-template-columns:repeat(3,minmax(0,1fr))}}@media(max-width:650px){.why-page main{width:calc(100% - 24px)}.why-page-header{padding:12px}.why-page .children-why h1{font-size:20px}}
/* Bilingual science books share the integrated cover treatment. */
.science-books-panel{margin:8px 0 30px}.science-books-panel>header{margin-bottom:18px}.science-books-panel h1{font-size:22px;line-height:1.5;font-weight:500;margin:4px 0}.science-books-panel p{font-size:14px;line-height:1.7;color:#657482;margin:5px 0}.science-book-grid{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:20px 16px}.science-book-cover{position:relative;display:block;aspect-ratio:3/4;border-radius:3px;overflow:hidden;box-shadow:2px 3px 0 #485b6e33;background:#263e49;color:#fff;text-decoration:none}.science-book-cover>img{width:100%;height:100%;display:block;object-fit:cover}.science-book-cover-copy{position:absolute;inset:auto 0 0;background:linear-gradient(transparent,#102827eb 48%);padding:42px 16px 18px;display:flex;flex-direction:column;gap:6px}.science-book-cover-copy strong{font-size:24px;font-weight:600;line-height:1.4;color:#fff9ea}.science-book-cover-copy>span{font:14px/1.4 Georgia,serif;color:#edf2ed}.science-book-cover-copy small{font-size:12px;line-height:1.5;color:#d3e2dc}.science-book-cover:focus-visible{outline:3px solid #4d94d2;outline-offset:4px}.why-page.dark .science-books-panel p{color:#adbed1}@media(max-width:900px){.science-book-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.science-book-cover-copy strong{font-size:20px}}@media(max-width:600px){.science-book-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}.science-book-cover-copy{padding:35px 10px 12px}.science-book-cover-copy strong{font-size:20px}}
/* The shelf preview uses the same portrait cover component as the science library. */
.why-preview .science-book-grid{margin-top:14px;gap:16px 12px}.children-why .science-book-cover{padding:0;min-height:0;min-width:0;border:0;background:#263e49;color:#fff}.why-preview .science-book-cover-copy{padding:34px 10px 12px;gap:4px}.why-preview .science-book-cover-copy strong{font-size:var(--sprout-type-nav-size,15px);font-weight:500;line-height:1.5}.why-preview .science-book-cover-copy>span{font-size:12px;line-height:1.5}.why-preview .science-book-cover-copy strong,.why-preview .science-book-cover-copy>span{display:-webkit-box;-webkit-box-orient:vertical;-webkit-line-clamp:2;overflow:hidden}.why-preview .science-book-cover-copy small{font-size:12px;line-height:1.5}
@media(max-width:1100px){.why-preview .science-book-grid{grid-template-columns:repeat(3,minmax(0,1fr))}}@media(max-width:600px){.why-preview .science-book-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}