/* Complete documents, with the original page and its explanation kept together. */
.hero-main>.eyebrow>strong{display:inline;font-weight:850;color:#123da2}.hero-main>.eyebrow{line-height:1.85}.lesson-subject-picker{display:none}.lesson-document-bar{display:flex;justify-content:space-between;align-items:center;gap:24px;padding:20px 23px;background:white;border:1px solid #d4dce8;border-radius:10px;margin:24px 0}.document-tag{font-size:10px;font-weight:800;letter-spacing:.09em;color:#1642aa}.lesson-document-bar p{font-size:14px;color:#4a515d;margin-top:4px}.document-actions{display:flex;align-items:center;gap:25px;flex-shrink:0}.document-actions .button{min-height:48px;padding:12px 19px;font-size:14px}.download-link{display:block;font-size:14px;font-weight:700;line-height:1.45;padding:4px 0}.download-link small{display:block;font-size:11px;font-weight:500;color:#555f70}.lesson-navigation{display:block;margin:0 0 20px}.lesson-pager{display:flex;align-items:center;justify-content:space-between;gap:10px}.lesson-pager>div{display:flex;gap:8px}.lesson-pager button{min-width:44px;min-height:44px;border:1px solid #bdc8d8;border-radius:7px;background:white;color:#1445bb;font-size:16px;padding:8px 13px;line-height:1.4}.lesson-pager button span{font-size:13px;font-weight:650}.lesson-pager button:disabled{opacity:.4}.lesson-pager.bottom{margin:20px 0 26px;padding-top:15px;border-top:1px solid #dbe1ea}.lesson-count{font-size:13px;font-weight:700;color:#3e4b5e}.lesson-thumbnails{display:flex;gap:9px;overflow-x:auto;padding:11px 4px 6px;scrollbar-width:thin}.lesson-thumbnails button{display:flex;align-items:center;gap:9px;flex:0 0 auto;min-width:66px;min-height:60px;padding:5px 10px 5px 5px;border:1px solid #ccd4df;border-radius:6px;background:#fff;font-size:12px;font-weight:700;color:#3d4f69}.lesson-thumbnails img{width:36px;height:48px;object-fit:contain;border:1px solid #e6e8ed;border-radius:2px}.lesson-thumbnails button[aria-pressed=true]{border-color:#1248d8;background:#eaf0ff;color:#123ca7;box-shadow:0 0 0 1px #1248d8}.lesson-frame{grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:38px;align-items:start}.lesson-paper{border:1px solid #d1d7df;border-radius:9px;background:var(--paper);box-shadow:0 10px 28px #14244508}.lesson-paper .note-open{background:var(--paper)}.lesson-paper img{display:block;width:100%;height:auto;padding:0;object-fit:contain;background:var(--paper);max-height:none}.lesson-paper figcaption{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:9px 14px;border-top:1px solid #e4e6ea;background:var(--paper);font-size:11px;line-height:1.5;color:#42516a}.lesson-paper figcaption a{font-size:12px;font-weight:750;min-height:38px;display:flex;align-items:center;white-space:nowrap}.lesson-commentary{font-size:16px;padding:5px 0;line-height:1.75}.lesson-commentary h4{font-size:25px;line-height:1.28;margin-top:10px}.lesson-commentary .eyebrow{font-size:11px}.lesson-commentary p+p{margin-top:18px}.lesson-commentary .equation{background:white;border-radius:0 5px 5px 0;font-size:18px}.pdf-cover{display:block;background:#fff;max-height:310px;overflow:hidden}.pdf-cover img{display:block;width:100%;height:310px;object-fit:contain;padding:12px}.pdf-caption a{display:block;margin-top:10px;min-height:32px;font-weight:650}.hero-manuscript .note-open{background:var(--paper)}
#doc-reader{margin:auto;width:min(1400px,calc(100vw - 40px));height:calc(100dvh - 40px);max-width:none;max-height:none;overflow:hidden;border:0;border-radius:14px;padding:0;background:white;color:#182332;box-shadow:0 30px 90px #111d4360}#doc-reader[open]{display:grid;grid-template-rows:auto auto minmax(0,1fr) auto auto}#doc-reader::backdrop{background:#122341c9;backdrop-filter:blur(3px)}.doc-header{display:flex;align-items:center;justify-content:space-between;gap:14px;padding:17px 22px 13px;border-bottom:1px solid #dce2ec}.doc-header .eyebrow{font-size:10px;letter-spacing:.08em}.doc-header h2{font-size:23px;letter-spacing:-.025em;line-height:1.3;margin-top:5px}.doc-header button{min-height:44px;min-width:84px;flex-shrink:0;border:1px solid #bdc8d8;border-radius:6px;background:#fff;padding:8px 13px;font-size:14px;font-weight:700}.doc-header button span{font-size:20px;margin-left:6px}.doc-toolbar{display:flex;align-items:center;justify-content:space-between;gap:12px;padding:10px 22px;background:#f6f8fb}.doc-toolbar>a{font-size:13px;font-weight:750;min-height:44px;display:flex;align-items:center}.doc-zoom{display:flex;align-items:center;gap:5px}.doc-zoom button{border:1px solid #c7d0de;background:white;border-radius:6px;min-width:44px;min-height:44px;font-size:22px;font-weight:600}.doc-zoom #doc-fit{font-size:12px;min-width:64px}.doc-zoom button:disabled{opacity:.4}.doc-tabs{display:none}.doc-main{display:grid;grid-template-columns:minmax(0,1.35fr) minmax(0,1fr);gap:0;min-height:0;min-width:0;overflow:hidden}.doc-sheet{position:relative;overflow:auto;min-width:0;min-height:0;background:var(--paper,#fff);overscroll-behavior:contain;scrollbar-width:thin;touch-action:pan-x pan-y}.doc-canvas{display:flex;align-items:center;justify-content:center;min-width:100%;min-height:100%}.doc-sheet img{display:block;max-width:none;flex:none;height:auto;user-select:none;-webkit-user-drag:none}.doc-sheet.is-zoomed{cursor:grab}.doc-sheet.is-panning{cursor:grabbing}.doc-explanation{font-size:16px;line-height:1.8;padding:25px 30px;overflow:auto;min-width:0;min-height:0;border-left:1px solid #dce2ec;overscroll-behavior:contain}.doc-explanation .eyebrow{font-size:10px}.doc-explanation h3{font-size:27px;line-height:1.24;letter-spacing:-.035em;margin:12px 0 22px}.doc-explanation .equation{font-size:18px;background:#f6f8fc;margin-block:20px}.doc-source{display:flex;justify-content:space-between;gap:15px;border-top:1px solid #dde3eb;padding:8px 22px;font-size:11px;color:#475974;line-height:1.6}.doc-source a{flex-shrink:0}.doc-pagination{display:flex;align-items:center;justify-content:center;gap:12px;padding:10px 22px 13px;background:#f6f8fb;border-top:1px solid #dce2ec}.doc-pagination button{width:44px;height:44px;flex-shrink:0;border:1px solid #bdc8d8;background:white;border-radius:7px;font-size:21px;color:#1647b8}.doc-pagination button:disabled{opacity:.35}.doc-pagination select{font:600 14px/1.4 Manrope,system-ui,sans-serif;max-width:470px;min-width:0;width:100%;height:44px;background:#fff;color:#172d53;border:1px solid #bdc8d8;border-radius:7px;padding:8px 32px 8px 12px;text-overflow:ellipsis}.doc-sheet:focus-visible,.doc-explanation:focus-visible{outline:3px solid #1248d8;outline-offset:-4px}.doc-reader-open .mobile-contact{visibility:hidden}#doc-image-error{padding:22px;position:absolute;inset:0;background:white;font-size:16px}.lesson-panel:focus-visible{outline-offset:7px}.lesson-subject-picker select:focus-visible,.doc-pagination select:focus-visible{outline:3px solid #1248d8;outline-offset:3px}
html:not(.js) .lesson-pager,html:not(.js) .lesson-thumbnails{display:none}html:not(.js) .lesson-frame{margin-bottom:35px}
@media(max-width:1000px){.lesson-intro{grid-template-columns:1fr;gap:13px}.lesson-intro h3,.lesson-intro p{max-width:670px}.lesson-frame{gap:25px}.lesson-commentary{font-size:16px}.lesson-commentary h4{font-size:23px}.lesson-document-bar{gap:18px;padding:18px}.document-actions{gap:18px}.doc-main{grid-template-columns:minmax(0,1.1fr) minmax(0,1fr)}.doc-explanation{padding:20px}.doc-explanation h3{font-size:24px}.tabs button{font-size:13px}}
@media(max-width:800px){html.js .lesson-subject-picker{display:block;margin-bottom:25px}html.js .examples .tabs{display:none}.lesson-subject-picker label{display:block;font-size:12px;font-weight:750;margin-bottom:7px;color:#465674}.lesson-subject-picker select{font:650 16px/1.4 Manrope,system-ui,sans-serif;height:54px;width:100%;padding:10px 40px 10px 15px;color:#153e96;background:#fff;border:1px solid #aebdd4;border-radius:8px}.lesson-frame{grid-template-columns:1fr;gap:22px}.lesson-paper{max-width:590px;width:100%;margin-inline:auto}.lesson-commentary{max-width:690px;font-size:16px}.lesson-commentary h4{font-size:26px}.lesson-paper figcaption{font-size:11px}.lesson-intro h3{font-size:28px}.lesson-intro p{font-size:15px;margin-top:12px}.lesson-document-bar{align-items:flex-start}.document-actions{gap:15px}.lesson-pager.bottom{margin-top:22px}.lesson-navigation button{min-width:44px}.lesson-pager button{padding:8px 12px}.lesson-thumbnails{gap:7px}.lesson-thumbnails button{min-width:53px;flex-direction:column;gap:2px;padding:4px;min-height:76px}.lesson-thumbnails img{width:32px;height:44px}.lesson-thumbnails span{font-size:11px;line-height:1.7}.lesson-commentary .equation{font-size:17px}.lesson-commentary p+p{margin-top:17px}
#doc-reader{width:100%;height:100dvh;max-height:100dvh;border-radius:0;margin:0}#doc-reader[open]{grid-template-rows:auto auto auto minmax(0,1fr) auto auto}.doc-header{padding:10px 14px;padding-top:max(10px,env(safe-area-inset-top))}.doc-header h2{font-size:19px;margin-top:3px}.doc-header button{padding:6px 10px;min-width:80px;font-size:13px}.doc-header .eyebrow{font-size:9px}.doc-toolbar{padding:6px 14px}.doc-toolbar>a{font-size:13px}.doc-tabs{display:grid;grid-template-columns:1fr 1fr;padding:0 14px;gap:6px;background:#f6f8fb;border-bottom:1px solid #d9e1ed}.doc-tabs button{min-height:44px;border:0;border-bottom:3px solid transparent;border-radius:5px 5px 0 0;background:transparent;color:#435774;font-size:14px;font-weight:750}.doc-tabs button[aria-selected=true]{color:#1248d8;background:#fff;border-bottom-color:#1248d8}.doc-main{display:block}.doc-sheet,.doc-explanation{height:100%;width:100%}.doc-explanation{font-size:16px;padding:22px 20px;border-left:0}.doc-explanation h3{font-size:26px}.doc-explanation .equation{font-size:17px}.doc-source{display:block;padding:7px 14px;font-size:10px}.doc-source a{display:block;font-size:11px;min-height:26px;line-height:26px}.doc-pagination{padding:9px 14px max(10px,env(safe-area-inset-bottom));gap:8px}.doc-pagination select{font-size:13px;max-width:none}.doc-pagination button{width:44px}.doc-sheet img{padding:0}.doc-zoom #doc-fit{min-width:60px}}
@media(max-width:560px){.lesson-document-bar{display:block;padding:16px;margin:20px 0 15px}.lesson-document-bar p{font-size:13px}.document-actions{margin-top:14px;gap:23px}.document-actions .button{flex:1;max-width:210px;min-height:48px}.download-link{font-size:13px}.document-tag{font-size:9px}.lesson-thumbnails{padding-top:13px}.lesson-intro h3{font-size:27px}.lesson-pager button span{font-size:12px}.lesson-pager .lesson-count{font-size:12px}.lesson-paper figcaption{padding:7px 11px;gap:9px}.lesson-paper figcaption a{font-size:11px}.lesson-commentary h4{font-size:25px}.hero-main>.eyebrow>strong{font-size:12px;letter-spacing:.11em}.examples .section-heading>p:not(.eyebrow){font-size:16px}.pdf-cover,.pdf-cover img{height:280px;max-height:280px}}
@media(max-width:360px){.lesson-pager button span{display:none}.lesson-pager button{width:44px}.lesson-thumbnails button{min-width:44px}.lesson-thumbnails{gap:4px}.lesson-thumbnails img{width:29px;height:41px}.lesson-thumbnails span{font-size:10px}.lesson-document-bar{padding:14px}.document-actions{gap:14px}.doc-header h2{font-size:17px}.doc-header .eyebrow{font-size:8px}.doc-toolbar>a{font-size:12px}.doc-zoom{gap:3px}.doc-zoom #doc-fit{min-width:54px}.doc-explanation{padding:18px 16px}}
@media(prefers-reduced-motion:reduce){.lesson-thumbnails{scroll-behavior:auto}}