/* Local library layout follows the Chermistry question-bank reference. */
@media screen {
  :root{--library-paper:#f4f1e9;--library-ink:#30445b;--library-blue:#43556d;--library-line:#dedbcf;--library-gold:#aa914b}
  body{background:var(--library-paper);color:var(--library-ink);font-family:"Segoe UI",Arial,sans-serif}
  .site-header{position:sticky;top:0;z-index:20;background:linear-gradient(#19202a,#10151c);border-bottom:2px solid var(--library-gold);min-height:58px;height:auto;padding:10px 26px;gap:18px}
  .brand,.brand strong,.brand small{color:#e4d494}.brand-mark{border-color:#9e874b;background:transparent;color:#e4d494}.brand-mark span{color:#e4d494}
  .header-actions{gap:16px;flex-wrap:wrap}.site-header .button-dark{background:#cbb473;color:#161d25;border-color:#cbb473}.periodic-table-link{color:#e4d494;text-decoration:none;font-size:11px;text-transform:uppercase;letter-spacing:.05em}
  .course-pills{display:flex;gap:0}.course-pill{padding:6px 10px;border:1px solid #917b44;background:transparent;color:#e4d494;font:11px Consolas,monospace;cursor:pointer}.course-pill[aria-pressed=true]{background:#cfb45c;color:#171c21}.course-pill:focus-visible{outline:3px solid #9dc5e4;outline-offset:3px}
  .page-shell{max-width:1500px;margin:auto;padding:32px 30px 28px}.intro{margin:0 0 24px 278px;max-width:none;display:block}.intro h1{font:700 34px/1.2 "Segoe UI",Arial,sans-serif;letter-spacing:-.02em;margin:9px 0 14px;color:var(--library-ink)}.intro-copy{font-size:14px;line-height:1.8;max-width:850px;color:#69777d}.eyebrow{color:#8c8d84;font-size:10px;letter-spacing:.15em}.intro .search-box{margin-top:22px;max-width:none;width:100%;height:46px;border:1px solid var(--library-line);border-radius:25px;background:white;box-shadow:none}.intro .search-box input{font-size:13px}
  .coverage-strip{margin:0 0 25px 278px;border:0;border-radius:0;background:transparent;box-shadow:none;padding:0;gap:30px;grid-template-columns:1.2fr 1fr 1fr auto}.coverage-cell{padding:0;border:0;min-height:74px;display:flex;flex-direction:column}.coverage-cell strong{order:-1;font:700 27px/1.2 "Segoe UI",Arial,sans-serif;color:var(--library-ink);margin-bottom:5px}.stat-label{font-size:11px;letter-spacing:0;text-transform:none;color:#858d88}.coverage-cell small{font-size:10px}.progress-track{height:4px;max-width:160px;margin-top:8px}.coverage-details{font-size:11px;align-self:start;padding-top:8px}.coverage-popover{z-index:30}
  .workspace{display:grid;grid-template-columns:240px minmax(0,1fr);gap:38px;align-items:start}.filter-panel{position:sticky;top:84px;align-self:start;max-height:calc(100vh - 104px);overflow:auto;background:transparent;border:0;padding:0 9px 15px 0;box-shadow:none;border-radius:0}.library-label{font-size:10px;font-weight:750;letter-spacing:.14em;color:#8c8d84;margin:0 12px 9px}.library-nav{display:grid;gap:4px;margin-bottom:28px}.library-nav button,.topic-nav-button{display:flex;justify-content:space-between;text-align:left;gap:12px;width:100%;padding:11px 12px;border:0;background:transparent;color:var(--library-ink);font:12px/1.6 "Segoe UI",Arial,sans-serif;border-radius:9px;cursor:pointer}.library-nav button.active,.topic-nav-button.active{background:var(--library-blue);color:white;font-weight:650}.library-nav button:hover,.topic-nav-button:hover{background:#e8e5da}.library-nav button.active:hover,.topic-nav-button.active:hover{background:#43556d}.topic-nav-button small{opacity:.6;font-size:10px;padding-top:1px;white-space:nowrap}.topic-nav{margin-bottom:28px}.filter-heading{border-top:1px solid var(--library-line);padding-top:16px;margin:15px 12px 12px}.filter-heading h2{font-size:11px}.filter-panel>.field,.filter-panel>.filter-pair{margin-left:12px;margin-right:4px}.field{font-size:11px;letter-spacing:0}.field select,.field input{border-color:var(--library-line);background:white;border-radius:18px;font-size:12px;min-height:39px;padding:9px 12px}.filter-pair{display:grid;grid-template-columns:1fr 1fr;gap:10px}.filter-pair .field{min-width:0}.filter-note{border:0;margin:12px;font-size:11px;color:#8a8d84}
  .results-panel{min-width:0}.view-tabs{border-bottom:1px solid var(--library-line);gap:26px}.view-tab{font-size:12px;color:#7d8785}.view-tab.active{color:var(--library-ink);border-color:var(--library-blue)}.results-toolbar{margin:22px 0 16px}.results-toolbar h2{font-size:17px;letter-spacing:0;color:var(--library-ink)}.results-toolbar p{font-size:12px}.sort-field{font-size:11px}.sort-field select{background:white;border:1px solid var(--library-line);border-radius:18px;padding:7px 12px}.question-list{display:block}.library-question{display:block;border:1px solid var(--library-line);border-radius:14px;background:white;padding:0;margin:12px 0;box-shadow:0 3px 8px #293b460b;overflow:hidden}.library-question-summary{display:flex;align-items:flex-start;list-style:none;gap:13px;padding:18px 20px;cursor:pointer}.library-question-summary::-webkit-details-marker{display:none}.library-question-summary:before{content:'▸';font-size:13px;color:#7296b8;margin-top:3px}.library-question[open]>.library-question-summary:before{content:'▾'}.library-question-summary:focus-visible{outline:3px solid #9dc5e4;outline-offset:-4px}.library-question-label{min-width:0;flex:1}.library-question .badges{margin-bottom:7px}.library-question .card-title{font:650 14px/1.5 "Segoe UI",Arial,sans-serif;color:#5b7e9d;margin:5px 0}.card-excerpt{font:14px/1.65 "Segoe UI",Arial,sans-serif;color:#4d5d67;margin:6px 0;max-width:950px}.library-question .card-metadata{font-size:11px;margin:7px 0 0;color:#8a8e85}.library-question .card-topics{font-size:11px;color:#8a8e85;margin:6px 0 0}.library-question-content{border-top:1px solid #efeee9;padding:0 20px 20px}.question-reader{min-width:0}.reader-toolbar{display:flex;align-items:center;justify-content:space-between;gap:10px;flex-wrap:wrap;margin:14px 0}.reader-source-links{display:flex;gap:7px;flex-wrap:wrap}.source-chip{display:inline-block;cursor:pointer;padding:6px 11px;font:11px/1.5 "Segoe UI",Arial,sans-serif;border:1px solid var(--library-line);border-radius:18px;background:#fff;color:#566b7d;text-decoration:none}.source-chip:hover{background:#f5f2e9}.bookmark-button[aria-pressed=true]{background:#fbf2d6;border-color:#d8c07b;color:#78602b}.reader-tabs{display:flex;gap:5px;flex-wrap:wrap;border-bottom:1px solid var(--library-line);margin:6px 0 18px}.reader-tab{border:0;border-bottom:2px solid transparent;border-radius:0;background:transparent;cursor:pointer;padding:11px 15px;font:600 12px "Segoe UI",Arial,sans-serif;color:#82908e}.reader-tab[aria-selected=true]{border-bottom-color:var(--library-blue);color:var(--library-ink);background:#f6f4ed}.reader-tab:focus-visible{outline:3px solid #9dc5e4;outline-offset:-3px}.reader-panel{min-width:0}.reader-panel .question-body img{height:auto;max-width:100%;object-fit:contain}.reader-panel>.question-body>figure{margin:12px 0}.reader-caption,.answer-provenance{font-size:12px;line-height:1.7;color:#7a8586}.ocr-status{font-size:12px;line-height:1.7;color:#837047;background:#fcf7e7;border:1px solid #eadfba;border-radius:8px;padding:11px 14px}.ocr-text{font:15px/1.9 "Segoe UI",Arial,sans-serif;white-space:pre-wrap;overflow-wrap:anywhere;color:#263d55;background:white;tab-size:4;margin:20px 0}.checked-answer h3{font:650 15px/1.5 "Segoe UI",Arial,sans-serif;color:var(--library-ink);margin:20px 0 9px}.source-key-letter{font-size:12px;color:#7d827f}.fact-link{display:block;font-size:12px;line-height:1.7;margin:7px 0;overflow-wrap:anywhere}.paper-links{display:flex;flex-wrap:wrap;gap:7px}.library-panel{border:1px solid var(--library-line);background:white;border-radius:14px;padding:22px;margin:16px 0}.library-panel h2{font:650 21px/1.4 "Segoe UI",Arial,sans-serif;margin:0 0 20px}.library-table-scroll{overflow:auto}.library-table{width:100%;border-collapse:collapse;text-align:left;font-size:12px}.library-table th{background:#efede3;font-size:11px;font-weight:600}.library-table td,.library-table th{padding:12px 14px;border-bottom:1px solid #e7e5db;vertical-align:top}.practice-options{display:flex;gap:10px;margin:22px 0}.practice-choice{border:1px solid #bec7cc;background:white;color:var(--library-ink);border-radius:8px;padding:12px 24px;font-weight:700;cursor:pointer}.practice-choice.correct{background:#e8f2df;border-color:#779660}.practice-choice.incorrect{background:#fbe9e5;border-color:#be8a81}.practice-nav{display:flex;justify-content:space-between;margin-top:20px}.practice-feedback{font-weight:600;color:var(--library-ink)}.source-note{font-size:12px;background:#fcf5df;color:#876f39;border-radius:8px;padding:11px 14px}.page-footer{margin-left:278px;font-size:11px;color:#92958c}.question-dialog{max-width:1150px;width:calc(100vw - 48px)}.question-dialog .dialog-content{max-height:calc(94dvh - 150px)}.dialog-content h2{font:700 23px/1.4 "Segoe UI",Arial,sans-serif}.button-dark{background:var(--library-blue);border-color:var(--library-blue)}.button-light{border-color:var(--library-line);color:var(--library-ink)}
  @media(max-width:1100px){.course-pills{order:3}.site-header{padding:10px 18px}.header-actions{justify-content:flex-end;gap:10px}.workspace{grid-template-columns:200px minmax(0,1fr);gap:24px}.intro,.coverage-strip,.page-footer{margin-left:224px}.coverage-strip{gap:18px;grid-template-columns:1fr 1fr 1fr}.coverage-details{grid-column:1/-1}.intro h1{font-size:30px}.coverage-cell strong{font-size:24px}.page-shell{padding:28px 20px}}
  @media(max-width:760px){.site-header{position:relative;padding:12px;align-items:flex-start}.header-actions{max-width:70%}.brand small{font-size:9px}.course-pills{width:100%;justify-content:flex-end}.course-pill{font-size:10px;padding:6px 8px}.intro,.coverage-strip,.page-footer{margin-left:0}.intro h1{font-size:28px}.page-shell{padding:24px 14px}.coverage-strip{gap:13px;margin-bottom:22px}.coverage-cell strong{font-size:22px}.stat-label{font-size:10px}.coverage-cell small{display:none}.workspace{display:block}.filter-panel{position:static;max-height:none;overflow:visible;padding:0;display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-bottom:22px}.library-label,.library-nav,.topic-nav{grid-column:1/-1}.library-label{margin:0;font-size:9px}.library-nav{display:flex;gap:6px;overflow:auto;margin:0 0 8px}.library-nav button{white-space:nowrap;width:auto;font-size:11px;padding:10px 12px}.topic-library-label{display:none}.topic-nav{display:flex;gap:6px;overflow:auto;margin:0 0 8px;padding-bottom:5px}.topic-nav-button{width:auto;white-space:nowrap;padding:8px 11px;font-size:11px;border:1px solid var(--library-line);background:white;border-radius:20px}.topic-nav-button small{display:none}.filter-heading,.filter-note{display:none}.filter-panel>.field,.filter-panel>.filter-pair{margin:0}.filter-pair{display:contents}.field select{max-width:100%;width:100%;min-width:0}.library-question-summary{padding:15px;gap:9px}.library-question-content{padding:0 13px 15px}.reader-tab{font-size:11px;padding:10px 11px}.reader-toolbar .button{font-size:10px}.reader-source-links{gap:5px}.source-chip{font-size:10px;padding:6px 9px}.reader-panel .question-body{font-size:14px}.ocr-text{font-size:14px}.library-panel{padding:15px}.library-table td,.library-table th{padding:9px}.question-dialog{width:calc(100vw - 16px)}.dialog-content{padding:18px}.coverage-details{grid-column:1/-1}.page-footer{margin-top:24px}}
}
@media screen and (min-width:761px){
  .page-shell{display:grid;grid-template-columns:240px minmax(0,1fr);column-gap:38px;align-items:start}
  .workspace{display:contents}
  .intro{grid-column:2;grid-row:1;margin-left:0}
  .coverage-strip{grid-column:2;grid-row:2;margin-left:0}
  .filter-panel{grid-column:1;grid-row:1 / 5}
  .results-panel{grid-column:2;grid-row:3}
  .page-footer{grid-column:2;grid-row:4;margin-left:0}
}
@media screen and (min-width:761px) and (max-width:1100px){.page-shell{grid-template-columns:200px minmax(0,1fr);column-gap:24px}}

/* Keep the reference library filters above the expandable question rows. */
@media screen {
 .library-filterbar{display:grid;grid-template-columns:minmax(230px,2fr) repeat(4,minmax(105px,1fr));gap:10px;align-items:end;margin:0 0 18px}
 .library-filterbar .search-box{min-width:0;width:100%;height:42px;margin:0;border:1px solid var(--library-line);border-radius:24px;background:white;box-shadow:none}
 .library-filterbar .search-box input{font-size:12px;min-width:0}
 .library-filterbar>.field,.library-filterbar .filter-pair .field{margin:0;min-width:0}
 .library-filterbar .field select{width:100%;min-width:0;height:42px}
 .library-filterbar .filter-pair{display:contents}
 .library-filterbar>.filter-heading{grid-column:1/-1;grid-row:2;display:flex;justify-content:flex-end;margin:0;padding:0;border:0}
 .library-filterbar>.filter-heading h2{display:none}
 .library-filterbar>[hidden]{display:none!important}
 @media(max-width:1200px){.library-filterbar{grid-template-columns:repeat(4,minmax(0,1fr))}.library-filterbar .search-box{grid-column:span 2}.library-filterbar>.filter-heading{grid-row:auto}}
 @media(max-width:760px){.library-filterbar{grid-template-columns:repeat(2,minmax(0,1fr))}.library-filterbar .search-box{grid-column:1/-1}.library-filterbar>.filter-heading{display:flex}.library-filterbar .field select{font-size:12px}}
}

/* Align the topic menu with the page introduction, as in the reference bank. */
@media screen and (min-width:761px){
 .page-shell{display:grid;grid-template-columns:240px minmax(0,1fr);column-gap:38px}
 .intro,.coverage-strip,.page-footer{grid-column:2;margin-left:0}
 .workspace{display:contents}
 .filter-panel{grid-column:1;grid-row:1/span 3}
 .results-panel{grid-column:2;grid-row:3}
}
@media screen and (min-width:761px) and (max-width:1100px){.page-shell{grid-template-columns:200px minmax(0,1fr);column-gap:24px}}