:root{--bg:#f5f7f7;--card:#fff;--ink:#132633;--muted:#607481;--navy:#0d1b2a;--teal:#0c817a;--teal-light:#d9f2ec;--line:#dce5e9;--soft:#eaf0f2;--danger:#a83d41;--shadow:0 15px 40px rgba(24,52,62,.065);color-scheme:light}
html[data-theme="dark"]{--bg:#0c1820;--card:#142630;--ink:#ecf5f4;--muted:#a0b3bd;--navy:#07121b;--teal:#42c7b7;--teal-light:#173a3c;--line:#29414b;--soft:#1b333e;--danger:#f18e88;--shadow:0 15px 45px rgba(0,0,0,.2);color-scheme:dark}
*{box-sizing:border-box}html{font-family:Inter,"Avenir Next",-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:16px}body{margin:0;background:var(--bg);color:var(--ink)}button,input,select{font:inherit}button{cursor:pointer}button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--teal);outline-offset:2px}.shell{max-width:820px;margin:auto;padding:0 21px 105px}.topbar{height:94px;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:12px}.brand-mark{background:var(--navy);color:#bcefe6;width:42px;height:42px;display:grid;place-items:center;border-radius:12px;font-family:Georgia,serif;font-size:28px}.eyebrow{font-size:10px;letter-spacing:.18em;text-transform:uppercase;font-weight:800;color:var(--teal)}.brand h1{font-size:19px;margin:1px 0;font-weight:750;letter-spacing:-.035em}.iconbtn{width:40px;height:40px;border-radius:50%;border:1px solid var(--line);background:var(--card);color:var(--ink);font-size:21px}.hero{min-height:206px;border-radius:22px;background:linear-gradient(128deg,#0d2330,#164e50);color:white;display:flex;justify-content:space-between;align-items:center;padding:27px 30px;overflow:hidden;position:relative}.hero .eyebrow{color:#88dfcd}.hero h2{font-size:clamp(27px,5vw,41px);line-height:1.09;letter-spacing:-.05em;margin:13px 0 11px}.hero h2 em{color:#9be7d1;font-style:normal}.hero p{font-size:13px;color:#c7e1de;line-height:1.6;max-width:330px;margin:0}.hero-orbit{height:145px;width:145px;flex:0 0 145px;border:1px solid #ffffff4b;border-radius:50%;transform:rotate(-28deg);display:grid;place-items:center;position:relative;margin-right:13px}.hero-orbit:before{content:"";position:absolute;inset:19px -17px;border:1px solid #ffffff36;border-radius:50%;transform:rotate(58deg)}.hero-orbit:after{content:"";position:absolute;inset:-15px 21px;border:1px solid #ffffff36;border-radius:50%;transform:rotate(-45deg)}.nucleus{font-family:Georgia,serif;color:#a5eadd;font-size:49px;transform:rotate(28deg)}.hero-orbit span{position:absolute;background:#a0ecdc;width:8px;height:8px;border-radius:50%;top:8px;left:39px}.hero-orbit span:last-child{top:auto;left:auto;right:13px;bottom:29px;width:5px;height:5px}.metrics{display:grid;grid-template-columns:repeat(3,1fr);background:var(--card);border:1px solid var(--line);border-radius:16px;margin:15px 0 34px;overflow:hidden}.metrics div{padding:18px 20px;display:flex;flex-direction:column;gap:5px}.metrics div+div{border-left:1px solid var(--line)}.metrics b{font-size:25px;letter-spacing:-.04em}.metrics span{font-size:11px;color:var(--muted);font-weight:650}.panel{display:none}.panel.active{display:block}.sectionhead{display:flex;justify-content:space-between;align-items:flex-end;gap:10px;margin:0 0 18px}.sectionhead h2{font-size:25px;margin:4px 0 0;letter-spacing:-.04em}.subtleBtn{border:0;background:transparent;color:var(--teal);padding:8px;font-weight:700;font-size:13px}.filters{display:grid;grid-template-columns:2fr 1.35fr 1.2fr;gap:10px;margin-bottom:19px}.filters label{display:flex;flex-direction:column;gap:7px;color:var(--muted);font-size:11px;font-weight:700}.filters select,.libcontrols input{width:100%;height:43px;background:var(--card);color:var(--ink);border:1px solid var(--line);border-radius:11px;padding:0 10px;min-width:0}.flashcard{border:1px solid var(--line);border-radius:19px;background:var(--card);box-shadow:var(--shadow);overflow:hidden}.cardtop{padding:22px 25px 4px;display:flex;align-items:center;justify-content:space-between;gap:8px}.pill{font-size:10px;padding:6px 9px;border-radius:30px;color:var(--teal);background:var(--teal-light);font-weight:800;letter-spacing:.03em}.bookmark{background:transparent;border:0;font-size:25px;color:var(--muted);line-height:1}.bookmark.saved{color:#b07b1c}.question{font-size:clamp(20px,4.5vw,27px);line-height:1.38;letter-spacing:-.025em;font-weight:700;margin:13px 26px 24px;min-height:88px}.source-meta{color:var(--muted);font-size:11px;margin:0 26px 20px}.revealArea{margin:0 17px 18px;padding:20px 18px;background:var(--bg);border:1px solid var(--line);border-radius:12px;min-height:90px;line-height:1.65;font-size:16px}.revealArea p{margin:0}.equationImage{width:auto;height:auto;max-width:100%;max-height:260px;object-fit:contain;display:block;background:#fff;border-radius:8px;padding:10px;margin:0 auto}.revealArea .equationImage{width:100%}.actionbar{display:flex;gap:9px;padding:0 17px 17px}.primaryBtn{border:0;background:var(--navy);color:white;font-weight:750;border-radius:11px;min-height:48px;padding:10px 16px;flex:1}.primaryBtn:disabled{opacity:.5}.secondaryBtn{border:1px solid var(--line);background:var(--card);color:var(--ink);border-radius:11px;font-weight:700;padding:13px 15px}.dangerBtn{background:transparent;border:1px solid var(--danger);color:var(--danger);border-radius:11px;padding:12px;font-weight:700}.gradebar{display:grid;grid-template-columns:repeat(4,1fr);gap:7px;padding:0 17px 17px}.gradebar button{min-height:49px;border-radius:11px;border:1px solid var(--line);background:var(--soft);color:var(--ink);font-weight:750;font-size:12px}.gradebar button small{display:block;color:var(--muted);font-weight:400;font-size:10px;margin-top:2px}.gradebar button:first-child{border-color:#ddaaa9}.gradebar button:last-child{border-color:var(--teal)}.microhint{color:var(--muted);font-size:11px;line-height:1.5;margin:13px 2px}.tag{background:var(--soft);color:var(--muted);padding:6px 9px;border-radius:20px;font-weight:700;font-size:11px}.libcontrols{margin-bottom:16px}.libcontrols input{height:49px;margin-bottom:12px;padding:0 14px}.libcontrols .filters{grid-template-columns:2fr 1fr}.library-list{display:grid;gap:9px}.libitem{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:14px 15px;display:flex;align-items:flex-start;gap:12px;text-align:left;width:100%;color:var(--ink)}.libitem h3{font-size:13px;margin:3px 0 4px;line-height:1.45}.libitem p{font-size:11px;color:var(--muted);margin:0}.libitem .arrow{margin-left:auto;color:var(--muted);font-size:20px}.library-list+.secondaryBtn{width:100%;margin-top:15px}.intro{font-size:13px;color:var(--muted);line-height:1.7;margin-top:0}.libicon{width:35px;height:35px;border-radius:9px;background:var(--soft);display:grid;place-items:center;font-size:13px;font-weight:850;flex:none}.statrow{display:flex;justify-content:space-between;align-items:center;padding:13px 0;border-bottom:1px solid var(--line);font-size:13px}.statrow b{font-variant-numeric:tabular-nums}.progressbox{padding:8px 21px;background:var(--card);border-radius:15px;border:1px solid var(--line)}.progressbar{height:10px;background:var(--soft);border-radius:20px;overflow:hidden;margin:8px 0}.progressbar>div{height:100%;background:var(--teal);width:0%;border-radius:20px;transition:width .2s}.smalltitle{font-size:15px;margin:28px 0 14px}.chapterstat{padding:11px 0}.chapterstat .titleline{display:flex;justify-content:space-between;font-size:12px;margin-bottom:7px}.chapterstat .titleline span:last-child{color:var(--muted)}.smallbar{height:7px;background:var(--soft);border-radius:7px;overflow:hidden}.smallbar div{height:100%;background:var(--teal)}.actions{display:flex;flex-wrap:wrap;gap:10px}.fileLabel{cursor:pointer}.details{margin-top:26px;border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:16px 0;font-size:13px;line-height:1.65}.details summary{cursor:pointer;font-weight:750}.details p{color:var(--muted)}.details code{font-size:12px}.sourceNote{color:var(--muted);font-size:11px;line-height:1.7;margin:22px 0}.empty{background:var(--card);border:1px dashed var(--line);padding:30px;border-radius:14px;text-align:center;color:var(--muted);font-size:13px}.tabbar{position:fixed;bottom:0;left:0;right:0;max-width:820px;margin:auto;display:grid;grid-template-columns:repeat(4,1fr);height:76px;padding-bottom:env(safe-area-inset-bottom);background:var(--card);border-top:1px solid var(--line);z-index:20;box-shadow:0 -10px 20px rgba(0,0,0,.03)}.tab{border:0;background:transparent;color:var(--muted);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:3px;font-size:23px}.tab span{font-size:10px;font-weight:750}.tab.active{color:var(--teal)}@media(max-width:570px){.shell{padding:0 15px 105px}.topbar{height:76px}.hero{padding:23px 22px;min-height:190px}.hero p{max-width:244px}.hero-orbit{position:absolute;right:-57px;top:30px;opacity:.4}.metrics div{padding:14px 12px}.metrics b{font-size:23px}.filters{grid-template-columns:1fr 1fr}.filters label:first-child{grid-column:span 2}.sectionhead h2{font-size:22px}.cardtop{padding:18px 19px 3px}.question{margin:12px 20px 20px}.source-meta{margin:0 20px 18px}.revealArea{padding:17px 13px}.gradebar{gap:5px}.gradebar button{font-size:11px}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{transition:none!important;animation:none!important}}

.sourceLink{color:var(--teal);font-weight:700;text-decoration:underline;text-underline-offset:3px}
/* Recall Lab v2 – overview, local typesetting, cross-device status */
.tabbar{grid-template-columns:repeat(3,1fr)}
.filters{grid-template-columns:1.6fr 1.15fr 1.2fr 1.2fr}
.overviewhead{display:flex;justify-content:space-between;align-items:end;gap:12px;margin:0 0 10px}.overviewhead>div{display:flex;flex-direction:column;gap:7px}.overview-help{font-size:11px;color:var(--muted)}
.overview-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px 12px;margin-bottom:30px}
.overviewtopic{border:1px solid var(--line);background:var(--card);color:var(--ink);border-radius:12px;padding:12px 13px;display:grid;grid-template-columns:1fr auto;text-align:left;gap:8px;font-size:11px;cursor:pointer}
.overviewtopic span:first-child{font-weight:700}.overviewtopic span:nth-child(2){font-variant-numeric:tabular-nums;color:var(--teal)}.overviewtopic .smallbar{grid-column:span 2;margin:0}
.overviewtopic:hover,.chapterstat:hover{border-color:var(--teal)}
.cardweight{display:flex;flex-wrap:wrap;align-items:center;gap:7px;margin:6px 24px 0;font-size:11px}
.importance{color:var(--teal);font-weight:750}.memorychip{color:var(--muted);border:1px solid var(--line);border-radius:30px;padding:3px 7px}
.priorityWhy{margin-top:14px;border-top:1px solid var(--line);padding-top:10px;font-size:12px;color:var(--muted)}.priorityWhy summary{cursor:pointer}
.chapterstat{width:100%;display:block;text-align:left;color:var(--ink);background:var(--card);border:1px solid var(--line);border-radius:11px;margin:0 0 9px;padding:13px 14px;cursor:pointer}
.chapterstat .titleline{gap:8px}.chapterstat .titleline span:first-child{font-weight:720}.chapterfooter{font-size:10px;color:var(--muted);margin-top:7px;display:flex;justify-content:space-between;gap:6px}
.smallbar.two{position:relative;height:9px}.smallbar.two .covered{height:100%;position:absolute;left:0;top:0;background:#95cfc6}.smallbar.two .mastered{height:100%;position:absolute;left:0;top:0;background:var(--teal)}
.syncbox{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:17px;display:flex;flex-direction:column;gap:10px}
.syncbox>label:first-child{font-size:12px;font-weight:750}.syncbox input[type=password]{border:1px solid var(--line);background:var(--bg);color:var(--ink);border-radius:9px;padding:12px;min-height:44px;width:100%}.rememberline{font-size:12px;display:flex;gap:8px;align-items:center;color:var(--muted)}.syncbuttons{display:flex;gap:9px}.syncbuttons .primaryBtn{flex:1}.syncStatus{font-size:12px;line-height:1.5;color:var(--muted);margin:0}.syncStatus[data-kind=success]{color:var(--teal)}.syncStatus[data-kind=error]{color:var(--danger)}.syncStatus[data-kind=warn]{color:var(--muted)}
.question mjx-container{max-width:100%;overflow-x:auto;overflow-y:hidden;vertical-align:middle}
.libtext{min-width:0;flex:1}.libtext h3 mjx-container{display:inline-block;vertical-align:middle;max-width:100%}
@media(max-width:570px){.filters{grid-template-columns:repeat(2,minmax(0,1fr))}.filters label:first-child{grid-column:auto}.overview-grid{grid-template-columns:1fr}.cardweight{margin:4px 20px 0}.question{min-height:72px}}
.overviewdetails{border:1px solid var(--line);background:var(--card);border-radius:12px;margin:0 0 26px}
.overviewdetails summary{list-style:none;cursor:pointer;padding:12px 16px;display:flex;justify-content:space-between;align-items:center;gap:14px}
.overviewdetails summary::-webkit-details-marker{display:none}
.overviewdetails summary>span:first-child{display:flex;flex-direction:column;gap:4px}.overviewdetails summary strong{font-size:12px}.overviewdetails summary small{font-size:11px;color:var(--muted)}
.overviewdetails[open] .overview-grid{padding:2px 12px 12px;margin:0}
