/* ---- board palette -------------------------------------------------------
   The site is one codebase serving two syllabuses, so the accent is a variable
   rather than a colour: AQA keeps its blue, Cambridge IGCSE runs in green, and
   everything that follows simply refers to the palette below.                */
:root{
  --brand:#174a7c;      --brand-lt:#1d6fb8;  --brand-dk:#173a5e;
  --brand-rgb:23,74,124; --brand-lt-rgb:29,111,184;
  --wash:#eef3f8; --chipbg:#e6f0fa; --btnwash:#e4eefa; --rowwash:#e2ecf6; --rim:#c9dcec;
  --brand-deep:#123c63; --brand-nav:#1d5285;
}
/* Cambridge IGCSE runs in green so the two syllabuses can never be mistaken for
   one another, even in a glance at the browser tab. */
body.board-cie{
  --brand:#2e7d32;      --brand-lt:#43a047;  --brand-dk:#1b5e20;
  --brand-rgb:46,125,50; --brand-lt-rgb:67,160,71;
  --wash:#f2f8f3; --chipbg:#e4f2e5; --btnwash:#dcefdc; --rowwash:#eaf5ea; --rim:#c5e0c9;
  --brand-deep:#145214; --brand-nav:#388e3c;
}
/* a few accents are laid on outside the variables: the gold brand mark stays
   gold, but the active chip and the hero headline follow the syllabus */
body.board-cie .bchip.active{background:var(--brand);border-color:var(--brand)}
body.board-cie .hero h1{color:var(--brand-deep)}
body.board-cie .navbtn.active{color:var(--brand-deep)}
body.board-cie .boardCard.active{border-color:var(--brand);box-shadow:0 0 0 3px var(--chipbg)}

*{margin:0;padding:0;box-sizing:border-box}
body{font-family:'Segoe UI','Microsoft YaHei',sans-serif;background:var(--wash);color:#1d2c3c}
.app{height:100vh;display:flex;flex-direction:column}
.topbar{display:flex;align-items:center;gap:18px;padding:10px 18px;background:var(--brand-deep);color:#fff}
.brand{font-size:17px;white-space:nowrap}
.brand b{color:#ffd166}
.search{flex:1;max-width:520px}
.search input{width:100%;padding:8px 14px;border-radius:22px;border:none;font-size:14px;outline:none}
.actions{display:flex;gap:8px}
.btn{border:none;border-radius:22px;padding:8px 16px;font-size:14px;cursor:pointer;font-family:inherit}
.btn.primary{background:#ffd166;color:#3d2c00}
.btn.primary:hover{background:#ffc233}
.btn.ghost{background:transparent;color:#cfe0f0;border:1px solid #4a7399}
.btn.green{background:#1e8e5a;color:#fff;padding:9px 20px;font-size:15px}
.btn.green:hover{background:#177a4c}
.btn.mini{background:var(--btnwash);color:var(--brand);padding:5px 12px;font-size:13px}
/* teachers only: "set this card as homework", sitting in the card's meta row */
.qmeta .btn.mini.fcAssign{padding:3px 10px;font-size:12px;white-space:nowrap;flex:0 0 auto}
.count{background:#b03a2e;color:#fff;border-radius:12px;padding:1px 8px;font-size:13px;margin-left:6px}
.layout{flex:1;display:flex;min-height:0}
.sidebar{width:260px;background:#fff;border-right:1px solid #d8e4ef;padding:14px;overflow:auto;flex-shrink:0}
.sidebar h3{font-size:14px;color:var(--brand);margin-bottom:8px}
.checklist{display:flex;flex-direction:column;gap:4px}
.checklist label{font-size:14px;display:flex;align-items:center;gap:7px;padding:4px 6px;border-radius:8px;cursor:pointer;color:#3c5570}
.checklist label:hover{background:#f0f6fc}
.checklist input{accent-color:var(--brand-lt)}
.checklist .n{margin-left:auto;font-size:12px;color:#93a7b8;background:var(--wash);padding:0 7px;border-radius:8px}
.topicRow.topic{font-weight:600;color:var(--brand)}
.filterRow{display:flex;gap:6px;margin-bottom:6px}
.filterRow select{flex:1;min-width:0;padding:5px 6px;border:1px solid #d8e4ef;border-radius:8px;font-size:13px;color:#2c4258;background:#fff;outline:none;font-family:inherit}
.filterBtns{display:flex;align-items:center;gap:8px;margin-bottom:6px}
.filterBtns button{border:none;border-radius:8px;padding:4px 12px;font-size:13px;cursor:pointer;background:var(--btnwash);color:var(--brand);font-family:inherit}
.filterBtns button:hover{background:#d3e3f7}
.hint{font-size:12px;color:#93a7b8;margin-left:auto}
.pages{flex:1;overflow-y:auto;padding:14px 18px;min-width:0}
.viewbar{display:flex;align-items:center;gap:12px;margin-bottom:12px;color:#5a7186;font-size:14px}
.spacer{flex:1}
.pagegrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px}
.card{background:#fff;border:1px solid #d8e4ef;border-radius:16px;padding:10px;box-shadow:0 3px 10px -6px rgba(var(--brand-rgb),.25);display:flex;flex-direction:column;gap:8px;transition:transform .15s}
.card:hover{transform:translateY(-2px)}
.card .thwrap{position:relative}
.card img{width:100%;height:180px;object-fit:contain;background:#f8fbfe;border-radius:8px;border:1px solid #edf2f7;cursor:zoom-in}
.card .add{position:absolute;right:8px;top:8px;background:var(--brand-lt);color:#fff;border:none;border-radius:50%;width:34px;height:34px;font-size:20px;cursor:pointer;opacity:.92}
.card .add:hover{background:#0f5f9e}
.card .meta{display:flex;flex-wrap:wrap;gap:6px;font-size:12px}
.chip{background:var(--chipbg);color:var(--brand);padding:2px 8px;border-radius:12px;font-weight:600}
.chip.ms{background:#fdeeee;color:#a13}
.chip.qp{background:#e3f5ea;color:#175c33}
.chip.topic{background:#fff3df;color:#8a5a00}
.card .txt{font-size:13px;color:#3c5570;line-height:1.45;max-height:52px;overflow:hidden}
.card .src{font-size:12px;color:#8ba0b3}
.mask{position:fixed;inset:0;background:rgba(10,25,45,.45);display:none;z-index:60}
.mask.show{display:flex;align-items:center;justify-content:center}
.cartPanel{background:#fff;width:min(960px,94vw);height:88vh;border-radius:16px;padding:16px 20px;display:flex;flex-direction:column;overflow:hidden}
.cartPanel .close,.detailPanel .close{position:absolute;right:14px;top:10px;border:none;background:var(--btnwash);color:var(--brand);font-size:22px;width:34px;height:34px;border-radius:50%;cursor:pointer}
.cartHead{display:flex;align-items:center;gap:12px;margin-bottom:12px;position:relative}
.cartHead h2{font-size:20px;color:var(--brand)}
.cartHead small{color:#5a7186;font-weight:400}
.cartOpts{display:flex;flex-wrap:wrap;gap:12px;align-items:center;padding:10px 14px;background:var(--wash);border-radius:12px;margin-bottom:12px}
.cartOpts label{display:flex;align-items:center;gap:8px;font-size:14px;color:#3c5570}
.cartOpts input[type=text]{width:280px;padding:6px 10px;border:1px solid var(--rim);border-radius:8px;font-size:14px}
.cartOpts .chk{width:auto}
.expBtns{display:flex;gap:8px;align-items:center}
#expMsg{font-size:13px;color:#1e8e5a}
.cartList{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:8px}
.cartItem{display:flex;align-items:center;gap:10px;background:#f8fbfe;border:1px solid var(--rowwash);border-radius:12px;padding:8px 12px}
.cartItem .thumb{width:52px;height:60px;object-fit:cover;border-radius:6px}
.cartItem .info{flex:1;font-size:14px;color:#3c5570;min-width:0}
.cartItem .info b{color:var(--brand);display:block;font-size:13px}
.cartItem .act{display:flex;gap:4px}
.cartItem .act button{border:none;background:var(--btnwash);color:var(--brand);width:28px;height:28px;border-radius:8px;cursor:pointer;font-size:15px}
.cartItem .act button.del{background:#fdeeee;color:#b03a2e}
.cartEmpty{color:#93a7b8;text-align:center;padding:40px}
.detailPanel{position:relative;background:#fff;width:min(880px,94vw);max-height:92vh;border-radius:16px;padding:22px;overflow-y:auto}
.detailPanel img{max-width:100%}
.detailHead{color:var(--brand);margin-bottom:8px}
.detailText{background:#f8fbfe;border:1px solid #edf2f7;border-radius:12px;padding:14px;white-space:pre-wrap;font-size:14px;line-height:1.7;color:#2a3d52;max-height:300px;overflow:auto;margin-bottom:14px}
.ansHint{font-size:13px;color:#1e8e5a;margin-top:10px}
.pagination{display:flex;justify-content:center;align-items:center;gap:12px;padding:16px}
.pagination button{background:#fff;border:1px solid var(--rim);color:var(--brand);padding:6px 16px;border-radius:12px;cursor:pointer;font-size:13px}
.pagination button:disabled{color:#bcccdc;cursor:not-allowed}
.pagination span{font-size:13px;color:#5a7186}
.chip.mcq{background:#e3f5ea;color:#175c33}
.chip.big{background:var(--chipbg);color:var(--brand)}
.sidebar .year{font-size:12px;color:#8ba0b3;margin:10px 0 4px;font-weight:700}
.segList{display:flex;flex-direction:column;gap:10px;margin:12px 0}
.segList img{width:100%;border:1px solid #d8e4ef;border-radius:12px;background:#fff}
@media (max-width:900px){.sidebar{display:none}.pagegrid{grid-template-columns:1fr}}

/* ---- question filters (difficulty / question type) ---- */
.sideLbl{display:flex;flex-direction:column;gap:4px;font-size:12px;color:#7b90a3;margin:6px 0 2px}
.sideLbl select{width:100%;padding:6px;border:1px solid #d8e4ef;border-radius:8px;font-size:13px;color:#2c4258;background:#fff;outline:none;font-family:inherit;cursor:pointer}
.chip.q{background:var(--chipbg);color:var(--brand)}
.chip.s-mcq{background:#e3f5ea;color:#175c33}
.chip.s-explain{background:#f1e3ff;color:#6b21a8}
.chip.s-other{background:var(--wash);color:#5a7186}
.chip.d-easy{background:#e3f5ea;color:#175c33}
.chip.d-medium{background:#fff3df;color:#8a5a00}
.chip.d-hard{background:#fdeeee;color:#b03a2e}

/* ================= app shell / navigation ================= */
.brand{cursor:pointer}
.mainNav{display:flex;gap:4px;margin-left:10px}
.navbtn{border:none;background:transparent;color:#d7e6f5;padding:7px 14px;border-radius:16px;font-size:14px;cursor:pointer;font-family:inherit}
.navbtn:hover{background:var(--brand-nav)}
.navbtn.active{background:#fff;color:var(--brand-deep);font-weight:600}
.topbar .search{display:none;margin-left:16px}
.actions{margin-left:auto}
body[data-view="bank"] .topbar .search{display:block}
/* "Make my own cards" is a long label — keep it on one line and tighten the bar
   so the navigation still fits on a laptop screen */
.actions .btn{white-space:nowrap}
@media (max-width:1320px){
  .topbar{gap:10px;padding:10px 12px}
  .boardSwitch{margin-left:0}
  .bchip{padding:7px 9px}
  .navbtn{padding:7px 10px}
}

.view{display:none;flex:1;min-height:0;overflow-y:auto}
.view.active{display:flex;flex-direction:column}
#viewBank.active{overflow:hidden}

/* ================= home ================= */
.pageWrap{width:100%;max-width:1060px;margin:0 auto;padding:30px 22px}
.hero{text-align:center;padding-top:16px}
.hero h1{font-size:32px;color:var(--brand-deep);letter-spacing:.3px}
.hero p{max-width:640px;margin:12px auto 0;color:#5a7186;font-size:16px;line-height:1.7}

/* board (syllabus) picker */
.boards{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:18px;margin-top:28px}
.boardCard{position:relative;background:linear-gradient(160deg,#1876a8,var(--brand-deep));color:#fff;border-radius:16px;padding:24px 22px 22px;cursor:pointer;box-shadow:0 14px 30px -20px rgba(18,60,99,.8);transition:transform .15s,box-shadow .15s}
.boardCard:hover{transform:translateY(-4px);box-shadow:0 20px 38px -18px rgba(18,60,99,.9)}
.boardCard.active{outline:3px solid #ffce4d;outline-offset:2px}
.boardCard h3{font-size:19px;margin:0 0 8px;letter-spacing:.2px}
.boardCard p{font-size:14px;line-height:1.65;color:#d7e6f2;margin:0 0 14px}
.boardCard .mlink{font-weight:700;font-size:14px}
.bTag{position:absolute;top:16px;right:18px;font-size:12px;font-weight:800;letter-spacing:.5px;background:rgba(255,255,255,.18);border-radius:22px;padding:4px 10px}
.boardSwitch{display:flex;gap:6px;margin-left:6px}
.bchip{border:1px solid #d3e3f0;background:#fff;color:#37536b;font-size:13px;font-weight:700;padding:7px 12px;border-radius:22px;cursor:pointer;transition:all .15s}
.bchip:hover{border-color:#1876a8;color:#1876a8}
.bchip.active{background:#1876a8;border-color:#1876a8;color:#fff}
.modules{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:22px;margin-top:36px}
.module{background:#fff;border:1px solid var(--rowwash);border-radius:16px;padding:26px 24px;box-shadow:0 10px 26px -18px rgba(18,60,99,.5);cursor:pointer;display:flex;flex-direction:column;gap:10px;transition:transform .15s,box-shadow .15s}
.module:hover{transform:translateY(-4px);box-shadow:0 18px 34px -18px rgba(18,60,99,.6)}
.micon{width:54px;height:54px;border-radius:16px;color:#fff;font-weight:800;display:flex;align-items:center;justify-content:center;font-size:15px;letter-spacing:.5px}
.micon.fc{background:#6b21a8}
.micon.pp{background:#b03a2e}
.micon.pb{background:var(--brand)}
.micon.kt{background:#0f766e}
.module h3{font-size:19px;color:var(--brand);margin-top:6px}
.module p{flex:1;font-size:14px;color:#46617a;line-height:1.65}
.mlink{color:var(--brand-lt);font-weight:600;font-size:14px}

/* ================= flash & cloze ================= */
.fbar{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:14px}
.ftabs{display:flex;background:#dce8f4;border-radius:22px;padding:3px}
.ftabs .tab{border:none;background:transparent;padding:7px 16px;border-radius:22px;cursor:pointer;font-size:14px;color:#345a7e;font-family:inherit}
.ftabs .tab.active{background:var(--brand);color:#fff}
.fbar select{padding:6px 10px;border:1px solid #d8e4ef;border-radius:8px;font-size:13px;color:#2c4258;background:#fff;outline:none;font-family:inherit}
.fbar input[type=search]{padding:6px 10px;border:1px solid #d8e4ef;border-radius:8px;font-size:13px;color:#2c4258;background:#fff;outline:none;font-family:inherit;min-width:180px}
.fbar input[type=search]:focus{border-color:var(--brand-lt);box-shadow:0 0 0 3px rgba(46,110,168,.12)}
.qtext mark,.ansblock mark,.qmeta mark{background:#ffe9a8;color:inherit;border-radius:3px;padding:0 1px}
.fprog{font-size:13px;color:#5a7186;white-space:nowrap}
.defCard{background:#fff;border:1px solid var(--rowwash);border-radius:16px;padding:26px 28px;box-shadow:0 10px 24px -20px rgba(18,60,99,.4)}
.qmeta{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-bottom:14px;color:#5a7186;font-size:13px}
.qtext{font-size:18px;color:#1d2c3c;line-height:1.7;white-space:pre-wrap}
.qimg{margin-top:14px}
.qimg img{max-width:100%;max-height:340px;border:1px solid #e3ecf5;border-radius:12px;background:#fff}
.ansblock{margin-top:18px;border-top:2px dashed #e0eaf4;padding-top:16px;white-space:pre-wrap;line-height:1.75;font-size:16px;color:#175c33;background:#f3faf6;border-radius:0 0 10px 10px}
.ansblock b.anscap{display:block;color:#1e8e5a;font-size:13px;letter-spacing:.4px;margin-bottom:6px}
.fnav{display:flex;align-items:center;gap:12px;margin-top:18px;flex-wrap:wrap}
.fnav .spacer{flex:1}
.btn.navdark{background:var(--btnwash);color:var(--brand)}
.btn.navdark:hover{background:#cbdcee}
.btn.small{font-size:13px;padding:7px 13px}
.btn.gapbtn{background:var(--brand-lt);color:#fff}
.btn.gapbtn:hover{background:#175d9c}
.clozeBar{display:flex;align-items:center;gap:14px;flex-wrap:wrap;background:#fff;border:1px solid var(--rowwash);padding:10px 18px;border-radius:12px;margin-bottom:14px}
.clozeTip{font-size:14px;color:#5a7186}
.clozeBar label{display:flex;align-items:center;gap:6px;font-size:14px;color:#345a7e}
.clozeBar select{padding:4px 8px;border:1px solid #d8e4ef;border-radius:8px;font-family:inherit;background:#fff;color:#2c4258}
.blank{display:inline-block;vertical-align:middle;min-width:0;max-width:100%;padding:3px 8px;margin:0;border:1px dashed var(--brand-lt);border-radius:8px;font-family:inherit;font-size:16px;color:var(--brand-deep);background:#fbfdff}
.blank:focus{outline:2px solid #bcd8f2;border-color:var(--brand-lt)}
.blank.correct{border-style:solid;border-color:#1e8e5a;background:#e3f5ea;color:#175c33}
.blank.wrong{border-style:solid;border-color:#b03a2e;background:#fdeeee;color:#b03a2e}
.bwrap{position:relative;display:inline-block;vertical-align:middle;margin:0 2px}
.bwrap .blank{margin:0}
.tick{position:absolute;right:-7px;top:-9px;width:17px;height:17px;border-radius:50%;background:#1e8e5a;color:#fff;font-size:12px;font-weight:700;line-height:17px;text-align:center;box-shadow:0 1px 4px rgba(30,142,90,.45);opacity:0;transform:scale(.3);transition:opacity .15s,transform .15s;pointer-events:none}
.tick.show{opacity:1;transform:scale(1)}
.cmsg{font-size:14px;font-weight:600;color:#1e8e5a;min-width:130px;text-align:center}
.cmsg.bad{color:#b03a2e}
.cmsg.neutral{color:#5a7186}

/* ================= past papers ================= */
.phead{display:flex;align-items:flex-end;justify-content:space-between;gap:14px;flex-wrap:wrap}
.phead h2{font-size:22px;color:var(--brand)}
.phead small{display:block;font-size:13px;color:#5a7186;font-weight:400;margin-top:4px}
.kinds{display:flex;gap:6px}
.kbtn{border:1px solid var(--rim);background:#fff;color:#345a7e;padding:6px 14px;border-radius:16px;cursor:pointer;font-size:13px;font-family:inherit}
.kbtn.active{background:var(--brand);border-color:var(--brand);color:#fff}
.papersList{display:flex;flex-direction:column;gap:16px;margin-top:18px}
.yearCard{background:#fff;border:1px solid var(--rowwash);border-radius:16px;overflow:hidden}
.yhead{display:flex;align-items:center;gap:14px;padding:12px 18px;background:var(--wash);border-bottom:1px solid var(--rowwash)}
.yhead b{font-size:18px;color:var(--brand)}
.ycnt{font-size:13px;color:#5a7186}
.yhead .btn{margin-left:auto}
.prow{display:flex;align-items:center;gap:12px;padding:10px 18px;border-bottom:1px solid #f0f5fa;flex-wrap:wrap}
.prow:last-child{border-bottom:none}
.prow .pname{flex:1;min-width:200px;font-size:14px;color:#2a3d52}
.prow a.btn{text-decoration:none}
.hidden{display:none}

@media (max-width:760px){
  .topbar{gap:8px;padding:8px 10px;flex-wrap:wrap}
  .mainNav{order:5;width:100%;overflow-x:auto;margin-left:0}
  .brand{font-size:15px}
  .viewbar,.fbar{flex-wrap:wrap}
}

a.btn{text-decoration:none}
.btn.small,.btn.mini{display:inline-flex;align-items:center;justify-content:center;line-height:1.2}

/* ---- collapsible year groups ---- */
.yearRow{display:flex;align-items:center;gap:8px;padding:6px 8px;border-radius:8px;background:var(--wash);color:var(--brand);font-weight:600;font-size:14px;cursor:pointer;user-select:none;margin:2px 0}
.yearRow:hover{background:var(--rowwash)}
.yearRow .chev,.yhead .chev{font-size:12px;color:#5a7186;transition:transform .15s;display:inline-block;flex-shrink:0}
.yearRow.open .chev,.yhead.open .chev{transform:rotate(90deg)}
.yearRow .ygSel{margin-left:auto;font-size:12px;font-weight:600;color:#5a7186;background:#fff;border:1px solid var(--rowwash);border-radius:8px;padding:1px 8px}
.checklist .pl{padding-left:14px}
.yhead{cursor:pointer;user-select:none;transition:background .15s}
.yhead:hover{background:#eaf3fb}

/* ---- nested Year > session > paper/file tree (builder + past papers) ---- */
.subHint{display:inline;font-size:12px;color:#8ba0b3;font-weight:400;margin-left:6px}
.trow{display:flex;align-items:center;gap:8px;padding:6px 8px;border-radius:8px;cursor:pointer;font-size:13px;color:#33506b;min-width:0}
.trow:hover{background:#eef4fa}
.trow .chev{flex:0 0 13px;width:13px;height:13px;color:#7c91a5;font-size:12px;display:inline-block;text-align:center;line-height:13px;transition:transform .15s}
.trow.open>.chev{transform:rotate(90deg)}
.trow label.tick{margin:0;padding:0;display:inline-flex;align-items:center;background:none;border:none;border-radius:0;cursor:pointer;color:inherit;font-size:inherit}
.trow label.tick:hover{background:none}
.trow input[type=checkbox]{width:15px;height:15px;margin:0;cursor:pointer;accent-color:var(--brand-lt)}
.trow .tn{flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.trow .tcnt{flex-shrink:0;font-size:12px;color:#5a7186;background:#fff;border:1px solid var(--rowwash);border-radius:8px;padding:0 8px;font-weight:600}
.trow .chip{flex-shrink:0;font-size:12px;padding:1px 7px}
.trow a.btn{text-decoration:none;flex-shrink:0}
.trow a.btn.small,.trow a.btn.mini{background:var(--btnwash);color:var(--brand);border-radius:16px}
.trow a.btn.small:hover,.trow a.btn.mini:hover{background:#d3e3f7}
.sub{margin:2px 0 6px 15px;padding:2px 0 2px 9px;border-left:1px dashed #d5e1ec;display:flex;flex-direction:column;gap:1px}
.sub .sub{margin-left:8px}
.papersList .yearCard>.trow.y{padding:11px 16px;gap:10px;border-radius:0}
.trow.y{background:var(--wash);font-weight:600;color:var(--brand);margin:0}
.trow.y .tn{font-size:14px}
.trow.s{color:#2c5d8f;font-weight:600}
.trow.p{cursor:default}
.trow.p:hover{background:#f6fafe}
.trow.p .tn{font-size:13px;color:#3c5570}
.trow.g{background:var(--brand);color:#fff;font-weight:700;border-radius:12px}
.trow.g .tn{color:#fff;font-size:15px}
.trow.g .chev{color:#cfe3f7}
.trow.g label.tick input{accent-color:var(--brand)}
.specBody .yearCard{margin:2px 0 8px}
.specBody .yearCard>.trow.y{border-radius:12px}
.btn.disabled{opacity:.5;pointer-events:none}

/* past-papers toolbar */
.ppbar{display:flex;align-items:center;gap:8px;margin-top:16px;padding:8px 14px;background:var(--wash);border:1px solid var(--rowwash);border-radius:12px}
.ppbar .ppInfo{font-size:13px;color:#345a7e;font-weight:600}
.ppbar .mini{border:none;border-radius:8px;padding:5px 12px;font-size:13px;cursor:pointer;background:var(--btnwash);color:var(--brand);font-family:inherit}
.ppbar .mini:hover{background:#d3e3f7}

/* ===== simulations ===== */
.simsWrap{max-width:1000px;margin:0 auto;padding:30px 22px 60px}
.simGroups{display:flex;flex-direction:column;gap:34px}
.simGroup h3{font-size:19px;color:var(--brand);margin-bottom:14px;padding-bottom:8px;border-bottom:2px solid var(--rowwash);text-transform:uppercase;letter-spacing:.5px}
.simGrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(215px,1fr));gap:14px}
.simCard{position:relative;background:#fff;border:1px solid #dde7f1;border-radius:12px;padding:12px;cursor:pointer;transition:.15s;display:flex;flex-direction:column;gap:10px}
.simCard:hover{border-color:var(--brand-lt);box-shadow:0 6px 18px rgba(var(--brand-lt-rgb),.15);transform:translateY(-2px)}
.simPreview{position:relative;width:100%;height:140px;border-radius:8px;overflow:hidden;background:#f0f6fc;border:1px solid var(--rowwash);display:block}
.simPreview .ph{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;color:#8aa3bb;font-size:12px}
.simPreview iframe.pv{width:100%;height:100%;border:0;pointer-events:none;display:block}
.simMeta{display:flex;flex-direction:column;gap:8px}
.simName{font-size:15px;font-weight:600;color:#2a4258;line-height:1.4}
.simPlay{align-self:flex-start;display:inline-flex;align-items:center;gap:6px;background:var(--btnwash);color:var(--brand);border-radius:16px;padding:4px 12px;font-size:13px}
.simStage{background:#fff;border:1px solid #dde7f1;border-radius:16px;overflow:hidden;box-shadow:0 8px 24px rgba(var(--brand-lt-rgb),.08)}
.simToolbar{display:flex;align-items:center;gap:12px;padding:10px 16px;background:var(--wash);border-bottom:1px solid #e6eef7}
.simToolbar .navdark{background:var(--brand-deep);color:#fff}
.simToolbar .navdark:hover{background:#1d5a94}
.simTitle{font-size:16px;font-weight:700;color:var(--brand);flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
#simFrame{width:100%;height:74vh;min-height:520px;border:0;display:block;background:#fff;transition:opacity .2s}
#simFrame.loading{opacity:.35}

/* ===== account + progress (login system) ===== */
#btnAcct{background:var(--btnwash);color:var(--brand);border-radius:22px}
#btnAcct.logged{background:#ffd166;color:#3d2c00}

.authPanel,.progPanel{background:#fff;width:min(430px,94vw);border-radius:16px;padding:18px 22px;position:relative;box-shadow:0 18px 50px rgba(10,25,45,.35)}
.authHead,.progHead{display:flex;align-items:center;gap:10px;position:relative}
.authHead h2,.progHead h2{font-size:20px;color:var(--brand);flex:1}
.authHead small,.progHead small{color:#5a7186;font-weight:400;font-size:13px}
.authPanel .close,.progPanel .close{position:static;margin-left:auto;background:var(--btnwash);color:var(--brand);border:none;font-size:20px;width:32px;height:32px;border-radius:50%;cursor:pointer;flex-shrink:0}
.authPanel .close:hover,.progPanel .close:hover{background:#d3e3f7}
.authPanel label{display:block;margin:14px 0 0;font-size:13px;color:#5a7186;font-weight:600}
.authPanel input{display:block;width:100%;margin-top:5px;padding:9px 12px;border:1px solid #ccdcec;border-radius:12px;font-size:15px;box-sizing:border-box;font-family:inherit}
.authPanel input:focus{outline:none;border-color:var(--brand-lt);box-shadow:0 0 0 3px rgba(var(--brand-lt-rgb),.12)}
.authTabs{display:flex;gap:8px;margin:14px 0 2px}
.authTabs .tab{border:none;background:var(--wash);padding:6px 14px;border-radius:16px;cursor:pointer;font-size:13px;color:#345a7e;font-family:inherit}
.authTabs .tab.active{background:var(--brand);color:#fff}
.authMsg{min-height:18px;font-size:13px;color:#b03a2e;margin:8px 0 2px;line-height:1.3}
.btn.wide{width:100%;margin-top:6px;padding:10px 0;font-size:15px;border:none;border-radius:12px;cursor:pointer}
.authHint{font-size:12px;color:#5a7186;margin:12px 0 0;line-height:1.5}
.authHint a{color:var(--brand-lt);cursor:pointer;text-decoration:underline}
.authHint b{color:#2a4258}
.authMsg.ok{color:#1c7c4a}
.pwSection{font-size:13px;font-weight:700;color:var(--brand);margin:20px 0 0}
.progHead .btn.ghost{font-size:13px;padding:5px 12px;margin-left:auto;color:var(--brand);border-color:#b9cee3}
.progHead .btn.ghost:hover{background:#eef4fa}
.progHead .close{margin-left:0}

.cardActs{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin-top:14px;padding-top:12px;border-top:1px dashed var(--rowwash)}
.cardActs .actLabel{font-size:13px;color:#5a7186;font-weight:700;margin-right:2px}
.progBtn{border:none;border-radius:16px;padding:6px 12px;font-size:13px;cursor:pointer;font-family:inherit;background:var(--wash);color:#3c5570;display:inline-flex;align-items:center;gap:5px}
.progBtn:hover{background:var(--rowwash)}
.progBtn.on{background:#fff3df;color:#8a5a00;font-weight:700}
.progBtn.on.known{background:#e3f5ea;color:#175c33}
.progBtn.on.unknown{background:#fdeeee;color:#b03a2e}
.progBtn.on.fav{background:#ffd166;color:#3d2c00}
.progBtn:disabled{opacity:.5;cursor:not-allowed}
#fActs:empty,#cActs:empty{display:none}

.progPanel{width:min(760px,96vw);max-height:88vh;display:flex;flex-direction:column}
.progHead{position:relative}
.progBody{overflow:auto;margin-top:12px;padding-right:4px}
.progSummary{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:14px}
.sumCard{background:var(--wash);border:1px solid var(--rowwash);border-radius:12px;padding:10px 14px;flex:1;min-width:150px}
.sumCard .sumN{font-size:20px;font-weight:800;color:var(--brand)}
.sumCard .sumL{font-size:12px;color:#5a7186;margin-top:2px}
.sumCard.fav .sumN{color:#b8750a}
.sumCard.own .sumN{color:#6b21a8}          /* cards the pupil made themselves */
.progRowAdd{background:var(--wash)}
.progRowAdd:hover{background:#f5eaff;border-color:#9a4fd0}
.chip.own{background:#f1e3ff;color:#6b21a8}
.progDeck{margin:6px 0 14px}
.progDeck h3{font-size:15px;color:var(--brand);margin-bottom:8px;display:flex;align-items:center;gap:8px}
.progDeck .deckCnt{font-size:12px;color:#5a7186;font-weight:600;background:var(--wash);border-radius:8px;padding:2px 8px}
.progRow{display:flex;align-items:center;gap:8px;padding:7px 10px;border-radius:12px;background:#fff;border:1px solid #e7eef6;margin-bottom:6px;font-size:13px;cursor:pointer}
.progRow:hover{background:var(--wash);border-color:var(--brand-lt)}
.progRow .src{font-weight:700;color:#2a4258;white-space:nowrap}
.progRow .topic{color:#5a7186;flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:13px}
.progRow .tags{display:flex;gap:5px;flex-shrink:0}
.progRow .tags .chip{padding:1px 8px;font-size:12px}
.progRow .tags .favchip{background:#fff3df;color:#8a5a00}
.progRow .tags .kchip{background:#e3f5ea;color:#175c33}
.progRow .tags .uchip{background:#fdeeee;color:#b03a2e}
.progEmpty{color:#7c91a5;font-size:13px;text-align:center;padding:26px 10px}
.progEmpty b{color:#2a4258}
.progActBtns{display:flex;gap:8px;margin-top:14px;border-top:1px solid #e7eef6;padding-top:12px}
.progActBtns .btn{background:var(--btnwash);color:var(--brand);border:none;border-radius:12px;padding:8px 14px;cursor:pointer;font-size:13px;font-family:inherit}
.progActBtns .btn:hover{background:#d3e3f7}
.logoutBtn{background:#fdeeee;color:#b03a2e!important}
#progUser{color:#8ba0b3}

/* ==================== classroom (teacher / student / homework) ==================== */
.clsPanel{background:#fff;width:min(720px,96vw);max-height:88vh;border-radius:16px;padding:18px 22px;position:relative;box-shadow:0 18px 50px rgba(10,25,45,.35);display:flex;flex-direction:column;overflow:hidden}
.clsTabs{display:flex;gap:8px;margin:12px 0 4px;flex-wrap:wrap}
.clsTab{border:none;background:var(--wash);padding:6px 14px;border-radius:16px;cursor:pointer;font-size:13px;color:#345a7e;font-family:inherit}
.clsTab.active{background:var(--brand);color:#fff}
.clsCount{background:#b03a2e;color:#fff;border-radius:12px;padding:1px 7px;font-size:12px;margin-left:6px}
.clsCount.ghost{background:var(--btnwash);color:var(--brand)}
.clsBody{overflow:auto;margin-top:8px;padding-right:4px;flex:1}
.clsFootMsg{margin:6px 0 0}
.clsSection{font-size:14px;color:var(--brand);margin:16px 0 8px}
.clsRow{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:12px;background:#fff;border:1px solid #e7eef6;margin-bottom:6px;font-size:13px}
.clsRow.gap{gap:14px;border:none;background:transparent;padding:4px 0;flex-wrap:wrap}
.clsRowName{font-weight:700;color:#2a4258}
.clsRowMeta{color:#8ba0b3;font-size:12px;flex:1}
.clsItem{border:1px solid #e7eef6;border-radius:12px;padding:12px 14px;margin-bottom:10px;background:#fff}
.clsItem.unread{border-color:#ffd166;background:#fffdf6}
.chip.new{background:#ffd166;color:#7a4b00;font-weight:700}
/* the two account buttons in the top bar: My progress, and My teacher / My class */
.btn.logged,.btn.clsTop{background:var(--wash);box-shadow:inset 0 0 0 1.5px var(--brand);
    color:var(--brand);font-weight:600}
.btn.logged:hover,.btn.clsTop:hover{background:var(--brand);color:#fff;box-shadow:none}
.btn.clsTop.hasNew{background:var(--brand);color:#fff;box-shadow:none}
.clsDot{display:inline-block;min-width:17px;height:17px;line-height:17px;border-radius:9px;
    background:#d93025;color:#fff;font-size:11px;font-weight:700;padding:0 5px;margin-left:6px;
    vertical-align:middle;text-align:center}
/* the "you have new homework" card that lands on the pupil's screen */
.clsAlert{position:fixed;right:18px;bottom:18px;z-index:1200;width:300px;
    max-width:calc(100vw - 36px);background:#fff;border:1px solid var(--rim);
    border-left:4px solid var(--brand);border-radius:12px;
    box-shadow:0 10px 28px rgba(0,0,0,.18);padding:12px 14px}
.clsAlertT{font-weight:600;font-size:14px;margin-bottom:4px}
.clsAlertS{font-size:13px;color:#5a6b7d;margin-bottom:10px;line-height:1.35}
.clsItemTop{display:flex;align-items:flex-start;gap:10px;flex-wrap:wrap}
.clsItemTitle{font-size:15px;font-weight:700;color:var(--brand);flex:1;min-width:0}
.clsFrom{font-size:12px;color:#8ba0b3}
.clsDue{font-size:12px;color:#8a5a00;background:#fff3df;border-radius:8px;padding:1px 7px}
.clsNote{font-size:13px;color:#3c5570;background:var(--wash);border-radius:8px;padding:8px 10px;margin:8px 0;white-space:pre-wrap}
.clsMeta{font-size:12px;color:#5a7186}
.clsBar{height:6px;background:var(--wash);border-radius:6px;overflow:hidden;margin:8px 0 4px}
.clsBar.mini{width:120px;margin:0 0 0 auto}
.clsBar i{display:block;height:100%;background:#1e8e5a;border-radius:6px}
.clsBtns{display:flex;gap:8px;flex-wrap:wrap;align-items:center;margin-top:10px}
.clsBtns.wide{margin-top:14px}
.clsSearch{display:flex;gap:8px;margin:6px 0 10px}
.clsSearch input{flex:1;padding:8px 12px;border:1px solid #ccdcec;border-radius:12px;font-size:14px;font-family:inherit}
.clsSearch input:focus{outline:none;border-color:var(--brand-lt)}
.clsFiles{display:flex;flex-wrap:wrap;gap:6px;margin-top:8px}
.clsFile{display:inline-flex;align-items:center;gap:6px;font-size:13px;color:var(--brand);background:var(--chipbg);border-radius:16px;padding:4px 10px;text-decoration:none}
.clsFile:hover{background:#d3e3f7}
.clsFile small{color:#5a7186}
.clsForm{display:flex;flex-direction:column}
.clsForm label{display:block;margin:12px 0 0;font-size:13px;color:#5a7186;font-weight:600}
.clsForm input[type=text],.clsForm textarea,.clsForm input[type=date],.clsForm input[type=file],.clsForm select{margin-top:5px;padding:9px 12px;border:1px solid #ccdcec;border-radius:12px;font-size:15px;font-family:inherit;width:100%;box-sizing:border-box;background:#fff;color:#2c4258}
.clsForm input:focus,.clsForm textarea:focus,.clsForm select:focus{outline:none;border-color:var(--brand-lt);box-shadow:0 0 0 3px rgba(var(--brand-lt-rgb),.12)}
.clsPickWrap{border:1px solid var(--rowwash);border-radius:12px;margin-top:12px;background:#fbfdff}
.clsPickBar{display:flex;align-items:center;gap:10px;padding:8px 12px;background:var(--wash);border-radius:12px 12px 0 0;flex-wrap:wrap}
.clsPickBar select{padding:5px 8px;border:1px solid #d8e4ef;border-radius:8px;font-family:inherit;color:#2c4258}
.clsPickList{max-height:280px;overflow:auto;padding:6px 10px 10px}
.clsGroupHead{display:flex;align-items:center;gap:8px;font-size:13px;font-weight:700;color:var(--brand);padding:6px 8px;border-radius:8px;cursor:pointer;background:var(--wash);margin:6px 0 4px}
.clsGroupHead.on{background:#e3f5ea;color:#175c33}
.clsGroupHead small{font-weight:600;color:#5a7186}
.clsPickCard{display:flex;align-items:center;gap:8px;padding:4px 8px;border-radius:8px;cursor:pointer}
.clsPickCard:hover{background:#f0f6fc}
.clsPickCard.on{background:#f3faf6}
.clsPickCard input{accent-color:var(--brand-lt);flex-shrink:0}
.clsPickNo{font-size:12px;color:#8ba0b3;min-width:26px}
.clsPickQ{font-size:13px;color:#3c5570;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.clsStudents{display:flex;flex-wrap:wrap;gap:8px;margin-top:6px}
.clsStudentBox{display:inline-flex;align-items:center;gap:6px;font-size:13px;color:#3c5570;background:#fff;border:1px solid #d8e4ef;border-radius:16px;padding:5px 12px;cursor:pointer}
.clsStudentBox.on{background:#ffd166;border-color:#ffd166;color:#3d2c00;font-weight:600}
.clsRunTop{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:10px}
.clsRunCount{font-size:14px;font-weight:700;color:var(--brand);flex:1}
.clsCardBox{border:1px solid var(--rowwash);border-radius:16px;background:#fff;padding:16px 18px}
.clsCardTopic{font-size:12px;color:#8a5a00;background:#fff3df;border-radius:8px;padding:2px 8px;display:inline-block;margin-bottom:8px}
.clsCardQ{font-size:16px;color:#1d2c3c;line-height:1.65;white-space:pre-wrap}
.clsCardImgs img{max-width:100%;max-height:240px;border:1px solid #e3ecf5;border-radius:12px;margin-top:10px}
.clsCardAns{margin-top:14px;border-top:2px dashed #e0eaf4;padding-top:12px;font-size:15px;color:#175c33;background:#f3faf6;border-radius:0 0 10px 10px;white-space:pre-wrap;line-height:1.7}
.clsSummary{font-size:13px;color:#5a7186;margin:8px 0 10px}
.clsResRow{border:1px solid #e7eef6;border-radius:12px;padding:10px 12px;margin-bottom:8px}
.clsResHead{display:flex;align-items:center;gap:10px;flex-wrap:wrap;font-size:14px;color:#2a4258}
.clsResHead .clsCaret{display:inline-block;width:12px;color:#8a9aac;font-size:12px}
/* one pupil's card sheet — every card of the homework, with their gaps filled in */
.clsSheet{margin:8px 0 2px}
.clsSheet .clsCard{border:1px solid #dfe9f3;border-radius:10px;background:#fff;padding:10px 12px;margin:0 0 8px}
.clsSheet .clsCard.hi{border-color:var(--brand-lt);box-shadow:0 0 0 3px rgba(29,111,184,.14)}
.clsSheet .clsCard.miss{background:#fbfcfe;color:#8a9aac}
.clsSheet .clsCardTop{display:flex;align-items:center;gap:8px;flex-wrap:wrap;font-size:13px;color:#2a4258;margin-bottom:6px}
.clsSheet .clsCardNo{min-width:26px;text-align:center;border-radius:6px;background:var(--chipbg);color:#5a7186;font-weight:700;font-size:12px;padding:2px 4px}
.clsSheet .clsQ{font-size:15px;line-height:1.65;color:#1d2c3c;white-space:pre-wrap}
.clsSheet .clsFigs img{max-width:240px;max-height:240px;border:1px solid #e3ecf5;border-radius:10px;margin:6px 8px 0 0}
.clsSheet .clsAns{margin-top:8px;font-size:15px;line-height:1.9;color:#175c33}
.clsSheet .clsAns b.cap{display:block;font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:#6b7f93;margin-bottom:2px}
.clsSheet .clsAns .clsGrid{margin-top:6px}
.clsGrid{display:flex;flex-wrap:wrap;gap:4px;margin-top:8px}
.clsCell{min-width:30px;text-align:center;font-size:12px;padding:3px 6px;border-radius:8px;background:var(--wash);color:#5a7186;cursor:help}
.clsCell.k{background:#e3f5ea;color:#175c33;font-weight:700}
.clsCell.u{background:#fdeeee;color:#b03a2e;font-weight:700}
.rolePick{display:flex;gap:8px;margin-top:6px}
.roleBtn{flex:1;border:1px solid #b9cee3;background:#fff;color:var(--brand);border-radius:12px;padding:10px 8px;font-size:14px;font-family:inherit;cursor:pointer}
.roleBtn.active{background:var(--brand);border-color:var(--brand);color:#fff;font-weight:600}
.roleHint{font-size:12px;color:#5a7186;margin-top:6px;line-height:1.45}

/* ---------------- Knowledge Tree ---------------- */
.ktSplit{display:block}
.ktMain{min-width:0}
.ktTools{display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.ktTools input{padding:7px 12px;border:1px solid #ccdcec;border-radius:12px;font-size:14px;font-family:inherit;min-width:210px}
.ktTools input:focus{outline:none;border-color:var(--brand-lt)}
.ktHead{display:flex;align-items:center;gap:12px;font-size:14px;color:#2c4258;margin:12px 0 10px;flex-wrap:wrap}
.ktN{margin-left:6px;font-size:12px;color:#8ba0b3;font-weight:600}
.ktDot{width:7px;height:7px;border-radius:50%;background:#c3d4e6;flex:none;margin-top:4px}
.ktSkill:hover .ktDot,.ktSkill.sel .ktDot{background:#ffd166}

/* ---------------- the tree, drawn as a chart ----------------
   Paper (trunk) -> topic -> sub-topic -> skill. Each branch adds up the
   skills ticked underneath it, so the trunk itself becomes a percentage. */
.ktChart{position:relative;overflow:auto;border:1px solid #dfeaf4;border-radius:16px;
  background:linear-gradient(180deg,#fbfdff,#f6fafe);padding:16px 14px 10px;
  max-height:min(64vh,680px);box-shadow:inset 0 1px 0 #fff}
/* the zoom wrapper carries the scaled size: without this the canvas keeps its
   full layout width and the scroll bar runs off into empty space */
.ktZoom{position:relative;margin:0;overflow:hidden}
.ktCanvas{position:relative;transform-origin:0 0;display:inline-block;min-width:100%}
.ktLinks{position:absolute;left:0;top:0;pointer-events:none}
.ktUnitTree{display:block;margin:0 0 26px}
/* only one paper is open at a time: the others sit in a row, waiting to be clicked */
.ktUnitTree.shut{display:inline-block;margin:0 14px 8px 0;vertical-align:top}
.ktBox.unit.shut{width:auto;min-width:0;padding:7px 15px;background:#fff;border-color:var(--rim)}
.ktBox.unit.shut .ktBoxT{color:var(--brand)}
.ktBox.unit.shut .ktPct{color:var(--brand)}
.ktBox.unit.shut .ktPct span{color:#7b8fa3}
.ktBox.unit.shut:hover{background:var(--brand-lt);border-color:var(--brand-lt)}
.ktBox.unit.shut:hover .ktBoxT,.ktBox.unit.shut:hover .ktPct,
.ktBox.unit.shut:hover .ktPct span,.ktBox.unit.shut:hover .ktBoxS{color:#fff}
.ktBranch{display:flex;flex-direction:column;align-items:center}
.ktKids{display:flex;align-items:flex-start;justify-content:center}
.ktKids.ktV{flex-direction:column;align-items:stretch;width:180px;padding:0 0 0 19px}
.ktBranch:not(:first-child){margin-left:0}
.ktKids>.ktBranch{padding:24px 6px 0}
.ktKids.ktV>.ktBranch{padding:0 0 6px}

.ktBox{position:relative;width:180px;border:1.5px solid var(--rowwash);border-radius:16px;
  padding:8px 10px;text-align:center;cursor:pointer;
  background:linear-gradient(180deg,#fff,var(--wash));
  transition:box-shadow .15s,border-color .15s,transform .15s;
  box-shadow:0 1px 0 rgba(255,255,255,.95) inset,0 2px 5px rgba(18,52,86,.09)}
.ktBox:hover{border-color:var(--brand-lt);transform:translateY(-2px);
  box-shadow:0 8px 18px rgba(18,52,86,.17),0 0 0 3px rgba(var(--brand-lt-rgb),.14)}
.ktBox.dim{opacity:.3}
/* a branch that is finished glows gold — the "skill unlocked" state */
.ktBox.full{border-color:#e9bf6a;background:linear-gradient(180deg,#fffaea,#ffefcd);
  box-shadow:0 0 0 1px #f6e2ab inset,0 3px 12px rgba(214,158,44,.24)}
.ktBox.full .ktBoxT{color:#8a5d0a}
.ktBox.full .ktPct{color:#a2761c}
.ktBox .ktBoxT{font-weight:700;font-size:13px;line-height:1.25;color:var(--brand-dk);white-space:pre-line}
.ktBox .ktBoxS{margin-top:2px;font-size:12px;color:#6b7f93}
.ktBox.sec{background:#eef5fb;border-color:#c6dcee}
/* a topic that has not been asked for yet: quiet, waiting to be clicked */
.ktBox.sec.shut{background:#fff;border-color:#d8e4ef;border-style:dashed}
.ktBox.sec.shut .ktBoxT{color:#5d7d9c;font-weight:600}
.ktBox.sec.shut:hover{border-style:solid;border-color:var(--brand-lt);background:#f5faff}
/* a sub-topic is a cluster of skills: folded it shows how many are inside it */
.ktBox.sub{background:linear-gradient(180deg,#f3f8fd,#e9f2fb);border-color:#cfe0ef}
.ktBox.sub.shut{background:#fff;border-color:#d8e4ef;border-style:dashed}
.ktBox.sub.shut .ktBoxS{color:#8aa3b8;font-weight:600}
.ktBox.sub.shut:hover{border-style:solid;border-color:var(--brand-lt);background:#f5faff}
.ktBox.unit{width:auto;min-width:250px;border-color:var(--brand-deep);
  background:linear-gradient(180deg,var(--brand),var(--brand-deep));
  box-shadow:0 4px 14px rgba(0,0,0,.22)}
.ktBox.unit .ktBoxT{color:#fff}
.ktBox.unit .ktPct{color:rgba(255,255,255,.8)}
.ktBox.unit .ktPct span{color:rgba(255,255,255,.55)}
.ktFold{position:absolute;top:-9px;right:-9px;width:20px;height:20px;border-radius:50%;
  background:#fff;border:1.5px solid var(--rim);color:var(--brand);font-size:13px;font-weight:700;
  line-height:17px;text-align:center;cursor:pointer;user-select:none;
  box-shadow:0 2px 5px rgba(18,52,86,.2);transition:transform .15s,background .15s,color .15s}
.ktFold:hover{background:var(--brand-lt);border-color:var(--brand-lt);color:#fff;transform:scale(1.16)}

/* A skill reads as something to be unlocked, not as a line in a list: an icon on
   the left, a little lift on hover, and gold once every question is ticked. */
.ktSkill{position:relative;display:flex;flex-direction:column;align-items:stretch;
  background:linear-gradient(180deg,#fff,var(--wash));
  border:1.5px solid var(--rowwash);border-radius:12px;padding:7px 9px 7px 29px;cursor:pointer;
  font-size:12px;line-height:1.32;color:#33506e;
  box-shadow:0 1px 0 rgba(255,255,255,.9) inset,0 1px 3px rgba(18,52,86,.08);
  transition:transform .15s,box-shadow .15s,border-color .15s,background .15s}
/* the badge: hollow when untouched, lit while in progress, a gold tick once mastered */
.ktSkill::before{content:'';position:absolute;left:8px;top:9px;width:16px;height:16px;
  border-radius:6px;background:var(--wash);border:1.5px solid var(--rim);
  font-size:12px;font-weight:700;line-height:15px;text-align:center;color:transparent;
  transition:background .15s,box-shadow .15s,border-color .15s}
.ktSkill.part::before{background:linear-gradient(160deg,var(--brand-lt),var(--brand));
  border-color:var(--brand);box-shadow:0 0 8px rgba(var(--brand-lt-rgb),.6)}
.ktSkill.done::before{content:'\2713';background:linear-gradient(160deg,#ffdd85,#efab2a);
  border-color:#cf8f1c;color:#6b4a06;box-shadow:0 0 10px rgba(240,175,45,.9)}
.ktSkill:hover{transform:translateY(-2px);border-color:var(--brand-lt);
  background:#fff;box-shadow:0 7px 16px rgba(18,52,86,.17)}
.ktSkill.sel{border-color:var(--brand-lt);box-shadow:0 0 0 3px rgba(var(--brand-lt-rgb),.2)}
.ktSkill.done{background:linear-gradient(180deg,#fffbf0,#fff5dd);border-color:#e9c169}
.ktSkill.dim{opacity:.3}
/* a syllabus point that arrived with two bullets welded together carries a
   newline where the number was — show it as a line break rather than a space */
.ktSkillT{flex:1;min-width:0;white-space:pre-line}
.ktSkill .ktN{flex:none;margin:1px 0 0;background:#f1f6fb;border-radius:22px;padding:0 6px}
.ktTick{flex:none;width:18px;height:18px;border-radius:6px;border:1.5px solid #c6d5e3;background:#fff;
  color:transparent;font-size:12px;line-height:15px;text-align:center;user-select:none}
.ktTick:hover{border-color:#4a9a63;color:#d5ecdc;background:#f6fcf7}
.ktSkill.done .ktTick{background:#4a9a63;border-color:#4a9a63;color:#fff}

/* the progress bar reads as an experience bar: notched, and gold once filled */
.ktBar{position:relative;height:6px;border-radius:6px;background:var(--rim);overflow:hidden;margin-top:7px;
  box-shadow:inset 0 1px 2px rgba(18,52,86,.14)}
.ktBar i{display:block;height:100%;border-radius:6px;background:linear-gradient(90deg,var(--brand-lt),var(--brand));
  box-shadow:0 0 6px rgba(var(--brand-lt-rgb),.55)}
.ktBar::after{content:'';position:absolute;inset:0;pointer-events:none;
  background:repeating-linear-gradient(90deg,transparent 0 17px,rgba(255,255,255,.6) 17px 19px)}
.ktBox.full .ktBar i,.ktSkill.done .ktBar i{background:linear-gradient(90deg,#ffd166,#f0961c);
  box-shadow:0 0 7px rgba(240,170,40,.8)}
.ktBar.big{display:inline-block;width:130px;height:7px;margin:0 8px 0 0;vertical-align:middle}
.ktPct{display:flex;justify-content:space-between;gap:8px;margin-top:4px;font-size:12px;
  font-weight:700;color:var(--brand)}
.ktPct span{font-weight:400;color:#7b8fa3}
.ktProg{display:inline-flex;align-items:center;font-size:13px;color:#4a6076}
.ktProg b{color:var(--brand)}
.ktProg span{color:#7b8fa3}
/* Drilled into one topic: the way back out, and where the pupil is */
.ktBack{display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:10px;
  width:max-content;max-width:100%;margin:0 auto 20px;
  padding:8px 14px;border:1.5px dashed var(--brand-lt);border-radius:12px;background:#fff;
  box-shadow:0 2px 6px rgba(18,52,86,.09)}
.ktBack .btn{min-width:0}
.ktBackT{font-weight:700;font-size:13px;color:var(--brand-dk)}
.ktBackH{font-size:12px;color:#7b8fa3}
/* ---------------- the five questions behind a skill ---------------- */
.ktPlan{background:var(--wash);border:1px solid var(--rim);border-radius:12px;padding:9px 12px;margin:0 0 12px}
.ktPlanH{display:flex;align-items:center;gap:10px;font-size:14px;color:#2c4258;margin-bottom:4px;flex-wrap:wrap}
.ktPlanH span{color:#7b8fa3;font-size:13px}
.ktPlanH .btn{margin-left:auto}
.ktPlanH .btn + .btn{margin-left:0}
.ktPlanRow{display:flex;align-items:center;gap:9px;padding:6px 4px;border-radius:8px;font-size:13px}
.ktPlanRow:hover{background:var(--rowwash)}
.ktPlanRow.done .ktPlanQ{color:#5f8a6e;text-decoration:line-through}
.ktPlanRow.empty{color:#93a7b8}
.ktPlanQ{flex:1;min-width:0;color:#3c5570}
.ktPlanQ i{color:#b0894f;font-style:normal;font-size:12px}
.ktPlanTip{font-size:12px;color:#93a7b8;white-space:nowrap}
.ktTag{font-size:12px;font-weight:700;border-radius:22px;padding:2px 8px;background:var(--wash);color:#5c7f9e}
.ktTag.def{background:var(--chipbg);color:var(--brand)}
.ktTag.basic{background:#eaf6ec;color:#2f7a45}
.ktTag.hard{background:#fdeeea;color:#a4502f}
.ktTick.off{border-style:dashed;color:#c6d5e3}
/* the box in the question list: the tick has to be drawn, not just implied by the
   row going green — it used to stay invisible, the tick being transparent */
.ktTick.on{background:#4a9a63;border-color:#4a9a63;color:#fff}
/* and the box the pupil just clicked pops, so the click is plainly answered */
@keyframes ktPop{0%{transform:scale(.7)}55%{transform:scale(1.18)}100%{transform:scale(1)}}
.ktTick.pop{animation:ktPop .26s ease-out}

/* the year / sitting filter: a chip per year, cross out the ones to leave alone */
.ktFiltBox{display:flex;flex-wrap:wrap;gap:10px 20px;align-items:center;padding:9px 12px;
  border:1px solid var(--rim);border-radius:12px;background:var(--wash);font-size:13px}
.ktFiltRow{display:flex;flex-wrap:wrap;gap:6px;align-items:center}
.ktFiltRow b{font-size:12px;text-transform:uppercase;letter-spacing:.5px;color:var(--brand)}
.ktChip{border:1px solid var(--rim);background:#fff;color:var(--brand);border-radius:22px;
  padding:3px 10px;font-size:12px;user-select:none}
.ktChip:hover{border-color:var(--brand-lt);background:var(--btnwash)}
.ktChip.off{background:#eef2f6;color:#a2b3c2;border-color:#e0e8ef;text-decoration:line-through}
.ktFiltFoot{color:#7b8fa3}
.ktTools .mini.on{background:var(--brand);color:#fff;border-color:var(--brand)}

/* ---------- revision notes ---------- */
.notesSplit{display:grid;grid-template-columns:260px 1fr;gap:16px;align-items:start}
@media(max-width:820px){.notesSplit{grid-template-columns:1fr}}
.notesList{border:1px solid var(--rim);border-radius:12px;background:#fff;padding:6px;
  position:sticky;top:8px;max-height:76vh;overflow:auto}
.notesSub{display:flex;gap:7px;align-items:baseline;padding:7px 10px;border-radius:8px;
  font-size:13px;line-height:1.35;cursor:pointer}
.notesSub:hover{background:var(--rowwash)}
.notesSub.on{background:var(--brand);color:#fff}
.notesSub b{flex:none;font-size:12px}
.notesSub.kid{padding-left:26px;font-size:12.5px}
.notesSub.kid b{font-weight:600;opacity:.8}
.notesCh{font-size:11px;font-weight:700;color:#7b8fa3;letter-spacing:.4px;text-transform:uppercase;
  padding:12px 10px 4px}
.notesSpec{font-size:11.5px;color:#7b8fa3;margin:-2px 0 10px}
.notes{background:#fff;border:1px solid var(--rim);border-radius:12px;padding:20px 24px;
  min-height:60vh;color:#1f2933;font-size:15px;line-height:1.7}
.notesH{font-size:22px;margin:0 0 2px;color:var(--brand)}
.notesSrc{font-size:11.5px;color:#7b8fa3;margin:16px 0 2px;text-transform:uppercase;letter-spacing:.5px}
.notesSec{font-size:19px;margin:26px 0 8px;padding-bottom:6px;border-bottom:3px solid var(--brand);
  display:flex;align-items:baseline;gap:10px}
.notesSec .num{background:var(--brand);color:#fff;font-size:12px;border-radius:8px;padding:2px 10px;white-space:nowrap}
.notesSec .cn{font-size:14px;color:#52606d;font-weight:400}
.notesSub3{font-size:16px;margin:18px 0 6px}
.notesEmpty{color:#7b8fa3;padding:24px;text-align:center}
.notes p{margin:8px 0}
.notes ul,.notes ol{margin:8px 0;padding-left:24px}
.notes li{margin:4px 0}
.notes sup,.notes sub{line-height:0}
.notes .keypoint{background:var(--wash);border-left:4px solid var(--brand);padding:10px 14px;
  border-radius:0 8px 8px 0;margin:12px 0}
.notes .formula{background:#eef4fb;border:1px solid #3b82f6;border-radius:12px;padding:12px 16px;
  margin:12px 0;text-align:center;font-size:18px;font-family:"Cambria Math",Georgia,serif}
.notes .formula small{display:block;font-family:inherit;font-size:12px;color:#52606d;margin-top:4px}
.notes .example{background:#fffbeb;border-left:4px solid #f59e0b;padding:12px 16px;
  border-radius:0 8px 8px 0;margin:14px 0}
.notes .example .tag{display:inline-block;background:#f59e0b;color:#fff;font-size:11px;border-radius:6px;
  padding:1px 8px;margin-bottom:6px;letter-spacing:.03em;text-transform:uppercase}
.notes .ans{color:#065f46;font-weight:600}
.notes .tip{background:#f0fdf4;border-left:4px solid #16a34a;padding:10px 14px;
  border-radius:0 8px 8px 0;margin:12px 0;font-size:14px}
.notesTable{overflow-x:auto}
.notes table{border-collapse:collapse;width:100%;margin:12px 0;font-size:14px}
.notes th,.notes td{border:1px solid #d9e2ec;padding:7px 10px;text-align:left;vertical-align:top}
.notes th{background:#f8fafc}
.notes figure.fig{margin:18px 0;text-align:center}
.notes figure.fig img{max-width:100%;height:auto;border:1px solid var(--rim);border-radius:12px;
  background:#fff;padding:6px}
.notes figure.fig figcaption{font-size:13px;color:#7b8fa3;margin-top:6px}
.notes .figrow{display:flex;gap:14px;justify-content:center;align-items:flex-start;flex-wrap:wrap}
.notes .figrow figure.fig{flex:1;min-width:220px;max-width:340px;margin:0}
.notes .grid2{display:grid;grid-template-columns:1fr 1fr;gap:14px}
@media(max-width:720px){.notes .grid2{grid-template-columns:1fr}}
.notes .card{border:1px solid var(--rim);border-radius:12px;padding:12px 14px;background:#f8fafc}
.notes .card .cardfig{margin:6px 0 10px;text-align:center}
.notes .card .cardfig img{width:100%;height:132px;object-fit:contain;padding:4px;background:#fff;
  border:1px solid var(--rim);border-radius:10px}
.notes .card .cardfig figcaption{font-size:11.5px;color:#8ba0b3;margin-top:4px;line-height:1.35}
/* the words the pupil has to supply: a chip until it is hidden, a box after */
.notes .kw{background:rgba(var(--brand-rgb),.10);border-bottom:1px solid var(--brand-lt);
  padding:0 3px;border-radius:4px;font-weight:600}
.notes .gap{display:inline-block;background:#fff;border:1px dashed var(--brand-lt);border-radius:6px;
  padding:0 4px;vertical-align:middle}
.notes .gapIn{border:0;outline:none;background:transparent;font:inherit;color:inherit;
  min-width:60px;padding:1px 2px}
.notes .gapIn.ok{color:#166534;font-weight:600}
.notes .shown{background:#f0fdf4;border-radius:4px;padding:0 3px;color:#065f46}
body.board-cie #navNotes{display:none}
/* the tree badges a sub-topic that has revision notes written for it */
.ktNoteMark{position:absolute;top:-9px;right:-7px;background:var(--brand);color:#fff;font-size:10px;
  font-weight:700;letter-spacing:.4px;text-transform:uppercase;padding:1px 7px;border-radius:10px;
  cursor:pointer;box-shadow:0 1px 4px rgba(18,52,86,.3)}
.ktNoteMark:hover{background:var(--brand-deep);transform:scale(1.06)}
.ktBar.mini{height:4px;margin-top:5px}
.ktSkillRow{display:flex;align-items:flex-start;gap:7px;width:100%}
.ktZoomBar{display:inline-flex;align-items:center;gap:4px;font-size:12px;color:#7b8fa3}
.ktZoomBar .mini{padding:3px 8px}
/* how far through this skill the pupil is: green lit, amber started, red stuck */
.ktDot.ok{background:#1f9d55;box-shadow:0 0 0 3px rgba(31,157,85,.16)}
.ktDot.half{background:#e9a600;box-shadow:0 0 0 3px rgba(233,166,0,.16)}
.ktDot.bad{background:#d1495b;box-shadow:0 0 0 3px rgba(209,73,91,.16)}
.ktLeaf.sel .ktDot.ok,.ktLeaf:hover .ktDot.ok{background:#1f9d55}
.ktStrip{display:flex;align-items:center;gap:8px;flex-wrap:wrap;padding:7px 10px;margin:0 0 10px;
  border:1px solid var(--rowwash);border-radius:8px;background:#f7fafd;font-size:13px;color:#3c5570}
.chip.skill{cursor:pointer;background:#eef2ff;border-color:#c7d2fe;color:#3b4a9c}
/* which half of the syllabus a skill belongs to: everyone sits Core, only
   Extended candidates need Supplement */
.ktBand{flex:none;font-size:12px;font-weight:700;text-transform:uppercase;
  padding:1px 4px;border-radius:22px;line-height:1.1;white-space:nowrap}
.ktBand.core{background:#e4eef9;color:#4a6c92}
.ktBand.supplement{background:#fdeadb;color:#a2541a}
/* what a flash card is asking for: recall a meaning, or describe and explain */
.chip.def{background:#e2eefb;color:#14507f}
.chip.de{background:#f1e3ff;color:#6b21a8}
/* a skill starts with its definition, then the questions that use it */
.ktDefs{margin:0 0 12px;border:1px solid #d9e6f2;border-radius:8px;background:#fbfdff;overflow:hidden}
.ktDefsH{padding:6px 10px;background:#eef6ff;border-bottom:1px solid #d9e6f2;
  font-weight:600;font-size:13px;color:#2c4a72}
.ktDef{padding:8px 10px;border-bottom:1px solid #eaf1f8;cursor:pointer}
.ktDef:last-child{border-bottom:0}
.ktDef:hover{background:#f5faff}
.ktDefQ{font-size:13px;font-weight:600;color:#22364d}
.ktDefA{display:none;margin-top:5px;font-size:13px;line-height:1.45;color:#3c5570;
  white-space:pre-wrap;background:#f4f8fc;border-left:3px solid #9dc3e6;padding:5px 8px;border-radius:6px}
.ktDef.open .ktDefA{display:block}
.ktDefTip{display:block;margin-top:3px;font-size:12px;color:#8aa3bd}
.ktDef.open .ktDefTip{display:none}
.ktGroupH{margin:2px 0 8px;font-size:12px;font-weight:600;color:#7b8ea6}
.card.isDef{box-shadow:inset 3px 0 0 #5b9bd5}
.ktHint{font-size:13px;color:#8ba0b3;padding:10px}
@media (max-width:900px){.ktChart{max-height:52vh}.ktTools input{min-width:150px}}

/* ---------- polish: the little things that make a page feel finished ---------- */
:focus-visible{outline:2px solid var(--brand-lt);outline-offset:2px;border-radius:6px}
/* the search box and the dropdowns used to swallow their focus ring altogether */
.search input:focus,.filterRow select:focus,.fbar select:focus,.ktTools input:focus,
.clsSearch input:focus,.clsForm input:focus,.clsForm textarea:focus,.clsForm select:focus{
  outline:none;box-shadow:0 0 0 3px rgba(var(--brand-lt-rgb),.18)}
.topbar{box-shadow:0 2px 12px -6px rgba(18,52,86,.55)}
::selection{background:rgba(var(--brand-rgb),.18)}
::placeholder{color:#9db0c2}
.ktChip,.ktTick,.ktSkill,.ktFold,.chip,.segList label{cursor:pointer}
.btn{transition:background .15s cubic-bezier(.4,0,.2,1),box-shadow .15s cubic-bezier(.4,0,.2,1)}
.btn:active{transform:translateY(1px)}
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:#c7d7e5;border-radius:6px;border:2px solid #fff}
::-webkit-scrollbar-thumb:hover{background:#a6bdd1}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;
    transition-duration:.01ms!important;scroll-behavior:auto!important}}