:root{
  --navy:#071937;--blue:#1262df;--blue-2:#2b7bff;--ink:#17243b;--mut:#61718b;--line:#e3e8f2;--soft:#f4f7fc;
  --ok:#13894f;--ok-bg:#e9f8ef;--bad:#c9353f;--bad-bg:#fdeeee;--warn:#b7791f;
  --c-grammar:#7c5cff;--c-expr:#2b7bff;--c-vocab:#f08c2b;--c-reading:#13a39a;--c-math:#e0447a;
  color-scheme:light;
}
*{box-sizing:border-box}
html,body{margin:0}
body{font:15px/1.5 system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;color:var(--ink);background:#0d2a63}
button{font:inherit;cursor:pointer;color:inherit}
.hidden{display:none!important}
button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline:3px solid #f2b631;outline-offset:2px}

/* ---------- buttons / chips ---------- */
.btn{display:inline-flex;align-items:center;gap:6px;border:1px solid var(--blue);background:var(--blue);color:#fff;border-radius:999px;padding:8px 18px;font-weight:700}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn.big{padding:11px 24px;font-size:15px}
.btn.ghost{background:#fff;color:var(--blue)}
.btn.danger{color:var(--bad);border-color:#f0c4c7}
.chiprow{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.chiprow .lbl{color:#cfe0ff;font-weight:700;font-size:13px;margin-right:2px}
.chip{border:1.5px solid rgba(255,255,255,.55);background:transparent;color:#fff;border-radius:10px;padding:5px 12px;font-weight:700;font-size:13px}
.chip.on{background:#fff;color:var(--blue);border-color:#fff}
.chip.on::before{content:"✓ ";}
.card .chip,.chiprow.small .chip{border-color:var(--line);color:var(--mut);background:#fff}
.card .chip.on{background:var(--blue);color:#fff;border-color:var(--blue)}
.card .chip.on::before{content:""}

/* ---------- picker ---------- */
.picker{min-height:100vh;background:linear-gradient(140deg,#071937 0%,#0f3c8f 50%,#1262df 100%);padding-bottom:110px}
.pk-wrap{max-width:780px;margin:0 auto;padding:24px 16px}
.pk-head{display:flex;gap:14px;align-items:center;color:#fff}
.pk-head h1{margin:0;font-size:30px;font-weight:850;letter-spacing:-.02em;line-height:1.1}
.pk-head p{margin:2px 0 0;color:#cfe0ff;font-size:14px}
.pk-back{width:38px;height:38px;border-radius:10px;background:rgba(255,255,255,.16);color:#fff;text-decoration:none;display:grid;place-items:center;font-size:18px;flex:none}
.pk-tabs{display:inline-flex;margin:20px 0 16px;background:rgba(255,255,255,.14);padding:4px;border-radius:12px}
.pk-tabs button{border:0;background:transparent;color:#fff;font-weight:700;font-size:14px;padding:8px 16px;border-radius:9px}
.pk-tabs button.on{background:#fff;color:var(--blue)}
.pk-stats{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-bottom:16px}
.pk-stats div{background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.18);border-radius:14px;padding:10px 14px;color:#fff}
.pk-stats b{display:block;font-size:22px;font-variant-numeric:tabular-nums;line-height:1.2}
.pk-stats span{font-size:12px;color:#cfe0ff}
.pk-filters{display:flex;flex-direction:column;gap:10px;margin-bottom:18px}

.cat{background:#fff;border-radius:18px;margin-bottom:14px;overflow:hidden;box-shadow:0 10px 30px rgba(3,14,40,.18)}
.cat::before{content:"";display:block;height:5px;background:var(--cc)}
.cat-h{display:flex;align-items:center;gap:12px;padding:14px 16px;cursor:pointer;user-select:none}
.cat-ic{width:36px;height:36px;border-radius:10px;display:grid;place-items:center;background:color-mix(in srgb,var(--cc) 12%,#fff);font-size:18px;flex:none}
.cat-h h2{margin:0;font-size:16px;font-weight:800;flex:1}
.cat-meta{color:var(--mut);font-size:12px;white-space:nowrap}
.chev{color:var(--mut);transition:transform .2s;width:20px;text-align:center}
.cat.closed .chev{transform:rotate(180deg)}
.cat.closed .rows{display:none}
.cb{appearance:none;-webkit-appearance:none;width:20px;height:20px;border:2px solid #c3cbdb;border-radius:6px;display:grid;place-items:center;margin:0;flex:none;cursor:pointer;background:#fff}
.cb:checked,.cb:indeterminate{background:var(--blue);border-color:var(--blue)}
.cb:checked::after{content:"";width:5px;height:10px;border:solid #fff;border-width:0 2.5px 2.5px 0;transform:translateY(-1px) rotate(45deg)}
.cb:indeterminate::after{content:"";width:10px;height:2.5px;background:#fff;border-radius:2px}
.cb:disabled{opacity:.4;cursor:not-allowed}
.row{display:grid;grid-template-columns:20px 1fr 92px 130px 44px;gap:12px;align-items:center;padding:10px 16px;border-top:1px solid var(--line);cursor:pointer}
.row:hover{background:var(--soft)}
.row.empty{cursor:default;opacity:.55}
.row-n{font-size:14px}
.row-c{font-size:12px;color:var(--mut);text-align:right}
.bar{height:6px;background:#edf0f6;border-radius:9px;overflow:hidden}
.bar i{display:block;height:100%;background:var(--cc,var(--blue));border-radius:9px}
.row-p small{display:block;font-size:11px;color:var(--mut);margin-top:3px}
.acc{font-size:12px;font-weight:800;text-align:right;color:var(--mut)}
.acc.hi{color:var(--ok)}.acc.mid{color:var(--warn)}.acc.lo{color:var(--bad)}
.pk-soon{border:1.5px dashed rgba(255,255,255,.45);border-radius:18px;padding:14px 18px;color:#fff;margin-top:6px}
.pk-soon p{margin:4px 0 0;color:#cfe0ff;font-size:13px}
.pk-fine{color:#a9c2ec;font-size:12px;margin-top:18px}
.pk-start{position:fixed;left:0;right:0;bottom:0;background:#fff;border-top:1px solid var(--line);box-shadow:0 -6px 24px rgba(3,14,40,.18);display:flex;align-items:center;justify-content:center;gap:18px;padding:12px 16px;flex-wrap:wrap;z-index:5}
#selCount{font-weight:700}
.switch{display:inline-flex;align-items:center;gap:8px;font-size:13px;font-weight:600;color:var(--mut);cursor:pointer}
.switch input{position:absolute;opacity:0;pointer-events:none}
.switch i{width:34px;height:20px;border-radius:20px;background:#cdd5e3;position:relative;transition:.2s}
.switch i::after{content:"";position:absolute;width:16px;height:16px;border-radius:50%;background:#fff;top:2px;left:2px;transition:.2s;box-shadow:0 1px 3px #0003}
.switch input:checked+i{background:var(--blue)}
.switch input:checked+i::after{left:16px}
.switch input:focus-visible+i{outline:3px solid #f2b631;outline-offset:2px}

/* history */
.card{background:#fff;border-radius:18px;padding:16px;margin-bottom:14px;box-shadow:0 10px 30px rgba(3,14,40,.18)}
.card-h{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;margin-bottom:8px}
.card-h h2{margin:0;font-size:16px}
.h-actions{display:flex;gap:8px;flex-wrap:wrap;margin:6px 0 12px}
.h-actions .btn{font-size:13px;padding:6px 14px}
.trow{display:grid;grid-template-columns:1fr 70px 1fr 44px;gap:10px;align-items:center;padding:7px 0;border-top:1px solid var(--line);font-size:14px}
.trow:first-child{border-top:0}
.trow small{color:var(--mut)}
.att{border-top:1px solid var(--line)}
.att summary{display:grid;grid-template-columns:22px 1fr auto;gap:10px;align-items:center;padding:10px 2px;cursor:pointer;list-style:none;font-size:14px}
.att summary::-webkit-details-marker{display:none}
.att summary small{color:var(--mut);font-size:12px}
.att .res{font-weight:800}
.att .res.ok{color:var(--ok)}.att .res.no{color:var(--bad)}
.att-body{padding:4px 4px 14px 32px;font-size:14px}
.att-body .pas{background:var(--soft);border-radius:10px;padding:10px 12px;white-space:pre-line;font-family:Georgia,serif}
.att-body .lineok{color:var(--ok);font-weight:700}
.att-body .lineno{color:var(--bad);font-weight:700}
.att-body .why{border-left:3px solid var(--blue);padding-left:10px;color:#2b3a55}
.empty-note{color:var(--mut);font-size:14px;padding:8px 0}

/* ---------- drill / Bluebook ---------- */
.drill{position:fixed;inset:0;background:#fff;display:flex;flex-direction:column;z-index:10}
.bb-top{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;padding:10px 20px 8px;background:#f6f8fd}
.bb-title strong{display:block;font-size:17px}
.bb-title{position:relative}
.link{border:0;background:none;padding:0;color:#3a4a66;font-size:13px}
.bb-clock{text-align:center}
#clock{font:600 20px/1.2 ui-monospace,SFMono-Regular,Menlo,monospace;font-variant-numeric:tabular-nums;display:block}
.pill{border:1px solid #8a96ab;background:#fff;border-radius:999px;font-size:11px;padding:1px 10px;margin:3px 2px 0}
.bb-tools{display:flex;justify-content:flex-end;gap:4px}
.tool{border:0;background:none;display:flex;flex-direction:column;align-items:center;font-size:11px;color:#3a4a66;padding:4px 8px;border-radius:8px}
.tool span{font-size:17px;line-height:1.1}
.tool:hover,.tool.on{background:#e6ecf8}
.bb-rule{height:3px;background:repeating-linear-gradient(90deg,#1c2a46 0 22px,transparent 22px 28px)}
.bb-main{flex:1;display:grid;grid-template-columns:1fr 1fr;overflow:hidden}
.bb-main.fb-on{grid-template-columns:1fr 1fr 300px}
.bb-main.solo{grid-template-columns:minmax(0,760px);justify-content:center}
.bb-main.solo.fb-on{grid-template-columns:minmax(0,700px) 300px}
.bb-main.solo .bb-passage{display:none}
.bb-passage{overflow:auto;padding:24px 28px;border-right:3px solid #1c2a46;font:18px/1.75 Georgia,"Times New Roman",serif;white-space:pre-line}
.bb-passage mark{background:#fde68a;cursor:pointer;border-radius:2px}
.bb-q{overflow:auto;padding:22px 28px 30px}
.bb-qbar{display:flex;align-items:center;gap:12px;background:#eef1f7;border-bottom:2px dashed #b5bfd0;padding:0 8px 0 0;margin-bottom:16px}
.qnum{background:#111;color:#fff;font-weight:800;min-width:30px;height:32px;display:grid;place-items:center;padding:0 8px}
.mark{border:0;background:none;font-size:14px;color:#2d3b57;flex:1;text-align:left}
.mark.on{font-weight:800;color:#b5361b}
.abc{border:1.5px solid #6f7d96;border-radius:6px;background:#fff;font-size:11px;font-weight:800;padding:2px 6px}
.abc[aria-pressed="true"]{background:var(--blue);color:#fff;border-color:var(--blue)}
.bb-stem{font:17px/1.6 Georgia,"Times New Roman",serif;margin-bottom:12px;white-space:pre-line}
.bb-stem .fig{margin:12px 0;text-align:center}
.bb-stem .fig svg{max-width:100%;height:auto}
.opt-row{display:flex;align-items:center;gap:10px;margin:10px 0}
.opt{flex:1;display:flex;align-items:center;gap:12px;text-align:left;border:1.5px solid #8794ab;background:#fff;border-radius:10px;padding:11px 14px;font:16px/1.45 Georgia,"Times New Roman",serif;min-height:48px}
.opt:hover:not(:disabled){border-color:var(--blue)}
.opt .L{width:26px;height:26px;border-radius:50%;border:1.5px solid #3e4a60;display:grid;place-items:center;font:700 13px system-ui,sans-serif;flex:none}
.opt.sel{border:2.5px solid var(--blue);padding:10px 13px}
.opt.sel .L{background:var(--blue);color:#fff;border-color:var(--blue)}
.opt.right{border:2px solid var(--ok);background:var(--ok-bg)}
.opt.right .L{background:var(--ok);color:#fff;border-color:var(--ok)}
.opt.wrong{border:2px solid var(--bad);background:var(--bad-bg)}
.opt.wrong .L{background:var(--bad);color:#fff;border-color:var(--bad)}
.opt.out{opacity:.5}
.opt.out .T{text-decoration:line-through}
.opt:disabled{cursor:default;color:inherit}
.strike{border:1.5px solid #6f7d96;background:#fff;border-radius:50%;width:26px;height:26px;font-size:11px;font-weight:800;flex:none}
.strike.on{background:#3e4a60;color:#fff}
.spr{display:flex;flex-direction:column;gap:8px;max-width:260px}
.spr input{font:20px/1.2 ui-monospace,Menlo,monospace;border:2px solid #8794ab;border-radius:8px;padding:10px 12px}
.spr input.right{border-color:var(--ok);background:var(--ok-bg)}
.spr input.wrong{border-color:var(--bad);background:var(--bad-bg)}
.spr small{color:var(--mut)}
.explain{margin-top:14px;background:#f2f6ff;border:1px solid #cfdcf6;border-radius:10px;padding:10px 12px}
.explain label{font-size:13px;font-weight:700;display:block;margin-bottom:6px}
.explain textarea,.notes textarea{width:100%;border:1px solid #c8d2e4;border-radius:8px;padding:8px;font:14px/1.45 system-ui,sans-serif;resize:vertical}
.bb-fb{overflow:auto;border-left:1px solid var(--line);padding:18px 18px 30px;background:#fbfcff;font-size:13.5px}
.verdict{display:inline-block;font-weight:800;border-radius:999px;padding:4px 12px;font-size:13px}
.verdict.ok{background:var(--ok-bg);color:var(--ok)}
.verdict.no{background:var(--bad-bg);color:var(--bad)}
.fb-box{border:1px solid var(--line);background:#fff;border-radius:10px;padding:9px 11px;margin:12px 0;color:#3a4a66;font-size:12.5px}
.fb-box b{color:var(--ink)}
.fb-lbl{font-size:11px;letter-spacing:.06em;text-transform:uppercase;color:var(--mut);margin:16px 0 6px;font-weight:700}
.fb-why{white-space:pre-line;line-height:1.6}
.fb-mine{background:#f2f6ff;border-radius:8px;padding:8px 10px;white-space:pre-line}
.flag{border:0;background:none;color:var(--mut);font-size:12px;padding:0;margin-top:14px;text-decoration:underline}
.bb-foot{display:grid;grid-template-columns:1fr auto 1fr;align-items:center;gap:10px;padding:10px 20px;border-top:3px solid transparent;border-image:repeating-linear-gradient(90deg,#1c2a46 0 22px,transparent 22px 28px) 3;background:#f6f8fd}
.bb-brand{font-size:14px;color:#3a4a66}
.qcount{background:#1c2a46;color:#fff;border:0;border-radius:8px;padding:7px 14px;font-weight:700;font-size:13px}
.bb-foot-r{display:flex;justify-content:flex-end;gap:8px}
.navwrap{position:relative}
.pop{position:absolute;z-index:20;background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:0 12px 32px rgba(3,14,40,.22);padding:14px;min-width:280px;max-width:min(420px,90vw);font-size:13.5px}
.pop.up{bottom:calc(100% + 10px);left:50%;transform:translateX(-50%)}
#dirPop{top:calc(100% + 6px);left:0}
.navgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(36px,1fr));gap:6px;margin-top:10px}
.navgrid button{border:1.5px dashed #8794ab;background:#fff;border-radius:6px;height:34px;font-weight:700;position:relative}
.navgrid button.ok{border:1.5px solid var(--ok);background:var(--ok-bg);color:var(--ok)}
.navgrid button.no{border:1.5px solid var(--bad);background:var(--bad-bg);color:var(--bad)}
.navgrid button.cur{outline:2px solid #1c2a46;outline-offset:1px}
.navgrid button.mk::after{content:"";position:absolute;top:-5px;right:-4px;width:9px;height:9px;background:#b5361b;border-radius:50%}
.legend{display:flex;gap:12px;flex-wrap:wrap;color:var(--mut);font-size:12px}
.notes,.calc{position:fixed;z-index:15;background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:0 12px 32px rgba(3,14,40,.25)}
.notes{left:16px;bottom:76px;width:min(320px,calc(100vw - 32px));padding:12px}
.calc{left:16px;top:90px;width:min(460px,calc(100vw - 32px));height:min(520px,calc(100vh - 180px));display:flex;flex-direction:column;overflow:hidden}
.calc-h{display:flex;justify-content:space-between;align-items:center;padding:8px 12px;background:#1c2a46;color:#fff}
.calc-h .x{color:#fff}
#calcBody{flex:1}
.notes-h{display:flex;justify-content:space-between;align-items:center;margin-bottom:6px}
.x{border:0;background:none;font-size:16px}
.tiny{font-size:12px;color:var(--mut);margin:0 0 8px}
.modal{position:fixed;inset:0;background:rgba(7,25,55,.5);display:grid;place-items:center;z-index:30;padding:16px}
.modal-c{background:#fff;border-radius:14px;padding:16px;max-width:560px;width:100%}
.refgrid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:10px;font-size:14px}
.refgrid div{background:var(--soft);border-radius:8px;padding:8px 10px}
.pause{position:absolute;inset:0;background:rgba(246,248,253,.97);display:grid;place-items:center;text-align:center;z-index:12}
.toast{position:fixed;bottom:84px;left:50%;transform:translateX(-50%);background:#1c2a46;color:#fff;padding:9px 16px;border-radius:999px;font-size:13px;z-index:40}

@media (max-width:900px){
  .bb-main,.bb-main.fb-on,.bb-main.solo,.bb-main.solo.fb-on{grid-template-columns:1fr;overflow:auto;display:block}
  .bb-passage{border-right:0;border-bottom:3px solid #1c2a46;font-size:17px;overflow:visible}
  .bb-q,.bb-fb{overflow:visible}
  .bb-fb{border-left:0;border-top:1px solid var(--line)}
}
@media (max-width:640px){
  .pk-stats{grid-template-columns:repeat(2,1fr)}
  .row{grid-template-columns:20px 1fr 44px;row-gap:4px}
  .row-c{display:none}
  .row-p{grid-column:2/4;grid-row:2}
  .pk-head h1{font-size:25px}
  .bb-top{grid-template-columns:1fr auto;padding:8px 12px}
  .bb-clock{order:-1;grid-column:1/3;display:flex;justify-content:center;gap:8px;align-items:center}
  .bb-title strong{font-size:14px}
  .tool{font-size:0;padding:4px 6px}.tool span{font-size:18px}
  .bb-passage,.bb-q{padding:16px}
  .bb-foot{grid-template-columns:auto 1fr;padding:8px 12px}
  .bb-brand{display:none}
  .trow{grid-template-columns:1fr 60px 44px}.trow .bar{display:none}
  .pk-start{gap:10px}
}