/* Study pages: Practice, Review, Flashcards and Exams in every course
   (docs/course-shell.md, W-C). Load after theme.css and course/base.css,
   before the course's own stylesheet.

   The quiz engines stay per course (NREMT practice-engine.js, Ochem
   session-runner.js and exams-page.js, A&P assets/apps, Bio assets/pages);
   they emit these classes so a page shell, a picker, an empty state and a
   question card look the same in every course. Nothing here names a course:
   the tint comes from --ctint/--cink (theme.css, body[data-course]).

   Contents
     1. Tokens and the page body
     2. "Your numbers" rail
     3. Step builder (practice) and exam settings
     4. Review
     5. Flashcards: deck picker, deck card, by-chapter list, the card itself
     6. In-session chrome and the question/answer card */

/* ---- 1. Tokens and the page body --------------------------------------- */
.page-head[hidden]{display:none;}
.cx-study{min-height:max(420px,calc(100vh - 200px));}
.cx-study .cx-body{margin-top:22px;}
.cx-loading{padding:20px 0;font:700 14px var(--font-ui);color:var(--muted);}
.cx-small{font:700 13px/1.5 var(--font-ui);color:var(--muted);margin:8px 0 0;}
.cx-small a{color:var(--accent-text);}
.cx-h2{font:900 18px var(--font-ui);color:var(--ink);margin:28px 0 12px;}
.cx-main{display:grid;gap:18px;align-content:start;min-width:0;}
.cx-main > *{margin-top:0;margin-bottom:0;}

/* ---- 2. "Your numbers" rail -------------------------------------------- */
.cx-rail-h{font:900 11px var(--font-ui);letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:0 0 -6px;}
.cx-rail .cx-stats{gap:2px;background:var(--line);border-radius:var(--radius-lg);overflow:hidden;box-shadow:var(--lift-sm);}
.cx-rail .cx-stat{border-radius:0;background:var(--white);padding:13px 15px;}
.cx-rail .cx-stat-num{font-size:22px;}
.cx-stat.is-due .cx-stat-num{color:var(--amber-text);}
.cx-qcard{padding:16px 18px;}
.cx-qcard h3{font:900 16px var(--font-ui);margin:0 0 4px;}
.cx-qcard p{font:600 13px/1.5 var(--font-ui);color:var(--muted);margin:0 0 12px;}
.cx-more{font:900 13px var(--font-ui);color:var(--cink);text-decoration:none;}
.cx-more:hover{text-decoration:underline;}
.cx-links{display:grid;gap:10px;}
.cx-link{display:flex;align-items:center;gap:12px;background:var(--navy);color:var(--on-accent);border-radius:var(--radius);padding:14px 18px;text-decoration:none;box-shadow:var(--btn-shadow, var(--lift-sm));}
.cx-link:hover{background:var(--navy-press);color:var(--on-accent);}
.cx-link:focus-visible{outline:3px solid var(--accent);outline-offset:2px;}
.cx-link b{flex:1;font:900 14.5px var(--font-ui);}
.cx-link small{display:block;font:700 12px var(--font-ui);margin-top:2px;}
.cx-link span[aria-hidden]{font:900 18px var(--font-ui);}
@media (min-width:960px){ .cx-rail{position:sticky;top:calc(var(--site-header-h, 112px) + 14px);} }

/* ---- 3. Step builder and exam settings --------------------------------- */
.cx-builder{padding:clamp(18px,3.5vw,28px);}
.cx-step{border:0;margin:0 0 22px;padding:0 0 22px;border-bottom:1px solid var(--line-soft);min-width:0;}
.cx-step[hidden]{display:none;}
.cx-step:last-of-type{border-bottom:0;padding-bottom:0;}
.cx-step-h,.cx-step > legend{width:100%;display:flex;align-items:center;gap:10px;margin:0 0 12px;padding:0;font:900 15.5px var(--font-ui);color:var(--ink);}
.cx-step-n{flex:0 0 24px;height:24px;border-radius:50%;background:var(--ctint);color:var(--cink);font:900 12px var(--font-ui);display:flex;align-items:center;justify-content:center;}
.cx-step .cx-choices{margin:0;grid-template-columns:repeat(3,minmax(0,1fr));}
.cx-choices .cx-choice span:empty{display:none;}
.cx-choice b .premium-badge,.cx-choice b [data-premium-badge]{margin-left:6px;}
.cx-fields{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px;}
.cx-field{display:flex;flex-direction:column;gap:6px;min-width:0;margin:0 0 12px;}
.cx-fields .cx-field{margin:0;}
.cx-field > span{font:900 11px var(--font-ui);letter-spacing:.05em;text-transform:uppercase;color:var(--muted);}
.cx-field select{width:100%;min-height:46px;padding:10px 14px;border:0;border-radius:var(--radius);background:var(--surface2);box-shadow:inset 0 0 0 1.5px var(--line);font:800 14.5px var(--font-ui);color:var(--ink);}
.cx-group{border:0;margin:0 0 14px;padding:0;min-width:0;}
.cx-group > legend{font:900 11px var(--font-ui);letter-spacing:.05em;text-transform:uppercase;color:var(--muted);margin:0 0 8px;padding:0;}
.cx-pill{position:relative;}
.cx-pill input{position:absolute;opacity:0;width:1px;height:1px;margin:0;}
.cx-pill:has(input:focus-visible){outline:3px solid var(--accent);outline-offset:2px;}
.cx-pill:has(input:disabled){opacity:.5;cursor:not-allowed;}
.cx-pill small{font-weight:700;color:var(--muted);}
.cx-pill input[type=checkbox] + span::before{content:'';display:inline-block;width:14px;height:14px;margin-right:7px;vertical-align:-2px;border-radius:4px;box-shadow:inset 0 0 0 2px var(--muted);}
.cx-pill input[type=checkbox]:checked + span::before{background:var(--cink);box-shadow:none;}
.cx-pills .cx-pill{min-width:58px;justify-content:center;}
.cx-avail{font:700 12.5px/1.5 var(--font-ui);color:var(--muted);margin:10px 0 0;}
.cx-avail a{color:var(--accent-text);}
.cx-check{display:flex;align-items:flex-start;gap:9px;padding:6px 0;font:700 14px/1.4 var(--font-ui);color:var(--ink);cursor:pointer;}
.cx-check input{width:18px;height:18px;margin:1px 0 0;flex:none;accent-color:var(--cink);}
.cx-start{display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap;background:var(--surface2);border-radius:var(--radius);padding:14px 16px;}
.cx-sum{margin:0;flex:1 1 220px;min-width:0;font:800 13.5px/1.45 var(--font-ui);color:var(--ink);}
.cx-sum small{display:block;font:700 12px var(--font-ui);color:var(--muted);margin-top:2px;}
.cx-start .btn-press{flex:none;}
.cx-start + .cx-free,.cx-start ~ .cx-free{margin-top:12px;}
.cx-free .premium-badge{margin-left:4px;}
.cx-builder .premium-slot:empty{display:none;}
.cx-notice{background:var(--white);border-radius:var(--radius);box-shadow:var(--lift-sm);padding:14px 18px;margin:0;font:700 14px/1.55 var(--font-ui);color:var(--ink);}
.cx-notice b{font-weight:900;}
.cx-note{padding:14px 16px;border-radius:var(--radius);background:var(--surface2);margin:0 0 14px;font:600 14px/1.6 var(--font-ui);color:var(--ink);}
.cx-note p{margin:0 0 8px;}
.cx-note p:last-child{margin-bottom:0;}
@media (max-width:760px){ .cx-step .cx-choices{grid-template-columns:repeat(2,minmax(0,1fr));} }
@media (max-width:640px){ .cx-start .btn-press{width:100%;} }
@media (max-width:380px){ .cx-step .cx-choices{grid-template-columns:minmax(0,1fr);} }

/* ---- 4. Review ---------------------------------------------------------- */
.cx-empty-num{min-width:84px;padding:12px;font-size:34px;}
.cx-empty .cx-actions{margin-top:4px;}
.cx-queue .cx-empty p + p{margin-top:-6px;}
.cx-list{list-style:none;margin:0;padding:0;display:grid;gap:8px;}
.cx-list li{display:flex;align-items:center;gap:10px;flex-wrap:wrap;padding:11px 14px;border-radius:var(--radius);background:var(--white);box-shadow:var(--lift-sm);}
.cx-list li > div{flex:1 1 180px;display:flex;flex-direction:column;min-width:0;font:800 14px var(--font-ui);}
.cx-list li > div span{font:700 12.5px var(--font-ui);color:var(--muted);}
@media (max-width:520px){ .cx-empty{flex-direction:column;gap:12px;} }

/* ---- 5. Flashcards ------------------------------------------------------ */
.cx-deck .cx-field{max-width:560px;}
.cx-deckcard h2{margin:0 0 12px;}
.cx-deckcard .cx-stats{grid-template-columns:repeat(4,minmax(0,1fr));margin:0 0 12px;}
.cx-deckcard .cx-stat{box-shadow:none;background:var(--surface2);}
.cx-deckcard .cx-actions{margin:14px 0 0;}
.cx-deckcard .cx-caught{font:800 14px var(--font-ui);color:var(--ink);margin:0;}
.cx-how{font:600 13px/1.55 var(--font-ui);color:var(--muted);margin:14px 0 0;max-width:72ch;}
.cx-plist{padding:6px 18px;}
.cx-prow{display:grid;grid-template-columns:1fr auto;align-items:center;gap:4px 12px;width:100%;text-align:left;background:none;border:0;border-top:1px solid var(--line-soft);padding:11px 4px;font:inherit;color:var(--ink);cursor:pointer;}
.cx-prow:first-child{border-top:0;}
.cx-prow:hover{background:var(--hover-tint);}
.cx-prow[aria-pressed=true]{background:var(--ctint);}
.cx-prow .n{font:800 14px var(--font-ui);}
.cx-prow .n b{color:var(--muted);font-weight:900;margin-right:6px;}
.cx-prow .c{font:700 12px var(--font-ui);color:var(--muted);white-space:nowrap;}
.cx-prow .c .due{color:var(--amber-text);}
.cx-prow .bar{grid-column:1 / -1;height:5px;border-radius:99px;background:var(--track);overflow:hidden;}
.cx-prow .bar span{display:block;height:100%;background:var(--cink);}
@media (max-width:640px){ .cx-deckcard .cx-stats{grid-template-columns:repeat(2,minmax(0,1fr));} }

/* The card (was assets/flashcards.css, shared by NREMT and Ochem). */
.fc-stage{margin-top:4px;}
.fc-card{perspective:1400px;cursor:pointer;touch-action:pan-y;-webkit-tap-highlight-color:transparent;user-select:none;-webkit-user-select:none;}
.fc-face{background:var(--white);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);padding:22px 22px 18px;min-height:260px;display:flex;flex-direction:column;}
.fc-card.is-turning .fc-face{animation:fc-turn .32s ease-in-out;}
@keyframes fc-turn{0%{transform:rotateY(0)}50%{transform:rotateY(90deg)}100%{transform:rotateY(0)}}
.fc-card.is-dragging .fc-face{transition:none;}
.fc-face.fc-back{cursor:auto;user-select:text;-webkit-user-select:text;}
.fc-meta{display:flex;flex-wrap:wrap;gap:6px;align-items:center;font:800 11.5px var(--font-ui);color:var(--muted);}
.fc-meta .tag{padding:4px 10px;}
.fc-ask{margin:16px 0 0;font:800 14px var(--font-ui);color:var(--muted);}
.fc-q{margin:8px 0 0;font:900 clamp(22px,5.6vw,30px)/1.2 var(--font-ui);color:var(--ink);overflow-wrap:anywhere;}
.fc-front .fc-q{flex:1;display:flex;align-items:center;}
.fc-back .fc-q{font-size:18px;}
.fc-tap{margin:14px 0 0;font:700 12.5px var(--font-ui);color:var(--muted);text-align:center;}
.fc-ans{margin:14px 0 0;display:grid;gap:8px;}
.fc-ans div{background:var(--surface2);border-radius:12px;padding:10px 12px;}
.fc-ans dt{font:900 11px var(--font-ui);letter-spacing:.04em;text-transform:uppercase;color:var(--muted);}
.fc-ans dd{margin:3px 0 0;font:700 16px/1.45 var(--font-ui);color:var(--ink);overflow-wrap:anywhere;}
.fc-hint{margin:14px 0 0;font:800 16px/1.45 var(--font-ui);color:var(--ink);}
.fc-teach{margin:10px 0 0;font:600 14.5px/1.6 var(--font-ui);color:var(--ink);}
.fc-teach.long{font-size:13.5px;}
.fc-from{margin:16px 0 0;padding-top:12px;border-top:1px solid var(--line-soft);font:700 13px/1.5 var(--font-ui);color:var(--muted);}
.fc-from a{color:var(--accent-text);font-weight:800;}
.fc-grades{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:16px;}
.fc-grades button{display:grid;gap:2px;justify-items:center;min-height:56px;padding:8px 4px;border:0;border-radius:14px;font:900 14px var(--font-ui);cursor:pointer;color:var(--ink);background:var(--white);box-shadow:var(--shadow-card);}
.fc-grades button small{font:700 11.5px var(--font-ui);color:var(--muted);}
.fc-grades button:active{transform:translateY(1px);}
.fc-grades .g1{box-shadow:inset 0 0 0 2px var(--bad),var(--shadow-card);color:var(--bad-text);}
.fc-grades .g2{box-shadow:inset 0 0 0 2px var(--amber),var(--shadow-card);color:var(--amber-text);}
.fc-grades .g3{box-shadow:inset 0 0 0 2px var(--accent-bright),var(--shadow-card);color:var(--accent-text);}
.fc-grades .g4{box-shadow:inset 0 0 0 2px var(--good),var(--shadow-card);color:var(--good-text);}
.fc-flip{margin-top:16px;}
.fc-keys{margin:14px 0 0;font:700 12px var(--font-ui);color:var(--muted);text-align:center;}
.fc-keys kbd{font:800 11px var(--font-mono);background:var(--surface2);box-shadow:inset 0 0 0 1px var(--line);border-radius:5px;padding:1px 5px;}
.fc-swipe-hint{display:none;}
@media (hover:none) and (pointer:coarse){.fc-keys{display:none;}.fc-swipe-hint{display:block;}}
@media (max-width:420px){
  .fc-face{padding:18px 16px 16px;min-height:230px;}
  .fc-grades{gap:6px;}
  .fc-grades button{font-size:13px;min-height:54px;}
}
@media (prefers-reduced-motion:reduce){ .fc-card.is-turning .fc-face{animation:none;} }

/* ---- 6. In-session chrome and the question/answer card ------------------
   One bar (what this is, where you are, End), one progress track, one card,
   one set of answer rows, one feedback box and one Next row. */
.cx-session{max-width:820px;}
.cx-sbar{display:flex;align-items:center;gap:10px 14px;flex-wrap:wrap;margin:18px 0 10px;}
.cx-sbar-t{flex:1 1 auto;min-width:0;font:900 12px var(--font-ui);letter-spacing:.06em;text-transform:uppercase;color:var(--cink);}
.cx-sbar-n{font:800 13px var(--font-ui);color:var(--muted);}
.cx-sbar .cx-end,.cx-end{min-height:40px;padding:8px 16px;border:0;border-radius:var(--radius-pill);background:var(--white);box-shadow:inset 0 0 0 1.5px var(--line);font:800 13px var(--font-ui);color:var(--ink);cursor:pointer;}
.cx-end:hover{background:var(--hover-tint);}
.cx-progress{display:block;height:8px;border-radius:var(--radius-pill);background:var(--track);overflow:hidden;margin:0 0 16px;}
.cx-progress > i,.cx-progress > .fill,.cx-progress > div{display:block;height:100%;width:0;border-radius:var(--radius-pill);background:var(--cink);transition:width .25s ease;}
.cx-q{background:var(--white);border-radius:var(--radius-lg);box-shadow:var(--shadow-card);padding:clamp(18px,3vw,24px);}
.cx-q .cx-q-stem,.cx-q-stem{font:800 17px/1.5 var(--font-ui);color:var(--ink);margin:0 0 14px;}

/* Answer rows. Selected = course tint; right/wrong = colour AND a labelled
   mark (WCAG 1.4.1), the same words in every course. The engines' own state
   classes are accepted: is-right/is-wrong (A&P, Bio), correct/incorrect
   (NREMT), correct/wrong (Ochem). Rules are scoped under .cx-q so they win
   over the course stylesheets that load after this one. */
.cx-q .cx-opt{display:flex;align-items:flex-start;flex-wrap:wrap;gap:4px 10px;width:100%;margin:0;text-align:left;padding:12px 14px;border:0;border-radius:var(--radius);background:var(--surface2);box-shadow:inset 0 0 0 1.5px var(--line);color:var(--ink);font:700 15px/1.45 var(--font-ui);cursor:pointer;transform:none;transition:box-shadow .1s ease,background .1s ease;}
.cx-q .cx-opt:hover:not([aria-disabled="true"]):not(:disabled){box-shadow:inset 0 0 0 2px var(--cink);background:var(--surface2);transform:none;}
.cx-q .cx-opt:focus-visible{outline:3px solid var(--accent);outline-offset:2px;}
.cx-q .cx-opt.selected,.cx-q .cx-opt[aria-checked="true"]{background:var(--ctint);box-shadow:inset 0 0 0 2px var(--cink);}
.cx-q .cx-opt[aria-disabled="true"],.cx-q .cx-opt:disabled{cursor:default;opacity:1;}
.cx-q .cx-opt .letter{flex:0 0 26px;width:26px;height:26px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;background:var(--white);box-shadow:inset 0 0 0 1.5px var(--line);color:var(--muted);font:900 12px var(--font-ui);border:0;}
.cx-q .cx-opt.selected .letter,.cx-q .cx-opt[aria-checked="true"] .letter{background:var(--cink);color:var(--white);box-shadow:none;}
.cx-q .cx-opt > span:not(.letter):not(.sr-only):not([class*="why"]):not(.bio-mark):not(.chem-mark){flex:1 1 0;min-width:0;}
.cx-q .cx-opt [class*="opt-why"]{flex-basis:100%;display:block;font:600 13.5px/1.5 var(--font-ui);color:var(--muted);margin:2px 0 0;}
.cx-q .cx-opt:is(.is-right,.correct){background:var(--tint-good);box-shadow:inset 0 0 0 2px var(--good-text);}
.cx-q .cx-opt:is(.is-wrong,.incorrect,.wrong){background:var(--tint-bad);box-shadow:inset 0 0 0 2px var(--bad-text);}
.cx-q .cx-opt:is(.is-right,.correct) .letter{background:var(--good-text);color:var(--white);box-shadow:none;}
.cx-q .cx-opt:is(.is-wrong,.incorrect,.wrong) .letter{background:var(--bad-text);color:var(--white);box-shadow:none;}
.cx-q .cx-opt:is(.is-right,.correct,.is-wrong,.incorrect,.wrong)::before{order:9;display:inline-block;margin:0;padding:1px 8px;border-radius:var(--radius-pill);font:800 12px/1.6 var(--font-ui);white-space:nowrap;color:var(--white);vertical-align:1px;}
.cx-q .cx-opt:is(.is-right,.correct)::before{content:"\2713  Correct";content:"\2713  Correct" / "";background:var(--good-text);}
.cx-q .cx-opt:is(.is-wrong,.incorrect,.wrong)::before{content:"\2715  Your answer";content:"\2715  Your answer" / "";background:var(--bad-text);}
.cx-q .cx-opt:is(.is-right,.correct):is(.selected,[aria-checked="true"])::before{content:"\2713  Your answer, correct";content:"\2713  Your answer, correct" / "";}
.cx-q .cx-opt[role="checkbox"].is-right[aria-checked="false"]::before{content:"\2713  Missed";content:"\2713  Missed" / "";}
.cx-q .cx-opts{display:grid;gap:10px;margin:0 0 4px;}

/* Feedback: a verdict line with an icon and a word, the answer when wrong,
   then the explanation. */
.cx-q .cx-fb{margin:14px 0 0;padding:14px 16px;border-radius:var(--radius);background:var(--surface2);font:600 14.5px/1.6 var(--font-ui);color:var(--ink);box-shadow:none;border:0;}
.cx-q .cx-fb.is-right{box-shadow:inset 4px 0 0 var(--good-text);}
.cx-q .cx-fb.is-wrong{box-shadow:inset 4px 0 0 var(--bad-text);}
.cx-q .cx-fb:empty{display:none;}
.cx-q .cx-fb .cx-fb-head{display:flex;align-items:center;gap:8px;font:900 15px var(--font-ui);margin:0 0 6px;letter-spacing:0;text-transform:none;}
.cx-q .cx-fb .cx-fb-head::before{flex:0 0 22px;height:22px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;font:900 13px/1 var(--font-ui);color:var(--white);}
.cx-q .cx-fb.is-right .cx-fb-head{color:var(--good-text);}
.cx-q .cx-fb.is-right .cx-fb-head::before{content:"\2713";content:"\2713" / "";background:var(--good-text);}
.cx-q .cx-fb.is-wrong .cx-fb-head{color:var(--bad-text);}
.cx-q .cx-fb.is-wrong .cx-fb-head::before{content:"\2715";content:"\2715" / "";background:var(--bad-text);}
.cx-q .cx-fb p{margin:0 0 8px;}
.cx-q .cx-fb > :last-child{margin-bottom:0;}
.cx-explain{margin:8px 0 0;}

/* The way on: Next on the right, a "from" note on the left. */
.cx-next-row{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;margin:14px 0 0;}
.cx-next-row > :first-child:not(.btn-press):not(button){flex:1 1 220px;min-width:0;font:700 13px var(--font-ui);color:var(--muted);margin:0;}
.cx-next-row .btn-press,.cx-next{margin-left:auto;}
@media (max-width:640px){
  .cx-next-row .btn-press,.cx-next{width:100%;}
  .cx-sbar{margin-top:12px;}
}

/* NREMT: the weak-spot step before any history exists. */
#weakDomainsPanel:empty::before{content:"Answer a few questions and your weakest areas show here, each with a one-click drill.";display:block;font:700 13px/1.5 var(--font-ui);color:var(--muted);}
.premium-slot:empty{display:none;}
.cx-tag{display:inline-block;margin-left:6px;padding:1px 7px;border-radius:var(--radius-pill);background:var(--cink);color:var(--white);font:900 9.5px/1.6 var(--font-ui);letter-spacing:.06em;text-transform:uppercase;vertical-align:1px;}
.cx-choice b .cx-tag{display:inline-block;}
/* Bio's and Chemistry's renderers write a visible mark chip themselves
   (.bio-mark, .chem-mark); keep one. */
.cx-q .cx-opt:has(.bio-mark,.chem-mark)::before{content:none;display:none;}
.cx-q .cx-opt :is(.bio-mark,.chem-mark){order:9;}
.cx-q .cx-opt :is(.bio-mark,.chem-mark){flex:0 0 auto;margin-left:auto;white-space:nowrap;}
.cx-q .cx-opt:is(.is-right,.correct,.is-wrong,.incorrect,.wrong)::before{margin-left:auto;}
.cx-q .cx-opt [class*="opt-why"]{order:10;}
/* NREMT pages sit in .wrap, which pads its top; the opener spaces itself. */
.wrap.cx-study{padding-top:0;padding-bottom:20px;}
/* base.css draws the Beta pill text in --ctint, which is near-transparent in
   dark mode; the paper colour reads on --cink in both themes. */
.page-head .cx-beta{color:var(--paper);}