/* ============================================================================
   questions.css  —  worksheet items + gated solutions
   Sits beside editor-notes.css: same left-border-accent language, same
   small-caps auto-headers, same .quarto-dark dark-mode hook.

   Worksheet content is authored as Quarto MARKDOWN inside fenced divs, so
   inline math is $ … $ and paragraphs/lists render normally. Choice letters
   (A, B, C, D) are drawn by a CSS counter, so a choice is just a list item.

   Semantic color coding (information, not decoration):
     indigo  = a solution / answer region
     green   = the correct choice / accepted answer
     red     = a named misconception
   ==========================================================================*/

:root {
  --q-ink:        #1f2328;
  --q-muted:      #5a5a5a;
  --q-line:       #e4e4e4;
  --q-card-bg:    #ffffff;

  --sol-accent:   #4b4f9a;   /* indigo: "here be answers" */
  --sol-bg:       #f5f5fb;
  --sol-rule:     #dedcef;

  --ok-ink:       #2f6249;   /* correct / accepted (matches editorial green) */
  --ok-bg:        #e7f2ec;
  --mis-ink:      #a13d2e;   /* misconception (matches editorial red) */
}

/* ---- Question card ---- */
.q {
  border: 1px solid var(--q-line);
  border-radius: 6px;
  background: var(--q-card-bg);
  padding: 1.1rem 1.3rem 1.25rem;
  margin: 1.6rem 0;
}

/* Header. Authored as [Question 1]{.q-num} [..]{.q-kind} [..]{.q-points}; */
.q-head {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 0.7rem;
  padding-bottom: 0.55rem;
  border-bottom: 1px solid var(--q-line);
}
.q-head > p { display: contents; margin: 0; }
.q-num    { font-weight: 700; letter-spacing: 0.01em; }
.q-kind {
  font-variant: small-caps; letter-spacing: 0.06em;
  font-size: 0.78rem; color: var(--q-muted);
}
.q-points {
  margin-left: auto; font-size: 0.8rem; color: var(--q-muted);
  white-space: nowrap;
}

.q-stem { margin: 0 0 0.9rem; }
.q-stem > p:first-child { margin-top: 0; }
.q-stem > p:last-child  { margin-bottom: 0; }

/* ---- Multiple choice (a plain ordered list; letters via counter) ---- */
.q-choices > ol {
  list-style: none; margin: 0; padding: 0;
  display: grid; gap: 0.5rem;
  counter-reset: choice;
}
.q-choices > ol > li {
  position: relative;
  padding: 0.55rem 0.7rem 0.55rem 3rem;   /* room for the badge on the left */
  border: 1px solid var(--q-line);
  border-radius: 5px;
  counter-increment: choice;
}
.q-choices > ol > li::before {
  content: counter(choice, upper-alpha);   /* A, B, C, D … */
  position: absolute;
  left: 0.55rem; top: 0.5rem;
  display: grid; place-items: center;
  width: 1.9rem; height: 1.9rem;
  border: 1px solid var(--sol-accent);
  border-radius: 50%;
  font-weight: 700; font-size: 0.9rem;
  color: var(--sol-accent);
}

/* ---- Free-response writing space (prints with room to write) ----- */
.q-response {
  min-height: 6.5rem;
  border: 1px dashed var(--q-line);
  border-radius: 5px;
  background:
    repeating-linear-gradient(
      to bottom, transparent, transparent 1.55rem,
      var(--q-line) 1.55rem, var(--q-line) calc(1.55rem + 1px));
  background-position: 0 0.9rem;
}
.q-response::before {
  content: "Your answer";
  display: block;
  font-variant: small-caps; letter-spacing: 0.06em;
  font-size: 0.72rem; color: var(--q-muted);
  padding: 0.3rem 0.6rem 0;
}

/* ---- Solution slot (filled by solutions.js on unlock) ---- */
.qsol {
  border-left: 3px solid var(--sol-accent);
  border-radius: 0 4px 4px 0;
  background: var(--sol-bg);
  padding: 0.9rem 1.15rem;
  margin-top: 1rem;
  font-size: 0.95rem; line-height: 1.55;
}
.qsol::before {
  content: "Solution";
  display: block;
  font-variant: small-caps; letter-spacing: 0.06em; font-weight: 600;
  color: var(--sol-accent);
  padding-bottom: 0.35rem; margin-bottom: 0.6rem;
  border-bottom: 1px solid var(--sol-rule);
}
.qsol > p:first-of-type { margin-top: 0; }
.qsol > *:last-child { margin-bottom: 0; }

@keyframes sol-in { from { opacity: 0; transform: translateY(2px); } to { opacity: 1; } }
.qsol.is-unlocked { animation: sol-in 180ms ease-out; }
@media (prefers-reduced-motion: reduce) { .qsol.is-unlocked { animation: none; } }

/* pieces inside a solution */
.sol-answer { font-size: 1.02rem; }
.sol-model {
  border-left: 2px solid var(--ok-ink);
  background: var(--ok-bg);
  padding: 0.55rem 0.8rem; border-radius: 0 4px 4px 0; margin: 0.7rem 0;
}
.sol-model > p:first-child { margin-top: 0; }
.sol-model > p:last-child  { margin-bottom: 0; }
.sol-explain { margin: 0.7rem 0; }
.sol-feedback-title {
  font-variant: small-caps; letter-spacing: 0.05em; font-weight: 600;
  color: var(--q-muted); margin: 0.9rem 0 0.4rem;
}

/* per-distractor feedback: badge in col 1, BOTH text spans in col 2 ---- */
.sol-feedback { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.6rem; }
.sol-feedback > li {
  display: grid;
  grid-template-columns: 1.9rem 1fr;   /* badge | body */
  gap: 0.6rem;
  align-items: start;
}
.sol-feedback .opt {
  display: grid; place-items: center; width: 1.9rem; height: 1.9rem;
  border-radius: 50%; font-weight: 700; font-size: 0.8rem;
  color: var(--mis-ink); border: 1px solid var(--mis-ink);
}
.sol-feedback .opt-body {           /* the single col-2 cell; fills 1fr */
  display: grid; gap: 0.25rem;
}
.sol-feedback .opt-mis { color: var(--mis-ink); font-style: italic; }
.sol-feedback .opt-why { color: var(--q-ink); }

/* rubric table */
.sol-rubric { width: 100%; border-collapse: collapse; margin: 0.7rem 0; font-size: 0.92rem; }
.sol-rubric caption {
  text-align: left; font-variant: small-caps; letter-spacing: 0.05em;
  font-weight: 600; color: var(--q-muted); padding-bottom: 0.35rem;
}
.sol-rubric th, .sol-rubric td {
  border-top: 1px solid var(--sol-rule); padding: 0.4rem 0.55rem; text-align: left;
  vertical-align: top;
}
.sol-rubric th:first-child, .sol-rubric td:first-child {
  width: 2.5rem; text-align: center; font-weight: 700; color: var(--ok-ink);
}

.sol-accepted { margin: 0.7rem 0; }
.sol-ref { margin-top: 0.7rem; font-size: 0.85rem; color: var(--q-muted); }

/* badges */
.badge {
  display: inline-block; font-variant: small-caps; letter-spacing: 0.05em;
  font-size: 0.72rem; font-weight: 700; padding: 0.05em 0.5em;
  border-radius: 999px; margin-right: 0.35em;
  background: var(--sol-rule); color: var(--sol-accent);
}
.badge-correct { background: var(--ok-bg); color: var(--ok-ink); }

/* ---- The password gate --- */
.solutions-gate { margin: 1.4rem 0; }
.gate-inner {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.6rem;
  padding: 0.75rem 1rem;
  border: 1px solid var(--sol-rule); border-left: 3px solid var(--sol-accent);
  border-radius: 0 5px 5px 0; background: var(--sol-bg);
}
.gate-lock {
  width: 0.8rem; height: 0.7rem; border: 2px solid var(--sol-accent);
  border-radius: 2px; position: relative; flex: none;
}
.gate-lock::before {
  content: ""; position: absolute; left: 50%; top: -0.42rem; transform: translateX(-50%);
  width: 0.5rem; height: 0.42rem; border: 2px solid var(--sol-accent);
  border-bottom: none; border-radius: 4px 4px 0 0;
}
.gate-lock.is-open::before { left: 20%; }
.gate-label { font-variant: small-caps; letter-spacing: 0.05em; font-weight: 600; color: var(--sol-accent); }
.gate-input {
  flex: 1 1 12rem; min-width: 9rem;
  padding: 0.4rem 0.6rem; border: 1px solid var(--sol-rule);
  border-radius: 4px; background: var(--q-card-bg); color: var(--q-ink);
}
.gate-btn {
  padding: 0.42rem 1rem; border: 1px solid var(--sol-accent); border-radius: 4px;
  background: var(--sol-accent); color: #fff; font-weight: 600; cursor: pointer;
}
.gate-btn:hover { filter: brightness(1.08); }
.gate-btn:disabled { opacity: 0.6; cursor: progress; }
.gate-btn-ghost { background: transparent; color: var(--sol-accent); }
.gate-status { flex-basis: 100%; margin: 0; font-size: 0.85rem; color: var(--q-muted); }
.solutions-gate.is-error .gate-input { border-color: var(--mis-ink); }
.solutions-gate.is-error .gate-status { color: var(--mis-ink); }
.gate-input:focus-visible, .gate-btn:focus-visible { outline: 2px solid var(--sol-accent); outline-offset: 2px; }

@media print {
  .solutions-gate { display: none; }
  .qsol[hidden] { display: none; }
  .q { break-inside: avoid; border-color: #bbb; }
}

/* ============================ Dark mode ================================= */
.quarto-dark {
  --q-ink:     #dfe2e7;
  --q-muted:   #a7adb6;
  --q-line:    #333a44;
  --q-card-bg: #1b1f26;

  --sol-accent: #9aa0e6;
  --sol-bg:     #20222e;
  --sol-rule:   #343755;

  --ok-ink:  #9dd3b4;
  --ok-bg:   #1b241f;
  --mis-ink: #e0a498;
}
.quarto-dark .gate-btn { color: #14161c; }