/* ==========================================================================
   OSN AI — practice banks
   Palette derives from matplotlib's tab10 cycle: the colour language these
   students already read in every plot they make.
   ========================================================================== */

:root {
  --paper:      #FAFAF7;
  --panel:      #FFFFFF;
  --ink:        #14181C;
  --muted:      #6E7671;
  --rule:       #DDE0DA;
  --rule-soft:  #ECEEE9;

  --blue:       #1F77B4;
  --blue-wash:  #EAF2F8;
  --orange:     #FF7F0E;
  --orange-wash:#FFF3E6;
  --green:      #2CA02C;
  --green-wash: #EBF6EB;
  --red:        #D62728;
  --red-wash:   #FBEDED;

  --display: "Space Grotesk", system-ui, sans-serif;
  --body: "Source Serif 4", Georgia, serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;

  --rail-w: 15rem;
  --measure: 42rem;
  color-scheme: light;
}

[data-theme="dark"] {
  --paper:      #15191D;
  --panel:      #1D2329;
  --ink:        #F2F4F0;
  --muted:      #B4BCB5;
  --rule:       #3A444B;
  --rule-soft:  #293139;

  --blue:       #64B5E9;
  --blue-wash:  #19384C;
  --orange:     #FFAD62;
  --orange-wash:#4A301B;
  --green:      #66C56B;
  --green-wash: #1D4124;
  --red:        #F47D7E;
  --red-wash:   #482527;
  color-scheme: dark;
}

[data-theme="dark"] .note.warn { color: #FFD4AB; }
[data-theme="dark"] .note.ok { color: #B7F3BB; }

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 1.0625rem;
  line-height: 1.65;
  font-variant-numeric: tabular-nums;
}

/* The plotting-canvas grid. Present everywhere, almost invisible. */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(to right, var(--rule-soft) 1px, transparent 1px),
    linear-gradient(to bottom, var(--rule-soft) 1px, transparent 1px);
  background-size: 2.5rem 2.5rem;
  mask-image: linear-gradient(to bottom, rgba(0,0,0,0.5), transparent 60rem);
  -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,0.5), transparent 60rem);
}

.shell { position: relative; z-index: 1; }

a { color: var(--blue); }

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
  border-radius: 2px;
}

h1, h2, h3 { font-family: var(--display); font-weight: 700; line-height: 1.15; margin: 0; }

/* --- Utility type ------------------------------------------------------- */

.eyebrow {
  font-family: var(--mono);
  font-size: 0.6875rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }

/* --- Masthead ----------------------------------------------------------- */

.masthead {
  border-bottom: 1px solid var(--rule);
  background: color-mix(in srgb, var(--paper) 85%, transparent);
  backdrop-filter: blur(8px);
}

.masthead-inner {
  max-width: 68rem;
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.625rem;
}

.wordmark {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.015em;
  text-decoration: none;
  color: var(--ink);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

/* A plot tick, drawn in the primary series colour. */
.wordmark::before {
  content: "";
  width: 0.5rem;
  height: 0.5rem;
  background: var(--blue);
  border-radius: 50%;
  box-shadow: 0 0 0 3px var(--blue-wash);
}

.masthead .spacer { flex: 1; }

.theme-toggle {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.04em;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 0.375rem 0.5rem;
  cursor: pointer;
  white-space: nowrap;
}

.theme-toggle:hover { border-color: var(--blue); color: var(--blue); }

/* --- Page frames -------------------------------------------------------- */

.page { max-width: 68rem; margin: 0 auto; padding: 1.75rem 1.5rem 4rem; }
.page-narrow { max-width: 46rem; }

.page-head { margin-bottom: 1.5rem; }
.page-head h1 {
  font-size: clamp(1.875rem, 4vw, 2.5rem);
  letter-spacing: -0.03em;
  margin: 0.375rem 0 0.5rem;
}
.page-head p {
  color: var(--muted);
  max-width: var(--measure);
  margin: 0;
}

/* --- Bank list ---------------------------------------------------------- */

.bank-list { display: grid; gap: 0.125rem; max-width: 42rem; }

.bank {
  display: grid;
  grid-template-columns: 2.25rem 1fr auto;
  gap: 0.5rem;
  align-items: center;
  padding: 0.25rem 0.5rem;
  background: var(--panel);
  border: 1px solid var(--rule);
  border-radius: 4px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.15s, transform 0.15s, box-shadow 0.15s;
}

.bank:hover {
  border-color: var(--blue);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px -6px rgba(31, 119, 180, 0.3);
}

.bank-num {
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 500;
  color: var(--blue);
  text-align: center;
  padding: 0;
  border: 1px solid var(--blue-wash);
  background: var(--blue-wash);
  border-radius: 3px;
}

.bank-title {
  font-family: var(--display);
  font-weight: 700;
  font-size: 1.1875rem;
  letter-spacing: -0.015em;
  margin: 0 0 0.125rem;
}

.bank-summary { color: var(--muted); font-size: 0.9375rem; margin: 0; line-height: 1.5; }

.bank-meta {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--muted);
  white-space: nowrap;
  text-align: right;
}

.bank-done {
  width: 1.125rem;
  height: 1.125rem;
  display: inline-grid;
  place-items: center;
  border-radius: 50%;
  background: var(--green);
  color: #fff;
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 500;
  margin-left: 0.375rem;
  vertical-align: 0.08em;
}

.bank-arrow { color: var(--blue); font-size: 1rem; }

/* --- Quiz layout: rail + column ---------------------------------------- */

.quiz-layout {
  display: grid;
  grid-template-columns: var(--rail-w) minmax(0, 1fr);
  gap: 1.75rem;
  align-items: start;
  max-width: 68rem;
  margin: 0 auto;
  padding: 1.5rem 1.5rem 4rem;
}

/* ==========================================================================
   SIGNATURE — the answer grid.
   During the quiz each cell reads "answered?". After submitting, the same
   cells re-read as "correct?". One instrument, two readings.
   ========================================================================== */

.rail { position: sticky; top: 1.5rem; }

.rail-label { margin-bottom: 0.75rem; display: block; }

.grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.3125rem;
  margin-bottom: 1.25rem;
}

.cell {
  aspect-ratio: 1;
  border: 1px solid var(--rule);
  background: var(--panel);
  border-radius: 2px;
  font-family: var(--mono);
  font-size: 0.625rem;
  color: var(--muted);
  cursor: pointer;
  padding: 0;
  display: grid;
  place-items: center;
  transition: background-color 0.15s, border-color 0.15s, color 0.15s;
}

.cell:hover { border-color: var(--ink); }

/* answered, not yet graded */
.cell.filled {
  background: var(--blue-wash);
  border-color: var(--blue);
  color: var(--blue);
}

/* graded readings */
.cell.correct { background: var(--green); border-color: var(--green); color: #fff; }
.cell.partial {
  border-color: var(--green);
  color: var(--green);
  background: linear-gradient(135deg, var(--green-wash) 50%, var(--panel) 50%);
}
.cell.wrong { background: var(--red-wash); border-color: var(--red); color: var(--red); }

/* Skipped reads as absence, not as failure: no colour, dashed edge. A student
   who ran out of time and one who misunderstood need different responses. */
.cell.skipped {
  background: var(--paper);
  border-style: dashed;
  border-color: var(--rule);
  color: var(--muted);
}

.rail-stat { display: flex; align-items: baseline; gap: 0.25rem; border-top: 1px solid var(--rule); padding-top: 0.875rem; }
.rail-stat-value { font-family: var(--mono); font-size: 1.5rem; font-weight: 500; }
.rail-stat-label { font-size: 0.75rem; color: var(--muted); font-family: var(--mono); }

.formula-card {
  margin-top: 1rem;
  padding-top: 0.875rem;
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 0.875rem;
  line-height: 1.45;
}
.formula-card[hidden] { display: none; }
.formula-card .eyebrow { display: block; margin-bottom: 0.5rem; }
.formula-card p { margin: 0.5rem 0; }
.formula-card .katex-display { margin: 0.5rem 0; font-size: 0.9em; }
.formula-card code { font-family: var(--mono); font-size: 0.9em; }

/* --- Quiz head ---------------------------------------------------------- */

.quiz-head { margin-bottom: 0.875rem; }
.quiz-head h1 {
  font-size: clamp(1.625rem, 3.5vw, 2.125rem);
  letter-spacing: -0.025em;
  margin: 0.375rem 0 0;
}

/* --- Name gate ---------------------------------------------------------- */

.gate {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--orange);
  border-radius: 4px;
  padding: 1rem;
  margin-bottom: 0.875rem;
}

.gate label { display: block; margin-bottom: 0.5rem; font-size: 0.9375rem; }

.field {
  font-family: var(--body);
  font-size: 1rem;
  padding: 0.625rem 0.75rem;
  border: 1px solid var(--rule);
  border-radius: 3px;
  background: var(--paper);
  color: var(--ink);
  width: 100%;
  max-width: 22rem;
}

.field:focus { outline: 2px solid var(--blue); outline-offset: 0; border-color: var(--blue); }
.field.invalid { border-color: var(--red); }

/* --- Part divider ------------------------------------------------------- */

.part-rule {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin: 1.5rem 0 0.75rem;
}
.part-rule::after { content: ""; flex: 1; height: 1px; background: var(--rule); }
.part-rule:first-child { margin-top: 0; }

/* Separate meetings clearly while keeping each meeting's bank rows compact. */
#banks .group + .group .part-rule { margin-top: 2rem; }

/* --- Question ----------------------------------------------------------- */

.q {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: 1.125rem 1.25rem;
  margin-bottom: 0.5rem;
  scroll-margin-top: 1.5rem;
}

.q-head { display: flex; align-items: baseline; gap: 0.75rem; margin-bottom: 0.625rem; }

.q-id {
  font-family: var(--mono);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--blue);
}

.q-type {
  font-family: var(--mono);
  font-size: 0.625rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  border: 1px solid var(--rule);
  border-radius: 2px;
  padding: 0.125rem 0.375rem;
}

.q-prompt > *:first-child { margin-top: 0; }
.q-prompt > *:last-child { margin-bottom: 0; }
.q-prompt p { margin: 0 0 0.75rem; }
.q-prompt ul { margin: 0 0 0.75rem; padding-left: 1.25rem; }
.q-prompt li { margin-bottom: 0.25rem; }
.q-prompt code {
  font-family: var(--mono);
  font-size: 0.875em;
  background: var(--rule-soft);
  padding: 0.1em 0.35em;
  border-radius: 2px;
}

.q-image {
  margin: 0.875rem 0;
  border: 1px solid var(--rule);
  border-radius: 3px;
  overflow: hidden;
  background: var(--panel);
}
.q-image img { display: block; width: 100%; height: auto; }

/* Figures authored as inline SVG in the bank rather than as an image file.
 * They draw with currentColor and carry no background, so they follow the
 * theme instead of punching a white slab into the dark one. */
.q-image svg { display: block; width: 100%; height: auto; }

/* Code listings. The renderer has no ``` fence: it joins lines with spaces,
   which would destroy indentation — the one thing Python cannot lose. Banks
   therefore write <pre class="code">, which passes through as raw HTML. */
pre.code {
  font-family: var(--mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  margin: 0.875rem 0;
  padding: 0.75rem 0.875rem;
  background: var(--rule-soft);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--blue);
  border-radius: 3px;
  overflow-x: auto;
  white-space: pre;
  tab-size: 4;
}

/* --- Code questions ----------------------------------------------------- */

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

.code-q { margin-top: 0.875rem; }

/* The tests are the specification, so they lead — she should read them before
   she writes anything. Orange marks them as a rule to obey, matching .hint. */
.code-q .uji {
  padding: 0.75rem 0.875rem 0.125rem;
  background: var(--orange-wash);
  border: 1px solid var(--rule);
  border-radius: 3px 3px 0 0;
  border-bottom: 0;
}
.code-q .uji .eyebrow { display: block; margin-bottom: 0.5rem; }
.code-q .uji pre.code {
  margin: 0 0 0.75rem;
  background: var(--panel);
  border-left-color: var(--orange);
}

.code-input {
  display: block;
  width: 100%;
  font-family: var(--mono);
  font-size: 0.8125rem;
  line-height: 1.6;
  tab-size: 4;
  padding: 0.75rem 0.875rem;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--rule);
  border-radius: 0;
  resize: vertical;
  white-space: pre;
  overflow-wrap: normal;
  overflow-x: auto;
}
.code-input:focus { outline: 2px solid var(--blue); outline-offset: -2px; border-color: var(--blue); }
.code-input:read-only { background: var(--rule-soft); color: var(--muted); }

.code-bar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.5rem 0.625rem;
  border: 1px solid var(--rule);
  border-top: 0;
  border-radius: 0 0 3px 3px;
  background: var(--rule-soft);
}
.btn-run { padding: 0.3125rem 0.875rem; font-size: 0.8125rem; }

.run-status { font-family: var(--mono); font-size: 0.75rem; color: var(--muted); }
.run-status.ok { color: var(--green); }
.run-status.no { color: var(--red); }

.code-help {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 0.6875rem;
  color: var(--muted);
}

.run-out { margin-top: 0.75rem; }

.uji-hasil { list-style: none; margin: 0; padding: 0; display: grid; gap: 0.25rem; }
.uji-hasil li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.5rem;
  align-items: baseline;
  padding: 0.375rem 0.625rem;
  border-radius: 3px;
  font-size: 0.8125rem;
}
.uji-hasil li.ok { background: var(--green-wash); }
.uji-hasil li.no { background: var(--red-wash); }
.uji-hasil code { font-family: var(--mono); font-size: 0.75rem; }
.uji-hasil .tick { font-family: var(--mono); font-weight: 700; }
.uji-hasil li.ok .tick { color: var(--green); }
.uji-hasil li.no .tick { color: var(--red); }
.uji-hasil .err {
  grid-column: 2;
  display: block;
  font-family: var(--mono);
  font-size: 0.6875rem;
  color: var(--red);
}

.run-fatal pre.code { border-left-color: var(--red); background: var(--red-wash); margin-top: 0.375rem; }
.run-stdout pre.code { border-left-color: var(--muted); margin-top: 0.375rem; }
.run-fatal .eyebrow, .run-stdout .eyebrow { display: block; }
.run-stdout { margin-top: 0.75rem; }

/* --- Choices ------------------------------------------------------------ */

.choices { display: grid; gap: 0.375rem; margin-top: 0.875rem; }

.choice {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.75rem;
  align-items: baseline;
  padding: 0.625rem 0.75rem;
  border: 1px solid var(--rule);
  border-radius: 3px;
  cursor: pointer;
  transition: border-color 0.12s, background-color 0.12s;
}

.choice:hover { border-color: var(--blue); background: var(--blue-wash); }
.choice input { margin: 0; accent-color: var(--blue); }
.choice-key { font-family: var(--mono); font-size: 0.8125rem; color: var(--muted); }
.choice.picked { border-color: var(--blue); background: var(--blue-wash); }

/* graded */
.choice.is-answer { border-color: var(--green); background: var(--green-wash); }
.choice.is-wrong  { border-color: var(--red);   background: var(--red-wash); }

.verdict {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  grid-column: 2;
}
.is-answer .verdict { color: var(--green); }
.is-wrong .verdict { color: var(--red); }

/* --- Blanks ------------------------------------------------------------- */

.blanks { display: grid; gap: 0.5rem; margin-top: 0.875rem; }

.blank {
  display: grid;
  grid-template-columns: auto 11rem;
  justify-content: end;
  gap: 0.5rem;
  align-items: center;
  padding: 0.5rem 0;
  border-bottom: 1px dotted var(--rule);
}
.blank:last-child { border-bottom: 0; }

.blank-label { font-size: 0.9375rem; text-align: right; }
.blank input { font-family: var(--mono); font-size: 0.9375rem; }

.blank-mark {
  font-family: var(--mono);
  font-size: 0.75rem;
  grid-column: 2;
  padding-top: 0.125rem;
}
.blank-mark.ok { color: var(--green); }
.blank-mark.no { color: var(--red); }

.blank input.ok { border-color: var(--green); background: var(--green-wash); }
.blank input.no { border-color: var(--red);   background: var(--red-wash); }

/* --- Solution ----------------------------------------------------------- */

.sol-toggle {
  margin-top: 0.875rem;
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  background: none;
  border: 1px solid var(--rule);
  border-radius: 3px;
  padding: 0.4375rem 0.75rem;
  color: var(--ink);
  cursor: pointer;
  transition: border-color 0.12s, color 0.12s;
}
.sol-toggle:hover { border-color: var(--orange); color: var(--orange); }
.sol-toggle[aria-expanded="true"] { border-color: var(--orange); color: var(--orange); }

.sol {
  margin-top: 1rem;
  padding: 1.25rem 1.25rem 1.25rem 1.5rem;
  border-left: 3px solid var(--orange);
  background: var(--orange-wash);
  border-radius: 0 3px 3px 0;
  font-size: 0.9375rem;
}
.sol[hidden] { display: none; }
.sol > *:first-child { margin-top: 0; }
.sol > *:last-child { margin-bottom: 0; }
.sol p { margin: 0 0 0.75rem; }
.sol ul, .sol ol { margin: 0 0 0.75rem; padding-left: 1.25rem; }
.sol li { margin-bottom: 0.375rem; }
.sol code {
  font-family: var(--mono);
  font-size: 0.875em;
  background: rgba(255, 127, 14, 0.13);
  padding: 0.1em 0.35em;
  border-radius: 2px;
}

/* --- Buttons ------------------------------------------------------------ */

.btn {
  font-family: var(--display);
  font-weight: 500;
  font-size: 0.9375rem;
  padding: 0.6875rem 1.25rem;
  border-radius: 3px;
  border: 1px solid var(--ink);
  background: var(--ink);
  color: var(--paper);
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: background-color 0.12s, border-color 0.12s, color 0.12s;
}
.btn:hover { background: var(--blue); border-color: var(--blue); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn:disabled:hover { background: var(--ink); border-color: var(--ink); }

.btn-ghost { background: none; color: var(--ink); border-color: var(--rule); }
.btn-ghost:hover { background: none; border-color: var(--ink); color: var(--ink); }

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
}

/* --- Result banner ------------------------------------------------------ */

.result {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--green);
  border-radius: 4px;
  padding: 1.25rem;
  margin-bottom: 1rem;
  scroll-margin-top: 1.5rem;
}
.result[hidden] { display: none; }

.result-score {
  font-family: var(--mono);
  font-size: clamp(2.25rem, 6vw, 3.25rem);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.03em;
  margin: 0.5rem 0;
}
.result-score .of { color: var(--muted); font-size: 0.4em; }
.result-line { color: var(--muted); font-size: 0.9375rem; margin: 0; }

.note {
  font-family: var(--mono);
  font-size: 0.75rem;
  margin-top: 1rem;
  padding: 0.5rem 0.75rem;
  border-radius: 3px;
}
.note.warn { background: var(--orange-wash); color: #8a4400; }
.note.ok { background: var(--green-wash); color: #1a6b1a; }
.note[hidden] { display: none; }

/* --- Admin table -------------------------------------------------------- */

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--panel);
}

table { border-collapse: collapse; width: 100%; font-size: 0.875rem; }

th {
  font-family: var(--mono);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  text-align: left;
  font-weight: 500;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--rule);
  white-space: nowrap;
}

td { padding: 0.75rem 1rem; border-bottom: 1px solid var(--rule-soft); }
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: var(--paper); }
td.num { font-family: var(--mono); text-align: right; font-variant-numeric: tabular-nums; }

.pct { font-family: var(--mono); font-weight: 500; }
.pct.hi { color: var(--green); }
.pct.mid { color: var(--orange); }
.pct.lo { color: var(--red); }

.empty { padding: 3rem 1.5rem; text-align: center; color: var(--muted); }

/* --- Instructions (Petunjuk jawaban) ------------------------------------ */

/* These banks mark a right value in the wrong format as wrong, so the format
   rules are load-bearing content, not boilerplate. */
.instructions {
  background: var(--blue-wash);
  border: 1px solid color-mix(in srgb, var(--blue) 25%, transparent);
  border-radius: 4px;
  padding: 0.875rem 1rem;
  margin-bottom: 0.875rem;
  font-size: 0.9375rem;
}
.instructions > *:first-child { margin-top: 0; }
.instructions > *:last-child { margin-bottom: 0; }
.instructions p { margin: 0 0 0.5rem; }
.instructions code {
  font-family: var(--mono);
  font-size: 0.875em;
  background: rgba(31, 119, 180, 0.14);
  padding: 0.1em 0.35em;
  border-radius: 2px;
}

.q-name {
  font-family: var(--display);
  font-weight: 500;
  font-size: 0.9375rem;
  color: var(--muted);
}

.hint {
  font-size: 0.8125rem;
  color: var(--orange);
  font-style: italic;
  margin-top: 0.5rem;
}

/* Fill-in format rules sit under the field they describe, not under the prompt. */
.blanks + .hint {
  width: 11rem;
  margin: 0.375rem 0 0 auto;
  text-align: right;
}

/* --- Rich content: tables and quotes ------------------------------------ */

.table-scroll {
  overflow-x: auto;
  margin: 1rem 0;
  border: 1px solid var(--rule);
  border-radius: 3px;
}

.table-scroll table { font-size: 0.875rem; width: 100%; }

/* Reset the admin-table treatment: headers here hold math, not field names. */
.table-scroll th {
  font-family: var(--body);
  font-size: 0.875rem;
  letter-spacing: 0;
  text-transform: none;
  color: var(--ink);
  font-weight: 600;
  background: var(--rule-soft);
  padding: 0.5rem 0.75rem;
  white-space: normal;
}
.table-scroll td { padding: 0.5rem 0.75rem; }
.table-scroll tbody tr:hover { background: transparent; }

.sol .table-scroll { border-color: color-mix(in srgb, var(--orange) 30%, transparent); }
.sol .table-scroll th { background: rgba(255, 127, 14, 0.1); }
.sol .table-scroll td { border-bottom-color: rgba(255, 127, 14, 0.15); }

blockquote {
  margin: 1rem 0;
  padding: 0.75rem 1rem;
  border-left: 3px solid var(--blue);
  background: var(--blue-wash);
  border-radius: 0 3px 3px 0;
}
blockquote p { margin: 0; }

/* --- KaTeX ------------------------------------------------------------- */

.katex { font-size: 1.03em; }
.katex-display { margin: 0.875rem 0; overflow-x: auto; overflow-y: hidden; padding: 0.125rem 0; }

/* --- Responsive --------------------------------------------------------- */

@media (max-width: 60rem) {
  .quiz-layout { grid-template-columns: minmax(0, 1fr); gap: 0.75rem; }

  /* Grid/flex children default to min-width:auto, so the 18 cells would set a
     min-content floor wider than a phone and push the whole layout sideways. */
  .rail, .grid { min-width: 0; }

  .rail {
    position: sticky;
    top: 0;
    z-index: 5;
    background: color-mix(in srgb, var(--paper) 92%, transparent);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--rule);
    padding: 0.75rem 0;
    margin: 0 -1.5rem;
    padding-inline: 1.5rem;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 0.5rem 1rem;
  }

  .rail-label { display: none; }

  .grid {
    grid-template-columns: repeat(auto-fit, minmax(1.25rem, 1fr));
    margin-bottom: 0;
    grid-column: 1;
  }

  .cell { font-size: 0; }

  .rail-stat { grid-column: 2; grid-row: 1; border-top: 0; padding-top: 0; text-align: right; white-space: nowrap; }
  .rail-stat-value { font-size: 1.125rem; }
  .rail-stat-label { display: inline; }
  .formula-card { grid-column: 1 / -1; margin-top: 0; padding-top: 0.5rem; }
}

@media (max-width: 40rem) {
  body { font-size: 1rem; }
  .masthead-inner { padding: 0.625rem 1.25rem; }
  .page { padding: 1.25rem 1.25rem 3rem; }
  .quiz-layout { padding: 1rem 1.25rem 3rem; }
  .rail { margin: 0 -1.25rem; padding-inline: 1.25rem; }
  .q { padding: 1rem; }
  .bank { grid-template-columns: 2.25rem 1fr; gap: 0.5rem; padding: 0.25rem; }
  .bank-meta, .bank-arrow { display: none; }
  .blank { grid-template-columns: auto minmax(9rem, 11rem); gap: 0.5rem; }
  .blank-mark { grid-column: 2; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

@media print {
  .rail, .actions, .sol-toggle, .masthead { display: none; }
  .sol[hidden] { display: block !important; }
  body::before { display: none; }
}