/* ===================================================================
   Tidal — Learn page styles (v2)
   -------------------------------------------------------------------
   Builds ON TOP of css/styles.css (loaded first): reuses every CSS
   custom property and the .scope / .wave-* / .ctrl / .seg / .t-btn
   component classes. This file adds the lesson map, the step-by-step
   lesson view, prose typography, and the demo / quiz / predict /
   classify / mission cards. The waveform scope stays dark in both themes.
   =================================================================== */

/* smooth in-page navigation (respect reduced-motion) */
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

/* ---------------- page chrome ---------------- */
.learn-body #topbar { position: sticky; top: 0; z-index: 50; }
.brand { text-decoration: none; }
a.brand:hover .brand-name { color: var(--accent); }

#app { max-width: 780px; margin: 0 auto; padding: 22px 22px 40px; min-height: 60vh; }

.part-kicker { font-size: 11px; font-weight: 700; letter-spacing: 1.6px; text-transform: uppercase; color: var(--accent); margin: 0 0 6px; }
:root[data-theme="light"] .part-kicker { color: var(--accent-dim); }
.sub-title { font-size: 18px; font-weight: 700; color: var(--text-bright); margin: 28px 0 8px; }

/* primary action button (accent fill) */
.hero-go {
  display: inline-block; margin-top: 14px; padding: 10px 16px; border-radius: 8px;
  background: var(--accent); color: #04110f; font-weight: 800; font-size: 14px; text-decoration: none;
}
.hero-go:hover { filter: brightness(1.08); }
a.t-btn { text-decoration: none; display: inline-flex; align-items: center; }

/* ---------------- lesson map (home) ---------------- */
.hero { padding: 10px 0 8px; }
.hero-title { font-size: 30px; font-weight: 800; color: var(--text-bright); margin: 0 0 8px; letter-spacing: -.3px; }
.hero-intro { font-size: 15.5px; line-height: 1.6; color: var(--text); margin: 0; max-width: 62ch; }
.tier { margin-top: 30px; }
.tier-title { font-size: 19px; font-weight: 800; color: var(--text-bright); margin: 0 0 4px; }
.tier-blurb { font-size: 14px; color: var(--text-dim); margin: 0 0 12px; }
.lgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 12px; }
.lcard {
  display: flex; flex-direction: column; gap: 6px; padding: 14px 15px; border-radius: 12px;
  background: var(--bg-panel); border: 1px solid var(--border-lt); text-decoration: none; color: var(--text);
}
a.lcard:hover { border-color: var(--accent); }
.lcard-num { font-size: 10.5px; font-weight: 700; letter-spacing: 1.2px; text-transform: uppercase; color: var(--text-dim); }
.lcard-title { font-size: 15.5px; font-weight: 800; color: var(--text-bright); line-height: 1.3; }
.lcard-obj { font-size: 13px; line-height: 1.45; color: var(--text); flex: 1; }
.lcard-foot { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-top: 4px; }
.lcard-min { font-family: var(--mono); font-size: 11.5px; color: var(--text-dim); }
.chip { font-size: 11px; font-weight: 700; padding: 2px 8px; border-radius: 10px; border: 1px solid var(--border-lt); color: var(--text-dim); white-space: nowrap; }
.chip-done { color: var(--good); border-color: var(--good); }
.chip-going { color: var(--accent); border-color: var(--accent-dim); }
.chip-new { color: var(--text); }

/* ---------------- lesson view ---------------- */
.lesson-back { display: inline-block; font-size: 13px; color: var(--text-dim); text-decoration: none; margin-bottom: 14px; }
.lesson-back:hover { color: var(--text-bright); }
.lesson-title { font-size: 28px; font-weight: 800; color: var(--text-bright); margin: 0 0 8px; letter-spacing: -.3px; line-height: 1.2; }
.lesson-obj { font-size: 15px; line-height: 1.55; color: var(--text); margin: 0; }
.lesson-obj b { color: var(--text-bright); }

.step { padding-top: 22px; }
.step + .step { border-top: 1px solid var(--border); margin-top: 26px; }
.step-kind { font-size: 11px; font-weight: 700; letter-spacing: 1.2px; text-transform: uppercase; color: var(--text-dim); }
.step-title { font-size: 21px; font-weight: 800; color: var(--text-bright); margin: 4px 0 10px; }

.continue-bar {
  display: flex; align-items: center; justify-content: flex-end; gap: 14px; flex-wrap: wrap;
  margin: 24px 0 0; padding: 14px 0 0; border-top: 1px dashed var(--border);
}
.continue-hint { font-size: 13px; color: var(--text-dim); }
.continue-btn {
  padding: 11px 20px; border-radius: 8px; border: none; cursor: pointer; font-family: inherit;
  background: var(--accent); color: #04110f; font-weight: 800; font-size: 14.5px;
}
.continue-btn:disabled { background: var(--bg-panel2); color: var(--text-dim); border: 1px solid var(--border-lt); cursor: not-allowed; }
.lesson-done {
  margin-top: 28px; padding: 18px; border-radius: 12px; text-align: center;
  background: color-mix(in srgb, var(--good) 10%, var(--bg-panel)); border: 1px solid color-mix(in srgb, var(--good) 50%, var(--border));
}
.lesson-done-title { font-size: 18px; font-weight: 800; color: var(--text-bright); }
.lesson-done-row { display: flex; gap: 10px; justify-content: center; align-items: center; flex-wrap: wrap; margin-top: 8px; }
.lesson-done-row .hero-go { margin-top: 0; }

/* ---------------- prose ---------------- */
.prose { font-size: 15.5px; line-height: 1.65; color: var(--text); }
.prose p { margin: 0 0 12px; }
.prose b, .prose strong { color: var(--text-bright); }
.prose ul, .prose ol { margin: 0 0 12px; padding-left: 22px; }
.prose li { margin-bottom: 7px; }
.prose a, .mission a { color: var(--accent); text-decoration: none; border-bottom: 1px solid var(--accent-dim); }
:root[data-theme="light"] .prose a, :root[data-theme="light"] .mission a { color: var(--accent-dim); }
.prose a:hover { color: var(--text-bright); }
.prose code, code.inl {
  font-family: var(--mono); font-size: .92em; background: var(--bg-panel2);
  border: 1px solid var(--border); border-radius: 4px; padding: 1px 5px; color: var(--text-bright);
}
.eqn {
  font-family: var(--mono); font-size: 15px; color: var(--text-bright);
  background: var(--bg-panel2); border: 1px solid var(--border); border-left: 3px solid var(--accent);
  border-radius: 8px; padding: 12px 16px; margin: 14px 0; overflow-x: auto; line-height: 1.5;
}
.eqn small { color: var(--text-dim); }

/* ---------------- layered concept tiers ---------------- */
.layer { margin: 14px 0; border: 1px solid var(--border); border-radius: 10px; overflow: hidden; }
.layer-tier { padding: 12px 15px; font-size: 14.5px; line-height: 1.6; color: var(--text); }
.layer-tier + .layer-tier { border-top: 1px solid var(--border); }
.layer-tier .tier-label {
  display: inline-block; font-size: 10px; font-weight: 700; letter-spacing: 1px; text-transform: uppercase;
  padding: 2px 8px; border-radius: 10px; margin-bottom: 7px;
}
.layer-tier p { margin: 0 0 10px; }
.layer-tier p:last-child { margin-bottom: 0; }
.tier-intuition { background: color-mix(in srgb, var(--accent) 7%, transparent); }
.tier-intuition .tier-label { color: var(--accent); border: 1px solid var(--accent-dim); }
.tier-mechanism .tier-label { color: var(--c-vol); border: 1px solid var(--c-vol); }
.tier-rigor { background: var(--bg-panel2); }
.tier-rigor[open] summary { margin-bottom: 9px; }
details.tier-rigor > summary { cursor: pointer; list-style: none; font-size: 13.5px; font-weight: 600; color: var(--text-dim); }
details.tier-rigor > summary::-webkit-details-marker { display: none; }
details.tier-rigor > summary::before { content: "▸ "; color: var(--c-effort); }
details.tier-rigor[open] > summary::before { content: "▾ "; }

/* ---------------- callout notes ---------------- */
.note {
  margin: 14px 0; padding: 12px 14px; border-radius: 8px; font-size: 14.5px; line-height: 1.58;
  border: 1px solid var(--border); border-left-width: 3px; background: var(--bg-panel);
}
.note b { color: var(--text-bright); }
.note .note-tag { font-weight: 700; letter-spacing: .3px; margin-right: 4px; }
.note-model { border-left-color: var(--warn); }
.note-model .note-tag { color: var(--warn); }
.note-clinical { border-left-color: var(--c-flow); }
.note-clinical .note-tag { color: var(--c-flow); }
.note-tip { border-left-color: var(--accent); }
.note-tip .note-tag { color: var(--accent); }
:root[data-theme="light"] .note-tip .note-tag { color: var(--accent-dim); }

/* ---------------- demo figures ---------------- */
.demo-fig { margin: 16px 0; background: var(--bg-panel); border: 1px solid var(--border); border-radius: 12px; padding: 12px; }
.demo-title { font-size: 13px; font-weight: 700; color: var(--text-bright); margin: 0 0 9px; letter-spacing: .2px; }
.demo-scope-wrap { position: relative; }
.scope.compact { padding: 5px 7px 5px 0; }
.scope.compact .wave-row { height: 112px; }
.demo-loops { margin-top: 10px; }
.demo-loops .loop-canvas { height: 210px; }
.demo-loops .loop-head > span { font-size: 10px; }

/* sandbox controls */
.demo-controls {
  margin-top: 11px; padding-top: 11px; border-top: 1px dashed var(--border);
  display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 8px 18px;
}
.demo-controls .ctrl { margin-bottom: 2px; }
.demo-controls .ctrl-label { font-size: 12px; }

/* key teaching sentences live in captions, so keep them readable */
.demo-caption { font-size: 14px; color: var(--text); line-height: 1.55; margin: 10px 2px 0; }
.demo-caption b { color: var(--text-bright); }
.demo-open {
  display: inline-block; margin-top: 10px; font-size: 12.5px; font-weight: 700; color: var(--accent);
  text-decoration: none; border: 1px solid var(--accent-dim); border-radius: 6px; padding: 5px 11px;
}
:root[data-theme="light"] .demo-open { color: var(--accent-dim); }
.demo-open:hover { background: var(--accent); color: #04110f; }

/* live monitor readouts */
.demo-readouts { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.ro {
  display: flex; align-items: baseline; gap: 6px; padding: 6px 10px; border-radius: 8px;
  background: var(--bg-scope); border: 1px solid #1d2633; min-width: 92px;
}
.ro-l { font-size: 11px; font-weight: 700; color: #7c8aa0; letter-spacing: .3px; }
.ro-v { font-family: var(--mono); font-size: 20px; font-weight: 700; color: #eef3fa; }
.ro-u { font-size: 10px; color: #7c8aa0; }
.ro.ro-wait .ro-v { color: #4b5768; }
.ro.ro-new { animation: roFlash 1.2s ease-out; }
@keyframes roFlash { 0% { border-color: var(--accent); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 35%, transparent); } 100% { border-color: #1d2633; box-shadow: none; } }
@media (prefers-reduced-motion: reduce) { .ro.ro-new { animation: none; border-color: var(--accent); } }

/* hold + effort buttons */
.demo-tools { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.dt-btn {
  padding: 7px 12px; border-radius: 7px; cursor: pointer; font-family: inherit; font-size: 13px; font-weight: 700;
  background: var(--bg-panel2); color: var(--text-bright); border: 1px solid var(--border-lt);
}
.dt-btn:hover { border-color: var(--accent-dim); }
.dt-btn.armed { background: var(--warn); border-color: var(--warn); color: #1a1205; }
.dt-effort.on { border-color: var(--c-effort); color: var(--c-effort); }

/* pressure budget: PEEP + elastic + resistive */
.budget { margin-top: 12px; }
.budget-title { font-size: 11px; font-weight: 700; letter-spacing: .4px; text-transform: uppercase; color: var(--text-dim); margin-bottom: 5px; }
.budget-bar { display: flex; height: 16px; border-radius: 5px; overflow: hidden; background: var(--bg-panel2); border: 1px solid var(--border); }
.bseg { height: 100%; transition: width .25s ease; }
.bseg-peep { background: #6f7e93; }
.bseg-el { background: var(--c-vol); }
.bseg-res { background: var(--c-paw); }
.budget-txt { font-family: var(--mono); font-size: 13px; color: var(--text); margin-top: 5px; }
.budget-txt b { color: var(--text-bright); }
.budget-txt small { color: var(--text-dim); }
.bt-peep { color: var(--text-dim); }
.bt-el { color: var(--c-vol); font-weight: 700; }
.bt-res { color: var(--c-paw); font-weight: 700; }
:root[data-theme="light"] .bt-el { color: #0b7fb3; }
:root[data-theme="light"] .bt-res { color: #a07800; }

/* fraction-positioned annotation overlay (legacy; data-anchored marks are drawn on canvas) */
.demo-anno-layer { position: absolute; inset: 0; pointer-events: none; }
.demo-anno {
  position: absolute; transform: translate(-50%, -50%);
  font-size: 10.5px; font-weight: 600; line-height: 1.25; color: var(--text-bright);
  background: rgba(8, 12, 19, .82); border: 1px solid var(--border-lt); border-radius: 6px;
  padding: 3px 7px; max-width: 180px;
}

/* side-by-side comparison */
.demo-compare { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 16px 0 0; }
.demo-compare .demo-fig { margin: 0; }

/* ---------------- predict + recap ---------------- */
.predict {
  margin: 16px 0; padding: 14px 16px; border-radius: 12px;
  background: color-mix(in srgb, var(--c-effort) 9%, var(--bg-panel)); border: 1px solid color-mix(in srgb, var(--c-effort) 45%, var(--border));
}
.predict-tag { font-size: 11px; font-weight: 800; letter-spacing: 1.2px; text-transform: uppercase; color: var(--c-effort); margin-bottom: 6px; }
.predict-stem { font-size: 16px; font-weight: 700; color: var(--text-bright); margin-bottom: 10px; line-height: 1.45; }
.predict-note { font-size: 13px; color: var(--text-dim); margin-top: 9px; }
.predict-note b { color: var(--text-bright); }
.quiz-choice.picked { border-color: var(--c-effort); background: color-mix(in srgb, var(--c-effort) 16%, var(--bg-panel2)); color: var(--text-bright); }
.quiz-choice.picked .qmark::before { content: "●"; color: var(--c-effort); }
.recap {
  margin: 4px 0 16px; padding: 12px 14px; border-radius: 10px; font-size: 14.5px; line-height: 1.58;
  background: var(--bg-panel); border: 1px solid var(--border); border-left: 3px solid var(--c-effort);
}
.recap.ok { border-left-color: var(--good); }
.recap.miss { border-left-color: var(--warn); }
.recap b { color: var(--text-bright); }
.recap-said { font-size: 13px; color: var(--text-dim); margin-bottom: 4px; }

/* ---------------- quizzes ---------------- */
.quizset, .classify { margin: 18px 0; background: var(--bg-panel); border: 1px solid var(--border-lt); border-radius: 12px; padding: 14px 16px; }
.quizset-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 4px; flex-wrap: wrap; }
.quizset-title { font-size: 13px; font-weight: 800; letter-spacing: .4px; text-transform: uppercase; color: var(--accent); margin: 0; }
:root[data-theme="light"] .quizset-title { color: var(--accent-dim); }
.quizset-score { font-family: var(--mono); font-size: 12px; color: var(--text-dim); }
.quizset-score b { color: var(--text-bright); }
.quizset-meta { display: flex; align-items: center; gap: 12px; }
.quizset-reset { background: none; border: 1px solid var(--border-lt); border-radius: 6px; color: var(--text-dim); font-size: 11px; padding: 3px 9px; cursor: pointer; }
.quizset-reset:hover:not(:disabled) { color: var(--text); border-color: var(--accent-dim); }
.quizset-reset:disabled { opacity: .4; cursor: default; }
.quizset-intro { font-size: 14px; color: var(--text); margin: 4px 0 6px; }

.quiz { margin: 14px 0 4px; padding-top: 12px; }
.quiz + .quiz { border-top: 1px solid var(--border); }
.quiz-stem { font-size: 15px; font-weight: 600; color: var(--text-bright); margin: 0 0 10px; line-height: 1.5; }
.quiz-stem .qnum { color: var(--text-dim); font-weight: 700; margin-right: 6px; }
.quiz-fig { margin: 0 0 11px; }
.quiz-choices { display: flex; flex-direction: column; gap: 7px; }
.quiz-choice {
  text-align: left; background: var(--bg-panel2); color: var(--text); border: 1px solid var(--border-lt);
  border-radius: 8px; padding: 10px 12px; font-size: 14.5px; cursor: pointer; line-height: 1.4;
  display: flex; gap: 9px; align-items: baseline; font-family: inherit;
}
.quiz-choice:hover:not(:disabled) { border-color: var(--accent-dim); }
.quiz-choice .qmark { font-weight: 800; width: 1em; flex: 0 0 auto; }
.quiz-choice[disabled] { cursor: default; opacity: 1; }
.quiz-choice.correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 12%, var(--bg-panel2)); color: var(--text-bright); }
.quiz-choice.correct .qmark::before { content: "✓"; color: var(--good); }
.quiz-choice.incorrect { border-color: var(--crit); background: color-mix(in srgb, var(--crit) 12%, var(--bg-panel2)); }
.quiz-choice.incorrect .qmark::before { content: "✗"; color: var(--crit); }
.quiz-why { display: none; margin: 9px 0 2px; font-size: 14px; line-height: 1.55; color: var(--text); border-left: 2px solid var(--accent-dim); padding: 2px 0 2px 11px; }
.quiz-why.show { display: block; }
.quiz-why b { color: var(--text-bright); }
.quiz-reveal { background: none; border: none; color: var(--text-dim); font-size: 12px; cursor: pointer; padding: 6px 0 0; text-decoration: underline; }
.quiz-reveal:hover { color: var(--text); }
.exam-result { margin-top: 14px; padding: 12px 14px; border-radius: 8px; font-size: 14px; background: var(--bg-panel2); border: 1px solid var(--border-lt); color: var(--text-bright); }
.exam-result b { color: var(--accent); }

/* classify: a trace + label buttons */
.cl-item { padding-top: 12px; margin-top: 12px; border-top: 1px solid var(--border); }
.cl-item:first-of-type { border-top: none; }
.cl-num { font-size: 11px; font-weight: 700; letter-spacing: 1px; text-transform: uppercase; color: var(--text-dim); margin-bottom: 6px; }
.cl-fig .demo-fig { margin: 0; padding: 8px; }
.cl-labels { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 9px; }
.cl-btn {
  padding: 8px 12px; border-radius: 8px; cursor: pointer; font-family: inherit; font-size: 13.5px; font-weight: 600;
  background: var(--bg-panel2); color: var(--text); border: 1px solid var(--border-lt);
}
.cl-btn:hover:not(:disabled) { border-color: var(--accent-dim); }
.cl-btn:disabled { cursor: default; opacity: .6; }
.cl-btn.correct { opacity: 1; border-color: var(--good); background: color-mix(in srgb, var(--good) 14%, var(--bg-panel2)); color: var(--text-bright); }
.cl-btn.correct::before { content: "✓ "; color: var(--good); }
.cl-btn.incorrect { opacity: 1; border-color: var(--crit); background: color-mix(in srgb, var(--crit) 12%, var(--bg-panel2)); }
.cl-btn.incorrect::before { content: "✗ "; color: var(--crit); }

/* ---------------- mission ---------------- */
.mission {
  margin: 16px 0; padding: 16px 18px; border-radius: 12px;
  background: linear-gradient(120deg, color-mix(in srgb, var(--accent) 14%, var(--bg-panel)), var(--bg-panel));
  border: 1px solid var(--accent-dim);
}
.mission.done { border-color: var(--good); }
.mission-tag { font-size: 11px; font-weight: 800; letter-spacing: 1.2px; text-transform: uppercase; color: var(--accent); }
:root[data-theme="light"] .mission-tag { color: var(--accent-dim); }
.mission-title { font-size: 18px; font-weight: 800; color: var(--text-bright); margin: 4px 0 6px; }
.mission-body { font-size: 15px; line-height: 1.6; color: var(--text); }
.mission-body p { margin: 0 0 8px; }
.mission-body b { color: var(--text-bright); }
.mission-sub { font-size: 12.5px; color: var(--text-dim); margin-top: 6px; }
.mission-goals { margin: 6px 0 0; padding-left: 20px; font-size: 14px; line-height: 1.5; }
.mission-row { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; margin-top: 14px; }
.mission-go {
  display: inline-block; padding: 10px 16px; border-radius: 8px; text-decoration: none;
  background: var(--accent); color: #04110f !important; font-weight: 800; font-size: 14px; border: none !important;
}
.mission-status { font-size: 13px; font-weight: 700; color: var(--text-dim); }
.mission.done .mission-status { color: var(--good); }
.mission-stretch { font-size: 13.5px; color: var(--text-dim); margin: 12px 0 0; }

/* ---------------- tabs + case cards ---------------- */
.tabs { margin: 14px 0; }
.tab-bar { display: flex; gap: 6px; overflow-x: auto; padding-bottom: 2px; }
.tab {
  flex: 0 0 auto; padding: 8px 12px; border-radius: 8px 8px 0 0; cursor: pointer; font-family: inherit;
  font-size: 13px; font-weight: 700; background: var(--bg-panel2); color: var(--text-dim);
  border: 1px solid var(--border); border-bottom: none;
}
.tab.active { background: var(--bg-panel); color: var(--text-bright); border-color: var(--border-lt); box-shadow: inset 0 2px 0 var(--accent); }
.tab-panel { background: var(--bg-panel); border: 1px solid var(--border-lt); border-radius: 0 10px 10px 10px; padding: 12px 14px; }
.casecard-title { font-size: 16px; font-weight: 800; color: var(--text-bright); margin: 0 0 4px; }
.casecard-lead { font-size: 14px; color: var(--text); margin: 0 0 4px; }
.casecard .demo-fig { margin: 10px 0; background: var(--bg-panel2); }
.casecard-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.casecard-cols h5 { font-size: 10.5px; letter-spacing: 1px; text-transform: uppercase; color: var(--text-dim); margin: 0 0 6px; }
.casecard-cols ul { margin: 0; padding-left: 18px; }
.casecard-cols li, .casecard-cols p { font-size: 14px; line-height: 1.5; color: var(--text); margin: 0 0 5px; }
.casecard-cols b { color: var(--text-bright); }

/* ---------------- reference: tables, glossary, svg ---------------- */
.tbl-wrap { overflow-x: auto; margin: 14px 0; }
table.cheat { border-collapse: collapse; width: 100%; font-size: 13.5px; min-width: 520px; }
table.cheat th, table.cheat td { text-align: left; padding: 8px 10px; border-bottom: 1px solid var(--border); vertical-align: top; line-height: 1.45; }
table.cheat th { color: var(--accent); font-size: 10.5px; letter-spacing: .6px; text-transform: uppercase; }
:root[data-theme="light"] table.cheat th { color: var(--accent-dim); }
table.cheat td b { color: var(--text-bright); }
table.cheat tr:hover td { background: var(--bg-panel); }

dl.glossary { margin: 12px 0; }
dl.glossary dt { font-weight: 700; color: var(--text-bright); font-size: 14.5px; margin-top: 12px; }
dl.glossary dd { margin: 3px 0 0; font-size: 14px; color: var(--text); line-height: 1.5; }

.svg-fig { margin: 16px 0; background: var(--bg-panel); border: 1px solid var(--border); border-radius: 12px; padding: 14px; text-align: center; }
.svg-fig svg { max-width: 100%; height: auto; }
.svg-fig figcaption { font-size: 13.5px; color: var(--text); margin-top: 8px; text-align: left; }

/* big "to the simulator" call-to-action */
.cta {
  display: block; margin: 18px 0; padding: 16px 18px; border-radius: 12px; text-decoration: none;
  background: linear-gradient(120deg, color-mix(in srgb, var(--accent) 16%, var(--bg-panel)), var(--bg-panel));
  border: 1px solid var(--accent-dim);
}
.cta .cta-title { font-size: 15px; font-weight: 800; color: var(--text-bright); }
.cta .cta-sub { font-size: 13.5px; color: var(--text-dim); margin-top: 3px; }
.cta:hover { border-color: var(--accent); }

/* ---------------- responsive ---------------- */
@media (max-width: 720px) {
  #app { padding: 16px 16px 30px; }
  .hero-title { font-size: 24px; }
  .lesson-title { font-size: 23px; }
  .step-title { font-size: 19px; }
  .scope.compact .wave-row { height: 96px; }
  .demo-compare { grid-template-columns: 1fr; }
  .casecard-cols { grid-template-columns: 1fr; gap: 10px; }
  .ro { min-width: 0; }
  .ro-v { font-size: 18px; }
}
@media (max-width: 460px) {
  .scope.compact .wave-row { height: 88px; }
}

/* ---------------- blood gas card (drawAbg tool, classify cards) ---------------- */
.demo-abg { margin-top: 10px; }
.abg {
  display: inline-block; min-width: 210px; font-family: var(--mono); font-size: 13px;
  background: var(--bg-scope); color: #dfe7f3; border: 1px solid #1d2633; border-radius: 9px; padding: 9px 12px;
}
.abg-head { font-family: var(--sans); font-size: 10.5px; font-weight: 700; letter-spacing: .6px; text-transform: uppercase; color: #7c8aa0; margin-bottom: 5px; }
.abg-row { display: grid; grid-template-columns: 62px 1fr auto; align-items: baseline; gap: 8px; padding: 1px 0; }
.abg-row span { color: #9aa8bd; }
.abg-row b { color: #eef3fa; font-size: 15px; }
.abg-row small { color: #7c8aa0; font-size: 10px; }
.abg-row.abg-flag b { color: #ffb15c; }
.abg-foot { font-family: var(--sans); font-size: 11px; color: #7c8aa0; margin-top: 5px; }
.cl-fig .abg { margin: 2px 0; }

/* ---------------- spot: click the trace ---------------- */
.spot-fig.spot-live .demo-scope-wrap { cursor: crosshair; }
.spot-fig .demo-fig { margin: 8px 0 0; }
.spot-tasks { margin: 10px 0 0; padding-left: 22px; font-size: 14.5px; line-height: 1.5; color: var(--text-dim); }
.spot-tasks li { margin-bottom: 4px; }
.spot-tasks li.now { color: var(--text-bright); font-weight: 700; }
.spot-tasks li.done { color: var(--text); }
.spot-tasks li.ok b { color: var(--good); }
.spot-tasks li.miss b { color: var(--crit); }
.spot-row { display: flex; justify-content: flex-end; }

/* ---------------- read: stepwise worked / faded read ---------------- */
.read { margin: 18px 0; background: var(--bg-panel); border: 1px solid var(--border-lt); border-radius: 12px; padding: 14px 16px; }
.read-fig .demo-fig { margin: 8px 0 4px; }
.read-steps { margin: 10px 0 0; padding-left: 0; list-style: none; counter-reset: rd; }
.read-step { position: relative; padding: 10px 0 10px 34px; border-top: 1px solid var(--border); counter-increment: rd; }
.read-step::before {
  content: counter(rd); position: absolute; left: 0; top: 10px; width: 22px; height: 22px; border-radius: 50%;
  display: grid; place-items: center; font-family: var(--mono); font-size: 12px; font-weight: 800;
  background: var(--bg-panel2); color: var(--text-dim); border: 1px solid var(--border-lt);
}
.read-step.done::before { background: var(--accent); color: #04110f; border-color: var(--accent); }
.read-step.now::before { border-color: var(--accent); color: var(--text-bright); }
.read-q { font-size: 15px; font-weight: 700; color: var(--text-bright); line-height: 1.45; }
.read-a { font-size: 14.5px; line-height: 1.58; color: var(--text); margin-top: 5px; }
.read-a b { color: var(--text-bright); }
.read-said { font-size: 13px; color: var(--text-dim); margin-top: 5px; }
.read-said.ok { color: var(--good); }
.read-said.miss { color: var(--warn); }
.read-go { margin-top: 8px; }
.read-hl { background: none; border: none; padding: 4px 0 0; color: var(--accent); font-size: 12.5px; cursor: pointer; text-decoration: underline; }
:root[data-theme="light"] .read-hl { color: var(--accent-dim); }
.read-step .quiz { margin: 8px 0 0; padding-top: 0; }
.read-done { padding: 10px 0 0; border-top: 1px solid var(--border); font-size: 14.5px; color: var(--text); }

/* ---------------- pbw calculator ---------------- */
.pbw { margin: 16px 0; padding: 14px 16px; border-radius: 12px; background: var(--bg-panel); border: 1px solid var(--border-lt); }
.pbw-title { font-size: 13px; font-weight: 800; letter-spacing: .4px; text-transform: uppercase; color: var(--accent); margin-bottom: 8px; }
:root[data-theme="light"] .pbw-title { color: var(--accent-dim); }
.pbw-row { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 18px; }
.pbw-row .seg { min-width: 160px; }
.pbw-h { display: flex; align-items: center; gap: 10px; flex: 1; min-width: 220px; font-size: 13px; color: var(--text-dim); }
.pbw-h input { flex: 1; }
.pbw-h b { font-family: var(--mono); color: var(--text-bright); min-width: 56px; }
.pbw-out { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.pbw-out > div { display: flex; align-items: baseline; gap: 6px; padding: 6px 10px; border-radius: 8px; background: var(--bg-scope); border: 1px solid #1d2633; color: #7c8aa0; font-size: 11px; }
.pbw-out span { font-weight: 700; }
.pbw-out b { font-family: var(--mono); font-size: 19px; color: #eef3fa; }
.pbw-out .pbw-good { border-color: color-mix(in srgb, var(--good) 60%, #1d2633); }
.pbw-out .pbw-good b { color: var(--good); }
.pbw-out .pbw-vt b { color: #ffb15c; }
.pbw-note { font-size: 12.5px; color: var(--text-dim); margin-top: 9px; line-height: 1.5; }

/* ---------------- self-check mission ---------------- */
.mission-check { list-style: none; padding-left: 0; }
.mission-check label { display: flex; gap: 9px; align-items: baseline; cursor: pointer; }
.mission-check input { accent-color: var(--accent); transform: translateY(1px); }
.read-why { display: block; color: var(--text); margin-top: 2px; }

/* ---------------- vignette (case stem from cases.js) ---------------- */
.vignette { margin: 14px 0; padding: 12px 16px; border-radius: 10px; background: var(--bg-panel); border: 1px solid var(--border); border-left: 3px solid var(--c-paw); }
.vignette-tag { font-size: 10.5px; font-weight: 800; letter-spacing: 1.1px; text-transform: uppercase; color: var(--text-dim); margin-bottom: 4px; }
.vignette p { margin: 0; font-size: 15px; line-height: 1.6; color: var(--text-bright); font-style: italic; }
.abg-pair { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.abg-arrow { font-size: 20px; color: var(--text-dim); }
.abg-block { display: flex; flex-wrap: wrap; gap: 12px 18px; margin: 14px 0; }
.abg-block > .demo-caption { flex-basis: 100%; margin-top: 0; }
.abg-title { font-size: 12px; font-weight: 800; letter-spacing: .6px; text-transform: uppercase; color: var(--text-dim); margin-bottom: 5px; }

/* ---------------- practice drill ---------------- */
.practice-body { margin-top: 18px; }
.practice-start, .practice-summary, .practice-item {
  background: var(--bg-panel); border: 1px solid var(--border-lt); border-radius: 12px; padding: 16px 18px;
}
.practice-start p { font-size: 15px; line-height: 1.6; color: var(--text); margin: 0 0 12px; }
.practice-boxes { font-size: 13px !important; color: var(--text-dim) !important; }
.practice-boxes b { color: var(--text-bright); font-family: var(--mono); }
.practice-bar { display: flex; align-items: center; gap: 12px; font-size: 12px; font-weight: 700; letter-spacing: .6px; text-transform: uppercase; color: var(--text-dim); }
.practice-prog { flex: 1; height: 5px; border-radius: 3px; background: var(--bg-panel2); overflow: hidden; }
.practice-prog > div { height: 100%; background: var(--accent); transition: width .3s ease; }
.practice-item .demo-fig { margin: 10px 0 4px; background: var(--bg-panel2); }
.practice-item .quiz { margin-top: 6px; }
.practice-item .continue-bar { border-top: none; padding-top: 4px; margin-top: 10px; }
.practice-summary .step-title { margin-top: 0; }
.practice-summary p { font-size: 15px; color: var(--text); }
.practice-table tr.practice-miss td:first-child b { color: var(--warn); }
.practice-table td a { color: var(--accent); text-decoration: none; }
:root[data-theme="light"] .practice-table td a { color: var(--accent-dim); }