/* Lesson-intro scenes: the opening Understand view prioritises definition, relationship and the exact mathematical visual. */
.intro-two-column{display:grid;grid-template-columns:minmax(330px,.78fr) minmax(0,1.45fr);gap:18px;height:100%;min-height:0}.intro-definition-card,.intro-context-card,.intro-visual-panel,.intro-full-scene{border:1px solid var(--line,#dfe7f2);border-radius:18px;background:#fff;box-shadow:0 10px 28px rgba(16,38,76,.035)}.intro-definition-card,.intro-context-card{padding:24px;display:flex;flex-direction:column;min-height:0;overflow:auto}.intro-eyebrow{text-transform:uppercase;letter-spacing:.11em;font-weight:800;font-size:12px;color:#078f84;margin-bottom:8px}.intro-definition-card h2,.intro-context-card h2,.intro-section-lead h2{margin:0;color:#0b2347;font-size:clamp(24px,2.3vw,36px);line-height:1.08}.intro-definition-copy{margin:16px 0 14px;font-size:clamp(16px,1.28vw,19px);line-height:1.58;font-weight:400;color:#243d62;letter-spacing:0}.intro-definition-reminder{margin-top:auto;border-radius:14px;padding:14px 16px;background:linear-gradient(135deg,#f1edff,#eaf9f7);display:grid;gap:3px}.intro-definition-reminder span,.intro-context-meaning span,.intro-distinction span,.intro-formula-strip span,.intro-vocab-example span{font-size:11px;font-weight:800;text-transform:uppercase;letter-spacing:.08em;color:#6650de}.intro-definition-reminder strong{font-size:13px;line-height:1.4;color:#263d61}.intro-formula-strip{margin-top:2px;border:1px solid #ddd6ff;border-radius:14px;padding:12px 14px;background:#faf8ff;display:grid;gap:5px}.intro-formula-strip strong{font-family:Georgia,'Times New Roman',serif;font-size:18px;color:#5537dc;overflow-wrap:anywhere}.intro-visual-panel{padding:14px;display:grid;grid-template-rows:auto minmax(0,1fr);min-height:0;overflow:hidden}.intro-panel-heading{display:flex;justify-content:space-between;gap:16px;align-items:flex-start;padding:2px 4px 10px}.intro-panel-heading span{font-size:12px;font-weight:800;text-transform:uppercase;letter-spacing:.09em;color:#078f84}.intro-panel-heading strong{font-size:12px;line-height:1.35;color:#5a6d8c;text-align:right}.intro-visual-stage{min-height:0;height:100%;display:grid;place-items:center;overflow:hidden}.intro-visual-stage>svg,.intro-visual-stage [data-visual-type]{max-width:100%;max-height:100%}.intro-context-lead{font-size:clamp(17px,1.45vw,21px);line-height:1.55;color:#243d62;margin:18px 0}.intro-context-meaning,.intro-distinction{border-radius:14px;padding:14px 16px;margin-top:10px}.intro-context-meaning{background:#eefaf7;border:1px solid #cdece5;display:grid;gap:5px}.intro-context-meaning strong{font-size:14px;line-height:1.45;color:#174a48}.intro-distinction{background:#fff9e8;border:1px solid #f5df9d}.intro-distinction span{color:#a66c00}.intro-distinction p{margin:5px 0 0;color:#5d4b22;font-size:13px;line-height:1.45}.intro-full-scene{height:100%;padding:22px 24px;overflow:auto}.intro-section-lead{max-width:930px;margin-bottom:18px}.intro-section-lead p{font-size:14px;line-height:1.45;color:#63728d;margin:8px 0 0}.intro-vocab-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.intro-vocab-card{position:relative;display:grid;grid-template-columns:auto 1fr;gap:12px;border:1px solid #e0e7f2;border-radius:15px;padding:15px;background:linear-gradient(180deg,#fff,#fbfcff)}.intro-vocab-number{width:30px;height:30px;border-radius:10px;background:#f0ebff;color:#623ce8;display:grid;place-items:center;font-weight:800}.intro-vocab-card h3{margin:0 0 5px;font-size:16px;color:#122c53}.intro-vocab-card p{margin:0;color:#4f6482;line-height:1.45;font-size:13px}.intro-vocab-example{margin-top:9px;display:flex;gap:8px;align-items:baseline;flex-wrap:wrap}.intro-vocab-example strong{font-size:13px;color:#0c7f76}.intro-roadmap{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;position:relative}.intro-roadmap-step{border:1px solid #e0e6f1;border-radius:16px;padding:15px;background:#fff;display:flex;gap:11px;min-height:105px}.intro-roadmap-number{flex:0 0 auto;width:32px;height:32px;border-radius:50%;background:#693ff0;color:#fff;display:grid;place-items:center;font-weight:800}.intro-roadmap-step small{display:block;text-transform:uppercase;letter-spacing:.07em;font-weight:800;color:#078f84;font-size:10px;margin-bottom:5px}.intro-roadmap-step strong{font-size:13px;line-height:1.42;color:#203857}.intro-stage-map{margin-top:18px;display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap;border-radius:14px;background:#f7f8fd;padding:12px}.intro-stage-map span{font-size:12px;font-weight:800;color:#344968}.intro-stage-map b{color:#6940ec}.intro-prior-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}.intro-prior-card{border:1px solid #dfe7f1;border-radius:16px;padding:16px;display:flex;gap:12px;background:#fff}.intro-prior-check{width:32px;height:32px;flex:0 0 auto;border-radius:50%;display:grid;place-items:center;background:#eaf8f5;color:#078f84;font-weight:900}.intro-prior-card small{display:block;font-size:10px;text-transform:uppercase;letter-spacing:.07em;color:#7c8da5;font-weight:800}.intro-prior-card h3{font-size:15px;line-height:1.35;margin:4px 0;color:#18345a}.intro-prior-card p{font-size:12px;line-height:1.4;color:#66768f;margin:6px 0 0}.intro-ready-card{margin-top:18px;border:1px solid #d7cffd;background:linear-gradient(90deg,#f8f5ff,#f0faf8);border-radius:16px;padding:16px 18px;display:flex;justify-content:space-between;gap:14px;align-items:center}.intro-ready-card span:first-child{display:block;color:#6840e8;font-weight:800;font-size:12px;text-transform:uppercase;letter-spacing:.08em}.intro-ready-card strong{font-size:14px;color:#243e62}.intro-ready-arrow{font-size:28px;color:#6840e8}.intro-definition-scene .intro-visual-stage svg{width:min(100%,880px);height:auto}.intro-context-scene .intro-visual-stage svg{width:min(100%,840px);height:auto}
@media(max-width:900px){.intro-two-column{grid-template-columns:1fr;height:auto}.intro-definition-card,.intro-context-card{min-height:320px}.intro-visual-panel{min-height:430px}.intro-vocab-grid{grid-template-columns:1fr}.intro-roadmap{grid-template-columns:repeat(2,minmax(0,1fr))}.intro-prior-grid{grid-template-columns:1fr}.intro-full-scene{height:auto;min-height:100%}}
@media(max-width:600px){.intro-definition-card,.intro-context-card,.intro-full-scene{padding:17px}.intro-definition-copy{font-size:16px;line-height:1.58;font-weight:400}.intro-visual-panel{min-height:340px}.intro-roadmap{grid-template-columns:1fr}.intro-roadmap-step{min-height:0}.intro-panel-heading{display:grid}.intro-panel-heading strong{text-align:left}.intro-stage-map{justify-content:flex-start}.intro-vocab-card{grid-template-columns:auto 1fr}.intro-full-scene{overflow:visible}}
@media(max-height:700px) and (min-width:901px){.intro-definition-card,.intro-context-card{padding:18px}.intro-definition-copy{font-size:16.5px;line-height:1.55;font-weight:400;margin:10px 0 12px}.intro-context-lead{font-size:16px;margin:12px 0}.intro-full-scene{padding:16px 18px}.intro-section-lead{margin-bottom:12px}.intro-section-lead h2{font-size:25px}.intro-vocab-card{padding:11px}.intro-vocab-card p{font-size:12px}.intro-roadmap-step{padding:12px;min-height:88px}.intro-prior-card{padding:12px}}

/* v1.8.3 focused Understand dashboard: definition + mathematical relationship + large visual, with filler cards removed. */
.intro-dashboard{
  display:grid;
  grid-template-columns:minmax(340px,.86fr) minmax(0,1.64fr);
  gap:14px;
  height:100%;
  min-height:0;
}
.intro-dashboard-primary,.intro-dashboard-support,.intro-dashboard-visual{
  min-width:0;
  min-height:0;
  border:1px solid var(--line,#dfe7f2);
  border-radius:18px;
  background:#fff;
  box-shadow:0 10px 28px rgba(16,38,76,.035);
}
.intro-dashboard-primary{
  padding:18px;
  display:flex;
  flex-direction:column;
  gap:12px;
  overflow:auto;
}
.intro-dashboard-title{padding:0 2px 2px}
.intro-dashboard-title h2{
  margin:0;
  color:#0b2347;
  font-size:clamp(23px,2.15vw,34px);
  line-height:1.08;
}
.intro-dashboard-title>p{
  margin:7px 0 0;
  font-size:13px;
  line-height:1.4;
  color:#526784;
}
.intro-dashboard-definition{
  border:1px solid #dfe7f2;
  border-left:4px solid #0c9b8d;
  border-radius:14px;
  padding:14px 15px;
  background:#fff;
}
.intro-support-heading{
  margin:0 0 8px;
  color:#078f84;
  font-size:11px;
  font-weight:800;
  text-transform:uppercase;
  letter-spacing:.09em;
}
.intro-dashboard-definition .intro-definition-copy{
  margin:0;
  font-size:clamp(15.5px,1.15vw,18px);
  line-height:1.55;
  font-weight:400;
  color:#324b6d;
}
.intro-dashboard-relationship,.intro-dashboard-start{
  border-radius:14px;
  padding:12px 14px;
  display:flex;
  gap:11px;
  align-items:flex-start;
}
.intro-dashboard-relationship{
  border:1px solid #ded5ff;
  background:linear-gradient(135deg,#faf8ff,#f5f2ff);
}
.intro-dashboard-relationship strong{
  display:block;
  color:#593dde;
  font-family:Georgia,'Times New Roman',serif;
  font-size:16px;
  line-height:1.35;
  font-weight:700;
}
.intro-relationship-content{min-width:0;flex:1}.intro-dashboard-relationship .intro-support-heading{margin-bottom:10px}.intro-dashboard-relationship strong{font-size:clamp(19px,1.55vw,26px);line-height:1.55;overflow:visible}.wtm-math-expression{display:inline-flex;align-items:center;gap:.18em;white-space:normal;flex-wrap:wrap;font-family:Cambria Math,'STIX Two Math','Times New Roman',serif;font-weight:600;color:inherit;letter-spacing:0}.wtm-math-expression i{font-family:inherit;font-style:italic;font-weight:500}.wtm-math-power{display:inline-flex;align-items:flex-start}.wtm-math-power>sup,.wtm-math-sup{font-size:.68em;line-height:1;vertical-align:super;margin-left:.04em}.wtm-math-sub{font-size:.68em;line-height:1;vertical-align:sub}.wtm-math-op{display:inline-block;padding:0 .14em}.wtm-math-divide{display:inline-block;padding:0 .13em}.wtm-math-frac{display:inline-grid;grid-template-rows:auto auto;line-height:1;text-align:center;vertical-align:middle;margin:0 .08em}.wtm-math-frac .wtm-math-num{border-bottom:1.4px solid currentColor;padding:0 .14em .08em}.wtm-math-frac .wtm-math-den{padding:.08em .14em 0}.wtm-math-frac-small{font-size:.84em;transform:translateY(-.03em)}.wtm-math-root{display:inline-flex;align-items:flex-start;position:relative;margin-left:.05em}.wtm-root-index{font-size:.48em;line-height:1;transform:translate(.22em,-.2em);margin-right:-.15em}.wtm-root-sign{font-size:1.18em;line-height:1.15}.wtm-radicand{border-top:1.5px solid currentColor;padding:.03em .12em 0 .06em;line-height:1.15}.wtm-rational-exponent{font-size:1.08em}.intro-definition-scene .intro-dashboard-primary{justify-content:flex-start}.intro-definition-scene .intro-dashboard-visual-stage{padding-inline:6px}.intro-definition-scene .intro-dashboard-visual-stage>svg{width:min(100%,1040px)}
.intro-relationship-icon,.intro-start-icon{
  flex:0 0 auto;
  width:28px;
  height:28px;
  border-radius:9px;
  display:grid;
  place-items:center;
  font-size:14px;
}
.intro-relationship-icon{background:#eee9ff;color:#6840e8}
.intro-dashboard-start{border:1px solid #cfe6fb;background:#f6fbff}
.intro-start-icon{background:#eaf4ff;color:#417dda}
.intro-dashboard-start p{margin:0;color:#4d6382;font-size:12.5px;line-height:1.42}
.intro-dashboard-support{
  padding:12px 14px;
  display:flex;
  flex-direction:column;
  overflow:auto;
}
.intro-support-block{padding:10px 0;border-bottom:1px solid #edf1f6}
.intro-support-block:first-child{padding-top:2px}
.intro-support-block:last-child{border-bottom:0;padding-bottom:0}
.intro-support-vocab ul,.intro-support-goals ul{list-style:none;margin:0;padding:0;display:grid;gap:4px}
.intro-support-vocab li{
  min-height:27px;
  display:grid;
  grid-template-columns:13px minmax(0,1fr) auto;
  gap:7px;
  align-items:center;
  color:#273f61;
  font-size:11.5px;
}
.intro-support-vocab li strong{font-weight:700;overflow-wrap:anywhere}
.intro-support-dot{width:9px;height:9px;border-radius:3px;background:#ede8ff;border:1px solid #d9d0ff}
.intro-support-chevron{color:#8797ad;font-size:17px;line-height:1}
.intro-support-why p{margin:0;color:#526784;font-size:11.5px;line-height:1.45}
.intro-support-goals li{display:grid;grid-template-columns:15px 1fr;gap:6px;align-items:start;color:#4e6381;font-size:11px;line-height:1.35}
.intro-goal-check{width:14px;height:14px;border-radius:50%;display:grid;place-items:center;background:#e9f8f5;color:#078f84;font-size:9px;font-weight:900;margin-top:1px}
.intro-dashboard-visual{
  padding:13px;
  display:grid;
  grid-template-rows:auto minmax(0,1fr) auto;
  overflow:hidden;
}
.intro-dashboard-visual-stage{
  min-height:0;
  overflow:hidden;
  display:grid;
  place-items:center;
}
.intro-dashboard-visual-stage>svg,.intro-dashboard-visual-stage [data-visual-type]{max-width:100%;max-height:100%}
.intro-dashboard-visual-stage>svg{width:min(100%,920px);height:auto}
.intro-visual-insight{
  margin-top:8px;
  border:1px solid #cfece5;
  border-radius:12px;
  background:#effbf8;
  padding:8px 10px;
  display:flex;
  gap:8px;
  align-items:flex-start;
}
.intro-visual-insight>span{width:18px;height:18px;flex:0 0 auto;border-radius:50%;display:grid;place-items:center;background:#0b998c;color:#fff;font-size:10px;font-weight:900}
.intro-visual-insight p{margin:0;color:#315e5a;font-size:11.5px;line-height:1.38}

@media(max-width:1050px) and (min-width:901px){
  .intro-dashboard{grid-template-columns:minmax(310px,.82fr) minmax(0,1.48fr);gap:10px}
  .intro-dashboard-primary{padding:14px;gap:9px}
  .intro-dashboard-support{padding:10px 11px}
  .intro-dashboard-title h2{font-size:24px}
  .intro-dashboard-definition{padding:11px 12px}
  .intro-dashboard-definition .intro-definition-copy{font-size:15.5px;line-height:1.5}
  .intro-dashboard-relationship,.intro-dashboard-start{padding:10px 11px}
  .intro-support-vocab li{font-size:10.8px;min-height:24px}
  .intro-support-why p{font-size:10.8px}
  .intro-support-goals li{font-size:10.4px}
  .intro-dashboard-visual{padding:10px}
  .intro-visual-insight p{font-size:10.8px}
}
@media(max-width:900px){
  .intro-dashboard{grid-template-columns:1fr;height:auto}
  .intro-dashboard-primary,.intro-dashboard-support,.intro-dashboard-visual{overflow:visible}
  .intro-dashboard-support{display:grid;grid-template-columns:1fr 1fr;gap:0 14px}
  .intro-support-vocab{grid-row:span 2}
  .intro-dashboard-visual{min-height:430px}
}
@media(max-width:600px){
  .intro-dashboard{gap:12px}
  .intro-dashboard-primary,.intro-dashboard-support,.intro-dashboard-visual{border-radius:15px}
  .intro-dashboard-primary{padding:15px}
  .intro-dashboard-title h2{font-size:24px}
  .intro-dashboard-definition .intro-definition-copy{font-size:16px;line-height:1.55}
  .intro-dashboard-support{display:block;padding:12px 14px}
  .intro-dashboard-visual{min-height:350px;padding:11px}
  .intro-dashboard-relationship strong{font-size:15px}
}
@media(max-height:700px) and (min-width:901px){
  .intro-dashboard{gap:10px}
  .intro-dashboard-primary{padding:13px;gap:8px}
  .intro-dashboard-title h2{font-size:23px}
  .intro-dashboard-title>p{font-size:11.5px;margin-top:4px}
  .intro-dashboard-definition{padding:10px 11px}
  .intro-dashboard-definition .intro-definition-copy{font-size:15px;line-height:1.46}
  .intro-dashboard-relationship,.intro-dashboard-start{padding:9px 10px}
  .intro-dashboard-relationship strong{font-size:14.5px}
  .intro-dashboard-start p{font-size:11px}
  .intro-dashboard-support{padding:9px 11px}
  .intro-support-block{padding:7px 0}
  .intro-support-heading{font-size:9.8px;margin-bottom:5px}
  .intro-support-vocab li{font-size:10px;min-height:21px}
  .intro-support-why p{font-size:10px;line-height:1.35}
  .intro-support-goals li{font-size:9.7px;line-height:1.28}
  .intro-dashboard-visual{padding:9px}
  .intro-panel-heading{padding-bottom:6px}
  .intro-visual-insight{padding:6px 8px;margin-top:5px}
  .intro-visual-insight p{font-size:10px}
}

/* v1.8.1: opening Understand scene deliberately has no vocabulary/why/goals support column. */
.intro-definition-scene>.intro-dashboard-support{display:none!important}
@media(max-width:900px){.intro-definition-scene{grid-template-columns:1fr}.intro-definition-scene .intro-dashboard-visual{min-height:430px}}
@media(max-width:600px){.intro-dashboard-relationship strong{font-size:20px}.wtm-rational-exponent{font-size:1em}}
.intro-definition-scene .intro-dashboard-relationship strong{font-size:clamp(23px,1.85vw,30px);line-height:1.7}
@media(max-height:700px) and (min-width:901px){.intro-definition-scene .intro-dashboard-relationship strong{font-size:23px;line-height:1.65}.intro-definition-scene .intro-dashboard-relationship{padding:11px 12px}}