:root {
  --navy: #003366;
  --deep-navy: #00284f;
  --cyan: #08b8eb;
  --soft-cyan: #dff7fd;
  --soft-blue: #eaf3f8;
  --lime: #9bd600;
  --dark-lime: #719e00;
  --ink: #172737;
  --muted: #5d6b78;
  --page: #f3f7f9;
  --line: #d9e3ea;
  --white: #ffffff;
  --shadow: 0 18px 55px rgba(0, 40, 79, 0.1);
}

* { box-sizing: border-box; }

html { color-scheme: light; }

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 12% 12%, rgba(8, 184, 235, 0.12), transparent 25rem),
    linear-gradient(180deg, #eef8fb 0, var(--page) 22rem);
  color: var(--ink);
  font: 1rem/1.65 Aptos, "Segoe UI", Arial, sans-serif;
}

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

.skip-link {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  z-index: 10;
  border-radius: 0.5rem;
  background: var(--white);
}

.skip-link:focus {
  top: 0.75rem;
  left: 0.75rem;
  width: auto;
  height: auto;
  padding: 0.75rem 1rem;
  overflow: visible;
  clip: auto;
  clip-path: none;
}

.site-header {
  min-height: 5.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 0.65rem max(1rem, calc((100vw - 72rem) / 2));
  background: var(--deep-navy);
  color: var(--white);
  border-bottom: 0.25rem solid var(--cyan);
}

.lesson-identity {
  max-width: 34rem;
  text-align: right;
}

.lesson-identity span {
  display: block;
  color: var(--soft-cyan);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.lesson-identity strong {
  display: block;
  margin-top: 0.1rem;
  color: var(--white);
  font-size: clamp(1rem, 2.2vw, 1.35rem);
  line-height: 1.2;
}

.course-experience-note {
  padding: 0.55rem 1rem;
  border-bottom: 1px solid #b9e8f5;
  background: var(--soft-cyan);
  color: var(--navy);
  font-size: 0.84rem;
  font-weight: 750;
  text-align: center;
}

.brand {
  display: block;
  width: 10.5rem;
  height: 3.25rem;
}

.brand img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: left center;
}

.sample-shell {
  width: min(52rem, calc(100% - 2rem));
  min-height: calc(100vh - 16rem);
  margin: clamp(1.25rem, 4vw, 3.5rem) auto;
}

.progress-wrap {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 1rem;
  margin: 0 0 0.8rem;
}

.progress-label {
  color: var(--muted);
  font-size: 0.875rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.progress-track {
  height: 0.5rem;
  overflow: hidden;
  border-radius: 999px;
  background: #dbe7ec;
}

.lesson-tools {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.7rem;
  margin: 0 0 0.8rem;
}

.tool-button {
  min-height: 2.75rem;
  padding: 0.55rem 0.9rem;
  border: 1px solid var(--navy);
  border-radius: 0.65rem;
  background: var(--white);
  color: var(--navy);
  font: inherit;
  font-size: 0.9rem;
  font-weight: 800;
  cursor: pointer;
}

.tool-button:hover { background: var(--soft-cyan); }

#progress-bar {
  display: block;
  width: 12.5%;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--cyan), var(--lime));
  transition: width 240ms ease;
}

.screen {
  position: relative;
  margin: 0 0 1.25rem;
  padding: clamp(1.4rem, 5vw, 3.25rem);
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 1.5rem;
  background: rgba(255, 255, 255, 0.98);
  box-shadow: var(--shadow);
}

.interactive-only { display: none; }
.js .screen { display: none; }
.js .screen.is-active { display: block; animation: enter 220ms ease-out; }
.js .interactive-only { display: none; }
.js .interactive-only.is-active { display: block; }
html:not(.js) .js-action { display: none; }
html:not(.js) .lesson-tools { display: none; }

@keyframes enter {
  from { opacity: 0; transform: translateY(0.4rem); }
  to { opacity: 1; transform: translateY(0); }
}

h1, h2 {
  max-width: 20ch;
  margin: 0.3rem 0 1.1rem;
  color: var(--navy);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.1;
}

h1 { font-size: clamp(2rem, 6vw, 3.35rem); }
h2 { font-size: clamp(1.9rem, 5vw, 3.25rem); }
h3 { margin: 1.7rem 0 0.7rem; color: var(--navy); font-size: 1.2rem; line-height: 1.25; }

p { margin: 0 0 1.1rem; }

.lead {
  max-width: 38rem;
  font-size: clamp(1.15rem, 2.5vw, 1.35rem);
  line-height: 1.55;
}

.eyebrow, .example-label {
  color: var(--navy);
  font-size: 0.875rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.practice-callout {
  display: grid;
  gap: 0.4rem;
  margin: 1.75rem 0;
  padding: 1.25rem 1.35rem;
  border-left: 0.45rem solid var(--lime);
  border-radius: 0 1rem 1rem 0;
  background: var(--deep-navy);
  color: var(--white);
}

.practice-callout span {
  color: var(--cyan);
  font-size: 0.8rem;
  font-weight: 900;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

.practice-callout strong { font-size: 1.15rem; line-height: 1.45; }
.fine-print { color: var(--muted); font-size: 0.9rem; }

.case-file {
  position: relative;
  margin-top: 1.5rem;
  padding: clamp(1.25rem, 4vw, 2rem);
  border-left: 0.45rem solid var(--lime);
  border-radius: 0 1rem 1rem 0;
  background: var(--deep-navy);
  color: var(--white);
}

.assignment-card { margin-top: 1.25rem; }
.lesson-task { margin-bottom: 1.25rem; }

.case-file p:last-child { margin-bottom: 0; }

.evidence-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.8rem;
  margin: 1.5rem 0 0;
}

.evidence-card {
  min-width: 0;
  padding: 1.15rem;
  border: 1px solid var(--line);
  border-top: 0.3rem solid var(--cyan);
  border-radius: 0.9rem;
  background: var(--white);
}

.evidence-card:last-child { border-top-color: var(--lime); }
.evidence-card span { display: block; margin-bottom: 0.35rem; color: var(--muted); font-size: 0.78rem; font-weight: 900; letter-spacing: 0.08em; text-transform: uppercase; }
.evidence-card strong { display: block; color: var(--navy); line-height: 1.35; }
.evidence-card small { display: block; margin-top: 0.65rem; color: var(--muted); line-height: 1.45; }

.rule-panel {
  margin: 1.7rem 0;
  padding: clamp(1.3rem, 4vw, 2rem);
  border: 0.15rem solid var(--cyan);
  border-radius: 1rem;
  background: var(--soft-cyan);
}

.rule-panel span {
  color: var(--navy);
  font-size: 0.8rem;
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.rule-panel p {
  margin: 0.45rem 0 0;
  color: var(--deep-navy);
  font-size: clamp(1.1rem, 2.5vw, 1.3rem);
  font-weight: 750;
}

.screen-example { border-top: 0.45rem solid var(--cyan); }
.example-label { display: inline-block; padding: 0.4rem 0.7rem; border-radius: 0.4rem; background: var(--soft-cyan); }
.section-intro { color: var(--muted); font-size: 1.05rem; font-weight: 700; }

.worked-answer {
  margin: 1.6rem 0 0;
  padding: 1.35rem;
  border-radius: 1rem;
  background: #f7fafc;
  border: 1px solid var(--line);
}

.worked-answer p:last-child { margin-bottom: 0; }

.noscript-stop {
  margin: 1.5rem 0;
  padding: 1.25rem;
  border: 0.15rem solid var(--navy);
  border-radius: 1rem;
  background: var(--soft-cyan);
  color: var(--navy);
}

.screen-decision { border-top: 0.45rem solid var(--lime); }

fieldset { margin: 1.5rem 0 0; padding: 0; border: 0; }

.option {
  display: flex;
  align-items: flex-start;
  gap: 0.8rem;
  margin: 0.75rem 0;
  padding: 1rem 1.1rem;
  border: 0.13rem solid var(--line);
  border-radius: 0.9rem;
  background: var(--white);
  cursor: pointer;
  transition: border-color 150ms ease, background 150ms ease, transform 150ms ease;
}

.option:hover { border-color: var(--cyan); }
.option:has(input:checked) { border-color: var(--navy); background: var(--soft-cyan); transform: translateX(0.2rem); }
.option:has(input:disabled) { cursor: default; }
.option:has(input:disabled):hover { border-color: var(--line); }
.option:has(input:checked:disabled) { border-color: var(--navy); }

.option input {
  width: 1.2rem;
  height: 1.2rem;
  margin: 0.2rem 0 0;
  flex: 0 0 auto;
  accent-color: var(--navy);
}

.option strong { color: var(--navy); }

.review-feedback, .feedback-message {
  margin-top: 1.4rem;
  padding: 1.2rem 1.3rem;
  border-left: 0.45rem solid var(--navy);
  border-radius: 0 0.9rem 0.9rem 0;
  background: var(--soft-cyan);
}

.review-feedback p, .feedback-message p { margin: 0; }

.evidence-path {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: stretch;
  gap: 0.65rem;
  margin: 1.8rem 0 0;
}

.evidence-path > div {
  display: grid;
  gap: 0.2rem;
  min-width: 0;
  padding: 1rem 0.75rem;
  border: 1px solid var(--line);
  border-radius: 0.85rem;
  background: var(--white);
  text-align: center;
}

.evidence-path small { color: var(--muted); }
.evidence-path .value-missing { border: 0.15rem dashed var(--navy); background: var(--soft-cyan); }
.path-number { color: var(--navy); font-size: 0.8rem; font-weight: 900; }
.path-arrow { align-self: center; color: var(--cyan); font-size: 1.5rem; font-weight: 900; }

.arc-grid { display: grid; gap: 0.8rem; margin: 1.7rem 0; }

.lesson-recap {
  margin: 1.5rem 0 0;
  padding: 1.2rem 1.35rem;
  border-left: 0.4rem solid var(--lime);
  border-radius: 0 0.85rem 0.85rem 0;
  background: var(--soft-cyan);
}

.lesson-recap p { margin-bottom: 0.45rem; }
.lesson-recap p:last-child { margin-bottom: 0; }
.course-path-note { margin-top: 1.3rem; }

.arc-card {
  padding: 1.15rem 1.25rem;
  border: 1px solid var(--line);
  border-radius: 1rem;
  background: var(--white);
}

.arc-card.current { border: 0.15rem solid var(--navy); box-shadow: inset 0.4rem 0 var(--lime); }
.arc-card p { margin: 0.35rem 0 0; }
.arc-card > strong { color: var(--muted); font-size: 0.9rem; }

.arc-top { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: 0.3rem; }
.arc-top > span:first-child { color: var(--navy); font-size: 1.25rem; font-weight: 900; }

.current-pill {
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
  background: var(--lime);
  color: var(--deep-navy);
  font-size: 0.78rem;
  font-weight: 900;
}

.close-mark {
  margin-bottom: 1.4rem;
  color: var(--navy);
  font-weight: 900;
  letter-spacing: 0.04em;
}

.close-mark span { padding: 0 0.35rem; color: var(--cyan); }

.coming-soon {
  display: grid;
  gap: 0.25rem;
  margin: 1.5rem 0;
  padding: 1.2rem 1.3rem;
  border-radius: 1rem;
  background: var(--deep-navy);
  color: var(--white);
}

.coming-soon span { color: var(--cyan); font-size: 0.8rem; font-weight: 900; letter-spacing: 0.1em; text-transform: uppercase; }
.coming-soon strong { font-size: 1.15rem; }

.actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.8rem;
  margin-top: 2rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
}

.actions-end { justify-content: flex-end; }
.close-actions { justify-content: flex-start; }

.button {
  min-height: 3.2rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.2rem;
  border: 0.13rem solid var(--navy);
  border-radius: 0.75rem;
  font: inherit;
  font-weight: 850;
  line-height: 1.25;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
}

.button.primary { border-color: var(--lime); background: var(--lime); color: var(--deep-navy); }
.button.primary:hover { border-color: var(--cyan); background: var(--cyan); }
.button.secondary { background: var(--white); color: var(--navy); }
.button.secondary:hover { background: var(--soft-cyan); }
.button:disabled { opacity: 0.48; cursor: not-allowed; }

.button:focus-visible, .tool-button:focus-visible, .dialog-close:focus-visible, .option:focus-within, a:focus-visible {
  outline: 0.2rem solid var(--navy);
  outline-offset: 0.2rem;
}

.site-footer {
  padding: 1.4rem max(1rem, calc((100vw - 52rem) / 2));
  background: var(--deep-navy);
  color: var(--soft-cyan);
  font-size: 0.78rem;
  line-height: 1.55;
  text-align: center;
}

.site-footer p { margin: 0; }
.site-footer strong { color: var(--white); }

/* Course-native lesson shell */
.course-shell {
  width: min(60rem, calc(100% - 2rem));
  min-height: calc(100vh - 16rem);
  margin: clamp(1.25rem, 4vw, 2.5rem) auto 4rem;
}

.course-shell > h1 {
  max-width: 28ch;
  margin: 0.3rem 0 1.2rem;
}

.course-shell > h1:focus { outline: none; }

.kicker {
  margin: 0;
  color: var(--navy);
  font-size: 0.84rem;
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.page-tools {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.7rem;
  margin-bottom: 1.1rem;
}

.progress-line {
  display: grid;
  grid-template-columns: auto minmax(8rem, 1fr);
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.35rem;
}

.card {
  margin: 0 0 1rem;
  padding: clamp(1.2rem, 4vw, 1.75rem);
  border: 1px solid var(--line);
  border-radius: 1rem;
  background: var(--white);
  box-shadow: 0 0.3rem 1rem rgba(0, 51, 102, 0.045);
}

.card h2 {
  max-width: none;
  margin: 0 0 0.75rem;
  font-size: clamp(1.3rem, 3vw, 1.65rem);
}

.card p:last-child, .card ul:last-child, .card ol:last-child { margin-bottom: 0; }

.card.assignment {
  border-left: 0.45rem solid var(--lime);
  background: var(--deep-navy);
  color: var(--white);
}

.card.assignment h2 { color: var(--white); }
.card.case-brief { border-top: 0.35rem solid var(--lime); }
.card.key-idea { border-left: 0.45rem solid var(--cyan); background: var(--soft-cyan); }
.card.exam-trap { border-left: 0.45rem solid var(--navy); background: linear-gradient(90deg, var(--soft-cyan), var(--white) 75%); }
.card.scenario { border-top: 0.3rem solid var(--cyan); }
.card.decision-brief { border-left: 0.45rem solid var(--lime); }

.case-snapshot {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
  margin: 1.35rem 0;
}

.case-stat {
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  background: #f8fbfc;
}

.case-stat span {
  display: block;
  margin-bottom: 0.25rem;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}

.case-stat strong { color: var(--navy); line-height: 1.35; }
.decision-prompt { padding-top: 1rem; border-top: 1px solid var(--line); }

fieldset { min-width: 0; }
legend { margin-bottom: 1rem; color: var(--ink); font-size: 1.13rem; font-weight: 850; line-height: 1.45; }

.match-board {
  display: grid;
  gap: 0.75rem;
  margin: 1rem 0;
}

.match-row {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(13rem, 0.75fr);
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  border: 1px solid var(--line);
  border-radius: 0.8rem;
  background: var(--white);
}

.match-row span { line-height: 1.45; }
.match-row select {
  width: 100%;
  min-height: 3rem;
  padding: 0.55rem 2.25rem 0.55rem 0.7rem;
  border: 1px solid #8ca1ae;
  border-radius: 0.55rem;
  background: var(--white);
  color: var(--ink);
  font: inherit;
}

.match-row select:disabled { color: var(--ink); opacity: 1; }

.validation {
  margin-top: 1rem;
  padding: 1rem 1.1rem;
  border: 0.13rem solid var(--cyan);
  border-radius: 0.75rem;
  background: var(--soft-cyan);
  color: var(--navy);
  font-weight: 800;
}

.feedback {
  margin-top: 1rem;
  padding: 1.15rem 1.25rem;
  border-left: 0.4rem solid var(--navy);
  border-radius: 0 0.8rem 0.8rem 0;
  background: var(--soft-cyan);
}

.feedback strong { display: block; margin-bottom: 0.3rem; color: var(--navy); font-size: 1.05rem; }
.feedback p { margin-bottom: 0; }
.feedback-correct { border-left-color: var(--dark-lime); background: #f1f9e5; }
.feedback-correct > strong::before { content: "✓ "; color: var(--dark-lime); }
.feedback-review { border-left-color: var(--cyan); }

.drag-workspace { margin: 1rem 0; }

.drag-directions {
  display: grid;
  gap: 0.15rem;
  margin-bottom: 0.6rem;
  padding: 0.9rem 1rem;
  border-left: 0.35rem solid var(--cyan);
  background: var(--soft-cyan);
}

.drag-directions strong { color: var(--navy); }
.drag-directions span { color: var(--muted); }
.drag-status { margin: 0 0 0.9rem; color: var(--muted); font-weight: 750; }
.drag-status:focus { outline: none; }

.drag-board {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1rem;
}

.drag-bank, .drop-area {
  display: flex;
  flex-direction: column;
  padding: 1rem;
  border: 1px solid #bed0db;
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.72);
}

.drag-bank h2, .drop-area h2 {
  display: grid;
  width: 100%;
  max-width: none;
  place-items: center;
  min-height: 2.8rem;
  margin: 0 0 0.8rem;
  color: var(--navy);
  font-size: 1rem;
  letter-spacing: 0.06em;
  text-align: center;
  text-transform: uppercase;
}

.drag-list, .drop-grid { display: grid; grid-auto-rows: 7rem; gap: 0.75rem; }
.drop-grid { grid-template-rows: repeat(3, 7rem); }

.drag-card {
  --pair-color: var(--navy);
  --pair-bg: var(--white);
  display: grid;
  grid-template-columns: 1.1rem minmax(0, 1fr);
  align-items: center;
  gap: 0.6rem;
  width: 100%;
  height: 7rem;
  min-height: 7rem;
  padding: 0.75rem;
  border: 0.12rem solid #9cb0bc;
  border-radius: 0.7rem;
  background: var(--pair-bg);
  color: var(--ink);
  font: inherit;
  text-align: left;
  cursor: grab;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

.drag-card:hover { border-color: var(--navy); }
.drag-card:active { cursor: grabbing; }
.drag-card:focus-visible, .drop-control:focus-visible { outline: 0.2rem solid var(--cyan); outline-offset: 0.12rem; }
.drag-card.is-active { border-color: var(--navy); box-shadow: 0 0 0 0.18rem rgba(0, 51, 102, 0.16); }

.pair-tone-0,
.pair-tone-1,
.pair-tone-2 { --pair-color: var(--navy); --pair-bg: #edf4fa; }

.drag-handle { color: var(--muted); font-size: 1.25rem; font-weight: 900; }

.drag-copy { min-width: 0; }
.drag-copy strong, .drag-copy small { display: block; }
.drag-copy strong { line-height: 1.35; }
.drag-copy small { margin-top: 0.2rem; color: var(--muted); line-height: 1.3; }
.mobile-copy { display: none; }

.drop-target {
  display: flex;
  flex-direction: column;
  height: 7rem;
  min-height: 7rem;
  overflow: hidden;
  border: 0.12rem dashed #88a3b3;
  border-radius: 0.8rem;
  background: #f8fbfc;
  transition: border-color 140ms ease, box-shadow 140ms ease, background 140ms ease;
}

.drop-target.is-drag-over {
  border-color: var(--cyan);
  background: #e7f9fd;
  box-shadow: 0 0 0 0.22rem rgba(0, 183, 216, 0.2);
}

.drop-control {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.6rem;
  width: 100%;
  min-height: 2.15rem;
  padding: 0.35rem 0.65rem;
  border: 0;
  border-bottom: 1px solid #c8d7df;
  background: #e9f0f4;
  color: var(--navy);
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.drop-control span { font-weight: 900; }
.drop-control small { display: none; }
.drop-slot { display: flex; flex: 1; min-height: 2.65rem; padding: 0.2rem; }
.drop-slot .drag-card { height: 100%; min-height: 0; padding: 0.3rem 0.45rem; grid-template-columns: 0.9rem minmax(0, 1fr); gap: 0.4rem; }
.drop-slot .drag-copy strong { line-height: 1.18; }
.drop-slot .drag-copy small { display: none; }
.drop-placeholder { display: grid; min-height: 2rem; margin: 0; place-items: center; color: var(--muted); font-size: 0.9rem; font-weight: 750; text-align: center; }
.bank-complete { margin: 0; padding: 1rem; border: 0.12rem dashed #9cb0bc; border-radius: 0.7rem; color: var(--muted); text-align: center; }

.drag-ghost {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 9999;
  width: min(26rem, calc(100vw - 2rem));
  pointer-events: none;
  opacity: 0.94;
  box-shadow: 0 0.9rem 2rem rgba(0, 33, 62, 0.22);
}

body.is-dragging, body.is-dragging * { cursor: grabbing !important; }

.drag-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 0.8rem;
}

.drag-footer .button { min-height: 2.7rem; padding: 0.5rem 0.85rem; }
.drag-footer span { color: var(--muted); font-weight: 750; }

.application-brief {
  margin-bottom: 1.35rem;
  padding: clamp(1.25rem, 4vw, 1.8rem);
  border-radius: 1rem;
  background: var(--deep-navy);
  color: var(--white);
}

.application-brief > span {
  color: var(--cyan);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.application-brief h2 { margin: 0.25rem 0 0.75rem; color: var(--white); }
.application-brief p { margin: 0; }

.chain-instruction {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.65rem;
}

.chain-instruction strong { color: var(--navy); font-size: 1.12rem; }
.chain-instruction span { color: var(--muted); text-align: right; }

.evidence-chain {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr) auto minmax(0, 1fr);
  grid-template-rows: auto auto auto auto;
  align-items: stretch;
  overflow: hidden;
  border: 1px solid #bed0db;
  border-top: 0.3rem solid var(--cyan);
  border-radius: 1rem;
  background: var(--white);
}

.evidence-chain-item {
  position: relative;
  display: grid;
  grid-row: 1 / span 4;
  grid-template-rows: subgrid;
  min-width: 0;
  row-gap: 0;
  padding: 1.15rem;
}

.evidence-chain-item p { margin: 0 0 0.8rem; line-height: 1.5; }
.evidence-chain-item.is-correct,
.evidence-chain-item.needs-review { background: var(--white); }

.evidence-chain select {
  width: 100%;
  min-height: 3rem;
  padding: 0.55rem 2rem 0.55rem 0.65rem;
  border: 1px solid #829aa8;
  border-radius: 0.55rem;
  background: var(--white);
  color: var(--ink);
  font: inherit;
}

.chain-arrow {
  grid-row: 1 / span 4;
  align-self: center;
  color: var(--navy);
  font-size: 1.5rem;
  font-weight: 900;
}

.chain-result { display: grid; grid-row: 2 / span 3; grid-template-rows: subgrid; align-content: start; gap: 0.2rem; padding-top: 0.7rem; border-top: 1px solid #bed0db; }
.chain-result span {
  justify-self: start;
  padding: 0.22rem 0.55rem;
  border-radius: 999px;
  background: var(--navy);
  color: var(--white);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.03em;
  line-height: 1.35;
  text-transform: uppercase;
}
.evidence-chain-item.needs-review .chain-result span { background: var(--cyan); color: var(--deep-navy); }
.chain-result strong { color: var(--navy); line-height: 1.35; }
.chain-result small { color: var(--ink); line-height: 1.4; }

.chain-summary {
  margin-top: 1rem;
  padding: 1rem 1.2rem;
  border-left: 0.4rem solid var(--cyan);
  background: var(--soft-cyan);
}

.chain-summary.is-correct { border-left-color: var(--cyan); background: var(--soft-blue); }
.chain-summary strong { display: block; margin-bottom: 0.2rem; color: var(--navy); }
.chain-summary p { margin: 0; }

.result-row {
  margin: 0.75rem 0;
  padding: 1rem 1.1rem;
  border: 1px solid var(--line);
  border-left: 0.35rem solid var(--navy);
  border-radius: 0.7rem;
  background: var(--white);
}

.result-row.correct { border-left-color: var(--dark-lime); }
.result-row.incorrect { border-left-color: var(--cyan); }
.result-row h3 { margin-top: 0; }
.result-row p:last-child { margin-bottom: 0; }

.rule-check { margin-top: 1.25rem; }

.reference-grid { display: grid; gap: 1rem; margin-top: 1.25rem; }
.reference-card { margin: 0; padding: 0; border-left: 0.35rem solid var(--cyan); box-shadow: none; }
.reference-card.related-reference { border: 0.13rem solid var(--navy); border-left: 0.45rem solid var(--lime); }

.reference-card summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.1rem 1.25rem;
  font-size: 1.1rem;
}

.reference-card summary::marker { color: var(--navy); }
.reference-card[open] summary { margin-bottom: 0; border-bottom: 1px solid var(--line); }
.reference-content { padding: 1.15rem 1.25rem 1.3rem; }

.related-label {
  display: inline-block;
  margin: 0;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  background: var(--lime);
  color: var(--deep-navy);
  font-size: 0.76rem;
  font-weight: 900;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.distinction-list { display: grid; }
.distinction-item { padding: 1rem 0; border-top: 1px solid var(--line); }
.distinction-item:first-child { padding-top: 0; border-top: 0; }
.distinction-item:last-child { padding-bottom: 0; }
.distinction-item h3 { margin: 0 0 0.4rem; font-size: 1.05rem; }
.distinction-item p { margin-bottom: 0.45rem; }
.reference-steps { padding-left: 1.4rem; }
.reference-steps li { margin: 0.55rem 0; padding-left: 0.25rem; }

details {
  margin: 1rem 0;
  padding: 0.9rem 1rem;
  border: 1px solid var(--line);
  border-radius: 0.8rem;
  background: var(--white);
}

summary { color: var(--navy); font-weight: 850; cursor: pointer; }
details[open] summary { margin-bottom: 1rem; }

.results-summary { border-top: 0.35rem solid var(--lime); }
.result-status {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 0;
  border-top: 1px solid var(--line);
}
.result-status strong { color: var(--navy); text-align: right; }
.course-invitation { border-left: 0.45rem solid var(--lime); background: var(--deep-navy); color: var(--white); }
.course-invitation h2 { color: var(--white); }

.noscript-course { min-height: 0; }

.lesson-dialog {
  width: min(42rem, calc(100% - 2rem));
  max-height: 82vh;
  overflow: auto;
  padding: 0;
  border: 0;
  border-radius: 1.1rem;
  color: var(--ink);
  box-shadow: 0 1.5rem 4rem rgba(0, 40, 79, 0.3);
}

.lesson-dialog::backdrop { background: rgba(0, 30, 60, 0.72); }

.lesson-dialog > p, .lesson-dialog > .reference-topic { margin-inline: 1.5rem; }
.lesson-dialog > p:last-child, .lesson-dialog > .reference-topic:last-child { margin-bottom: 1.5rem; }

.dialog-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.3rem;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--line);
  background: var(--deep-navy);
}

.dialog-header h2 { margin: 0; color: var(--white); font-size: 1.45rem; }

.dialog-close {
  min-height: 2.5rem;
  padding: 0.45rem 0.75rem;
  border: 1px solid var(--cyan);
  border-radius: 0.55rem;
  background: transparent;
  color: var(--white);
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}

.reference-topic { padding: 1rem 1.1rem; border: 1px solid var(--line); border-radius: 0.8rem; background: #f8fbfc; }
.reference-topic + .reference-topic { margin-top: 0.8rem; }
.reference-topic h3 { margin: 0 0 0.3rem; }
.reference-topic p { margin: 0; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 40rem) {
  .site-header { align-items: flex-start; flex-direction: column; gap: 0.15rem; padding-block: 0.65rem; }
  .lesson-identity { margin-left: 0.25rem; text-align: left; }
  .brand { width: 9.5rem; height: 2.9rem; }
  .sample-shell { width: min(100% - 1rem, 52rem); margin-block: 1rem; }
  .screen { border-radius: 1.05rem; }
  .progress-wrap { margin-inline: 0.5rem; }
  .lesson-tools { justify-content: stretch; margin-inline: 0.5rem; }
  .tool-button { flex: 1 1 10rem; }
  .evidence-grid { grid-template-columns: 1fr; }
  .evidence-path { grid-template-columns: 1fr; }
  .path-arrow { justify-self: center; transform: rotate(90deg); }
  .actions, .close-actions { flex-direction: column-reverse; }
  .actions .button { width: 100%; }
  .close-actions .primary { order: 2; }
  .course-shell { width: min(100% - 1rem, 60rem); margin-block: 1rem 2rem; }
  .page-tools { display: grid; grid-template-columns: 1fr 1fr; }
  .page-tools .button { width: 100%; padding-inline: 0.55rem; }
  .progress-line { grid-template-columns: 1fr; gap: 0.45rem; }
  .match-row { grid-template-columns: 1fr; gap: 0.65rem; }
  .drag-board { grid-template-columns: 1fr; }
  .desktop-copy { display: none; }
  .mobile-copy { display: block; }
  .drag-handle { opacity: 0.35; font-size: 1rem; }
  .drag-bank, .drop-area { padding: 0.8rem; }
  .drag-card { min-height: 4.7rem; }
  .drop-control { align-items: flex-start; flex-direction: column; gap: 0.1rem; }
  .drop-control small { text-align: left; }
  .drag-footer { align-items: stretch; flex-direction: column; }
  .drag-footer .button { width: 100%; }
  .chain-instruction { align-items: flex-start; flex-direction: column; gap: 0.2rem; }
  .chain-instruction span { text-align: left; }
  .evidence-chain { grid-template-columns: 1fr; }
  .evidence-chain-item { display: flex; grid-row: auto; flex-direction: column; gap: 0.8rem; }
  .chain-arrow { grid-row: auto; transform: rotate(90deg); }
  .chain-result { grid-row: auto; grid-template-rows: auto; min-height: 0; }
  .result-status { align-items: flex-start; flex-direction: column; gap: 0.1rem; }
  .result-status strong { text-align: left; }
  .case-snapshot { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation: none !important; transition: none !important; }
}

@media (forced-colors: active) {
  .practice-callout, .case-file, .coming-soon { border: 2px solid CanvasText; }
  .current-pill { border: 1px solid CanvasText; }
}