/* Game Engine I · Week 03
   One script, many component instances, visible change over time. */

html.game-engine-week-three-root {
  scroll-behavior: auto;
}

body.course-game-engine-1.game-engine-week-three {
  --w3-lesson-header-height: 58px;
  --w3-sticky-toc-height: 48px;
  --w3-accent: #a94731;
  --w3-accent-strong: #713020;
  --w3-accent-soft: #f1ded7;
  --w3-teal: #2f6170;
  --w3-teal-soft: #dce8e6;
  --w3-rule: color-mix(in srgb, var(--accent) 25%, var(--line));
  --w3-code: #132a32;
  --w3-code-muted: #9bb2b5;
  --w3-code-ink: #f1f5ef;
  --w3-success: #3f6848;
  --w3-danger: #8b3f35;
  background: var(--bg);
}

body.course-game-engine-1.game-engine-week-three [id] {
  scroll-margin-top: calc(var(--w3-lesson-header-height) + var(--w3-sticky-toc-height) + 24px);
}

body.course-game-engine-1.game-engine-week-three a:focus-visible,
body.course-game-engine-1.game-engine-week-three button:focus-visible,
body.course-game-engine-1.game-engine-week-three input:focus-visible,
body.course-game-engine-1.game-engine-week-three summary:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--w3-accent) 58%, transparent);
  outline-offset: 3px;
}

body.course-game-engine-1.game-engine-week-three .lesson-header {
  background: color-mix(in srgb, var(--paper) 96%, transparent);
}

body.course-game-engine-1.game-engine-week-three .week-three-hero {
  background: var(--paper);
}

body.course-game-engine-1.game-engine-week-three .week-three-hero .hero-inner {
  min-height: min(570px, calc(100dvh - 58px));
  padding: clamp(42px, 7vh, 70px) 0;
  grid-template-columns: minmax(330px, 0.82fr) minmax(450px, 1.18fr);
  gap: clamp(38px, 5vw, 68px);
  align-items: center;
}

body.course-game-engine-1.game-engine-week-three .week-three-hero h1 {
  max-width: 560px;
  font-size: clamp(40px, 4.9vw, 60px);
  line-height: 1.02;
}

body.course-game-engine-1.game-engine-week-three .week-three-hero .lead {
  max-width: 520px;
  margin-top: 20px;
  font-size: 17px;
  line-height: 1.62;
}

.week-three-hero-visual {
  min-width: 0;
  margin: 0;
  border: 1px solid var(--w3-rule);
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
  box-shadow: 0 26px 70px color-mix(in srgb, var(--accent-strong) 14%, transparent);
}

.week-three-hero-visual img {
  width: 100%;
  height: auto;
  border: 0;
  display: block;
}

body.course-game-engine-1.game-engine-week-three .layout,
body.course-game-engine-1.game-engine-week-three main.layout {
  padding: 72px 0 122px;
  grid-template-columns: minmax(0, 820px) minmax(210px, 240px);
  gap: clamp(52px, 7vw, 86px);
}

body.course-game-engine-1.game-engine-week-three .article {
  padding: 0;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

body.course-game-engine-1.game-engine-week-three .article p,
body.course-game-engine-1.game-engine-week-three .article li,
body.course-game-engine-1.game-engine-week-three .article dd,
body.course-game-engine-1.game-engine-week-three .article td,
body.course-game-engine-1.game-engine-week-three .article th {
  word-break: keep-all;
  overflow-wrap: break-word;
}

.week-three-intro {
  margin-bottom: 82px;
}

.week-three-lesson-facts {
  margin: 0;
  border-top: 1px solid var(--line-strong);
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.week-three-lesson-facts > div {
  min-width: 0;
  padding: 17px 18px 18px 0;
  border-bottom: 1px solid var(--line);
}

.week-three-lesson-facts > div:nth-child(3n + 2),
.week-three-lesson-facts > div:nth-child(3n + 3) {
  padding-left: 18px;
  border-left: 1px solid var(--line);
}

.week-three-lesson-facts dt {
  margin-bottom: 6px;
  color: var(--quiet);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .025em;
  text-transform: uppercase;
}

.week-three-lesson-facts dd {
  margin: 0;
  color: var(--ink-strong);
  font-size: 14px;
  font-weight: 650;
  line-height: 1.48;
}

.arrival-card {
  margin-top: 28px;
  padding: 24px 26px;
  border: 1px solid var(--w3-rule);
  border-left: 4px solid var(--w3-accent);
  border-radius: 6px;
  background: color-mix(in srgb, var(--w3-accent-soft) 40%, var(--paper));
}

.teaching-mode,
.mission-mode {
  margin-top: 28px;
  padding: 20px 22px;
  border: 1px solid var(--w3-rule);
  border-radius: 6px;
  background: var(--paper);
}

.teaching-mode {
  border-left: 4px solid var(--w3-teal);
}

.mission-mode {
  border-left: 4px solid var(--w3-accent);
  background: color-mix(in srgb, var(--w3-accent-soft) 34%, var(--paper));
}

.teaching-mode > span,
.mission-mode > span,
.mission-statement > span,
.starter-kit article > span,
.constraint-grid article > span,
.prediction-grid article > span {
  color: var(--w3-accent-strong);
  font: 650 12px/1.35 var(--mono);
  letter-spacing: .035em;
  text-transform: uppercase;
}

.teaching-mode > strong,
.mission-mode > strong {
  margin-top: 7px;
  display: block;
  color: var(--ink-strong);
  font-size: 16px;
  line-height: 1.45;
}

.teaching-mode > p,
.mission-mode > p {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.arrival-card > span,
.section-label,
.visual-label,
.step-label,
.quiz-kicker,
.submit-label,
.source-label,
.code-filename,
.lab-label,
.rubric-points {
  color: var(--w3-accent-strong);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 650;
  letter-spacing: .035em;
  text-transform: uppercase;
}

.arrival-card strong {
  margin-top: 7px;
  display: block;
  color: var(--ink-strong);
  font-size: clamp(20px, 2.4vw, 26px);
  font-weight: 760;
  letter-spacing: -.028em;
  line-height: 1.35;
}

.arrival-card p {
  margin: 9px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.session-track {
  margin: 26px 0 0;
  padding: 0;
  border-top: 1px solid var(--line-strong);
  list-style: none;
}

.session-track li {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: 88px minmax(155px, .6fr) minmax(0, 1.4fr);
  gap: 18px;
  align-items: baseline;
}

.session-track time {
  color: var(--w3-accent-strong);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 600;
}

.session-track strong {
  color: var(--ink-strong);
  font-size: 15px;
}

.session-track p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.week-three-section {
  margin-top: 96px;
}

.week-three-section > header {
  margin-bottom: 28px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line-strong);
}

.week-three-section h2 {
  margin: 8px 0 0;
  color: var(--ink-strong);
  font-size: clamp(27px, 3.4vw, 36px);
  font-weight: 770;
  letter-spacing: -.045em;
  line-height: 1.12;
}

.week-three-section > header > p {
  max-width: 680px;
  margin: 11px 0 0;
  color: var(--muted);
  font-size: 15px;
}

.week-three-section h3 {
  margin: 34px 0 10px;
  color: var(--ink-strong);
  font-size: 20px;
  font-weight: 730;
  letter-spacing: -.025em;
}

.week-three-section > p {
  margin: 15px 0 0;
}

.mental-model {
  margin: 27px 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 9px;
}

.mental-model > div {
  min-height: 138px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
}

.mental-model span {
  color: var(--w3-accent);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 650;
}

.mental-model strong {
  margin-top: 21px;
  display: block;
  color: var(--ink-strong);
  font-size: 15px;
}

.mental-model p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.52;
}

.concept-grid,
.type-grid,
.variant-grid,
.evidence-grid,
.rubric-grid,
.source-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.concept-grid,
.type-grid,
.source-grid {
  column-gap: 32px;
  row-gap: 0;
}

.variant-grid,
.evidence-grid,
.rubric-grid {
  gap: 12px;
}

.concept-card,
.type-card,
.source-card {
  min-width: 0;
  padding: 21px 0 24px;
  border: 0;
  border-top: 1px solid var(--line);
  border-radius: 0;
  background: transparent;
}

.variant-card,
.evidence-card,
.rubric-card {
  min-width: 0;
  padding: 21px 22px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
}

.concept-card code,
.type-card code {
  color: var(--w3-accent-strong);
  font-size: 12px;
}

.concept-card h3,
.type-card h3,
.variant-card h3,
.evidence-card h3,
.rubric-card h3,
.source-card h3 {
  margin: 10px 0 7px;
  font-size: 17px;
}

.concept-card p,
.type-card p,
.variant-card p,
.evidence-card p,
.rubric-card p,
.source-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.58;
}

.type-card-example {
  margin-top: 13px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--ink-strong);
  font-family: var(--mono);
  font-size: 12px;
}

.code-card {
  margin: 25px 0;
  border: 1px solid #27444c;
  border-radius: 7px;
  overflow: hidden;
  background: var(--w3-code);
  box-shadow: 0 20px 50px rgba(15, 34, 40, .14);
}

.code-card-header {
  min-height: 48px;
  padding: 10px 12px 10px 18px;
  border-bottom: 1px solid rgba(221, 237, 233, .13);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.code-filename {
  color: #d4e0de;
}

.copy-code {
  min-height: 31px;
  padding: 6px 9px;
  border: 1px solid rgba(226, 239, 235, .24);
  border-radius: 4px;
  background: transparent;
  color: #dfe9e6;
  font: 600 12px/1 var(--mono);
  letter-spacing: .02em;
  text-transform: uppercase;
  cursor: pointer;
}

.copy-code[data-copied="true"] {
  border-color: #8bc29a;
  color: #bde5c8;
}

.code-card pre {
  margin: 0;
  padding: 22px;
  overflow-x: auto;
  color: var(--w3-code-ink);
  font: 14px/1.75 var(--mono);
  tab-size: 4;
}

.code-card code {
  color: inherit;
  font-family: inherit;
}

.code-card .code-comment { color: var(--w3-code-muted); }
.code-card .code-keyword { color: #91d0db; }
.code-card .code-type { color: #d5c77f; }
.code-card .code-value { color: #f09b78; }
.code-card .code-method { color: #b9dc9e; }

.code-reading {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-strong);
  list-style: none;
}

.code-reading li {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: minmax(150px, .8fr) minmax(0, 1.2fr);
  gap: 22px;
}

.code-reading code {
  color: var(--w3-accent-strong);
  font-size: 13px;
  font-weight: 650;
}

.code-reading span {
  color: var(--muted);
  font-size: 14px;
}

.lifecycle {
  margin: 28px 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  list-style: none;
}

.lifecycle li {
  position: relative;
  min-height: 132px;
  padding: 18px 18px 18px 20px;
  border-top: 3px solid var(--w3-teal);
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

.lifecycle li + li {
  border-left: 1px solid var(--line);
}

.lifecycle li:not(:last-child)::after {
  content: "→";
  position: absolute;
  top: -15px;
  right: -10px;
  z-index: 2;
  width: 20px;
  height: 20px;
  border: 1px solid var(--w3-rule);
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--paper);
  color: var(--w3-teal);
  font-size: 12px;
}

.lifecycle code {
  color: var(--ink-strong);
  font-size: 13px;
  font-weight: 650;
}

.lifecycle strong {
  margin-top: 18px;
  display: block;
  color: var(--w3-accent-strong);
  font: 650 12px/1.35 var(--mono);
  text-transform: uppercase;
}

.lifecycle p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.frame-compare {
  margin: 26px 0;
  border: 1px solid var(--line);
  border-radius: 6px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  overflow: hidden;
  background: var(--paper);
}

.frame-case {
  padding: 23px;
}

.frame-case + .frame-case {
  border-left: 1px solid var(--line);
}

.frame-case[data-correct="true"] {
  background: color-mix(in srgb, var(--w3-teal-soft) 55%, var(--paper));
}

.frame-case strong {
  margin-top: 10px;
  display: block;
  color: var(--ink-strong);
  font-size: 15px;
}

.frame-case p {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.equation {
  margin: 17px 0 0;
  color: var(--w3-accent-strong);
  font: 650 12px/1.6 var(--mono);
}

.responsive-table {
  margin: 28px 0;
  border-top: 1px solid var(--line-strong);
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  scrollbar-gutter: stable;
}

.responsive-table:focus-visible {
  outline-offset: 5px;
}

.calculation-table,
.test-matrix {
  width: 100%;
  min-width: 670px;
  border-collapse: collapse;
  table-layout: fixed;
}

.calculation-table th,
.calculation-table td,
.test-matrix th,
.test-matrix td {
  padding: 13px 16px 13px 0;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  font-weight: 400;
  line-height: 1.55;
  text-align: left;
  vertical-align: top;
}

.calculation-table thead th,
.test-matrix thead th {
  color: var(--ink-strong);
  font: 650 12px/1.4 var(--mono);
  letter-spacing: .025em;
  text-transform: uppercase;
}

.calculation-table tbody th,
.test-matrix tbody th {
  color: var(--w3-accent-strong);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 650;
  text-transform: uppercase;
}

.calculation-table th:nth-child(1) { width: 17.5%; }
.calculation-table th:nth-child(2) { width: 25%; }
.calculation-table th:nth-child(3) { width: 36%; }
.calculation-table th:nth-child(4) { width: 21.5%; }
.test-matrix th:nth-child(1) { width: 14%; }
.test-matrix th:nth-child(2) { width: 28%; }
.test-matrix th:nth-child(3) { width: 34%; }
.test-matrix th:nth-child(4) { width: 24%; }

.responsive-table::after {
  content: "좁은 화면에서는 표를 좌우로 이동할 수 있습니다.";
  padding-top: 9px;
  display: none;
  color: var(--quiet);
  font: 500 12px/1.45 var(--mono);
}

.callout {
  margin: 25px 0;
  padding: 21px 23px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
}

.callout-info { border-left: 4px solid var(--w3-teal); }
.callout-warning { border-left: 4px solid var(--w3-accent); }
.callout-success { border-left: 4px solid var(--w3-success); }

.callout-title {
  margin: 0 0 8px !important;
  color: var(--ink-strong) !important;
  font-size: 14px !important;
  font-weight: 730;
}

.callout p,
.callout li {
  color: var(--muted);
  font-size: 14px;
}

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

.knowledge-check {
  margin: 34px 0;
  padding: 24px;
  border: 1px solid var(--w3-rule);
  border-radius: 7px;
  background: color-mix(in srgb, var(--w3-teal-soft) 40%, var(--paper));
}

.knowledge-check h3 {
  margin: 7px 0 8px;
  font-size: 18px;
}

.knowledge-check > p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.quiz-options {
  margin-top: 18px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.quiz-option {
  min-height: 44px;
  padding: 10px 12px;
  border: 1px solid var(--line-strong);
  border-radius: 4px;
  background: var(--paper);
  color: var(--ink-strong);
  font: 650 13px/1.35 var(--mono);
  cursor: pointer;
}

.quiz-option[data-state="correct"] {
  border-color: var(--w3-success);
  background: color-mix(in srgb, #dbe9dd 70%, var(--paper));
  color: var(--w3-success);
}

.quiz-option[data-state="incorrect"] {
  border-color: var(--w3-danger);
  background: color-mix(in srgb, #efdcd8 65%, var(--paper));
  color: var(--w3-danger);
}

.quiz-feedback {
  min-height: 1.5em;
  margin-top: 12px !important;
  color: var(--ink) !important;
  font-weight: 620;
}

.practice-route {
  margin: 28px 0;
  padding: 0;
  border-top: 1px solid var(--line-strong);
  list-style: none;
  counter-reset: practice-step;
}

.practice-step {
  counter-increment: practice-step;
  padding: 25px 0 28px;
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr);
  gap: 22px;
}

.practice-step::before {
  content: counter(practice-step, decimal-leading-zero);
  color: var(--w3-accent);
  font: 650 14px/1 var(--mono);
}

.practice-step h3 {
  margin: -3px 0 8px;
  font-size: 19px;
}

.practice-step p,
.practice-step li {
  color: var(--muted);
  font-size: 14px;
}

.practice-step ul,
.practice-step ol {
  margin: 12px 0 0;
  padding-left: 20px;
}

.checkpoint {
  margin-top: 17px;
  padding: 15px 17px;
  border-left: 3px solid var(--w3-teal);
  background: color-mix(in srgb, var(--w3-teal-soft) 46%, var(--paper));
}

.checkpoint strong {
  color: var(--ink-strong);
  font-size: 12px;
}

.checkpoint p {
  margin: 5px 0 0;
  font-size: 12px;
}

.motion-lab {
  margin: 30px 0;
  border: 1px solid var(--w3-rule);
  border-radius: 8px;
  overflow: hidden;
  background: var(--paper);
}

.motion-lab-header {
  padding: 20px 22px;
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: start;
}

.motion-lab-header h3 {
  margin: 6px 0 0;
  font-size: 18px;
}

.motion-toggle {
  min-height: 36px;
  padding: 8px 11px;
  border: 1px solid var(--line-strong);
  border-radius: 4px;
  background: var(--paper);
  color: var(--ink-strong);
  font: 650 12px/1 var(--mono);
  cursor: pointer;
}

.motion-stage {
  position: relative;
  height: 235px;
  overflow: hidden;
  background:
    linear-gradient(90deg, color-mix(in srgb, var(--w3-teal) 12%, transparent) 1px, transparent 1px),
    linear-gradient(180deg, color-mix(in srgb, var(--w3-teal) 12%, transparent) 1px, transparent 1px),
    color-mix(in srgb, var(--w3-teal-soft) 54%, var(--paper));
  background-size: 32px 32px;
}

.motion-stage::after {
  content: "resetAtX";
  position: absolute;
  top: 16px;
  right: 14px;
  bottom: 16px;
  border-right: 1px dashed var(--w3-accent);
  color: var(--w3-accent-strong);
  font: 600 12px/1 var(--mono);
}

.motion-object {
  position: absolute;
  top: 92px;
  left: 0;
  width: 52px;
  height: 52px;
  border: 3px solid var(--paper);
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--w3-accent);
  color: #fff;
  box-shadow: 0 12px 24px rgba(76, 47, 37, .24);
  font: 700 12px/1 var(--mono);
  will-change: transform;
}

.motion-controls {
  padding: 20px 22px 23px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.motion-control label {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--ink-strong);
  font: 600 12px/1.4 var(--mono);
}

.motion-control output {
  color: var(--w3-accent-strong);
}

.motion-control input[type="range"] {
  width: 100%;
  margin-top: 11px;
  accent-color: var(--w3-accent);
}

.motion-check {
  align-self: center;
  display: flex;
  gap: 9px;
  align-items: center;
  color: var(--ink-strong);
  font-size: 12px;
  font-weight: 650;
}

.motion-check input {
  width: 18px;
  height: 18px;
  accent-color: var(--w3-accent);
}

.lecture-cues,
.debug-protocol {
  margin: 30px 0;
  padding: 24px;
  border: 1px solid var(--w3-rule);
  border-radius: 7px;
  background: color-mix(in srgb, var(--w3-teal-soft) 34%, var(--paper));
}

.lecture-cues > ol,
.debug-protocol > ol {
  margin: 17px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  list-style: none;
}

.lecture-cues li,
.debug-protocol li {
  min-width: 0;
  padding: 16px 16px 3px 0;
}

.lecture-cues li:nth-child(even),
.debug-protocol li:nth-child(even) {
  padding-left: 16px;
  border-left: 1px solid var(--line);
}

.lecture-cues strong,
.debug-protocol strong {
  color: var(--ink-strong);
  font-size: 13px;
}

.lecture-cues p,
.debug-protocol p {
  margin: 5px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.prediction-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
}

.prediction-grid article {
  min-width: 0;
  padding: 19px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
}

.prediction-grid strong {
  margin-top: 14px;
  display: block;
  color: var(--ink-strong);
  font-size: 14px;
}

.prediction-grid p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}

.install-checklist,
.assignment-checklist {
  margin: 24px 0 0;
  padding: 0;
  border-top: 1px solid var(--line-strong);
  list-style: none;
}

.install-check,
.assignment-check {
  padding: 15px 0;
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr);
  gap: 13px;
  align-items: start;
}

.install-check input,
.assignment-check input {
  width: 18px;
  height: 18px;
  margin: 2px 0 0;
  accent-color: var(--w3-success);
}

.install-check label,
.assignment-check label {
  color: var(--ink-strong);
  font-size: 13px;
  font-weight: 620;
  cursor: pointer;
}

.install-check p,
.assignment-check p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 13px;
  font-weight: 400;
}

.install-check[data-checked="true"] label,
.assignment-check[data-checked="true"] label {
  color: var(--quiet);
  text-decoration: line-through;
  text-decoration-color: color-mix(in srgb, var(--quiet) 55%, transparent);
}

.checklist-progress {
  margin-top: 13px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
}

.checklist-progress span {
  color: var(--w3-success);
  font: 650 12px/1.3 var(--mono);
}

.checklist-reset {
  min-height: 34px;
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: transparent;
  color: var(--muted);
  font: 600 12px/1 var(--mono);
  cursor: pointer;
}

.checklist-reset[data-confirming="true"] {
  border-color: var(--w3-danger);
  background: color-mix(in srgb, var(--w3-danger) 8%, transparent);
  color: var(--w3-danger);
}

.checklist-reset:disabled {
  opacity: 0.48;
  cursor: not-allowed;
}

.variant-card {
  position: relative;
  padding-top: 49px;
}

.variant-card::before {
  content: attr(data-variant);
  position: absolute;
  top: 20px;
  left: 22px;
  color: var(--w3-accent);
  font: 650 12px/1 var(--mono);
}

.parameter-list {
  margin: 16px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.parameter-list li {
  padding: 8px 0;
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--muted);
  font: 12px/1.4 var(--mono);
}

.parameter-list code {
  color: var(--ink-strong);
  font-size: inherit;
}

.evidence-card strong,
.rubric-card strong {
  display: block;
  color: var(--ink-strong);
  font-size: 17px;
}

.rubric-card {
  min-height: 165px;
}

.rubric-points {
  float: right;
  color: var(--w3-teal);
}

.submission-box {
  margin: 28px 0;
  padding: 26px;
  border: 1px solid var(--w3-rule);
  border-radius: 7px;
  background: var(--paper);
}

.submission-box h3 {
  margin: 8px 0 16px;
  font-size: 21px;
}

.submission-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.submission-list li {
  padding: 12px 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 16px;
  font-size: 13px;
}

.submission-list strong {
  color: var(--w3-accent-strong);
  font: 650 12px/1.5 var(--mono);
  text-transform: uppercase;
}

.mission-contract {
  margin: 28px 0;
  border: 1px solid var(--w3-rule);
  border-radius: 8px;
  overflow: hidden;
  background: var(--paper);
}

.mission-statement {
  padding: 26px;
  background: color-mix(in srgb, var(--w3-accent-soft) 34%, var(--paper));
}

.mission-statement strong {
  margin-top: 8px;
  display: block;
  color: var(--ink-strong);
  font-size: clamp(20px, 2.5vw, 26px);
  letter-spacing: -.025em;
  line-height: 1.35;
}

.mission-statement p {
  max-width: 680px;
  margin: 9px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.mission-facts {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.mission-facts > div {
  min-width: 0;
  padding: 18px;
  border-top: 1px solid var(--line);
}

.mission-facts > div + div {
  border-left: 1px solid var(--line);
}

.mission-facts dt {
  color: var(--quiet);
  font: 650 12px/1.35 var(--mono);
  text-transform: uppercase;
}

.mission-facts dd {
  margin: 7px 0 0;
  color: var(--ink-strong);
  font-size: 12px;
  font-weight: 650;
}

.starter-kit,
.constraint-grid,
.pass-gate {
  display: grid;
  gap: 12px;
}

.starter-kit,
.constraint-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.pass-gate {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.starter-kit article,
.constraint-grid article,
.pass-gate article {
  min-width: 0;
  padding: 21px 22px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
}

.starter-kit h3,
.constraint-grid h3 {
  margin: 10px 0 8px;
  font-size: 17px;
}

.starter-kit ul {
  margin: 10px 0 0;
  padding-left: 18px;
}

.starter-kit li,
.constraint-grid p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

.constraint-grid article[data-state="required"] {
  border-top: 3px solid var(--w3-teal);
}

.constraint-grid article[data-state="forbidden"] {
  border-top: 3px solid var(--w3-accent);
  background: color-mix(in srgb, var(--w3-accent-soft) 24%, var(--paper));
}

.pass-gate article {
  min-height: 152px;
}

.pass-gate article > span {
  color: var(--w3-accent);
  font: 650 12px/1 var(--mono);
}

.pass-gate article > strong {
  margin-top: 20px;
  display: block;
  color: var(--ink-strong);
  font-size: 14px;
}

.pass-gate article > p {
  margin: 6px 0 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.52;
}

.hint-ladder {
  margin-top: 28px;
  border-top: 1px solid var(--line-strong);
}

.hint-ladder details {
  border-bottom: 1px solid var(--line);
  background: transparent;
}

.hint-ladder summary {
  min-height: 68px;
  padding: 17px 4px;
  display: grid;
  grid-template-columns: 170px minmax(0, 1fr);
  gap: 18px;
  align-items: center;
  color: var(--ink-strong);
  cursor: pointer;
  list-style-position: inside;
}

.hint-ladder summary::marker {
  color: var(--w3-accent);
}

.hint-ladder summary span {
  color: var(--w3-accent-strong);
  font: 650 12px/1.35 var(--mono);
  text-transform: uppercase;
}

.hint-ladder summary strong {
  font-size: 14px;
}

.hint-ladder details > div {
  margin: 0 0 18px 188px;
  padding: 17px 19px;
  border-left: 3px solid var(--w3-teal);
  background: color-mix(in srgb, var(--w3-teal-soft) 38%, var(--paper));
}

.hint-ladder details p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.source-grid {
  margin-top: 25px;
}

.source-card a {
  color: var(--ink-strong);
  font-size: 14px;
  font-weight: 700;
}

.next-lesson {
  margin-top: 78px;
  padding: 26px 0;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr);
  gap: 28px;
}

.next-lesson > span {
  color: var(--w3-accent);
  font: 650 12px/1.4 var(--mono);
  text-transform: uppercase;
}

.next-lesson h3 {
  margin: 0;
  font-size: 21px;
}

.next-lesson p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 13px;
}

body.course-game-engine-1.game-engine-week-three .toc {
  top: 85px;
  max-height: calc(100vh - 108px);
  padding: 0;
  border: 0;
  border-top: 1px solid var(--line-strong);
  border-radius: 0;
  overflow: auto;
  background: transparent;
  box-shadow: none;
}

body.course-game-engine-1.game-engine-week-three .toc-title {
  padding: 15px 0 10px;
  color: var(--ink-strong);
  font: 650 12px/1.3 var(--mono);
  text-transform: uppercase;
}

body.course-game-engine-1.game-engine-week-three .toc ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

body.course-game-engine-1.game-engine-week-three .toc li {
  border-top: 1px solid var(--line);
}

body.course-game-engine-1.game-engine-week-three .toc a {
  padding: 10px 0;
  border: 0;
  display: block;
  color: var(--quiet);
  font-size: 12px;
  line-height: 1.45;
}

body.course-game-engine-1.game-engine-week-three .toc a[aria-current="location"] {
  color: var(--w3-accent-strong);
  text-decoration: none;
}

body.course-game-engine-1.game-engine-week-three .toc a[aria-current="location"] {
  padding-left: 11px;
  box-shadow: inset 2px 0 0 var(--w3-accent);
}

@media (hover: hover) and (pointer: fine) {
  .copy-code:hover {
    border-color: rgba(226, 239, 235, .6);
  }

  .quiz-option:hover {
    border-color: var(--w3-teal);
  }

  .source-card a:hover,
  body.course-game-engine-1.game-engine-week-three .toc a:hover {
    color: var(--w3-accent-strong);
    text-decoration: none;
  }
}

.footer-note {
  margin: 0;
  padding: 20px 24px 30px;
  color: var(--quiet);
  font: 500 12px/1.4 var(--mono);
  text-align: center;
  text-transform: uppercase;
}

@media (max-width: 980px) {
  body.course-game-engine-1.game-engine-week-three .week-three-hero .hero-inner {
    grid-template-columns: minmax(0, 1fr);
  }

  .week-three-hero-visual {
    max-width: 720px;
  }

  body.course-game-engine-1.game-engine-week-three .layout,
  body.course-game-engine-1.game-engine-week-three main.layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 34px;
  }

  body.course-game-engine-1.game-engine-week-three .toc {
    position: sticky;
    top: var(--w3-lesson-header-height);
    z-index: 18;
    order: -1;
    max-height: none;
    margin: -34px calc(50% - 50vw) 4px;
    padding: 0 24px;
    border-top: 0;
    border-bottom: 1px solid var(--line);
    overflow-x: auto;
    background: color-mix(in srgb, var(--bg) 96%, transparent);
    backdrop-filter: blur(12px);
    scrollbar-width: none;
  }

  body.course-game-engine-1.game-engine-week-three .toc::-webkit-scrollbar {
    display: none;
  }

  body.course-game-engine-1.game-engine-week-three .toc-title {
    display: none;
  }

  body.course-game-engine-1.game-engine-week-three .toc ol {
    width: max-content;
    display: flex;
  }

  body.course-game-engine-1.game-engine-week-three .toc li {
    border: 0;
  }

  body.course-game-engine-1.game-engine-week-three .toc a {
    min-height: 48px;
    padding: 16px 12px 13px;
    border-bottom: 2px solid transparent;
    white-space: nowrap;
  }

  body.course-game-engine-1.game-engine-week-three .toc a[aria-current="location"] {
    padding-left: 12px;
    border-bottom-color: var(--w3-accent);
    box-shadow: none;
  }

  .mental-model,
  .lifecycle {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .pass-gate {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .mission-facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .mission-facts > div:nth-child(3) {
    border-left: 0;
  }

  .lifecycle li:nth-child(3) {
    border-left: 0;
  }
}

@media (max-width: 760px) {
  body.course-game-engine-1.game-engine-week-three {
    --w3-lesson-header-height: 68px;
  }

  body.course-game-engine-1.game-engine-week-three .week-three-hero .hero-inner {
    min-height: 0;
    padding: 36px 0 42px;
  }

  body.course-game-engine-1.game-engine-week-three .week-three-hero h1 {
    font-size: clamp(34px, 10.5vw, 47px);
  }

  body.course-game-engine-1.game-engine-week-three .layout,
  body.course-game-engine-1.game-engine-week-three main.layout {
    padding-bottom: 86px;
  }

  .week-three-lesson-facts,
  .concept-grid,
  .type-grid,
  .variant-grid,
  .evidence-grid,
  .rubric-grid,
  .source-grid,
  .frame-compare,
  .motion-controls,
  .starter-kit,
  .constraint-grid,
  .pass-gate,
  .prediction-grid,
  .lecture-cues > ol,
  .debug-protocol > ol,
  .mission-facts {
    grid-template-columns: minmax(0, 1fr);
  }

  .week-three-lesson-facts > div,
  .week-three-lesson-facts > div:nth-child(3n + 2),
  .week-three-lesson-facts > div:nth-child(3n + 3) {
    padding-left: 0;
    border-left: 0;
  }

  .session-track li {
    grid-template-columns: 72px minmax(0, 1fr);
    gap: 6px 14px;
  }

  .session-track p {
    grid-column: 2;
  }

  .mental-model,
  .lifecycle {
    grid-template-columns: minmax(0, 1fr);
  }

  .lifecycle li + li,
  .lifecycle li:nth-child(3) {
    border-left: 0;
  }

  .lifecycle li:not(:last-child)::after {
    display: none;
  }

  .frame-case + .frame-case {
    border-top: 1px solid var(--line);
    border-left: 0;
  }

  .responsive-table::after {
    display: block;
  }

  .quiz-options {
    grid-template-columns: minmax(0, 1fr);
  }

  .code-reading li {
    grid-template-columns: minmax(0, 1fr);
    gap: 5px;
  }

  .practice-step {
    grid-template-columns: 42px minmax(0, 1fr);
    gap: 14px;
  }

  .motion-lab-header {
    display: block;
  }

  .motion-toggle {
    margin-top: 14px;
  }

  .motion-stage {
    height: 200px;
  }

  .motion-object {
    top: 74px;
  }

  .submission-list li,
  .next-lesson {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

  .lecture-cues li:nth-child(even),
  .debug-protocol li:nth-child(even),
  .mission-facts > div + div,
  .mission-facts > div:nth-child(3) {
    padding-left: 0;
    border-left: 0;
  }

  .hint-ladder summary {
    grid-template-columns: minmax(0, 1fr);
    gap: 5px;
  }

  .hint-ladder details > div {
    margin-left: 0;
  }

  .arrival-card,
  .knowledge-check,
  .submission-box,
  .teaching-mode,
  .mission-mode,
  .lecture-cues,
  .debug-protocol {
    padding: 20px;
  }
}

@media (prefers-color-scheme: dark) {
  body.course-game-engine-1.game-engine-week-three {
    --bg: #111714;
    --paper: #171f1b;
    --surface: #202b26;
    --surface-strong: #2a3832;
    --ink: #d7dfd8;
    --ink-strong: #f1f4ee;
    --muted: #aab4ab;
    --quiet: #929d94;
    --line: rgba(227, 236, 229, .13);
    --line-strong: rgba(227, 236, 229, .25);
    --accent: #90b4bd;
    --accent-strong: #b9d1d5;
    --link: #a7c7ce;
    --w3-accent: #e08065;
    --w3-accent-strong: #f1ad98;
    --w3-accent-soft: #4a2d26;
    --w3-teal: #7cb2bc;
    --w3-teal-soft: #213c3e;
    --w3-success: #91c69d;
    --w3-danger: #e49a8e;
    --shadow: 0 18px 48px rgba(0, 0, 0, .26);
  }

  .week-three-hero-visual img {
    filter: brightness(.88) saturate(.9);
  }

  .motion-object {
    border-color: #f3eee6;
  }

  .quiz-option[data-state="correct"] {
    background: color-mix(in srgb, var(--w3-success) 16%, var(--paper));
    color: var(--w3-success);
  }

  .quiz-option[data-state="incorrect"] {
    background: color-mix(in srgb, var(--w3-danger) 16%, var(--paper));
    color: var(--w3-danger);
  }
}

@media (prefers-reduced-motion: reduce) {
  html.game-engine-week-three-root {
    scroll-behavior: auto;
  }

  body.course-game-engine-1.game-engine-week-three *,
  body.course-game-engine-1.game-engine-week-three *::before,
  body.course-game-engine-1.game-engine-week-three *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: .001ms !important;
  }
}

@media print {
  body.course-game-engine-1.game-engine-week-three {
    --bg: #fff;
    --paper: #fff;
    --ink: #222;
    --ink-strong: #000;
    --muted: #444;
    --quiet: #555;
    --line: #d7d7d7;
    --line-strong: #999;
    background: #fff;
  }

  body.course-game-engine-1.game-engine-week-three .lesson-header,
  body.course-game-engine-1.game-engine-week-three .toc,
  .copy-code,
  .motion-toggle,
  .checklist-reset,
  .footer-note {
    display: none !important;
  }

  body.course-game-engine-1.game-engine-week-three .week-three-hero .hero-inner,
  body.course-game-engine-1.game-engine-week-three .layout,
  body.course-game-engine-1.game-engine-week-three main.layout {
    width: 100%;
    min-height: 0;
    padding: 24px 0;
    display: block;
  }

  .week-three-hero-visual {
    max-width: 620px;
    margin-top: 24px;
    box-shadow: none;
  }

  .week-three-section {
    break-before: auto;
  }

  .code-card,
  .concept-card,
  .type-card,
  .variant-card,
  .evidence-card,
  .rubric-card,
  .source-card,
  .knowledge-check,
  .motion-lab,
  .mission-contract,
  .starter-kit article,
  .constraint-grid article,
  .pass-gate article,
  .hint-ladder details {
    break-inside: avoid;
    box-shadow: none;
  }
}