.concept-hero h1 {
  max-width: 940px;
  font-size: clamp(2.8rem, 5.5vw, 5.65rem);
  line-height: 1.02;
}

.concept-title-unit { display: inline-block; }

.concept-lab .endpoint-controls {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.concept-lab .endpoint-controls button {
  flex-direction: column;
  align-items: center;
  gap: 3px;
  min-height: 78px;
  font-size: 1.02rem;
}

.concept-lab .endpoint-stage {
  min-height: 0;
}

.concept-lab .endpoint-explanation {
  min-height: 450px;
}

.concept-lab .endpoint-explanation > p {
  min-height: 9.2em;
}

.concept-lab #conceptCanvas[hidden] {
  display: none !important;
}

.concept-generated-image {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid #d5e2e2;
  border-radius: 14px;
  background: #fff;
  box-shadow: 0 24px 60px rgba(9, 47, 55, 0.12);
}

.concept-static-header span {
  display: block;
  color: var(--academy-copper);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.concept-static-header strong {
  display: block;
  max-width: 760px;
  margin-top: 7px;
  color: #0c3038;
  font-family: var(--display);
  font-size: clamp(1.7rem, 4vw, 3.2rem);
  line-height: 1.08;
  letter-spacing: 0;
}

.concept-static-flow {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.concept-static-flow li {
  min-height: 120px;
  padding: 18px 16px;
  border: 1px solid rgba(121, 161, 166, 0.58);
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 18px 40px rgba(11, 48, 56, 0.07);
}

.concept-static-flow li span {
  display: block;
  color: var(--academy-copper);
  font-size: 0.72rem;
  font-weight: 900;
}

.concept-static-flow li strong {
  display: block;
  margin-top: 18px;
  color: #0d333b;
  font-size: clamp(1rem, 1.8vw, 1.28rem);
  line-height: 1.28;
}

.concept-static-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid rgba(126, 165, 170, 0.58);
  background: rgba(126, 165, 170, 0.58);
}

.concept-static-grid div {
  padding: 15px 16px;
  background: rgba(255, 255, 255, 0.86);
}

.concept-static-grid span {
  display: block;
  color: var(--academy-copper);
  font-size: 0.7rem;
  font-weight: 900;
  letter-spacing: 0.12em;
}

.concept-static-grid strong {
  display: block;
  margin-top: 7px;
  color: #314f55;
  font-size: 0.9rem;
  line-height: 1.55;
}

.lesson-body #lessonSections > section {
  padding-top: 24px;
  margin-top: 58px;
  border-top: 1px solid var(--academy-line);
  scroll-margin-top: 110px;
}

.lesson-body #lessonSections > section > p {
  color: #304d54;
  font-size: 1.08rem;
  line-height: 1.92;
}

.lesson-body #lessonSections .lesson-example {
  margin-top: 28px;
  padding: 24px;
  border-left: 3px solid var(--academy-copper);
  color: #29474e;
  background: #f0f6f5;
  line-height: 1.72;
}

.lesson-body #lessonSections .lesson-example strong {
  display: block;
  margin-bottom: 7px;
  color: var(--academy-teal);
}

.concept-checklist {
  margin-top: 58px !important;
}

.concept-terms {
  padding-top: 34px !important;
  border-top: 2px solid #123f48 !important;
}

.concept-terms > div {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 28px;
  border: 1px solid var(--academy-line);
  background: var(--academy-line);
}

.concept-term {
  padding: 20px;
  background: #f7faf9;
}

.concept-term strong {
  display: block;
  color: var(--academy-teal);
  font-family: var(--display);
  font-size: 1.08rem;
}

.concept-term p {
  margin: 7px 0 0;
  color: #5a6f74;
  font-size: 0.88rem;
  line-height: 1.6;
}

.concept-source-list {
  margin-top: 26px;
  padding-top: 16px;
  border-top: 1px solid var(--academy-line);
  color: #617579;
  font-size: 0.76rem;
  line-height: 1.7;
}

.concept-source-list a {
  color: var(--academy-teal);
}

@media (max-width: 900px) {
  .concept-lab .endpoint-stage,
  .concept-lab .endpoint-explanation { min-height: 0; }
  .concept-lab .endpoint-explanation > p { min-height: 0; }
  .concept-generated-image { border-radius: 12px; }
}

@media (max-width: 680px) {
  .concept-hero h1 { font-size: 2.65rem; }
  .concept-lab .endpoint-controls { grid-template-columns: 1fr; }
  .concept-lab .endpoint-controls button { min-height: 58px; flex-direction: row; justify-content: flex-start; padding: 0 18px; }
  .concept-lab .endpoint-stage { min-height: 0; }
  .concept-lab .endpoint-explanation { min-height: 0; }
  .concept-generated-image { border-radius: 10px; box-shadow: 0 14px 34px rgba(9, 47, 55, 0.1); }
  .concept-static-flow,
  .concept-static-grid { grid-template-columns: 1fr; }
  .concept-static-flow li { min-height: 0; }
  .concept-terms > div { grid-template-columns: 1fr; }
}