@font-face {
  font-display: swap;
  font-family: "Handlee Local";
  src: url("/assets/fonts/handlee/Handlee-Regular.ttf") format("truetype");
}

.knowledge-lesson-page {
  --kp-hand: "Handlee Local", "Segoe Print", "Bradley Hand ITC", cursive;
  --kp-marker-blue: #0b55d9;
  --kp-marker-green: #16824c;
  --kp-marker-red: #e33d45;
  --kp-board-line: rgba(53, 88, 82, 0.055);
  background:
    radial-gradient(circle at 12% 8%, rgba(255, 255, 255, 0.35), transparent 18rem),
    linear-gradient(90deg, #9ba8a7, #c3cac7 14%, #eef4f0 50%, #c3cac7 86%, #929d9c);
}

.knowledge-lesson-page main {
  overflow: visible;
}

.kp-detail {
  position: relative;
  width: min(1480px, calc(100% - 1rem));
  max-width: none;
  min-height: calc(100vh - 96px);
  margin-block: 0.5rem 1.25rem;
  padding: clamp(1rem, 2vw, 1.6rem) clamp(1rem, 2.4vw, 2rem) 3rem;
  border: 12px solid #aab4b2;
  border-color: #c7cfcd #768381 #6f7a78 #b8c1bf;
  border-radius: 0.35rem;
  background:
    linear-gradient(var(--kp-board-line) 1px, transparent 1px),
    linear-gradient(90deg, rgba(53, 88, 82, 0.035) 1px, transparent 1px),
    radial-gradient(circle at 82% 12%, rgba(255, 255, 255, 0.92), transparent 20rem),
    #fbfffc;
  background-size: 100% 2rem, 2rem 100%, auto, auto;
  box-shadow:
    inset 0 0 34px rgba(22, 44, 44, 0.08),
    0 20px 40px rgba(9, 27, 29, 0.24);
}

.kp-detail::before,
.kp-detail::after {
  position: absolute;
  z-index: 1;
  width: 18px;
  height: 18px;
  border-radius: 2px;
  background: linear-gradient(135deg, #101719, #3a4545);
  box-shadow: 0 1px 5px rgba(0, 0, 0, 0.25);
  content: "";
}

.kp-detail::before {
  top: -16px;
  left: -16px;
}

.kp-detail::after {
  right: -16px;
  bottom: -16px;
}

.kp-detail > .kp-hero {
  width: min(980px, 100%);
  max-width: none;
  padding: 1rem 0 1.25rem;
  border: 0;
  background: transparent;
  box-shadow: none;
}

.kp-hero h1 {
  max-width: none;
  margin: 0.3rem 0 0.1rem;
  color: var(--kp-marker-blue);
  font-family: var(--kp-hand);
  font-size: clamp(3rem, 8vw, 5.4rem);
  font-weight: 400;
  letter-spacing: 0.015em;
  line-height: 0.92;
  overflow-wrap: anywhere;
  text-decoration: underline;
  text-decoration-thickness: 0.035em;
  text-underline-offset: 0.16em;
}

.kp-hero > p:not(.kicker, .article-date) {
  max-width: 48rem;
  color: var(--ink-soft);
  font-size: 1.05rem;
  line-height: 1.65;
}

.kp-content-grid {
  display: grid;
  grid-template-columns: minmax(210px, 250px) minmax(0, 1fr);
  gap: clamp(1.25rem, 2.5vw, 2rem);
  align-items: stretch;
}

.kp-page-rail {
  position: relative;
  grid-column: 1;
  grid-row: 1;
  min-width: 0;
  font-family: var(--kp-hand);
}

.kp-page-rail-inner {
  display: flex;
  position: sticky;
  top: 94px;
  flex-direction: column;
  gap: 0.75rem;
}

.kp-on-this-page,
.kp-course-invite {
  border: 0;
  border-bottom: 2px solid rgba(22, 130, 76, 0.55);
  border-radius: 0;
  background: transparent;
}

.kp-on-this-page {
  padding: 0.35rem 0 0.75rem;
}

.kp-on-this-page h2,
.kp-course-invite h2 {
  margin: 0 0 0.45rem;
  color: var(--kp-marker-blue);
  font-family: var(--kp-hand);
  font-size: clamp(1.45rem, 2vw, 1.75rem);
  font-weight: 400;
  text-decoration: underline;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.16em;
}

.kp-on-this-page ul {
  display: grid;
  gap: 0.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.kp-on-this-page a {
  display: block;
  padding: 0.38rem 0.2rem;
  border-radius: 0.25rem;
  color: #456268;
  font-size: 1.08rem;
  font-weight: 400;
  text-decoration: none;
}

.kp-on-this-page a:hover,
.kp-on-this-page a:focus-visible {
  background: rgba(29, 97, 222, 0.08);
  color: var(--kp-marker-blue);
}

.kp-on-this-page a[aria-current="location"] {
  outline: 2px solid rgba(22, 130, 76, 0.55);
  outline-offset: -2px;
  background: rgba(22, 130, 76, 0.06);
  color: var(--kp-marker-green);
}

.kp-course-invite {
  padding: 0.8rem 0 1rem;
  background: transparent;
}

.kp-course-invite p {
  color: var(--ink-soft);
  font-size: 0.9rem;
  line-height: 1.55;
}

.kp-rail-label,
.kp-final-label {
  margin: 0 0 0.35rem;
  color: #326660;
  font-size: 0.72rem !important;
  font-weight: 850;
  letter-spacing: 0.075em;
  text-transform: uppercase;
}

.kp-course-invite a,
.kp-final-course a {
  display: inline-block;
  min-height: 44px;
  padding: 0.5rem 0.2rem;
  border-bottom: 2px solid currentColor;
  border-radius: 0;
  background: transparent;
  color: var(--kp-marker-blue);
  font-family: var(--kp-hand);
  font-size: 1.05rem;
  font-weight: 400;
  text-decoration: none;
}

.kp-course-invite a:hover,
.kp-course-invite a:focus-visible,
.kp-final-course a:hover,
.kp-final-course a:focus-visible {
  background: #0b625c;
}

.kp-back-to-top {
  display: block;
  padding: 0.55rem 0.2rem;
  border: 0;
  border-bottom: 2px solid rgba(29, 97, 222, 0.55);
  border-radius: 0;
  background: transparent;
  color: var(--kp-marker-blue);
  font-size: 1.05rem;
  font-weight: 400;
  text-align: center;
  text-decoration: none;
}

.kp-reading-column {
  grid-column: 2;
  grid-row: 1;
  min-width: 0;
}

.kp-reading-column > .kp-body {
  max-width: none;
  padding-bottom: 0;
}

.kp-tool-embed {
  margin: clamp(1.5rem, 4vw, 2.5rem) 0;
  border: 1px solid #bdd2cd;
  border-radius: 18px;
  padding: clamp(14px, 2.5vw, 22px);
  background: #f7fbfa;
  box-shadow: 0 12px 30px rgba(19, 52, 63, 0.07);
}

.kp-tool-embed-intro {
  margin-bottom: 1rem;
}

.kp-tool-embed-intro .kicker {
  margin-bottom: 0.25rem;
  color: #32736c;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.kp-tool-embed-intro p:last-child {
  margin-bottom: 0;
  color: #455d66;
}

.kp-tool-embed-status {
  margin: 0 0 0.75rem;
  color: #4c676d;
  font-size: 0.88rem;
}

.kp-tool-embed-mount {
  min-width: 0;
}

.kp-tool-embed-link {
  margin: 0.85rem 0 0;
  font-weight: 700;
}

.kp-chapter {
  scroll-margin-top: 7rem;
  padding-top: clamp(2rem, 4vw, 3rem);
}

.kp-chapter + .kp-chapter {
  margin-top: clamp(1.4rem, 3vw, 2.4rem);
  border-top: 2px solid rgba(227, 61, 69, 0.35);
}

.kp-chapter-title {
  margin: 0 0 0.75rem;
  color: var(--kp-marker-blue);
  font-family: var(--kp-hand);
  font-size: clamp(2rem, 4vw, 3.25rem);
  font-weight: 400;
  line-height: 1;
}

.kp-chapter > .knowledge-block {
  margin: 1.3rem 0 0;
  color: #27454d;
  font-family: var(--kp-hand);
  font-size: clamp(1.08rem, 1.5vw, 1.22rem);
  line-height: 1.42;
}

.kp-chapter > .knowledge-prose {
  padding: 0;
  background: transparent;
}

.kp-chapter > .knowledge-prose h2 {
  margin-top: 0;
  font-size: clamp(1.2rem, 2.2vw, 1.45rem);
}

.kp-chapter > .knowledge-definition {
  padding: 1.05rem 1.2rem;
  border: 2px solid rgba(11, 85, 217, 0.72);
  border-radius: 0.25rem 0.85rem 0.4rem 0.7rem;
  background: rgba(255, 255, 255, 0.46);
}

.kp-chapter > .knowledge-definition h2 {
  margin: 0 0 0.45rem;
}

.kp-chapter > .knowledge-emphasis {
  padding: 1.1rem 1.2rem;
  border: 2px solid rgba(22, 130, 76, 0.7);
  border-radius: 0.8rem 0.35rem 0.9rem 0.28rem;
  background: rgba(245, 255, 249, 0.5);
}

.kp-chapter > .knowledge-emphasis h2 {
  margin-top: 0;
}

.kp-chapter > .knowledge-table,
.kp-chapter > .knowledge-figure {
  padding: 1.1rem;
  border: 1px solid rgba(75, 97, 95, 0.18);
  border-radius: 0.35rem;
  background: rgba(255, 255, 255, 0.38);
  box-shadow: none;
}

.kp-chapter > .knowledge-table caption {
  color: #123f4a;
}

.kp-chapter > .knowledge-check {
  padding: 1rem 1.15rem;
  border: 2px solid rgba(22, 130, 76, 0.72);
  border-radius: 0.25rem 1rem 0.35rem 0.8rem;
  background: rgba(255, 255, 255, 0.34);
  box-shadow: none;
}

.kp-chapter > .knowledge-check h2 {
  margin-top: 0;
  font-size: 1rem;
}

.kp-chapter > .knowledge-check details {
  margin-top: 0.8rem;
  padding-top: 0.75rem;
  border-top: 1px solid #d7e1de;
}

.kp-chapter > .knowledge-check summary {
  width: fit-content;
  color: #075f58;
  font-weight: 800;
  cursor: pointer;
}

.kp-chapter > .knowledge-worked-example {
  padding: 1.35rem;
  border: 2px solid rgba(11, 85, 217, 0.62);
  border-radius: 0.8rem 0.35rem 0.75rem 0.35rem;
  background: rgba(255, 255, 255, 0.36);
  box-shadow: none;
}

.kp-chapter > .knowledge-worked-example > h2 {
  margin-top: 0;
}

.kp-chapter > .knowledge-worked-example .worked-steps > li {
  margin-top: 0.75rem;
  padding: 0.9rem 1rem;
  border: 1px dashed rgba(11, 85, 217, 0.45);
  border-radius: 0.45rem;
  background: rgba(255, 255, 255, 0.22);
}

.kp-chapter > .knowledge-common-error {
  padding: 1rem 1.15rem;
  border: 2px solid rgba(227, 61, 69, 0.65);
  border-radius: 0.7rem 0.25rem 0.9rem 0.35rem;
  background: rgba(255, 248, 232, 0.45);
}

.kp-chapter > .knowledge-common-error h2 {
  margin-top: 0;
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.kp-chapter > .knowledge-resource-links {
  padding: 1.2rem 1.25rem;
  border: 2px solid rgba(22, 130, 76, 0.68);
  border-radius: 0.7rem 0.35rem;
  background: rgba(243, 250, 248, 0.42);
}

.kp-chapter > .knowledge-resource-links .kicker {
  margin-bottom: 0.25rem;
}

.kp-chapter > .knowledge-resource-links h2 {
  margin: 0 0 0.5rem;
}

.kp-chapter > .knowledge-resource-links ul {
  margin: 0.9rem 0 0;
  padding: 0;
  list-style: none;
}

.kp-chapter > .knowledge-resource-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  min-height: 44px;
  padding: 0.7rem 0.95rem;
  border-bottom: 2px solid currentColor;
  border-radius: 0;
  background: transparent;
  color: var(--kp-marker-blue);
  font-weight: 400;
  text-decoration: none;
}

.kp-chapter > .knowledge-resource-links a:hover,
.kp-chapter > .knowledge-resource-links a:focus-visible {
  background: #0b625c;
}

.kp-chapter > .knowledge-resource-links li > small {
  display: block;
  margin-top: 0.5rem;
  color: #4c676d;
}

.kp-chapter > .knowledge-figure img {
  display: block;
  width: auto;
  max-width: min(100%, 24rem);
  height: auto;
  max-height: 15rem;
  margin-inline: auto;
  object-fit: contain;
}

.kp-chapter > .knowledge-figure--portrait img {
  max-width: min(100%, 13rem);
  max-height: 18rem;
}

@media (prefers-reduced-motion: reduce) {
  .kp-chapter > .knowledge-figure--animation img {
    display: none;
  }
}

.knowledge-inline-animation {
  display: grid;
  gap: 0.65rem;
  width: min(100%, 18rem);
  margin: 1.25rem auto 0;
}

.knowledge-inline-animation-stage {
  position: relative;
  overflow: hidden;
  border: 1px solid #cbd9d6;
  border-radius: 0.65rem;
  background: #fff;
}

.knowledge-inline-animation img {
  display: block;
  width: auto;
  max-width: 100%;
  height: auto;
  max-height: 14rem;
  margin-inline: auto;
  object-fit: contain;
}

.knowledge-inline-animation-toggle {
  position: absolute;
  right: 0.65rem;
  bottom: 0.65rem;
  min-height: 40px;
  padding: 0.5rem 0.75rem;
  border: 1px solid rgba(255, 255, 255, 0.8);
  border-radius: 999px;
  background: rgba(13, 68, 65, 0.94);
  color: #fff;
  font: inherit;
  font-size: 0.82rem;
  font-weight: 800;
  cursor: pointer;
}

.knowledge-inline-animation-toggle:focus-visible {
  outline: 3px solid #f1b84b;
  outline-offset: 2px;
}

.knowledge-inline-animation figcaption {
  display: grid;
  gap: 0.25rem;
  color: #40565c;
  font-size: 0.9rem;
  line-height: 1.45;
}

.knowledge-inline-animation figcaption small {
  color: #61747a;
}

.knowledge-video-embed {
  overflow: hidden;
  aspect-ratio: 16 / 9;
  width: 100%;
  margin-top: 1rem;
  border-radius: 0.65rem;
  background: #102f34;
}

.knowledge-video-embed iframe {
  width: 100%;
  height: 100%;
  border: 0;
}

.kp-chapter > .knowledge-figure figcaption {
  line-height: 1.55;
}

.kp-detail code,
.kp-detail var {
  font-family: "Cambria Math", "STIX Two Math", Georgia, serif;
}

.kp-detail .physics-symbol {
  white-space: nowrap;
}

.kp-detail .physics-symbol sub {
  font-size: 0.72em;
  line-height: 0;
}

.kp-final-course {
  margin-top: 2.6rem;
  padding: clamp(1.35rem, 3vw, 2rem);
  border: 2px solid rgba(11, 85, 217, 0.65);
  border-radius: 0.45rem 0.95rem 0.5rem 0.8rem;
  background: rgba(255, 255, 255, 0.4);
  color: #27454d;
}

.kp-final-course h2 {
  margin: 0 0 0.65rem;
  color: var(--kp-marker-blue);
  font-family: var(--kp-hand);
  font-weight: 400;
}

.kp-final-course p:not(.kp-final-label) {
  max-width: 46rem;
  color: #405b61;
}

@media (max-width: 900px) {
  .kp-detail {
    width: min(880px, calc(100% - 2rem));
  }

  .kp-content-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 1rem;
  }

  .kp-page-rail,
  .kp-reading-column {
    grid-column: 1;
  }

  .kp-page-rail {
    grid-row: 1;
  }

  .kp-reading-column {
    grid-row: 2;
  }

  .kp-page-rail-inner {
    display: grid;
    position: static;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 0.8rem;
  }

  .kp-back-to-top {
    grid-column: 1 / -1;
  }
}

@media (max-width: 700px) {
  .kp-detail {
    width: min(100% - 1rem, 880px);
    padding-top: 0.75rem;
  }

  .kp-page-rail-inner {
    grid-template-columns: 1fr;
  }

  .kp-hero {
    padding: 1.25rem;
  }

  .kp-hero h1 {
    max-width: 100%;
    font-size: clamp(2rem, 9vw, 2.35rem);
    line-height: 0.98;
    overflow-wrap: anywhere;
  }

  .kp-chapter {
    padding-top: 1.7rem;
  }

  .kp-chapter > .knowledge-table,
  .kp-chapter > .knowledge-figure,
  .kp-chapter > .knowledge-worked-example,
  .kp-chapter > .knowledge-check,
  .kp-chapter > .knowledge-common-error {
    padding: 0.9rem;
  }

  .kp-chapter > .knowledge-table th,
  .kp-chapter > .knowledge-table td {
    padding: 0.55rem;
    font-size: 0.84rem;
  }

  .kp-final-course {
    margin-top: 1.8rem;
    padding: 1.25rem;
  }
}

@media print {
  .kp-page-rail {
    display: none;
  }

  .kp-detail {
    display: block;
    width: 100%;
  }
}

/* Approved whiteboard-shell adaptation for normal Knowledge lesson pages.
   This intentionally follows the working free-fall whiteboard route rather
   than the earlier generic framed article experiment. */
body.free-fall-whiteboard-preview.knowledge-lesson-page {
  height: 100vh;
  overflow: hidden;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page main {
  height: 100vh;
  overflow: hidden;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-detail {
  position: relative;
  display: grid;
  grid-template-rows: 66px minmax(0, 1fr);
  box-sizing: border-box;
  width: 100%;
  max-width: none;
  height: 100vh;
  min-height: 0;
  margin: 0;
  overflow: hidden;
  padding: 12px;
  border: 0;
  border-radius: 0;
  background:
    linear-gradient(96deg, #636d70 0%, #e5e9e8 9%, #7f898b 24%, #f2f4f3 49%, #788184 73%, #dfe4e3 91%, #626b6d 100%);
  box-shadow: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-detail::before,
body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-detail::after {
  display: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-wb-top-menu,
body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-content-grid {
  position: relative;
  z-index: 1;
  background:
    radial-gradient(ellipse at 16% 11%, rgba(72, 104, 96, 0.035), transparent 28%),
    radial-gradient(ellipse at 83% 45%, rgba(30, 75, 114, 0.025), transparent 30%),
    repeating-linear-gradient(2deg, rgba(51, 84, 78, 0.01) 0 1px, transparent 1px 15px),
    #fcfdfa;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-wb-top-menu {
  grid-row: 1;
  width: 100%;
  max-width: none;
  justify-self: stretch;
  grid-template-columns: 238px minmax(0, 1fr);
  min-height: 0;
  padding: 0;
  box-shadow: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-wb-top-menu::after {
  right: 1.25rem;
  bottom: 0;
  left: 1.25rem;
  height: 2px;
  background: rgba(6, 79, 209, 0.25);
  transform: rotate(-0.08deg);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero {
  position: relative;
  z-index: 1;
  width: fit-content;
  max-width: min(100%, 46rem);
  margin: 0 0 2.2rem;
  padding: 3.8rem 3rem 0.4rem;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero .breadcrumb-link {
  color: var(--wb-green);
  font-family: var(--wb-hand);
  font-size: 1.35rem;
  font-weight: 400;
  letter-spacing: 0.12em;
  text-decoration: none;
  text-transform: uppercase;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero h1 {
  width: fit-content;
  max-width: min(100%, 18ch);
  color: var(--wb-blue);
  font-family: var(--wb-hand);
  font-size: clamp(4rem, 6.4vw, 6.4rem);
  font-weight: 400;
  line-height: 0.92;
  overflow-wrap: normal;
  text-decoration: none;
  transform: rotate(-1deg);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero h1::after {
  display: block;
  width: 105%;
  height: 0.26rem;
  margin-top: 0.35rem;
  border-radius: 50%;
  background: var(--wb-blue);
  content: "";
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-content-grid {
  grid-row: 2;
  display: grid;
  grid-template-columns: 238px minmax(0, 1fr);
  min-height: 0;
  overflow: hidden;
  gap: 0;
  box-shadow:
    inset 0 0 2.8rem rgba(45, 67, 62, 0.11),
    inset 0 0 0 1px rgba(46, 63, 61, 0.16);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-page-rail {
  grid-column: 1;
  grid-row: 1;
  min-height: 0;
  overflow: hidden;
  border-right: 2px solid rgba(8, 122, 60, 0.22);
  font-family: var(--wb-hand);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-page-rail-inner {
  position: static;
  display: flex;
  height: 100%;
  overflow: hidden;
  flex-direction: column;
  gap: 0;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-curriculum-top {
  display: grid;
  gap: 0.25rem;
  padding: 0.45rem 0.7rem;
  border-bottom: 2px solid rgba(6, 79, 209, 0.32);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-curriculum-back {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.45rem;
  min-height: 2rem;
  padding: 0.25rem 0.1rem;
  border-bottom: 2px solid rgba(6, 79, 209, 0.55);
  border-radius: 0;
  background: transparent;
  color: var(--wb-blue);
  font-size: 0.8rem;
  font-weight: 400;
  line-height: 1.15;
  text-decoration: none;
  transform: rotate(-0.35deg);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-curriculum-back small {
  display: block;
  margin-bottom: 0.12rem;
  color: var(--wb-red);
  font-size: 0.64rem;
  font-weight: 400;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-on-this-page {
  overflow: hidden;
  padding: 0.5rem 0.7rem;
  border: 0;
  background: transparent;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-on-this-page h2 {
  width: fit-content;
  margin: 0 0 0.35rem;
  color: var(--wb-blue);
  font-family: var(--wb-hand);
  font-size: 1.08rem;
  font-weight: 400;
  text-decoration: none;
  transform: rotate(-1deg);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-on-this-page h2::after {
  display: block;
  width: 108%;
  height: 2px;
  margin-top: 0.06rem;
  background: currentColor;
  content: "";
  transform: rotate(1deg);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-on-this-page a {
  padding: 0.27rem 0.25rem;
  border-radius: 0.18rem;
  color: #28454c;
  font-family: var(--wb-hand);
  font-size: 0.8rem;
  font-weight: 400;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-on-this-page a[aria-current="location"] {
  outline: 2px solid rgba(8, 122, 60, 0.58);
  outline-offset: -2px;
  background: rgba(8, 122, 60, 0.1);
  color: #075b48;
  transform: rotate(-0.5deg);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-page-rail .kp-course-invite {
  margin: 0.45rem 0.7rem;
  padding: 0.5rem 0.65rem;
  border: 2px solid var(--wb-blue);
  border-radius: 48% 52% 49% 51% / 4% 3% 5% 4%;
  background: transparent;
  color: #173e4b;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-page-rail .kp-course-invite p:not(.kp-rail-label),
body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-back-to-top {
  display: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-reading-column {
  grid-column: 2;
  grid-row: 1;
  min-height: 0;
  overflow-x: hidden;
  overflow-y: auto;
  overscroll-behavior: contain;
  scroll-behavior: smooth;
  padding: 0 0 2rem;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-body {
  display: grid;
  gap: 1rem;
  max-width: none;
  padding: 0;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter {
  position: relative;
  min-width: 0;
  min-height: min(760px, calc(100vh - 80px));
  margin: 0;
  padding: 3.2rem 3rem 2.8rem;
  scroll-margin-top: 1.25rem;
  border: 12px solid transparent;
  border-image: linear-gradient(96deg, #6b7376 0%, #e9eded 7%, #878f92 18%, #f3f5f5 38%, #737b7e 57%, #e0e4e5 77%, #656d70 100%) 12;
  background: transparent;
  color: var(--wb-ink);
  font-family: var(--wb-hand);
  line-height: 1.32;
}

/* Board-composition correction: keep the approved whiteboard shell but make
   normal lessons behave like actual marker-board pages, not a skinned article. */
body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-content-grid {
  grid-template-columns: 238px minmax(0, 1fr) !important;
  background: transparent;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-reading-column {
  background: transparent;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-body {
  display: block;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter {
  display: grid !important;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-auto-flow: row dense;
  grid-auto-rows: minmax(8rem, auto);
  gap: 1.45rem 1.85rem;
  min-height: min(760px, calc(100vh - 80px));
  padding: 3rem 3rem 2.8rem;
  border: 12px solid transparent;
  border-image: linear-gradient(96deg, #6b7376 0%, #e9eded 7%, #878f92 18%, #f3f5f5 38%, #737b7e 57%, #e0e4e5 77%, #656d70 100%) 12;
  background:
    radial-gradient(ellipse at 16% 11%, rgba(72, 104, 96, 0.035), transparent 28%),
    radial-gradient(ellipse at 83% 45%, rgba(30, 75, 114, 0.025), transparent 30%),
    repeating-linear-gradient(2deg, rgba(51, 84, 78, 0.01) 0 1px, transparent 1px 15px),
    #fcfdfa;
  box-shadow:
    0 0.6rem 1.4rem rgba(18, 39, 43, 0.2),
    0 0.2rem 0.4rem rgba(18, 39, 43, 0.18),
    inset 0 0 2.8rem rgba(45, 67, 62, 0.11),
    inset 0 0 0 1px rgba(46, 63, 61, 0.22);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter::after {
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(96deg, transparent 0 48%, rgba(62, 91, 84, 0.018) 50%, transparent 52%),
    linear-gradient(3deg, transparent 0 63%, rgba(45, 79, 73, 0.012) 65%, transparent 67%);
  content: "";
  pointer-events: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > * {
  position: relative;
  z-index: 2;
  min-width: 0;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter-title {
  grid-column: 1 / -1;
  max-width: min(100%, 36rem);
  margin-bottom: 0.25rem;
  font-size: clamp(2.25rem, 3.4vw, 3.35rem);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > :where(.knowledge-prose, .knowledge-definition, .knowledge-equation, .knowledge-check, .knowledge-worked-example, .knowledge-common-error, .knowledge-resource-links, .knowledge-figure, .kp-tool-embed, .knowledge-ap-focus) {
  grid-column: span 1;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > :where(.knowledge-table, .knowledge-worked-example, .kp-tool-embed) {
  grid-column: span 2;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > :where(.knowledge-figure) {
  align-self: start;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > :where(.knowledge-prose:first-of-type) {
  grid-column: span 2;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero {
  margin: 0 0 0.85rem;
  padding: 1.45rem 3rem 0.9rem;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero h1 {
  max-width: min(100%, 58rem);
  font-size: clamp(3.15rem, 4.9vw, 5.45rem);
  line-height: 0.92;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero p {
  max-width: 54rem;
  margin-top: 0.45rem;
  font-size: clamp(1rem, 1.55vw, 1.35rem);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-reading-column {
  gap: 0.9rem;
}

@media (max-width: 1100px) {
  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 820px) {
  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter {
    display: block !important;
  }
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter + .kp-chapter {
  margin-top: 1rem;
  border-top-width: 12px;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter-title {
  width: fit-content;
  max-width: 100%;
  margin: 0 0 0.85rem;
  color: var(--wb-blue);
  font-family: var(--wb-hand);
  font-size: clamp(2.2rem, 4vw, 3.2rem);
  font-weight: 400;
  line-height: 1.02;
  transform: rotate(-0.35deg);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter-title::after {
  display: block;
  width: 104%;
  height: 0.16rem;
  margin-top: 0.14rem;
  border-radius: 50%;
  background: currentColor;
  content: "";
  opacity: 0.72;
  transform: rotate(0.8deg);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > .knowledge-block {
  color: #28454c;
  font-family: var(--wb-hand);
  font-size: 1.13rem;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter :where(h1, h2, h3, h4, p, li, label, button, input, select, summary, caption, th, td, dt, dd, output) {
  font-family: var(--wb-hand) !important;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter :where(.knowledge-block, .knowledge-enhancement, .knowledge-check, .knowledge-worked-example, .knowledge-common-error, .knowledge-resource-links) {
  background: transparent;
  box-shadow: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter :where(.knowledge-check, .knowledge-worked-example, .knowledge-definition, .knowledge-equation, .knowledge-ap-focus) {
  border: 2.5px solid var(--wb-green);
  border-radius: 48% 52% 49% 51% / 4% 3% 5% 4%;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter :where(.knowledge-figure, .knowledge-inline-animation, .knowledge-inline-media) {
  width: min(100%, 480px);
  margin: 0.8rem auto;
  padding: 0;
  border: 0;
  background: transparent;
  box-shadow: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter :where(.knowledge-figure, .knowledge-inline-animation, .knowledge-inline-media) img {
  display: block;
  width: auto;
  max-width: 100%;
  max-height: 350px;
  margin: auto;
  border: 2px solid var(--wb-blue);
  border-radius: 1.5% 1% 2% 1%;
  background: #fff;
  object-fit: contain;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-final-course,
body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-curriculum-nav {
  margin: 1rem 3rem 2rem;
}

@media (max-width: 820px) {
  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-detail {
    grid-template-rows: auto minmax(0, 1fr);
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-wb-top-menu {
    display: block;
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-wb-top-menu__brand {
    justify-content: center;
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero {
    max-width: 100%;
    margin-bottom: 1.2rem;
    padding: 1.8rem 1rem 0.2rem;
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero h1 {
    max-width: 100%;
    font-size: clamp(3rem, 15vw, 4.8rem);
    overflow-wrap: anywhere;
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-content-grid {
    grid-template-columns: 11rem minmax(0, 1fr);
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-reading-column {
    padding-bottom: 1rem;
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-page-rail .kp-course-invite,
  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-page-rail .kp-course-invite {
    display: none;
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter {
    min-height: 0;
    padding: 2.3rem 1rem;
  }
}

/* Final board-composition override. Must stay last: the accepted design uses
   multi-panel marker-board scenes, not one-column article cards. */
body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-content-grid {
  grid-template-columns: 238px minmax(0, 1fr) !important;
  background: transparent;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-body {
  display: block;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter {
  display: grid !important;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  grid-auto-flow: row dense;
  grid-auto-rows: minmax(8rem, auto);
  gap: 1.45rem 1.85rem;
  min-height: min(760px, calc(100vh - 80px));
  padding: 3rem 3rem 2.8rem;
  border: 12px solid transparent;
  border-image: linear-gradient(96deg, #6b7376 0%, #e9eded 7%, #878f92 18%, #f3f5f5 38%, #737b7e 57%, #e0e4e5 77%, #656d70 100%) 12;
  background:
    radial-gradient(ellipse at 16% 11%, rgba(72, 104, 96, 0.035), transparent 28%),
    radial-gradient(ellipse at 83% 45%, rgba(30, 75, 114, 0.025), transparent 30%),
    repeating-linear-gradient(2deg, rgba(51, 84, 78, 0.01) 0 1px, transparent 1px 15px),
    #fcfdfa;
  box-shadow:
    0 0.6rem 1.4rem rgba(18, 39, 43, 0.2),
    0 0.2rem 0.4rem rgba(18, 39, 43, 0.18),
    inset 0 0 2.8rem rgba(45, 67, 62, 0.11),
    inset 0 0 0 1px rgba(46, 63, 61, 0.22);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter::after {
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(96deg, transparent 0 48%, rgba(62, 91, 84, 0.018) 50%, transparent 52%),
    linear-gradient(3deg, transparent 0 63%, rgba(45, 79, 73, 0.012) 65%, transparent 67%);
  content: "";
  pointer-events: none;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > * {
  position: relative;
  z-index: 2;
  min-width: 0;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter-title {
  grid-column: 1 / -1;
  max-width: min(100%, 36rem);
  margin-bottom: 0.25rem;
  font-size: clamp(2.25rem, 3.4vw, 3.35rem);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > :where(.knowledge-prose, .knowledge-definition, .knowledge-equation, .knowledge-check, .knowledge-common-error, .knowledge-resource-links, .knowledge-figure, .knowledge-ap-focus) {
  grid-column: span 1;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > :where(.knowledge-table, .knowledge-worked-example, .kp-tool-embed) {
  grid-column: span 2;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > :where(.knowledge-prose:first-of-type) {
  grid-column: span 2;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter > .kp-chapter-title:nth-last-child(2) + .knowledge-block {
  grid-column: 1 / -1;
  max-width: min(100%, 66rem);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero {
  margin: 0 0 0.65rem;
  padding: 0.9rem 3rem 0.55rem;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero h1 {
  max-width: min(100%, 58rem);
  font-size: clamp(2.65rem, 3.9vw, 4.45rem);
  line-height: 0.92;
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-hero p {
  max-width: 54rem;
  margin-top: 0.3rem;
  font-size: clamp(0.95rem, 1.25vw, 1.1rem);
}

body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-reading-column {
  gap: 0.9rem;
}

@media (max-width: 1100px) {
  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 820px) {
  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-content-grid {
    grid-template-columns: 11rem minmax(0, 1fr) !important;
  }

  body.free-fall-whiteboard-preview.knowledge-lesson-page .kp-chapter {
    display: block !important;
    min-height: 0;
  }
}