.lu-classroom {
  box-sizing: border-box;
  width: min(1600px, calc(100% - 20px));
  max-width: none;
  max-height: calc(100dvh - 20px);
  margin: auto;
  padding: 0;
  overflow: auto;
  overscroll-behavior: contain;
  border: 1px solid #e5dced;
  border-radius: 12px;
  background: #fffefa;
  color: #23173a;
  box-shadow: 0 25px 100px #23173a50;
}

.lu-classroom::backdrop {
  background: #23173aa3;
  backdrop-filter: blur(4px);
}

.lu-classroom .lu-room-shell {
  padding: clamp(10px, 1.5vw, 20px);
}

.lu-classroom .lu-room-header,
.lu-classroom .lu-board-header,
.lu-classroom .lu-board-tools,
.lu-classroom .lu-media-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.lu-classroom .lu-room-header,
.lu-classroom .lu-board-header {
  justify-content: space-between;
}

.lu-classroom .lu-room-header {
  align-items: start;
  padding: 0 0 9px;
  border-bottom: 1px solid #e7deeb;
}

.lu-classroom h2,
.lu-classroom h3,
.lu-classroom h4,
.lu-classroom p {
  margin: 0;
}

.lu-classroom h2 {
  margin-block: 3px;
  color: #23173a;
  font-size: clamp(1.55rem, 2.7vw, 2.25rem);
  line-height: 1;
  letter-spacing: -.05em;
}

.lu-classroom h3 {
  color: #23173a;
  font-size: 1.14rem;
  line-height: 1.22;
  letter-spacing: -.02em;
}

.lu-classroom .lu-room-header p:last-child,
.lu-classroom .lu-room-status {
  color: #5d5268;
}

.lu-classroom .lu-room-header p:last-child {
  font-size: .84rem;
}

.lu-classroom .lu-room-kicker,
.lu-classroom .lu-brief-label {
  color: #5f3599;
  font-size: .74rem;
  font-weight: 750;
  letter-spacing: .085em;
  text-transform: uppercase;
}

.lu-classroom .lu-room-icon,
.lu-classroom .lu-room-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 7px 12px;
  border: 1px solid #ded2e8;
  border-radius: 6px;
  background: #fff;
  color: #3e275e;
  font: inherit;
  font-size: .78rem;
  font-weight: 700;
  line-height: 1.15;
  cursor: pointer;
}

.lu-classroom .lu-room-icon {
  width: 42px;
  height: 42px;
  font-size: 1.65rem;
  font-weight: 400;
}

.lu-classroom .lu-room-icon:hover,
.lu-classroom .lu-room-button:not(:disabled):hover {
  border-color: #a389ca;
  background: #efe7fa;
}

.lu-classroom .lu-room-button[aria-pressed="true"] {
  border-color: #a389ca;
  background: #eee4fa;
  color: #50229b;
}

.lu-classroom .lu-room-button:disabled {
  opacity: .5;
  cursor: default;
}

.lu-classroom :focus-visible {
  outline: 3px solid #8157cb;
  outline-offset: 3px;
}

.lu-classroom .lu-room-content {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 260px);
  align-items: start;
  gap: clamp(12px, 1.6vw, 24px);
  margin-top: 9px;
}

.lu-classroom.lu-board-full-width .lu-room-content {
  grid-template-columns: minmax(0, 1fr);
}

.lu-classroom.lu-board-full-width .lu-room-brief {
  display: none;
}

.lu-classroom .lu-room-workspace {
  min-width: 0;
}

.lu-classroom .lu-board-header {
  flex-wrap: wrap;
  margin-bottom: 6px;
}

.lu-classroom .lu-board-tools,
.lu-classroom .lu-media-controls {
  flex-wrap: wrap;
}

.lu-classroom .lu-board-tools {
  max-width: 100%;
  gap: 5px;
}

.lu-classroom .lu-board-tools .lu-room-button {
  min-height: 32px;
  padding: 4px 9px;
  border-color: transparent;
  background: transparent;
}

.lu-classroom .lu-board-tools .lu-room-button[hidden] { display: none; }
.lu-classroom .lu-board-tools .lu-board-upload,
.lu-classroom .lu-board-tools .lu-board-lock { border-color: #ded2e8; background: #fff; }

.lu-classroom .lu-board-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 12px;
  margin-top: 7px;
}

.lu-classroom .lu-board-zoom {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 3px;
  margin-left: auto;
}

.lu-classroom .lu-board-zoom .lu-room-button {
  min-width: 34px;
}

.lu-classroom .lu-board-zoom-value {
  min-width: 4ch;
  color: #5d5268;
  font-size: .76rem;
  font-variant-numeric: tabular-nums;
  text-align: center;
}

.lu-classroom .lu-board-stage {
  display: grid;
  grid-template-columns: 41px minmax(0, 1fr);
  align-items: start;
  gap: 8px;
}

.lu-classroom .lu-board-dock {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 3px;
  border: 1px solid #e1d6eb;
  border-radius: 8px;
  background: #fff;
  box-shadow: 0 2px 7px #23173a0c;
}

.lu-classroom .lu-board-dock .lu-room-button {
  min-width: 33px;
  min-height: 34px;
  padding: 6px;
  border-color: transparent;
}

.lu-classroom .lu-board-dock svg {
  width: 19px;
  height: 19px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.lu-classroom .lu-board-style {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 7px 12px;
  min-height: 38px;
  margin-bottom: 6px;
  color: #3e275e;
  font-size: .76rem;
  font-weight: 650;
}

.lu-classroom .lu-board-style [hidden] { display: none; }
.lu-classroom .lu-board-style label,
.lu-classroom .lu-board-swatches {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.lu-classroom .lu-board-color {
  width: 29px;
  height: 27px;
  padding: 2px;
  border: 1px solid #ded2e8;
  border-radius: 4px;
  background: #fff;
}

.lu-classroom .lu-board-swatches button {
  width: 17px;
  height: 17px;
  padding: 0;
  border: 1px solid #38244a20;
  border-radius: 3px;
  background: var(--swatch);
}

.lu-classroom .lu-board-size {
  width: clamp(65px, 10vw, 110px);
  margin: 0;
  accent-color: #6739c6;
}

.lu-classroom .lu-board-size-value {
  min-width: 2ch;
  font-variant-numeric: tabular-nums;
}

.lu-classroom .lu-board-text-form:not([hidden]) {
  display: grid;
  gap: 5px;
  max-width: 370px;
  margin-bottom: 8px;
  color: #3e275e;
  font-size: .82rem;
}

.lu-classroom .lu-board-text-form textarea {
  width: 100%;
  min-width: 0;
  padding: 6px;
  border: 1px solid #b9a3cb;
  border-radius: 4px;
  color: #23173a;
}

.lu-classroom .lu-board {
  display: block;
  width: 100%;
  height: clamp(280px, calc(100dvh - 243px), 1050px);
  overflow: hidden;
  border: 1px solid #e1d6eb;
  border-radius: 5px;
  background: radial-gradient(circle, #d7d0de 1px, transparent 1px) var(--lu-grid-offset, 0 0) /
    var(--lu-grid-step, 19px) var(--lu-grid-step, 19px), #fcfbfd;
  cursor: crosshair;
  touch-action: none;
}

.lu-classroom:has(.lu-book-panel:not([hidden])) .lu-board {
  height: clamp(270px, calc(100dvh - 283px), 1000px);
}

.lu-classroom .lu-board.lu-mode-select {
  cursor: default;
}

.lu-classroom .lu-board.lu-mode-text { cursor: text; }
.lu-classroom .lu-board.lu-mode-eraser { cursor: cell; }
.lu-classroom .lu-board.lu-mode-eraser .lu-board-annotation-stroke { pointer-events: stroke; }
.lu-classroom .lu-board.lu-mode-select .lu-board-text-hit,
.lu-classroom .lu-board.lu-mode-text .lu-board-text-hit { pointer-events: all; }
.lu-classroom .lu-board.lu-mode-select .lu-board-text-hit { cursor: move; }
.lu-classroom .lu-board-text.is-selected .lu-board-text-hit { stroke: #6739c6; }

.lu-classroom:not(.lu-board-history) .lu-board-previous-pages,
.lu-classroom.lu-board-history .lu-board-pages,
.lu-classroom.lu-board-history .lu-board-marks,
.lu-classroom.lu-board-history .lu-board-style {
  display: none;
}

.lu-classroom .lu-board.lu-mode-hand,
.lu-classroom .lu-board.lu-mode-select .lu-board-page {
  cursor: grab;
}

.lu-classroom .lu-board.lu-mode-select .lu-board-page.is-locked { cursor: default; }

.lu-classroom .lu-board.lu-is-dragging,
.lu-classroom .lu-board.lu-is-dragging .lu-board-page {
  cursor: grabbing;
}

.lu-classroom .lu-board.lu-is-dragging .lu-board-page.is-locked { cursor: grabbing; }

.lu-classroom .lu-board-page-outline {
  fill: none;
  stroke: #6739c6;
  stroke-width: 2;
  vector-effect: non-scaling-stroke;
  opacity: 0;
  pointer-events: none;
}

.lu-classroom .lu-board-page.is-selected > .lu-board-page-outline {
  opacity: 1;
}

.lu-classroom .lu-board-page.is-locked > .lu-board-page-outline { stroke-dasharray: 4 3; }
.lu-classroom .lu-board-lock-badge { display: none; pointer-events: none; }
.lu-classroom .lu-mode-select .lu-board-page.is-locked > .lu-board-lock-badge { display: inline; }

.lu-classroom .lu-board-source-highlight {
  fill: #f6cf5b15;
  stroke: #a26712;
  stroke-width: 2.5;
  stroke-dasharray: 7 4;
  vector-effect: non-scaling-stroke;
  pointer-events: none;
}

.lu-classroom .lu-room-status {
  font-size: .77rem;
  line-height: 1.45;
}

.lu-classroom .lu-room-status:not(:empty) {
  margin-top: 10px;
}

.lu-classroom .lu-board-footer .lu-room-status {
  margin: 0;
}

.lu-classroom .lu-board-footer .lu-room-status:empty {
  display: none;
}

.lu-classroom .lu-media {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 14px;
  margin-top: 12px;
}

.lu-classroom .lu-media .lu-room-status:not(:empty) {
  margin: 0;
}

.lu-classroom .lu-room-video:not([hidden]) {
  display: block;
  width: min(100%, 230px);
  aspect-ratio: 4 / 3;
  margin-top: 4px;
  border: 1px solid #ded2e8;
  border-radius: 12px;
  background: #23173a;
  object-fit: cover;
  transform: scaleX(-1);
}

.lu-classroom .lu-room-brief {
  min-width: 0;
  padding-left: 16px;
  border-left: 1px solid #e7dbee;
}

.lu-classroom .lu-room-brief h3 {
  margin-top: 5px;
  font-size: 1.5rem;
}

.lu-classroom .lu-brief-entry,
.lu-classroom .lu-brief-resource {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid #e9dff0;
}

.lu-classroom .lu-brief-entry h4,
.lu-classroom .lu-brief-resource h4 {
  font-size: .88rem;
  line-height: 1.3;
}

.lu-classroom .lu-brief-entry p,
.lu-classroom .lu-brief-resource p {
  margin-top: 4px;
  color: #5d5268;
  font-size: .78rem;
  line-height: 1.45;
}

.lu-classroom .lu-brief-resource p {
  margin: 0 0 3px;
  color: #5f3599;
  font-size: .69rem;
  font-weight: 700;
}

.lu-classroom .lu-board-insert {
  margin-top: 10px;
  border-color: #6739c6;
  background: #6739c6;
  color: #fff;
}

.lu-classroom .lu-board-insert:not(:disabled):hover {
  border-color: #4d269a;
  background: #4d269a;
}

.lu-classroom .lu-brief-followup {
  display: inline-block;
  margin-top: 12px;
  color: #50229b;
  font-size: .77rem;
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: .15em;
}

.lu-classroom .lu-brief-followup[hidden],
.lu-classroom .lu-brief-resource[hidden] {
  display: none;
}

@media (max-width: 780px) {
  .lu-classroom .lu-room-content {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .lu-classroom .lu-room-brief {
    padding: 16px 0 0;
    border: 0;
    border-top: 1px solid #e7dbee;
  }
}

@media (max-width: 580px) {
  .lu-classroom .lu-board-stage { grid-template-columns: minmax(0, 1fr); gap: 5px; }
  .lu-classroom .lu-board-dock { flex-direction: row; flex-wrap: wrap; width: max-content; max-width: 100%; }
}

@media (max-width: 460px) {
  .lu-classroom {
    width: calc(100% - 12px);
    max-height: calc(100dvh - 12px);
    border-radius: 8px;
  }

  .lu-classroom .lu-board {
    height: clamp(250px, calc(100dvh - 293px), 710px);
  }

  .lu-classroom:has(.lu-book-panel:not([hidden])) .lu-board {
    height: clamp(240px, calc(100dvh - 310px), 710px);
  }

  .lu-classroom .lu-board-tools .lu-room-button {
    min-height: 37px;
    padding-inline: 8px;
  }
}