* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
a {
  color: var(--ui-primary);
  text-underline-offset: 0.22em;
}
button {
  font: inherit;
  cursor: pointer;
}
a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--ui-focus);
  outline-offset: 5px;
}
[hidden] {
  display: none !important;
}
.brand {
  color: var(--ui-primary);
  font-weight: 800;
  letter-spacing: -0.035em;
}
.brand span {
  font-weight: 400;
  letter-spacing: -0.02em;
}
.document {
  max-width: 1040px;
  margin: 0 auto;
  padding: 48px 32px 72px;
}
.document .brand {
  font-size: 24px;
  margin-bottom: 72px;
}
.document h1 {
  font-size: clamp(32px, 5vw, 52px);
  letter-spacing: -0.04em;
  margin: 0 0 12px;
}
.intro {
  color: var(--ui-text-muted);
  margin: 0 0 48px;
  max-width: 56ch;
}
.document h2 {
  margin: 44px 0 16px;
  font-size: 20px;
}
.material-list {
  list-style: none;
  padding: 0;
  margin: 0;
}
.material-list li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  padding: 24px 0;
  border-top: 1px solid #c7d7e1;
}
.material-title {
  display: block;
  font-size: 20px;
  font-weight: 600;
}
.material-meta {
  font-size: 14px;
  color: var(--ui-text-muted);
}
.material-actions {
  display: flex;
  gap: 24px;
  flex-shrink: 0;
}
.material-actions a {
  padding: 10px 0;
  font-size: 15px;
}
.placeholder {
  min-height: 100svh;
  display: grid;
  place-items: center;
}
.placeholder h1 {
  font-size: clamp(28px, 5vw, 48px);
}

.presentation {
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  background: var(--ui-surface);
}
.presentation:fullscreen {
  overflow: auto;
}
.deck-header,
.deck-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 20px clamp(24px, 5vw, 80px);
}
.deck-header .brand {
  font-size: 22px;
}
.deck-label {
  font-size: 12px;
  color: var(--ui-text-muted);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
.slides {
  flex: 1;
  width: 100%;
  max-width: 1600px;
  margin: 0 auto;
  display: flex;
}
.slide {
  width: 100%;
  padding: 18px clamp(24px, 5vw, 80px) 24px;
}
.slide h1 {
  color: var(--ui-primary);
  font-size: clamp(32px, 4.3vw, 66px);
  line-height: 1.12;
  letter-spacing: -0.045em;
  margin: 8px 0 16px;
  font-weight: 700;
}
.description {
  margin: 0;
  font-size: clamp(16px, 1.4vw, 20px);
  color: var(--ui-text-muted);
}
.setup {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 44px;
}
.setup figure {
  margin: 0;
}
.setup img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1.15;
  object-fit: contain;
  background: var(--ui-canvas);
}
.setup figcaption {
  font-size: clamp(18px, 2.1vw, 30px);
  color: var(--ui-primary);
  font-weight: 600;
  margin-top: 20px;
}
.setup-number {
  display: block;
  font-size: 12px;
  color: var(--ui-text-muted);
  font-weight: 400;
  margin-bottom: 8px;
}
.comparison {
  width: 100%;
  border-collapse: collapse;
  margin-top: 34px;
  table-layout: fixed;
}
.comparison col:first-child {
  width: 45%;
}
.comparison td {
  border-top: 1px solid var(--ui-border);
  padding: 16px 0;
  vertical-align: middle;
}
.comparison td:first-child {
  font-size: clamp(19px, 2.1vw, 30px);
  font-weight: 600;
  padding-right: 32px;
}
.comparison td:nth-child(2) {
  font-size: clamp(17px, 1.9vw, 27px);
  color: var(--ui-primary);
  padding-left: 28px;
}
.comparison .group th {
  height: 38px;
  vertical-align: bottom;
  padding: 12px 0 8px;
  font-size: 12px;
  font-weight: 600;
  text-align: left;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--ui-text-muted);
}
.comparison .school th {
  padding-top: 25px;
}
.concept {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  line-height: 1.5;
  font-weight: 700;
  color: #795800;
}
.answer {
  min-height: 57px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.unrevealed .answer {
  visibility: hidden;
}
.prompt {
  margin: 28px 0 0;
  font-size: 19px;
  font-weight: 600;
  color: var(--ui-primary);
}
.prompt::before {
  content: '';
  display: inline-block;
  width: 24px;
  height: 4px;
  background: var(--classroom-gold);
  margin: 0 12px 4px 0;
}
.walkthrough {
  margin: clamp(36px, 7vh, 90px) 0 0;
  padding: 0;
  list-style: none;
}
.walkthrough li {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-bottom: 22px;
}
.walkthrough .step {
  font-size: 14px;
  color: var(--ui-text-muted);
  border-bottom: 3px solid var(--classroom-gold);
  padding-bottom: 6px;
}
.walkthrough strong {
  font-size: clamp(29px, 4vw, 58px);
  line-height: 1.2;
  font-weight: 600;
  letter-spacing: -0.04em;
  color: var(--ui-primary);
}
.deck-footer {
  margin-top: auto;
  border-top: 1px solid var(--ui-border);
  padding-top: 16px;
  padding-bottom: 16px;
}
.slide-counter {
  font-size: 14px;
  color: var(--ui-text-muted);
  min-width: 48px;
}
.controls {
  display: flex;
  align-items: center;
  gap: 10px;
}
.controls button {
  min-height: 44px;
  border: 1px solid var(--ui-border);
  border-radius: 6px;
  background: var(--ui-surface);
  padding: 8px 18px;
  font-size: 14px;
  color: var(--ui-primary);
}
.controls .next {
  background: var(--ui-primary);
  color: white;
  border-color: var(--ui-primary);
}
.controls button:hover:not(:disabled) {
  background: var(--ui-canvas);
}
.controls .next:hover:not(:disabled) {
  background: var(--ui-primary-hover);
}
.controls button:disabled {
  opacity: 0.4;
  cursor: default;
}
.fullscreen-status {
  margin: 0;
  padding: 0 24px 12px;
  color: var(--ui-text-muted);
  font-size: 14px;
}
.fullscreen-status:empty {
  display: none;
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

@media (min-width: 761px) and (max-height: 780px) {
  .deck-header {
    padding-top: 14px;
    padding-bottom: 12px;
  }
  .slide {
    padding-top: 0;
  }
  .slide h1 {
    font-size: clamp(30px, 3.4vw, 50px);
  }
  .setup {
    margin-top: 24px;
  }
  .setup img {
    max-height: 35vh;
  }
  .comparison {
    margin-top: 16px;
  }
  .comparison td {
    padding-top: 8px;
    padding-bottom: 8px;
  }
  .comparison td:first-child {
    font-size: 24px;
  }
  .comparison td:nth-child(2) {
    font-size: 22px;
  }
  .comparison .school th {
    padding-top: 14px;
  }
  .prompt {
    margin-top: 16px;
  }
  .walkthrough {
    margin-top: 36px;
  }
}
@media (max-width: 760px) {
  .document {
    padding: 32px 24px;
  }
  .document .brand {
    margin-bottom: 48px;
  }
  .material-list li {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }
  .deck-header {
    align-items: flex-start;
  }
  .deck-label {
    display: none;
  }
  .slide {
    padding-top: 16px;
  }
  .setup {
    grid-template-columns: 1fr;
    gap: 32px;
    margin-top: 28px;
  }
  .setup img {
    max-height: 280px;
  }
  .setup figcaption {
    margin-top: 12px;
  }
  .comparison {
    margin-top: 24px;
  }
  .comparison col:first-child {
    width: 46%;
  }
  .comparison td:first-child {
    padding-right: 12px;
    font-size: 18px;
  }
  .comparison td:nth-child(2) {
    padding-left: 12px;
    font-size: 16px;
  }
  .answer {
    min-height: 104px;
  }
  .walkthrough li {
    gap: 16px;
  }
  .deck-footer {
    padding: 16px;
    gap: 12px;
  }
  .controls {
    gap: 6px;
  }
  .controls button {
    padding: 8px 10px;
    font-size: 12px;
  }
}
@media (prefers-reduced-motion: no-preference) {
  .slide:not([hidden]) {
    animation: enter 180ms ease-out;
  }
  @keyframes enter {
    from {
      opacity: 0;
    }
    to {
      opacity: 1;
    }
  }
}
@media print {
  .deck-header,
  .deck-footer,
  .fullscreen-status {
    display: none;
  }
  .slides {
    display: block;
  }
  .slide,
  .slide[hidden] {
    display: block !important;
    break-after: page;
  }
  .slide {
    padding: 24px;
  }
}