/* 25–28 — one progressive interaction-logic story, grounded in the source PPT. */
#p25.interaction-story {
  /* Primitive tokens */
  --interaction-black-950: #050505;
  --interaction-black-900: #111111;
  --interaction-black-800: #1c1c1d;
  --interaction-white-50: #f5f5f7;
  --interaction-gray-300: #b4b4b9;
  --interaction-gray-500: #7d7d83;
  --interaction-rule-alpha: rgb(255 255 255 / .18);
  --interaction-rule-strong-alpha: rgb(255 255 255 / .38);

  /* Semantic tokens */
  --interaction-surface: var(--interaction-black-950);
  --interaction-surface-raised: var(--interaction-black-800);
  --interaction-text: var(--interaction-white-50);
  --interaction-text-muted: var(--interaction-gray-300);
  --interaction-text-faint: var(--interaction-gray-500);
  --interaction-rule: var(--interaction-rule-alpha);
  --interaction-rule-strong: var(--interaction-rule-strong-alpha);
  --interaction-motion-ease: cubic-bezier(.22, .76, .2, 1);

  /* Component tokens */
  --interaction-story-gutter: clamp(26px, 4.2vw, 80px);
  --interaction-story-top: clamp(22px, 2.2vw, 40px);
  --interaction-story-support: clamp(12px, .82vw, 15px);
  --interaction-story-title: clamp(46px, 4.9vw, 86px);
  --interaction-story-gap: clamp(24px, 3vw, 52px);
  --interaction-story-speed: 430ms;

  position: relative;
  display: block !important;
  width: 100%;
  min-height: 400svh !important;
  padding: 0 !important;
  overflow: visible !important;
  color: var(--interaction-text);
  background: var(--interaction-surface) !important;
  isolation: isolate;
}

#p25.interaction-story *,
#p25.interaction-story *::before,
#p25.interaction-story *::after {
  box-sizing: border-box;
}

#p26.interaction-story__source-page,
#p27.interaction-story__source-page,
#p28.interaction-story__source-page {
  display: none !important;
}

.interaction-story__sticky {
  position: sticky;
  top: 0;
  height: 100svh;
  min-height: 650px;
  overflow: hidden;
  padding: var(--interaction-story-top) var(--interaction-story-gutter) clamp(28px, 3vw, 48px);
  background: var(--interaction-surface);
}

.interaction-story__masthead {
  position: relative;
  z-index: 8;
  display: grid;
  grid-template-columns: minmax(220px, .8fr) minmax(200px, .65fr) minmax(520px, 1.55fr);
  gap: var(--interaction-story-gap);
  align-items: start;
  min-height: 62px;
  color: var(--interaction-text-muted);
  isolation: isolate;
  contain: paint;
  background: var(--interaction-surface);
  transform: translateZ(0);
  font-size: var(--interaction-story-support);
  line-height: 1.3;
  letter-spacing: .08em;
}

.interaction-story__eyebrow,
.interaction-story__status,
.interaction-story__masthead-center,
.interaction-story__act-no {
  margin: 0;
  font-size: var(--interaction-story-support);
  line-height: 1.3;
  letter-spacing: .12em;
  text-transform: uppercase;
}

.interaction-story__eyebrow {
  color: var(--interaction-text);
  font-weight: 700;
}

.interaction-story__status {
  margin-top: 4px;
  color: var(--interaction-text-faint);
}

.interaction-story__masthead-center {
  justify-self: center;
  color: var(--interaction-text-muted);
  text-align: center;
  text-transform: none;
}

.interaction-story__steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(14px, 1.8vw, 32px);
}

.interaction-story__steps button {
  appearance: none;
  display: inline-flex;
  gap: 7px;
  align-items: baseline;
  justify-content: flex-end;
  min-height: 28px;
  margin: 0;
  padding: 3px 0;
  border: 0;
  border-radius: 0;
  color: var(--interaction-text-faint);
  background: transparent;
  font: inherit;
  font-size: var(--interaction-story-support);
  line-height: 1.3;
  letter-spacing: .04em;
  white-space: nowrap;
  cursor: pointer;
  transition: color 180ms ease, transform 180ms var(--interaction-motion-ease);
}

.interaction-story__steps button span {
  color: inherit;
  font-variant-numeric: tabular-nums;
}

.interaction-story__steps button:hover,
.interaction-story__steps button:focus-visible,
.interaction-story__steps button[aria-current='step'] {
  color: var(--interaction-text);
}

.interaction-story__steps button:hover,
.interaction-story__steps button:focus-visible {
  transform: translateY(-1px);
}

.interaction-story__steps button:focus-visible {
  outline: 1px solid currentColor;
  outline-offset: 5px;
}

.interaction-story__steps button[aria-current='step'] {
  font-weight: 700;
}

.interaction-story__stage {
  position: absolute;
  inset: clamp(112px, 11.6vh, 138px) var(--interaction-story-gutter) clamp(44px, 6.2vh, 72px);
}

.interaction-story__act {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--interaction-story-gap);
  align-items: start;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translate3d(0, 4vh, 0) scale(.982);
  transform-origin: top center;
  transition:
    opacity var(--interaction-story-speed) ease,
    transform calc(var(--interaction-story-speed) + 90ms) var(--interaction-motion-ease),
    visibility 0s linear var(--interaction-story-speed);
}

.interaction-story__act.is-current {
  z-index: 2;
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translate3d(0, 0, 0) scale(1);
  transition-delay: 60ms, 0ms, 0s;
}

.interaction-story__act.is-past {
  transform: translate3d(0, -3.2vh, 0) scale(.988);
}

.interaction-story__copy {
  grid-column: 1 / span 4;
  align-self: start;
  max-width: 520px;
}

.interaction-story__act-no {
  margin-bottom: clamp(18px, 2.4vh, 28px);
  color: var(--interaction-text-muted);
}

.interaction-story__copy h2,
.interaction-story__definition-visual h3 {
  margin: 0;
  color: var(--interaction-text);
  font-size: var(--interaction-story-title);
  line-height: .98;
  font-weight: 500;
  letter-spacing: -.055em;
}

.interaction-story__copy > p:last-child,
.interaction-story__definition-visual > p:last-child,
.interaction-story__principle,
.interaction-story__chain-list,
.interaction-story__keywords,
.interaction-story__motion-item figcaption {
  font-size: var(--interaction-story-support);
  line-height: 1.55;
}

.interaction-story__copy > p:last-child {
  margin: clamp(24px, 3.6vh, 42px) 0 0;
  max-width: 37ch;
  color: var(--interaction-text-muted);
}

.interaction-story__definition-visual {
  grid-column: 6 / -1;
  align-self: start;
}

.interaction-story__definition-visual h3 {
  max-width: 9ch;
  font-size: clamp(60px, 6.5vw, 116px);
  line-height: .9;
}

.interaction-story__definition-visual h3 span {
  display: inline-block;
  color: var(--interaction-text-muted);
  font-size: .42em;
  transform: translateY(-.22em);
}

.interaction-story__definition-visual > p:last-child {
  margin: clamp(26px, 4vh, 48px) 0 0;
  color: var(--interaction-text-muted);
}

.interaction-story__act--principles .interaction-story__copy,
.interaction-story__act--chain .interaction-story__copy,
.interaction-story__act--motion .interaction-story__copy {
  grid-column: 1 / span 3;
}

.interaction-story__principle-matrix {
  grid-column: 4 / -1;
  display: grid;
  grid-template-columns: 1.18fr .82fr;
  min-width: 0;
  border-top: 1px solid var(--interaction-rule-strong);
}

.interaction-story__principle {
  min-width: 0;
  padding: clamp(22px, 3vh, 38px) clamp(24px, 3vw, 52px) 0 0;
  color: var(--interaction-text-muted);
}

.interaction-story__principle + .interaction-story__principle {
  padding-right: 0;
  padding-left: clamp(24px, 3vw, 52px);
  border-left: 1px solid var(--interaction-rule);
}

.interaction-story__principle header p,
.interaction-story__principle header strong {
  display: block;
  margin: 0;
  font-size: var(--interaction-story-support);
  line-height: 1.55;
}

.interaction-story__principle header strong {
  margin: 5px 0;
  color: var(--interaction-text);
  font-weight: 700;
}

.interaction-story__density-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 2vw, 32px);
  margin-top: clamp(34px, 5.2vh, 64px);
  padding-top: clamp(20px, 2.8vh, 34px);
  border-top: 1px solid var(--interaction-rule);
}

.interaction-story__density-grid article,
.interaction-story__density-grid p,
.interaction-story__density-grid strong {
  margin: 0;
  color: var(--interaction-text-muted);
  font-size: var(--interaction-story-support);
  line-height: 1.55;
}

.interaction-story__density-grid strong {
  color: var(--interaction-text);
  font-weight: 700;
}

.interaction-story__density-grid p:nth-child(2) {
  color: var(--interaction-text-faint);
}

.interaction-story__density-grid p:last-child {
  margin-top: clamp(18px, 3vh, 34px);
}

.interaction-story__adaptive {
  margin-top: clamp(34px, 5.2vh, 64px);
  padding-top: clamp(20px, 2.8vh, 34px);
  border-top: 1px solid var(--interaction-rule);
}

.interaction-story__adaptive > p {
  margin: 0;
  color: var(--interaction-text-muted);
  font-size: var(--interaction-story-support);
  line-height: 1.55;
}

.interaction-story__adaptive > p:first-child {
  color: var(--interaction-text);
  font-weight: 700;
}

.interaction-story__adaptive > div {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: clamp(28px, 4vh, 48px);
}

.interaction-story__adaptive span,
.interaction-story__adaptive strong {
  display: block;
  color: var(--interaction-text-faint);
  font-size: var(--interaction-story-support);
  line-height: 1.55;
}

.interaction-story__adaptive strong {
  color: var(--interaction-text);
}

.interaction-story__chain-list {
  grid-column: 4 / -1;
  min-width: 0;
  border-top: 1px solid var(--interaction-rule-strong);
}

.interaction-story__chain-list section {
  display: grid;
  grid-template-columns: minmax(130px, .28fr) minmax(0, 1fr);
  gap: clamp(28px, 4vw, 72px);
  align-items: center;
  min-height: clamp(118px, 16vh, 176px);
  padding: clamp(22px, 3vh, 36px) 0;
  border-bottom: 1px solid var(--interaction-rule);
}

.interaction-story__chain-list p,
.interaction-story__chain-list strong,
.interaction-story__chain-list span {
  display: block;
  margin: 0;
  color: var(--interaction-text-muted);
  font-size: var(--interaction-story-support);
  line-height: 1.55;
}

.interaction-story__chain-list section > p,
.interaction-story__chain-list strong {
  color: var(--interaction-text);
  font-weight: 700;
}

.interaction-story__chain-list span {
  margin-top: 4px;
  color: var(--interaction-text-faint);
}

.interaction-story__keywords {
  display: grid;
  gap: 9px;
  margin: clamp(28px, 4vh, 46px) 0 0;
  padding: clamp(18px, 2.5vh, 28px) 0 0;
  border-top: 1px solid var(--interaction-rule);
}

.interaction-story__keywords div {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 12px;
}

.interaction-story__keywords dt,
.interaction-story__keywords dd {
  margin: 0;
  color: var(--interaction-text-muted);
  font-size: var(--interaction-story-support);
  line-height: 1.45;
}

.interaction-story__keywords dt {
  color: var(--interaction-text);
  font-weight: 700;
}

.interaction-story__motion-grid {
  grid-column: 4 / -1;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  min-width: 0;
  height: min(70vh, 720px);
  border-top: 1px solid var(--interaction-rule-strong);
  border-bottom: 1px solid var(--interaction-rule);
}

.interaction-story__motion-item {
  display: grid;
  grid-template-rows: minmax(0, 1fr) auto;
  min-width: 0;
  min-height: 0;
  margin: 0;
  overflow: hidden;
  border-left: 1px solid var(--interaction-rule);
  opacity: .9;
  transition: opacity 280ms ease, transform 420ms var(--interaction-motion-ease);
}

.interaction-story__motion-item:first-child {
  border-left: 0;
}

.interaction-story__act--motion.is-current .interaction-story__motion-item {
  animation: interaction-motion-enter 660ms var(--interaction-motion-ease) both;
}

.interaction-story__act--motion.is-current .interaction-story__motion-item:nth-child(2) { animation-delay: 80ms; }
.interaction-story__act--motion.is-current .interaction-story__motion-item:nth-child(3) { animation-delay: 160ms; }
.interaction-story__act--motion.is-current .interaction-story__motion-item:nth-child(4) { animation-delay: 240ms; }

@keyframes interaction-motion-enter {
  from { opacity: 0; transform: translate3d(0, 24px, 0) scale(.97); }
  to { opacity: .9; transform: translate3d(0, 0, 0) scale(1); }
}

.interaction-story__motion-media {
  min-height: 0;
  overflow: hidden;
  background: var(--interaction-black-900);
}

.interaction-story__motion-media video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  filter: saturate(.78) contrast(1.04);
}

.interaction-story__motion-item figcaption {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 8px;
  min-height: 56px;
  align-items: center;
  margin: 0;
  padding: 12px 14px;
  color: var(--interaction-text-faint);
  background: var(--interaction-black-900);
}

.interaction-story__motion-item figcaption span,
.interaction-story__motion-item figcaption strong {
  overflow: hidden;
  color: inherit;
  font-size: var(--interaction-story-support);
  line-height: 1.35;
  font-weight: 400;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.interaction-story__motion-item figcaption strong {
  color: var(--interaction-text-muted);
}

.interaction-story__progress {
  position: absolute;
  right: var(--interaction-story-gutter);
  bottom: 14px;
  left: var(--interaction-story-gutter);
  height: 1px;
  margin: 0;
  overflow: hidden;
  background: var(--interaction-rule);
}

.interaction-story__progress span {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(.25);
  transform-origin: left center;
  background: var(--interaction-text);
  transition: transform var(--interaction-story-speed) var(--interaction-motion-ease);
}

.interaction-story__page-no {
  position: absolute;
  right: var(--interaction-story-gutter);
  bottom: 20px;
  z-index: 8;
  display: none;
  color: var(--interaction-text-faint);
  font-size: var(--interaction-story-support);
}

@media (max-width: 1220px) {
  .interaction-story__masthead {
    grid-template-columns: minmax(190px, .72fr) minmax(170px, .58fr) minmax(440px, 1.5fr);
  }

  .interaction-story__steps {
    gap: 12px;
  }

  .interaction-story__act--principles .interaction-story__copy,
  .interaction-story__act--chain .interaction-story__copy,
  .interaction-story__act--motion .interaction-story__copy {
    grid-column: 1 / span 4;
  }

  .interaction-story__principle-matrix,
  .interaction-story__chain-list,
  .interaction-story__motion-grid {
    grid-column: 5 / -1;
  }

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

  .interaction-story__motion-item:nth-child(3) {
    border-left: 0;
    border-top: 1px solid var(--interaction-rule);
  }

  .interaction-story__motion-item:nth-child(4) {
    border-top: 1px solid var(--interaction-rule);
  }
}

@media (max-width: 900px) and (min-width: 761px) {
  .interaction-story__masthead {
    grid-template-columns: 1fr 1fr;
  }

  .interaction-story__masthead-center {
    display: none;
  }

  .interaction-story__steps {
    grid-column: 2;
  }

  .interaction-story__steps button {
    justify-content: flex-start;
  }

  .interaction-story__definition-visual {
    grid-column: 5 / -1;
  }

  .interaction-story__principle-matrix {
    grid-template-columns: 1fr;
  }

  .interaction-story__principle + .interaction-story__principle {
    margin-top: 24px;
    padding-top: 24px;
    padding-left: 0;
    border-top: 1px solid var(--interaction-rule);
    border-left: 0;
  }

  .interaction-story__density-grid,
  .interaction-story__adaptive {
    margin-top: 24px;
  }
}

@media (max-width: 760px) {
  #p25.interaction-story {
    min-height: auto !important;
    overflow: clip !important;
  }

  .interaction-story__sticky {
    position: relative;
    height: auto;
    min-height: 0;
    overflow: visible;
    padding: 24px 20px 68px;
  }

  .interaction-story__masthead {
    display: grid;
    grid-template-columns: 1fr;
    gap: 18px;
    min-height: 0;
  }

  .interaction-story__masthead-center {
    justify-self: start;
    text-align: left;
  }

  .interaction-story__steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px 18px;
  }

  .interaction-story__steps button {
    justify-content: flex-start;
    white-space: normal;
  }

  .interaction-story__stage {
    position: relative;
    inset: auto;
    display: grid;
    gap: 104px;
    margin-top: 70px;
  }

  .interaction-story__act,
  .interaction-story__act.is-current,
  .interaction-story__act.is-past,
  .interaction-story__act.is-next {
    position: relative;
    inset: auto;
    display: grid;
    grid-template-columns: 1fr;
    gap: 42px;
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: none;
    transition: none;
  }

  .interaction-story__act[aria-hidden='true'] {
    visibility: visible;
  }

  .interaction-story__copy,
  .interaction-story__act--principles .interaction-story__copy,
  .interaction-story__act--chain .interaction-story__copy,
  .interaction-story__act--motion .interaction-story__copy,
  .interaction-story__definition-visual,
  .interaction-story__principle-matrix,
  .interaction-story__chain-list,
  .interaction-story__motion-grid {
    grid-column: 1;
  }

  .interaction-story__copy h2,
  .interaction-story__definition-visual h3 {
    font-size: clamp(42px, 13vw, 62px);
  }

  .interaction-story__copy > p:last-child {
    max-width: 40ch;
  }

  .interaction-story__principle-matrix {
    grid-template-columns: 1fr;
  }

  .interaction-story__principle,
  .interaction-story__principle + .interaction-story__principle {
    padding: 24px 0 0;
    border-left: 0;
  }

  .interaction-story__principle + .interaction-story__principle {
    margin-top: 46px;
    border-top: 1px solid var(--interaction-rule-strong);
  }

  .interaction-story__density-grid,
  .interaction-story__adaptive > div {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .interaction-story__density-grid article {
    padding-bottom: 20px;
    border-bottom: 1px solid var(--interaction-rule);
  }

  .interaction-story__chain-list section {
    grid-template-columns: 86px minmax(0, 1fr);
    gap: 24px;
    min-height: 0;
  }

  .interaction-story__motion-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    height: auto;
  }

  .interaction-story__motion-item {
    min-height: 300px;
  }

  .interaction-story__motion-item:nth-child(3) {
    border-left: 0;
    border-top: 1px solid var(--interaction-rule);
  }

  .interaction-story__motion-item:nth-child(4) {
    border-top: 1px solid var(--interaction-rule);
  }

  .interaction-story__motion-media {
    min-height: 245px;
  }

  .interaction-story__progress,
  .interaction-story__page-no {
    display: none;
  }
}

@media (max-width: 480px) {
  .interaction-story__motion-grid {
    grid-template-columns: 1fr;
  }

  .interaction-story__motion-item,
  .interaction-story__motion-item:nth-child(2),
  .interaction-story__motion-item:nth-child(3),
  .interaction-story__motion-item:nth-child(4) {
    border-top: 1px solid var(--interaction-rule);
    border-left: 0;
  }

  .interaction-story__motion-item:first-child {
    border-top: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  #p25.interaction-story {
    min-height: auto !important;
  }

  .interaction-story__sticky {
    position: relative;
    height: auto;
    min-height: 0;
    overflow: visible;
  }

  .interaction-story__stage {
    position: relative;
    inset: auto;
    display: grid;
    gap: clamp(90px, 12vw, 160px);
    margin-top: 70px;
  }

  .interaction-story__act,
  .interaction-story__act.is-current,
  .interaction-story__act.is-past,
  .interaction-story__act.is-next {
    position: relative;
    inset: auto;
    min-height: min(760px, 86vh);
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: none;
    transition: none;
  }

  .interaction-story__act[aria-hidden='true'] {
    visibility: visible;
  }

  .interaction-story__motion-item {
    animation: none !important;
    transition: none;
  }

  .interaction-story__progress,
  .interaction-story__page-no {
    display: none;
  }
}