.intro-page {
  --intro-gutter: clamp(24px, 4.5vw, 90px);
  overflow-x: clip;
}

.intro-motion-scene {
  position: relative;
}

.has-scroll-motion .intro-reveal {
  opacity: var(--reveal-opacity, 1);
  transform: translateY(var(--reveal-y, 0px));
}

.has-scroll-motion .intro-reveal:focus-within {
  opacity: 1;
  transform: none;
}

.intro-scene:not(.intro-motion-scene),
.intro-stage {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: clamp(24px, 3.5vw, 64px);
  min-height: 100svh;
  padding: 90px var(--intro-gutter);
}

.intro-copy {
  position: relative;
  z-index: 1;
  min-width: 0;
}

.intro-eyebrow {
  margin-bottom: 28px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.intro-copy h1,
.intro-copy h2,
.intro-finale h2 {
  font-family: Georgia, 'Times New Roman', serif;
  font-size: clamp(3.2rem, 5.7vw, 6.6rem);
  line-height: 0.99;
  font-weight: 700;
  letter-spacing: -0.06em;
  text-wrap: balance;
}

.intro-page em {
  color: var(--accent);
  font-style: normal;
}

.intro-description {
  max-width: 500px;
  margin-top: 28px;
  color: var(--muted);
  font-size: clamp(1rem, 1.2vw, 1.2rem);
  line-height: 1.8;
}

.intro-scroll-hint {
  margin-top: 40px;
  font-size: 0.73rem;
}

.intro-art {
  position: relative;
  min-width: 0;
  aspect-ratio: 1;
  isolation: isolate;
}

.intro-art::before {
  content: '';
  position: absolute;
  inset: 8%;
  z-index: -1;
  background: radial-gradient(ellipse, rgb(7 154 163 / 17%), transparent 70%);
}

.intro-orbit {
  position: absolute;
  inset: 12% 0;
  border: 1px solid rgb(7 154 163 / 25%);
  border-radius: 50%;
  transform: rotate(-25deg);
}

.part {
  position: absolute;
  display: block;
  height: auto;
  object-fit: contain;
  opacity: var(--part-opacity, 1);
  transform: translate(var(--part-x, 0px), var(--part-y, 0px))
    rotate(calc(var(--rest-rotation, 0deg) + var(--part-turn, 0deg))) scale(var(--part-scale, 1));
}

.part-board {
  top: 17%;
  right: -2%;
  width: 64%;
  --rest-rotation: 10deg;
}

.part-ram {
  top: 8%;
  left: 2%;
  width: 45%;
  --rest-rotation: -14deg;
}

.part-cpu {
  top: -2%;
  right: 20%;
  width: 27%;
  --rest-rotation: 12deg;
}

.part-gpu {
  z-index: 1;
  top: 36%;
  left: -5%;
  width: 92%;
  --rest-rotation: -9deg;
}

.part-ssd {
  right: 2%;
  bottom: 0;
  width: 44%;
  --rest-rotation: -18deg;
}

.intro-building {
  color: var(--white);
  background: var(--black);
}

.intro-building .intro-description,
.intro-building .intro-status {
  color: rgb(255 255 255 / 70%);
}

.build-case {
  top: 20%;
  right: -2%;
  width: 58%;
  z-index: 0;
  transform: none;
}

.build-cpu {
  top: 2%;
  left: 28%;
  width: 22%;
  --rest-rotation: 8deg;
}

.build-board {
  top: 43%;
  left: 3%;
  width: 29%;
  --rest-rotation: -8deg;
}

.build-ram {
  top: 8%;
  left: 0;
  width: 29%;
  --rest-rotation: -10deg;
}

.build-ram-secondary {
  top: 25%;
  left: 12%;
  width: 30%;
}

.build-ssd {
  top: 81%;
  left: -1%;
  width: 25%;
  --rest-rotation: -15deg;
}

.build-gpu {
  bottom: -3%;
  left: 10%;
  width: 56%;
  --rest-rotation: -12deg;
}

.build-fan {
  top: 29%;
  left: -1%;
  width: 17%;
  --rest-rotation: -12deg;
}

.intro-choices {
  display: grid;
  gap: 0;
  margin-top: 32px;
}

.intro-choices button {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 18px 0;
  border: 0;
  border-bottom: 1px solid rgb(255 255 255 / 25%);
  background: transparent;
  color: var(--white);
  font: inherit;
  font-size: 0.92rem;
  text-align: left;
  opacity: 1;
  cursor: not-allowed;
}

.intro-choices button span {
  color: var(--accent);
  font-size: 0.65rem;
}

.intro-status {
  max-width: 440px;
  margin-top: 18px;
  color: var(--muted);
  font-size: 0.7rem;
  line-height: 1.7;
}

.intro-understanding {
  --topic-icon-size: clamp(54px, 4.7vw, 88px);
  position: relative;
  isolation: isolate;
  grid-template-columns: 1.1fr 1fr;
  gap: clamp(36px, 5vw, 100px);
  padding-block: clamp(80px, 7vw, 140px);
  overflow: hidden;
  background: var(--paper);
}

.intro-understanding::before {
  content: '';
  position: absolute;
  z-index: -1;
  top: -42%;
  left: 28%;
  width: 34%;
  height: 190%;
  border: 1px solid rgb(7 154 163 / 7%);
  border-radius: 50%;
  background: rgb(7 154 163 / 2%);
  transform: rotate(39deg);
  pointer-events: none;
}

.intro-understanding::after {
  content: '';
  position: absolute;
  z-index: -1;
  inset: 18px;
  background-image: radial-gradient(circle, rgb(7 154 163 / 40%) 1px, transparent 1px);
  background-size: 18px 18px;
  mask-image:
    radial-gradient(ellipse 110px 70px at top right, #000 98%, transparent),
    radial-gradient(ellipse 110px 70px at bottom left, #000 98%, transparent);
  pointer-events: none;
}

.intro-understanding .intro-eyebrow {
  display: flex;
  align-items: center;
  gap: 22px;
}

.intro-understanding .intro-eyebrow::before {
  content: '';
  width: 38px;
  height: 3px;
  background: var(--accent);
}

.intro-understanding h2 {
  font-size: clamp(3.2rem, 5.8vw, 7.8rem);
  line-height: 1.04;
}

.intro-understanding .intro-description {
  max-width: 560px;
  margin-top: 34px;
}

.intro-side-note {
  margin-top: 32px;
  padding-left: 16px;
  border-left: 4px solid var(--accent);
  font-size: 0.85rem;
}

.intro-explanations {
  margin: 0;
  padding: 0;
  list-style: none;
}

.intro-explanations > li {
  display: grid;
  grid-template-columns: var(--topic-icon-size) 44px minmax(0, 1fr);
  align-items: start;
  gap: 22px;
  padding-block: 30px;
}

.intro-explanations > li + li {
  border-top: 1px solid var(--line);
}

.intro-topic-icon {
  display: grid;
  place-items: center;
  width: var(--topic-icon-size);
  height: var(--topic-icon-size);
  border-radius: 24%;
  background: rgb(7 154 163 / 6%);
  color: var(--accent);
}

.intro-topic-icon svg {
  width: 65%;
  height: 65%;
}

.intro-topic-number {
  align-self: stretch;
  padding-left: 18px;
  border-left: 1px solid var(--line);
  color: var(--accent);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
}

.intro-explanations h3 {
  font-size: clamp(1.15rem, 1.65vw, 1.8rem);
  font-weight: 700;
  letter-spacing: -0.025em;
}

.intro-explanations p {
  margin-top: 10px;
  color: var(--muted);
  font-size: clamp(0.9rem, 1.1vw, 1.1rem);
  line-height: 1.6;
}

.intro-finale {
  position: relative;
  isolation: isolate;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100svh;
  padding: 100px var(--intro-gutter) 160px;
  overflow: hidden;
  border-top: 1px solid var(--line);
  text-align: center;
}

.intro-finale h2 {
  font-size: clamp(4.5rem, 9.5vw, 10.5rem);
}

.intro-finale .intro-description {
  max-width: 480px;
}

.intro-continue {
  display: inline-flex;
  align-items: center;
  gap: 48px;
  margin-top: 32px;
  padding: 18px 24px;
  border: 1px solid var(--ink);
  border-radius: 40px;
  background: var(--ink);
  color: var(--paper);
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  transition:
    background 180ms ease,
    color 180ms ease;
}

.intro-continue:hover {
  background: var(--accent);
  color: var(--black);
}

.intro-finale-word {
  position: absolute;
  bottom: -0.4em;
  z-index: -1;
  color: rgb(0 0 0 / 4%);
  font-size: 20vw;
  font-weight: 800;
  letter-spacing: -0.08em;
  white-space: nowrap;
}

.intro-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 22px var(--intro-gutter);
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.65rem;
}

@media (min-width: 761px) and (min-height: 620px) and (prefers-reduced-motion: no-preference) {
  .has-scroll-motion .intro-motion-scene {
    min-height: 200svh;
  }

  .has-scroll-motion .intro-stage {
    position: sticky;
    top: 0;
  }
}

@media (min-width: 1600px) {
  .intro-page {
    --intro-gutter: max(96px, calc((100vw - 1500px) / 2));
  }
}

@media (max-width: 760px) {
  .intro-scene:not(.intro-motion-scene),
  .intro-stage {
    grid-template-columns: 1fr;
    gap: 48px;
    padding-block: 64px;
  }

  .intro-copy h1,
  .intro-copy h2 {
    max-width: 540px;
    font-size: clamp(3rem, 9.2vw, 4.8rem);
  }

  .intro-art {
    width: min(100%, 560px);
    margin-inline: auto;
  }

  .intro-build-art {
    grid-row: 2;
    margin-bottom: 20px;
  }

  .intro-understanding {
    grid-template-columns: 1fr;
  }

  .intro-understanding h2 {
    font-size: clamp(3rem, 9.2vw, 4.8rem);
  }

  .intro-explanations > li {
    grid-template-columns: var(--topic-icon-size) 30px minmax(0, 1fr);
    gap: 12px;
    padding-block: 24px;
  }

  .intro-topic-number {
    padding-left: 10px;
    font-size: 0.85rem;
  }

  .intro-finale {
    padding-block: 80px 120px;
  }

  .intro-footer {
    flex-direction: column;
    gap: 8px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .part {
    opacity: 1;
    transform: none;
  }

  .has-scroll-motion .intro-reveal {
    opacity: 1;
    transform: none;
  }

  .intro-continue {
    transition: none;
  }
}