/* Research and Innovation — prototype-aligned page */

.research-page {
  --research-ink: var(--neutral-black);
  --research-paper: var(--purple-milky);
  --strategy-theme: var(--r);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  color: var(--research-ink);
  background: var(--research-paper);
}

.research-page main {
  flex: 1 0 auto;
}

.research-page > .site-footer {
  margin-top: auto;
  background: var(--cuhk-purple);
}

.research-page .nav-link.active {
  color: var(--cuhk-purple);
}

.research-page .research-page-content {
  overflow: clip;
}

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.research-hero {
  position: relative;
  background: #fff;
  isolation: isolate;
}

.research-hero-inner {
  position: relative;
  width: min(100%, var(--max));
  min-height: clamp(500px, 50vw, 642px);
  margin: 0 auto;
  padding: 0 var(--content-inset);
  display: grid;
  grid-template-columns: minmax(0, 49%) minmax(0, 51%);
  align-items: stretch;
  overflow: hidden;
}

.research-hero-copy {
  position: relative;
  z-index: 3;
  align-self: center;
  max-width: 590px;
}

.research-hero h1 {
  max-width: 590px;
  margin: 0;
  color: var(--r);
  font-size: clamp(54px, 5.3vw, 88px);
  font-weight: var(--fw-medium);
  letter-spacing: -.055em;
  line-height: .99;
  text-wrap: balance;
}

.research-hero h1 span {
  display: block;
}

.research-hero-message {
  max-width: 35ch;
  margin: clamp(34px, 4vw, 48px) 0 0;
  color: var(--research-ink);
  font-size: 18px;
  font-weight: var(--fw-light);
  line-height: 24px;
}

.research-hero-visual {
  position: relative;
  min-height: 0;
  margin: 0 calc(-1 * var(--content-inset)) 0 0;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: visible;
  pointer-events: none;
}

.research-hero-art {
  position: absolute;
  width: min(100%, 576px);
  height: auto;
  object-fit: contain;
}

.research-hero-art {
  z-index: 1;
  max-height: 473px;
}

.research-hero-prev,
.research-hero-next {
  position: absolute;
  top: 50%;
  z-index: 4;
  width: 50px;
  height: 50px;
  text-decoration: none;
  transform: translateY(-50%);
}

.research-hero-prev { left: clamp(24px, 3.4vw, 44px); }
.research-hero-next { right: clamp(24px, 3.4vw, 44px); }

.research-hero-arrow-icon {
  display: block;
  width: 50px;
  height: 50px;
}

.research-hero-prev .research-hero-arrow-icon { transform: rotate(180deg); }

.research-hero-prev:hover .research-hero-arrow-icon path,
.research-hero-next:hover .research-hero-arrow-icon path,
.research-hero-prev:focus-visible .research-hero-arrow-icon path,
.research-hero-next:focus-visible .research-hero-arrow-icon path {
  fill: var(--r);
}

.research-strategy-section {
  padding: var(--section-padding);
  background: var(--research-paper);
}

.research-strategy-inner {
  width: min(100%, var(--max));
  margin: 0 auto;
  padding: 0;
}

.research-strategy-intro {
  width: min(100%, var(--content));
  margin: 0 auto 32px;
}

.research-strategy-kicker {
  margin: 0;
  color: var(--r);
  font-size: clamp(24px, 2.8vw, 38px);
  font-weight: var(--fw-medium);
  letter-spacing: -.03em;
  line-height: 1;
}

.research-strategy-grid {
  width: 100%;
  max-width: var(--content);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.research-strategy-grid .strategy-flip-card:nth-child(1) .strategy-card-front > img,
.research-strategy-grid .strategy-flip-card:nth-child(3) .strategy-card-front > img {
  object-position: center 34%;
}

.research-closing {
  background: #100a16;
}

.research-closing-image {
  position: relative;
  aspect-ratio: 1280 / 461;
  overflow: hidden;
  isolation: isolate;
}

.research-closing-image > img {
  position: absolute;
  inset: 0;
  z-index: -1;
  width: 100%;
  height: 100%;
  max-width: none;
  object-fit: cover;
  object-position: center 80%;
}

@media (max-width: 1199px) {
  .research-strategy-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 1023px) {
  .research-hero-inner {
    min-height: 0;
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    padding: 0;
  }

  .research-hero-copy {
    width: 100%;
    max-width: none;
    padding: clamp(48px, 7vw, 72px) var(--content-inset) clamp(32px, 5vw, 56px);
  }

  .research-hero h1 {
    max-width: none;
    font-size: clamp(48px, 7vw, 72px);
  }

  .research-hero-message {
    max-width: 72ch;
    margin-top: 28px;
  }

  .research-hero-visual {
    width: 100%;
    height: clamp(300px, 44vw, 460px);
    min-height: 0;
    margin: 0;
    overflow: hidden;
  }

  .research-hero-art {
    position: absolute;
    width: min(76%, 576px);
    max-height: 100%;
  }

  .research-hero-prev,
  .research-hero-next {
    top: auto;
    bottom: calc(clamp(300px, 44vw, 460px) / 2);
  }

  .research-hero-prev { left: clamp(12px, 3vw, 32px); }
  .research-hero-next { right: clamp(12px, 3vw, 32px); }

}

@media (max-width: 767px) {
  .research-hero-inner {
    --research-hero-media-height: clamp(250px, 58vw, 330px);
    min-height: 0;
    display: block;
    padding: 0;
  }

  .research-hero-copy {
    width: 100%;
    max-width: none;
    padding: clamp(32px, 7vw, 52px) var(--content-pad) clamp(20px, 4vw, 32px);
  }

  .research-hero h1 {
    max-width: none;
    font-size: clamp(32px, 9vw, 46px);
    letter-spacing: -.045em;
    line-height: 1.05;
  }

  .research-hero-message {
    max-width: none;
    margin-top: 24px;
    font-size: clamp(16px, 3.8vw, 18px);
    line-height: 1.55;
  }

  .research-hero-visual {
    width: auto;
    height: var(--research-hero-media-height);
    min-height: 0;
    margin: 0;
    align-items: center;
    overflow: hidden;
  }

  .research-hero-art {
    width: min(86%, 576px);
    max-height: 100%;
  }

  .research-hero-prev,
  .research-hero-next {
    top: auto;
    bottom: calc(var(--research-hero-media-height) / 2);
  }

  .research-hero-prev { left: 4px; }
  .research-hero-next { right: 4px; }

  .research-strategy-inner {
    padding: 0;
  }

  .research-strategy-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

}

@media (max-width: 399px) {
  .research-hero-copy {
    padding-top: 32px;
  }

  .research-hero h1 { font-size: clamp(32px, 11vw, 40px); }

  .research-hero-message {
    max-width: none;
    margin-top: 20px;
    font-size: 14px;
    line-height: 1.45;
  }

  .research-hero-art {
    width: 88%;
  }

  .research-strategy-inner {
    padding: 0;
  }

  .research-strategy-grid { gap: 16px; }
}

@media (prefers-reduced-motion: reduce) {
  .research-page a,
  .research-hero-art,
  .strategy-card-scene {
    transition: none !important;
  }
}