:root {
  --ink: #101820;
  --muted: #60717f;
  --line: #dce5ea;
  --paper: #f6f9f8;
  --white: #ffffff;
  --deep: #071218;
  --teal: #00a88f;
  --teal-dark: #006d63;
  --gold: #d8b45d;
  --blue: #1d5d8f;
  --shadow: 0 24px 70px rgba(13, 32, 46, 0.18);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  line-height: 1.65;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  display: block;
  max-width: 100%;
}

.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  padding: 0 clamp(20px, 4vw, 64px);
  color: var(--white);
  background: rgba(6, 17, 24, 0.18);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
  backdrop-filter: blur(14px);
  transition: background 180ms ease, color 180ms ease, box-shadow 180ms ease;
}

.site-header.is-scrolled {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.92);
  box-shadow: 0 12px 34px rgba(15, 29, 39, 0.08);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-logo {
  width: 36px;
  height: 36px;
  object-fit: contain;
  background: #2f2f2f;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 8px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(18px, 2.4vw, 36px);
  font-size: 14px;
  font-weight: 700;
}

.site-nav a {
  opacity: 0.86;
}

.site-nav a:hover {
  opacity: 1;
}

.lang-link {
  padding: 7px 11px;
  border: 1px solid currentColor;
  border-radius: 999px;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 0;
  background: transparent;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  margin: 7px auto;
  background: currentColor;
}

.hero {
  position: relative;
  min-height: 100svh;
  overflow: hidden;
  color: var(--white);
  background: var(--deep);
}

.hero-media {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-shade {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 70% 48%, rgba(0, 229, 217, 0.24), transparent 31%),
    linear-gradient(90deg, rgba(2, 9, 14, 0.9) 0%, rgba(2, 9, 14, 0.76) 34%, rgba(2, 9, 14, 0.16) 72%),
    linear-gradient(180deg, rgba(3, 13, 20, 0.08), rgba(3, 13, 20, 0.88));
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(rgba(125, 241, 229, 0.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(125, 241, 229, 0.06) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(90deg, transparent, #000 48%, #000 100%);
  opacity: 0.48;
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  width: min(760px, calc(100% - 40px));
  padding: 22vh 0 210px clamp(20px, 7vw, 116px);
}

.eyebrow,
.section-kicker,
.card-label {
  margin: 0 0 18px;
  color: var(--teal);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.eyebrow {
  color: #8df4e3;
}

h1,
h2,
h3,
p,
blockquote {
  margin-top: 0;
}

h1 {
  max-width: 720px;
  margin-bottom: 24px;
  font-size: clamp(42px, 7.2vw, 92px);
  line-height: 1.04;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 18px;
  font-size: clamp(30px, 4.6vw, 58px);
  line-height: 1.12;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 12px;
  font-size: clamp(20px, 2vw, 28px);
  line-height: 1.22;
}

.hero-copy {
  max-width: 650px;
  margin-bottom: 34px;
  color: rgba(255, 255, 255, 0.84);
  font-size: clamp(17px, 1.6vw, 21px);
}

.hero-actions,
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  padding: 12px 22px;
  border-radius: 8px;
  font-weight: 800;
  line-height: 1.2;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button.primary {
  color: var(--white);
  background: var(--teal);
}

.button.secondary {
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.45);
}

.button.text-button {
  min-height: 42px;
  color: var(--teal-dark);
  background: rgba(0, 168, 143, 0.1);
}

.hero-metrics {
  position: absolute;
  right: clamp(20px, 5vw, 82px);
  bottom: 34px;
  left: clamp(20px, 5vw, 82px);
  z-index: 3;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(6, 24, 33, 0.66);
  backdrop-filter: blur(18px);
}

.hero-metrics div {
  min-height: 118px;
  padding: 24px;
  border-right: 1px solid rgba(255, 255, 255, 0.16);
}

.hero-metrics div:last-child {
  border-right: 0;
}

.hero-metrics strong {
  display: block;
  margin-bottom: 8px;
  color: #a8fff0;
  font-size: clamp(18px, 2vw, 28px);
  line-height: 1.12;
}

.hero-metrics span {
  color: rgba(255, 255, 255, 0.72);
}

.section {
  padding: clamp(78px, 10vw, 150px) clamp(20px, 6vw, 96px);
}

.page-main {
  padding-top: 76px;
}

.page-index {
  background: var(--paper);
}

.page-link-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.page-link-card {
  display: grid;
  min-height: 230px;
  align-content: space-between;
  padding: clamp(24px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: 0 16px 46px rgba(17, 38, 52, 0.08);
}

.page-link-card p {
  color: var(--muted);
}

.page-link-card .button {
  justify-self: start;
}

.intro,
.about,
.research,
.news,
.videos {
  background: var(--white);
}

.intro-grid,
.about-layout,
.feature-layout,
.trial,
.applications {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: clamp(34px, 6vw, 84px);
  align-items: start;
}

.intro-copy {
  max-width: 650px;
  color: var(--muted);
  font-size: clamp(17px, 1.35vw, 20px);
}

.about {
  background:
    linear-gradient(180deg, #f8fbfa 0%, #ffffff 100%);
}

.about-layout {
  align-items: stretch;
}

.about-lead {
  display: grid;
  align-content: start;
}

.about-lead p {
  max-width: 720px;
  color: var(--muted);
  font-size: clamp(18px, 1.45vw, 21px);
}

.about-proof {
  display: grid;
  gap: 18px;
}

.about-proof article {
  padding: clamp(24px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdfd;
  box-shadow: 0 16px 46px rgba(17, 38, 52, 0.08);
}

.about-proof span {
  display: block;
  margin-bottom: 16px;
  color: var(--teal-dark);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.about-proof p {
  margin-bottom: 0;
  color: var(--muted);
}

.about-person-card {
  display: grid;
  grid-template-columns: minmax(180px, 0.74fr) minmax(0, 1fr);
  gap: clamp(18px, 3vw, 28px);
  align-items: start;
}

.about-person-photo {
  overflow: hidden;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--deep);
}

.about-person-photo img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.about-person-photo figcaption {
  padding: 10px 12px;
  color: var(--muted);
  background: var(--white);
  font-size: 13px;
  font-weight: 800;
}

.about-sources {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(28px, 4vw, 46px);
}

.section-kicker.light {
  color: #94fff0;
}

.feature-band {
  position: relative;
  overflow: hidden;
  color: var(--white);
  background:
    linear-gradient(135deg, rgba(0, 93, 82, 0.92), rgba(11, 43, 63, 0.96)),
    var(--deep);
}

.feature-band::before,
.feature-band::after {
  content: "";
  position: absolute;
  pointer-events: none;
}

.feature-band::before {
  inset: 0;
  background:
    linear-gradient(90deg, rgba(4, 19, 28, 0.98) 0%, rgba(4, 19, 28, 0.7) 42%, rgba(4, 19, 28, 0.9) 100%),
    linear-gradient(135deg, rgba(0, 168, 143, 0.72), rgba(29, 93, 143, 0.46)),
    url("assets/yushan-original-features.jpg") right 12% center / min(58vw, 760px) auto no-repeat;
  opacity: 0.72;
  mix-blend-mode: screen;
}

.feature-band::after {
  inset: auto 0 0;
  height: 46%;
  background:
    linear-gradient(rgba(148, 255, 240, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 255, 240, 0.06) 1px, transparent 1px);
  background-size: 52px 52px;
  mask-image: linear-gradient(0deg, #000, transparent);
  opacity: 0.55;
}

.feature-band p {
  color: rgba(255, 255, 255, 0.75);
}

.feature-band > * {
  position: relative;
  z-index: 1;
}

.capability-list {
  display: grid;
  gap: 1px;
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.capability-list article {
  padding: 26px;
  background: rgba(4, 19, 28, 0.58);
}

.capability-list span {
  display: inline-block;
  margin-bottom: 22px;
  color: var(--gold);
  font-weight: 900;
}

.section-heading {
  display: flex;
  justify-content: space-between;
  gap: 34px;
  margin-bottom: 42px;
}

.section-heading h2 {
  max-width: 760px;
}

.section-heading p {
  max-width: 420px;
  color: var(--muted);
  font-size: 18px;
}

.research-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.research-card,
.news-grid article,
.application-grid article,
.lead-form {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: 0 16px 46px rgba(17, 38, 52, 0.08);
}

.research-card {
  min-height: 290px;
  padding: clamp(24px, 3vw, 38px);
}

.research-card.large {
  grid-column: span 2;
  color: var(--white);
  background:
    linear-gradient(135deg, rgba(15, 70, 87, 0.92), rgba(7, 25, 36, 0.96)),
    var(--deep);
}

.research-card.large p,
.research-card.wide p {
  color: rgba(255, 255, 255, 0.76);
}

.research-card.wide {
  grid-column: span 2;
  color: var(--white);
  background: linear-gradient(135deg, var(--blue), #0f2e42);
}

.research-card:not(.large):not(.wide) p,
.news-grid p,
.application-grid p {
  color: var(--muted);
}

.trial {
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(7, 18, 24, 0.94), rgba(0, 99, 88, 0.86)),
    var(--deep);
}

.lead-form {
  display: grid;
  gap: 18px;
  padding: clamp(22px, 3vw, 34px);
  color: var(--ink);
}

.lead-form label {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
}

.lead-form input,
.lead-form textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 13px 14px;
  color: var(--ink);
  background: #fbfdfd;
  font: inherit;
}

.lead-form input:focus,
.lead-form textarea:focus {
  outline: 2px solid rgba(0, 168, 143, 0.28);
  border-color: var(--teal);
}

.news-grid,
.application-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.news-grid article,
.application-grid article {
  padding: 26px;
}

.news-thumb {
  display: block;
  width: calc(100% + 52px);
  aspect-ratio: 16 / 9;
  margin: -26px -26px 22px;
  object-fit: cover;
  background: var(--deep);
}

.news-grid time {
  display: block;
  margin-bottom: 14px;
  color: var(--teal-dark);
  font-size: 13px;
  font-weight: 900;
}

.news-grid a {
  text-decoration: underline;
  text-decoration-color: rgba(0, 168, 143, 0.35);
  text-underline-offset: 5px;
}

.news-grid a:hover {
  color: var(--teal-dark);
}

.news-article {
  max-width: 980px;
}

.news-article-hero {
  overflow: hidden;
  margin-top: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: 0 16px 46px rgba(17, 38, 52, 0.08);
}

.news-article-hero img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.news-article-body {
  display: grid;
  gap: 24px;
  margin-top: 34px;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.78;
}

.news-article-body h3 {
  margin-bottom: 8px;
  color: var(--ink);
  font-size: 24px;
}

.news-article-body ul {
  margin: 0;
  padding-left: 22px;
}

.section-link {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.video-grid {
  display: grid;
  gap: 18px;
}

.video-card {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(320px, 0.8fr);
  gap: clamp(24px, 4vw, 48px);
  align-items: center;
  padding: clamp(18px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfdfd;
  box-shadow: 0 16px 46px rgba(17, 38, 52, 0.08);
}

.video-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border-radius: 8px;
  background: var(--deep);
}

.video-frame iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.video-copy p:not(.card-label) {
  color: var(--muted);
}

.applications {
  background: var(--paper);
}

.quote-panel blockquote {
  margin-bottom: 0;
  color: var(--ink);
  font-size: clamp(30px, 4.2vw, 56px);
  font-weight: 850;
  line-height: 1.16;
}

.application-grid {
  grid-template-columns: repeat(2, 1fr);
}

.site-footer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 38px;
  padding: 54px clamp(20px, 6vw, 96px);
  color: rgba(255, 255, 255, 0.76);
  background: #071218;
}

.footer-brand {
  color: var(--white);
  margin-bottom: 16px;
}

.footer-contact {
  display: grid;
  gap: 4px;
  margin-top: 18px;
}

.footer-contact span {
  color: rgba(255, 255, 255, 0.54);
  font-size: 12px;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.footer-contact a {
  color: var(--white);
  font-weight: 800;
}

.footer-links {
  align-items: start;
  justify-content: flex-end;
  color: var(--white);
  font-weight: 800;
}

.copyright {
  grid-column: 1 / -1;
  margin-bottom: 0;
  font-size: 13px;
}

@media (max-width: 980px) {
  .site-header {
    min-height: 68px;
  }

  .nav-toggle {
    display: block;
    color: inherit;
  }

  .site-nav {
    position: absolute;
    top: 68px;
    right: 16px;
    left: 16px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 12px;
    color: var(--ink);
    background: rgba(255, 255, 255, 0.96);
    border: 1px solid var(--line);
    border-radius: 8px;
    box-shadow: var(--shadow);
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    padding: 13px 12px;
  }

  .lang-link {
    border-radius: 8px;
  }

  .hero-content {
    padding: 18vh 20px 340px;
  }

  .hero-metrics,
  .intro-grid,
  .about-layout,
  .feature-layout,
  .trial,
  .applications,
  .section-heading,
  .site-footer {
    grid-template-columns: 1fr;
  }

  .hero-metrics {
    right: 20px;
    left: 20px;
  }

  .research-grid,
  .news-grid,
  .page-link-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .application-grid {
    grid-template-columns: 1fr;
  }

  .video-card {
    grid-template-columns: 1fr;
  }

  .about-person-card {
    grid-template-columns: 1fr;
  }

  .footer-links {
    justify-content: flex-start;
  }
}

@media (max-width: 640px) {
  .hero {
    min-height: 940px;
  }

  .hero-content {
    padding-bottom: 440px;
  }

  .hero-metrics,
  .research-grid,
  .news-grid,
  .page-link-grid {
    grid-template-columns: 1fr;
  }

  .hero-metrics div {
    min-height: auto;
    padding: 18px;
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.16);
  }

  .hero-metrics div:last-child {
    border-bottom: 0;
  }

  .research-card.large,
  .research-card.wide {
    grid-column: auto;
  }

  .section {
    padding-right: 18px;
    padding-left: 18px;
  }
}