:root {
  --ink: #162026;
  --muted: #5d686d;
  --paper: #f6f0e6;
  --paper-strong: #fffaf1;
  --sea: #0f6f78;
  --sea-dark: #0b3e46;
  --red: #b84233;
  --gold: #c7994b;
  --line: rgba(22, 32, 38, 0.16);
  --shadow: 0 18px 60px rgba(10, 30, 34, 0.18);
  --header-height: 76px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.7;
}

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

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

button {
  font: inherit;
}

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(18px, 4vw, 54px);
  color: #fff;
  background: linear-gradient(to bottom, rgba(8, 17, 18, 0.72), rgba(8, 17, 18, 0.18));
  transition:
    background 220ms ease,
    color 220ms ease,
    box-shadow 220ms ease;
}

.site-header.is-scrolled {
  color: var(--ink);
  background: rgba(246, 240, 230, 0.94);
  box-shadow: 0 1px 0 var(--line);
  backdrop-filter: blur(14px);
}

.brand {
  display: grid;
  gap: 0;
  min-width: 152px;
  font-weight: 800;
  letter-spacing: 0;
}

.brand span {
  font-size: 1rem;
}

.brand small {
  color: currentColor;
  font-size: 0.72rem;
  font-weight: 500;
  opacity: 0.72;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(8px, 2vw, 22px);
  font-size: 0.95rem;
  white-space: nowrap;
}

.site-nav a {
  position: relative;
  padding: 8px 0;
  opacity: 0.82;
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 180ms ease;
}

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

.site-nav a:hover::after,
.site-nav a.is-active::after {
  transform: scaleX(1);
}

.hero {
  position: relative;
  min-height: 82svh;
  display: grid;
  align-items: end;
  padding: calc(var(--header-height) + 54px) clamp(20px, 6vw, 84px) 84px;
  color: #fff;
  background-image: var(--hero-image);
  background-size: cover;
  background-position: center;
  overflow: hidden;
}

.hero-home {
  background-position: 58% center;
}

.hero-sub {
  min-height: 70svh;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(8, 16, 17, 0.82), rgba(8, 16, 17, 0.48) 42%, rgba(8, 16, 17, 0.08)),
    linear-gradient(0deg, rgba(8, 16, 17, 0.62), rgba(8, 16, 17, 0.06) 52%);
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--gold);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-family: "Songti SC", "STSong", "SimSun", serif;
  font-size: clamp(4.2rem, 14vw, 12rem);
  line-height: 0.92;
  letter-spacing: 0;
  text-shadow: 0 18px 54px rgba(0, 0, 0, 0.42);
}

.hero-sub h1 {
  max-width: 920px;
  font-size: clamp(2.8rem, 8vw, 7.2rem);
}

.hero__lead {
  max-width: 620px;
  margin: 24px 0 0;
  color: rgba(255, 255, 255, 0.88);
  font-size: clamp(1rem, 1.8vw, 1.25rem);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: 6px;
  padding: 10px 18px;
  font-weight: 800;
  transition:
    transform 180ms ease,
    background 180ms ease,
    border-color 180ms ease;
}

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

.button-primary {
  color: #19120b;
  background: var(--gold);
}

.button-quiet {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.5);
  background: rgba(255, 255, 255, 0.08);
}

.scroll-cue {
  position: absolute;
  z-index: 2;
  right: clamp(20px, 5vw, 72px);
  bottom: 28px;
  color: rgba(255, 255, 255, 0.8);
  font-size: 0.9rem;
}

.section {
  width: min(1180px, calc(100% - 40px));
  margin: 0 auto;
  padding: clamp(64px, 8vw, 112px) 0;
}

main > .section:first-child {
  padding-top: clamp(48px, 6vw, 72px);
}

.section-heading {
  max-width: 740px;
  margin-bottom: clamp(28px, 5vw, 54px);
}

.section h2,
.section-copy h2,
.step h2 {
  margin: 0;
  font-family: "Songti SC", "STSong", "SimSun", serif;
  font-size: clamp(2rem, 4.8vw, 4.8rem);
  line-height: 1.05;
  letter-spacing: 0;
}

.section p,
.section-copy p {
  color: var(--muted);
  font-size: 1.04rem;
}

.intro-grid,
.two-column,
.split-band {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1.1fr);
  gap: clamp(28px, 6vw, 78px);
  align-items: center;
}

.split-band {
  grid-template-columns: minmax(320px, 1.05fr) minmax(0, 0.95fr);
}

.section-copy {
  max-width: 560px;
}

.feature-media {
  margin: 0;
}

.feature-media img,
.process-preview img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.feature-media figcaption {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.92rem;
}

.video-section {
  width: 100%;
  padding-inline: clamp(20px, 6vw, 84px);
  background: #10272b;
  color: #fff;
}

.video-section .section-heading {
  width: min(1180px, 100%);
  margin-inline: auto;
}

.video-section p {
  color: rgba(255, 255, 255, 0.72);
}

.video-frame {
  width: min(1180px, 100%);
  margin: 0 auto;
}

.video-frame video {
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 8px;
  background: #000;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.42);
}

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

.portal {
  position: relative;
  min-height: 430px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  overflow: hidden;
  border-radius: 8px;
  color: #fff;
  isolation: isolate;
}

.portal img {
  position: absolute;
  inset: 0;
  z-index: -2;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 520ms ease;
}

.portal::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(0deg, rgba(7, 18, 20, 0.82), rgba(7, 18, 20, 0.06) 58%);
}

.portal:hover img {
  transform: scale(1.05);
}

.portal span,
.portal strong {
  margin-inline: 24px;
}

.portal span {
  width: max-content;
  margin-bottom: 8px;
  color: var(--gold);
  font-size: 0.84rem;
  font-weight: 900;
}

.portal strong {
  margin-bottom: 24px;
  font-size: clamp(1.2rem, 2vw, 1.6rem);
  line-height: 1.35;
}

.closing-band,
.next-strip {
  width: 100%;
  background: var(--sea-dark);
  color: #fff;
}

.closing-band__inner {
  width: min(960px, calc(100% - 40px));
  margin: 0 auto;
  text-align: center;
}

.closing-band p,
.next-strip p {
  color: rgba(255, 255, 255, 0.74);
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--red);
  font-weight: 900;
}

.closing-band .text-link,
.next-strip a {
  color: var(--gold);
}

.text-link::after,
.next-strip a::after {
  content: "→";
  transition: transform 160ms ease;
}

.text-link:hover::after,
.next-strip a:hover::after {
  transform: translateX(4px);
}

.timeline-section {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
}

.timeline li {
  min-height: 260px;
  padding: 28px;
  background: var(--paper);
}

.timeline span,
.step span,
.gallery-item span {
  color: var(--red);
  font-weight: 900;
}

.timeline p,
.step p {
  margin-bottom: 0;
}

.process-layout {
  display: grid;
  grid-template-columns: minmax(280px, 0.85fr) minmax(340px, 1.15fr);
  gap: clamp(28px, 6vw, 72px);
  align-items: center;
}

.segmented,
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 28px;
}

.segmented button,
.filter-bar button {
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 8px 14px;
  color: var(--ink);
  background: rgba(255, 250, 241, 0.58);
  cursor: pointer;
  transition:
    background 160ms ease,
    border-color 160ms ease,
    color 160ms ease;
}

.segmented button:hover,
.segmented button.is-active,
.filter-bar button:hover,
.filter-bar button.is-active {
  border-color: var(--sea);
  color: #fff;
  background: var(--sea);
}

.process-copy h3 {
  margin: 0;
  font-size: clamp(1.8rem, 3vw, 3rem);
  line-height: 1.1;
}

.process-preview {
  margin: 0;
}

.step-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  width: 100%;
  background: var(--line);
}

.step {
  min-height: 320px;
  padding: clamp(24px, 4vw, 40px);
  background: var(--paper-strong);
}

.step h2 {
  margin-top: 18px;
  font-size: clamp(1.7rem, 2.8vw, 3rem);
}

.next-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(1180px, calc(100% - 40px));
  border-radius: 8px;
  padding: 28px clamp(22px, 5vw, 44px);
}

.next-strip p {
  margin: 0;
  font-weight: 900;
}

.next-strip a {
  font-size: clamp(1.1rem, 2.3vw, 1.7rem);
  font-weight: 900;
}

.gallery-section {
  padding-bottom: 48px;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.gallery-item {
  margin: 0;
  transition:
    opacity 180ms ease,
    transform 180ms ease;
}

.gallery-item.is-hidden {
  display: none;
}

.gallery-item button {
  width: 100%;
  border: 0;
  border-radius: 8px;
  padding: 0;
  overflow: hidden;
  background: transparent;
  cursor: zoom-in;
}

.gallery-item img {
  width: 100%;
  aspect-ratio: 5 / 4;
  object-fit: cover;
  transition: transform 420ms ease;
}

.gallery-item button:hover img {
  transform: scale(1.04);
}

.gallery-item figcaption {
  display: grid;
  gap: 3px;
  padding-top: 10px;
  color: var(--ink);
  font-weight: 800;
  line-height: 1.4;
}

.gallery-item figcaption span {
  font-size: 0.82rem;
}

.lightbox {
  width: min(1040px, calc(100% - 28px));
  border: 0;
  border-radius: 8px;
  padding: 0;
  color: #fff;
  background: #081112;
  box-shadow: 0 30px 90px rgba(0, 0, 0, 0.46);
}

.lightbox::backdrop {
  background: rgba(0, 0, 0, 0.72);
}

.lightbox img {
  width: 100%;
  max-height: 78svh;
  object-fit: contain;
  background: #081112;
}

.lightbox p {
  margin: 0;
  padding: 14px 18px 18px;
}

.lightbox__close {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 40px;
  height: 40px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 999px;
  color: #fff;
  background: rgba(0, 0, 0, 0.48);
  cursor: pointer;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 28px clamp(20px, 6vw, 84px);
  color: rgba(255, 255, 255, 0.72);
  background: #081112;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: var(--gold);
  font-weight: 800;
}

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 620ms ease,
    transform 620ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 900px) {
  :root {
    --header-height: 92px;
  }

  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
    padding-block: 12px;
  }

  .site-nav {
    width: 100%;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .hero {
    min-height: 78svh;
    padding-bottom: 64px;
  }

  .intro-grid,
  .two-column,
  .split-band,
  .process-layout {
    grid-template-columns: 1fr;
  }

  .portal-grid,
  .timeline,
  .step-list,
  .gallery-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .portal {
    min-height: 360px;
  }
}

@media (max-width: 620px) {
  :root {
    --header-height: 116px;
  }

  .brand span {
    font-size: 0.96rem;
  }

  .site-nav {
    font-size: 0.88rem;
  }

  .hero {
    min-height: 76svh;
    padding-inline: 18px;
  }

  .hero h1 {
    font-size: clamp(4.2rem, 24vw, 6.6rem);
  }

  .hero-sub h1 {
    font-size: clamp(2.7rem, 13vw, 4.6rem);
  }

  .hero__lead {
    font-size: 0.98rem;
  }

  .section {
    width: min(100% - 32px, 1180px);
    padding-block: 58px;
  }

  .video-section {
    padding-inline: 16px;
  }

  .portal-grid,
  .timeline,
  .step-list,
  .gallery-grid {
    grid-template-columns: 1fr;
  }

  .portal {
    min-height: 300px;
  }

  .feature-media img,
  .process-preview img {
    aspect-ratio: 1 / 1;
  }

  .next-strip,
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .scroll-cue {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}