:root {
  --ink: #191714;
  --paper: #fff8ec;
  --paper-soft: #f5ebdc;
  --muted: #6f6356;
  --line: rgba(40, 32, 24, .14);
  --gold: #e9a936;
  --red: #b9342d;
  --green: #5e7f52;
  --teal: #2f7c7e;
  --night: #15130f;
  --night-2: #252018;
  --white: #fffdf8;
  --shadow: 0 20px 60px rgba(28, 20, 11, .16);
  --scroll: #fff4dc;
  --scroll-deep: #ead4a8;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 15% 8%, rgba(233, 169, 54, .12), transparent 28%),
    linear-gradient(180deg, var(--paper) 0%, #f8efdf 48%, var(--paper) 100%);
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 15px;
  line-height: 1.7;
  text-rendering: optimizeLegibility;
}

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

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

p {
  margin: 0 0 1rem;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.2;
  letter-spacing: 0;
}

h1 {
  font-size: clamp(1.9rem, 4.8vw, 3.85rem);
  font-weight: 900;
}

h2 {
  font-size: clamp(1.42rem, 3vw, 2.12rem);
  font-weight: 850;
}

h3 {
  font-size: 1rem;
  font-weight: 800;
}

.container {
  width: min(1080px, calc(100% - 36px));
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: -60px;
  z-index: 1000;
  padding: 10px 14px;
  color: var(--night);
  background: var(--gold);
  border-radius: 4px;
  transition: top .2s ease;
}

.skip-link:focus {
  top: 16px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(21, 19, 15, .86);
  border-bottom: 1px solid rgba(255, 248, 236, .12);
  backdrop-filter: blur(16px);
}

.nav-wrap {
  width: min(1100px, calc(100% - 28px));
  min-height: 64px;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--white);
  font-weight: 900;
  font-size: .96rem;
  white-space: nowrap;
}

.brand img {
  width: 48px;
  height: 32px;
  object-fit: cover;
  border-radius: 4px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, .28);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 4px;
}

.site-nav a {
  color: rgba(255, 253, 248, .82);
  padding: 8px 11px;
  border-radius: 4px;
  font-size: .9rem;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--white);
  background: rgba(255, 248, 236, .1);
  outline: none;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 248, 236, .18);
  border-radius: 4px;
  background: rgba(255, 248, 236, .07);
  color: var(--white);
  cursor: pointer;
  position: relative;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 5px auto;
  background: currentColor;
  transform-origin: center;
  transition: transform .2s ease, opacity .2s ease;
}

.nav-toggle.is-open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.hero {
  position: relative;
  min-height: clamp(560px, 86vh, 760px);
  display: grid;
  align-items: end;
  overflow: hidden;
  color: var(--white);
  background: var(--night);
}

.hero-media,
.hero-media img,
.hero-shade {
  position: absolute;
  inset: 0;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center center;
  transform: scale(1.045);
}

.hero-shade {
  background:
    linear-gradient(90deg, rgba(13, 12, 10, .92) 0%, rgba(20, 17, 12, .78) 40%, rgba(20, 17, 12, .26) 100%),
    linear-gradient(0deg, rgba(21, 19, 15, .96) 0%, rgba(21, 19, 15, .22) 42%, rgba(21, 19, 15, .18) 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 104px 0 58px;
  display: grid;
  grid-template-columns: minmax(0, 680px) minmax(300px, 420px);
  column-gap: clamp(34px, 6vw, 90px);
  align-items: end;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--gold);
  font-weight: 800;
  font-size: .86rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-bottom: 14px;
}

.eyebrow::before {
  content: "";
  width: 28px;
  height: 2px;
  background: currentColor;
}

.hero-copy {
  max-width: 660px;
  color: rgba(255, 253, 248, .9);
  font-size: clamp(.95rem, 1.45vw, 1.08rem);
  margin-top: 18px;
}

.hero-content > .eyebrow,
.hero-content > h1,
.hero-copy,
.hero-actions {
  grid-column: 1;
}

.hero-brief {
  grid-column: 2;
  grid-row: 1 / span 5;
  align-self: center;
  padding: 26px 26px 24px;
  color: #332417;
  background:
    linear-gradient(90deg, rgba(139, 91, 42, .14), transparent 12%, transparent 88%, rgba(139, 91, 42, .14)),
    linear-gradient(180deg, #fff7e8, var(--scroll));
  border: 1px solid rgba(139, 91, 42, .34);
  box-shadow: 0 22px 60px rgba(0, 0, 0, .28);
}

.scroll-panel::before,
.scroll-panel::after {
  content: "";
  position: absolute;
  left: 18px;
  right: 18px;
  height: 3px;
  background: linear-gradient(90deg, transparent, rgba(139, 91, 42, .44), transparent);
}

.scroll-panel::before {
  top: 10px;
}

.scroll-panel::after {
  bottom: 10px;
}

.hero-brief h2 {
  color: #23180a;
  font-size: 1.15rem;
  margin-bottom: 14px;
}

.hero-brief ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.hero-brief li {
  position: relative;
  padding: 13px 0 13px 18px;
  border-top: 1px solid rgba(139, 91, 42, .18);
}

.hero-brief li:first-child {
  border-top: 0;
  padding-top: 0;
}

.hero-brief li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.35em;
  width: 7px;
  height: 7px;
  background: var(--gold);
}

.hero-brief strong {
  color: #9b2f28;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 13px 28px;
  border-radius: 999px;
  font-weight: 850;
  font-size: 1rem;
  border: 1px solid transparent;
  transition: transform .18s ease, background-color .18s ease, border-color .18s ease, color .18s ease;
}

.btn:hover,
.btn:focus-visible {
  transform: translateY(-2px);
  outline: none;
}

.btn-primary,
.btn-download {
  color: #23180a;
  background: var(--gold);
  box-shadow: 0 14px 28px rgba(233, 169, 54, .22);
}

.btn-primary:hover,
.btn-download:hover {
  background: #f4bd52;
}

.btn-secondary {
  color: var(--white);
  border-color: rgba(255, 253, 248, .42);
  background: rgba(255, 253, 248, .08);
}

.btn-secondary:hover {
  background: rgba(255, 253, 248, .14);
}

.section {
  padding: clamp(54px, 7.5vw, 88px) 0;
}

.section-dark {
  background: var(--night);
}

.section-muted {
  background:
    linear-gradient(180deg, rgba(255, 248, 236, .7), rgba(245, 235, 220, .94)),
    var(--paper-soft);
}

.split,
.content-layout,
.download-wrap,
.footer-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, .88fr);
  gap: clamp(24px, 4vw, 52px);
  align-items: center;
}

.section-copy p {
  color: var(--muted);
  font-size: .98rem;
}

.section-copy h2,
.section-head h2 {
  margin-bottom: 18px;
}

.section-head {
  max-width: 760px;
  margin-bottom: 28px;
}

.section-head p {
  color: var(--muted);
  font-size: .98rem;
}

.media-panel {
  margin: 0;
  background: #1f1b16;
  box-shadow: var(--shadow);
  border: 1px solid rgba(28, 20, 11, .12);
}

.media-panel img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.feature-grid,
.guide-grid,
.gallery {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.feature-card,
.guide-card,
.version-box,
.faq-item {
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(255, 253, 248, .9), rgba(255, 246, 229, .82));
  box-shadow: 0 16px 40px rgba(28, 20, 11, .08);
}

.feature-card {
  padding: 20px;
  min-height: 218px;
}

.card-index {
  display: inline-flex;
  color: var(--red);
  font-weight: 900;
  margin-bottom: 28px;
}

.feature-card h3,
.guide-card h3,
.system-list h3,
.timeline h3,
.version-box h3 {
  margin-bottom: 10px;
}

.feature-card p,
.guide-card li,
.system-list p,
.timeline p,
.version-box p,
.faq-item p {
  color: var(--muted);
}

.content-layout {
  grid-template-columns: minmax(320px, .96fr) minmax(0, 1fr);
}

.system-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.system-list article {
  padding: 16px;
  border-left: 4px solid var(--green);
  background:
    linear-gradient(180deg, #fffaf1, #fff3df);
}

.section-guide {
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(255, 248, 236, .05) 1px, transparent 1px),
    linear-gradient(135deg, rgba(185, 52, 45, .24), rgba(47, 124, 126, .18)),
    var(--night-2);
  background-size: 44px 44px, auto, auto;
}

.section-guide .section-head p,
.section-guide .guide-card li {
  color: rgba(255, 253, 248, .76);
}

.section-guide .guide-card {
  background: rgba(255, 253, 248, .07);
  border-color: rgba(255, 248, 236, .14);
  box-shadow: none;
}

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

.guide-card {
  padding: 22px;
  border-radius: 6px;
}

.guide-card ol {
  margin: 14px 0 0;
  padding-left: 1.2rem;
}

.guide-card li + li {
  margin-top: 8px;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  border: 1px solid var(--line);
  background: #fffaf1;
  box-shadow: var(--shadow);
}

.timeline article {
  min-height: 198px;
  padding: 22px;
  border-right: 1px solid var(--line);
}

.timeline article:last-child {
  border-right: 0;
}

.timeline span {
  display: inline-flex;
  color: var(--teal);
  font-weight: 900;
  margin-bottom: 32px;
}

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

.gallery-item {
  margin: 0;
  overflow: hidden;
  background: var(--night);
  box-shadow: var(--shadow);
}

.gallery-item img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transition: transform .35s ease;
}

.gallery-item:hover img {
  transform: scale(1.035);
}

.clean-list {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.clean-list li {
  position: relative;
  padding-left: 22px;
  color: var(--muted);
}

.clean-list li + li {
  margin-top: 8px;
}

.clean-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 8px;
  height: 8px;
  background: var(--red);
}

.version-box {
  padding: 24px;
  background: var(--night-2);
  color: var(--white);
}

.version-box p {
  color: rgba(255, 253, 248, .76);
}

.update-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(330px, .82fr);
  gap: clamp(24px, 4vw, 52px);
  align-items: start;
}

.update-section .section-copy {
  padding: 28px;
  background:
    linear-gradient(90deg, rgba(139, 91, 42, .1), transparent 14%, transparent 86%, rgba(139, 91, 42, .1)),
    linear-gradient(180deg, #fff8ec, #fff0d8);
  border: 1px solid rgba(139, 91, 42, .18);
  box-shadow: 0 18px 46px rgba(28, 20, 11, .09);
}

.version-timeline h3 {
  margin-bottom: 18px;
}

.version-timeline ol {
  position: relative;
  margin: 0;
  padding: 0 0 0 18px;
  list-style: none;
}

.version-timeline ol::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 6px;
  bottom: 8px;
  width: 2px;
  background: rgba(233, 169, 54, .5);
}

.version-timeline li {
  position: relative;
  padding: 0 0 18px 18px;
}

.version-timeline li:last-child {
  padding-bottom: 0;
}

.version-timeline li::before {
  content: "";
  position: absolute;
  left: -18px;
  top: 6px;
  width: 10px;
  height: 10px;
  background: var(--gold);
  border: 3px solid var(--night-2);
  border-radius: 50%;
}

.version-timeline strong {
  display: block;
  color: var(--gold);
  margin-bottom: 4px;
}

.version-timeline span {
  display: block;
  color: rgba(255, 253, 248, .76);
}

.download-section {
  padding: clamp(58px, 7vw, 86px) 0;
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(21, 19, 15, .96), rgba(21, 19, 15, .74)),
    url("img/tu7.png") center / cover no-repeat;
}

.download-wrap {
  grid-template-columns: minmax(0, 1fr) auto;
  padding: 30px;
  border: 1px solid rgba(255, 248, 236, .16);
  background: rgba(21, 19, 15, .58);
  box-shadow: 0 26px 70px rgba(0, 0, 0, .25);
  backdrop-filter: blur(10px);
}

.download-wrap p {
  max-width: 760px;
  color: rgba(255, 253, 248, .78);
  margin-bottom: 0;
}

.faq-wrap {
  max-width: 920px;
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-item {
  padding: 0;
}

.faq-item summary {
  cursor: pointer;
  padding: 20px 22px;
  font-weight: 850;
  list-style: none;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  float: right;
  color: var(--red);
  font-size: 1.25rem;
  line-height: 1;
}

.faq-item[open] summary::after {
  content: "-";
}

.faq-item p {
  padding: 0 22px 20px;
}

.site-footer {
  color: rgba(255, 253, 248, .72);
  background: var(--night);
  padding: 30px 0;
}

.footer-wrap {
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
}

.site-footer strong {
  color: var(--white);
  font-size: 1.18rem;
}

.site-footer p {
  margin: 8px 0 0;
  max-width: 620px;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.site-footer a:hover,
.site-footer a:focus-visible {
  color: var(--gold);
  outline: none;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .55s ease, transform .55s ease;
}

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

::selection {
  color: #23180a;
  background: rgba(233, 169, 54, .55);
}

.brand,
.brand img,
.site-nav a,
.nav-toggle,
.media-panel,
.media-panel img,
.feature-card,
.guide-card,
.system-list article,
.timeline article,
.gallery-item,
.gallery-item img,
.version-box,
.faq-item,
.faq-item summary,
.clean-list li::before {
  transition-property: transform, color, background-color, border-color, box-shadow, filter, opacity;
  transition-duration: .22s;
  transition-timing-function: ease;
}

.brand:hover,
.brand:focus-visible {
  color: var(--gold);
  transform: translateY(-1px);
  outline: none;
}

.brand:hover img,
.brand:focus-visible img {
  transform: scale(1.04);
  box-shadow: 0 12px 30px rgba(0, 0, 0, .34);
}

.site-nav a {
  position: relative;
}

.site-nav a::after {
  content: "";
  position: absolute;
  left: 11px;
  right: 11px;
  bottom: 5px;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform .2s ease;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  transform: translateY(-1px);
}

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

.nav-toggle:hover,
.nav-toggle:focus-visible {
  background: rgba(255, 248, 236, .14);
  border-color: rgba(255, 248, 236, .34);
  transform: translateY(-1px);
  outline: none;
}

.btn-primary:hover,
.btn-primary:focus-visible,
.btn-download:hover,
.btn-download:focus-visible {
  box-shadow: 0 18px 34px rgba(233, 169, 54, .32);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  border-color: rgba(255, 253, 248, .68);
}

.media-panel,
.feature-card,
.guide-card,
.version-box,
.faq-item {
  position: relative;
  overflow: hidden;
}

.media-panel:hover {
  transform: translateY(-4px);
  border-color: rgba(185, 52, 45, .28);
  box-shadow: 0 26px 70px rgba(28, 20, 11, .2);
}

.media-panel:hover img {
  transform: scale(1.035);
  filter: saturate(1.06) contrast(1.03);
}

.feature-card::before,
.guide-card::before,
.version-box::before,
.faq-item::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: var(--gold);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform .24s ease;
}

.feature-card:hover,
.guide-card:hover,
.faq-item:hover {
  transform: translateY(-4px);
  border-color: rgba(185, 52, 45, .26);
  background: #fffaf1;
  box-shadow: 0 22px 54px rgba(28, 20, 11, .13);
}

.section-guide .guide-card:hover {
  background: rgba(255, 253, 248, .11);
  border-color: rgba(233, 169, 54, .3);
  box-shadow: 0 20px 48px rgba(0, 0, 0, .18);
}

.feature-card:hover::before,
.guide-card:hover::before,
.version-box:hover::before,
.faq-item:hover::before {
  transform: scaleY(1);
}

.system-list article:hover {
  transform: translateX(4px);
  border-left-color: var(--red);
  background: #fff6e5;
  box-shadow: 0 12px 30px rgba(28, 20, 11, .1);
}

.timeline article:hover {
  background: #fff5e1;
  transform: translateY(-3px);
}

.gallery-item:hover {
  transform: translateY(-4px);
  box-shadow: 0 26px 70px rgba(28, 20, 11, .2);
}

.gallery-item:hover img {
  transform: scale(1.045);
  filter: saturate(1.06) contrast(1.03);
}

.clean-list li:hover::before {
  transform: rotate(45deg) scale(1.15);
  background: var(--gold);
}

.version-box:hover {
  transform: translateY(-4px);
  background: #2a241b;
  box-shadow: 0 24px 60px rgba(28, 20, 11, .24);
}

.faq-item summary::after {
  transition: transform .18s ease, color .18s ease;
}

.faq-item:hover summary,
.faq-item[open] summary {
  color: var(--red);
}

.faq-item:hover summary::after {
  transform: rotate(90deg);
  color: var(--gold);
}

@media (max-width: 980px) {
  .hero-content {
    grid-template-columns: 1fr;
  }

  .hero-brief {
    grid-column: 1;
    grid-row: auto;
    align-self: auto;
    max-width: 650px;
    margin-top: 28px;
  }

  .update-layout {
    grid-template-columns: 1fr;
  }

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

  .split,
  .content-layout,
  .download-wrap,
  .footer-wrap {
    grid-template-columns: 1fr;
  }

  .timeline article {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .timeline article:nth-last-child(-n + 2) {
    border-bottom: 0;
  }
}

@media (max-width: 760px) {
  .container {
    width: min(100% - 24px, 1080px);
  }

  .nav-wrap {
    min-height: 64px;
  }

  .nav-toggle {
    display: inline-block;
  }

  .site-nav {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 64px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 10px;
    background: rgba(21, 19, 15, .98);
    border: 1px solid rgba(255, 248, 236, .12);
  }

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

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

  .hero {
    min-height: 620px;
    align-items: end;
  }

  .hero-shade {
    background:
      linear-gradient(0deg, rgba(13, 12, 10, .96) 0%, rgba(13, 12, 10, .72) 58%, rgba(13, 12, 10, .28) 100%);
  }

  .hero-content {
    padding: 88px 0 38px;
  }

  .hero-brief {
    padding: 18px;
    margin-top: 22px;
  }

  .hero-brief h2 {
    font-size: 1.02rem;
  }

  .hero-brief li {
    padding-top: 10px;
    padding-bottom: 10px;
  }

  .feature-grid,
  .guide-grid,
  .system-list,
  .gallery,
  .timeline {
    grid-template-columns: 1fr;
  }

  .timeline article:nth-last-child(-n + 2) {
    border-bottom: 1px solid var(--line);
  }

  .timeline article:last-child {
    border-bottom: 0;
  }

  .feature-card {
    min-height: auto;
  }

  .download-wrap {
    gap: 22px;
    padding: 22px;
  }

  .btn {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }

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