:root {
  --header-h: 76px;
  --gold: #D4A24E;
  --night: #0A1428;
  --purple: #8B30F5;
  --orange: #FF6B00;
  --moon: #F5F6F8;
  --fog: #B8C0CC;
  --black: #05070D;
  --cyan: #00D4FF;
  --font-heading: "Noto Sans SC", "Montserrat", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --shadow-card: 0 20px 50px rgba(0, 0, 0, 0.28);
}

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body, h1, h2, h3, h4, p {
  margin: 0;
}

ul, ol {
  margin: 0;
}

button, input, textarea, select {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

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

body {
  min-height: 100vh;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 85% 15%, rgba(139, 48, 245, 0.20), transparent 32rem),
    radial-gradient(circle at 8% 90%, rgba(0, 212, 255, 0.10), transparent 28rem),
    linear-gradient(180deg, #071020 0%, #0A1428 48%, #05070D 100%);
  background-attachment: fixed;
  color: var(--moon);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: 900;
  color: var(--moon);
  line-height: 1.2;
}

h1 {
  font-size: clamp(1.8rem, 4vw, 3rem);
}

h2 {
  font-size: clamp(1.4rem, 3vw, 2.2rem);
}

h3 {
  font-size: clamp(1.2rem, 2vw, 1.6rem);
}

a {
  color: inherit;
}

::selection {
  background: var(--gold);
  color: var(--black);
}

:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 2px;
}

.container {
  width: min(1180px, 100% - 2.5rem);
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  top: -100%;
  left: 1rem;
  z-index: 2000;
  background: var(--gold);
  color: var(--black);
  padding: 0.6rem 1rem;
  font-weight: 900;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 1rem;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: linear-gradient(180deg, rgba(5, 7, 13, 0.82), rgba(5, 7, 13, 0.36));
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(212, 162, 78, 0.16);
  transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.site-header.is-scrolled {
  background: rgba(5, 7, 13, 0.92);
  border-bottom-color: rgba(0, 212, 255, 0.22);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
}

.site-header__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: var(--header-h);
  transition: height 0.3s ease;
}

.site-header.is-scrolled .site-header__bar {
  height: 64px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  color: var(--moon);
  text-decoration: none;
}

.brand__mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, #E4B962, #D4A24E 55%, #8B30F5 140%);
  color: var(--black);
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 900;
  letter-spacing: 0.02em;
  clip-path: polygon(0 0, 100% 0, 100% 68%, 68% 100%, 0 100%);
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.05;
}

.brand__zh {
  font-weight: 900;
  letter-spacing: 0.08em;
  font-size: 1.12rem;
}

.brand__en {
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: 0.22em;
  color: var(--cyan);
  text-transform: uppercase;
  margin-top: 0.18rem;
}

.brand--footer .brand__mark {
  background: linear-gradient(135deg, var(--purple), var(--gold));
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.site-nav {
  flex: 1;
  display: flex;
  justify-content: center;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(0.5rem, 2vw, 1.4rem);
  list-style: none;
  justify-content: center;
}

.site-nav__link {
  display: block;
  padding: 0.7rem 0.1rem;
  color: var(--moon);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.9rem;
  letter-spacing: 0.04em;
  position: relative;
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0.35rem;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--orange));
  transition: width 0.25s ease;
}

.site-nav__link:hover::after,
.site-nav__link:focus-visible::after,
.site-nav__link[aria-current="page"]::after {
  width: 100%;
}

.site-nav__link[aria-current="page"] {
  color: var(--gold);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 0.95rem;
  background: var(--orange);
  color: var(--black);
  text-decoration: none;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  transition: background 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.header-cta::after {
  content: "";
  width: 0.65rem;
  height: 0.65rem;
  border-top: 2px solid currentColor;
  border-right: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform 0.2s ease;
}

.header-cta:hover {
  background: #FF7F1A;
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(255, 107, 0, 0.3);
}

.header-cta:hover::after {
  transform: translateX(3px) rotate(45deg);
}

.header-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  height: 2px;
  width: 0;
  background: linear-gradient(90deg, var(--gold), var(--orange));
  box-shadow: 0 0 12px rgba(255, 107, 0, 0.6);
}

.nav-toggle {
  display: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 1.25rem;
  background: transparent;
  color: var(--moon);
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 0.9rem;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease, color 0.2s ease;
}

.btn--primary {
  background: var(--orange);
  color: var(--black);
  box-shadow: 0 8px 20px rgba(255, 107, 0, 0.22);
}

.btn--primary:hover {
  background: #FF7E14;
  transform: translateY(-2px);
  box-shadow: 0 14px 32px rgba(255, 107, 0, 0.28);
}

.btn--ghost {
  box-shadow: inset 0 0 0 1px rgba(184, 192, 204, 0.35);
}

.btn--ghost:hover {
  box-shadow: inset 0 0 0 2px var(--gold);
  color: var(--gold);
  transform: translateY(-2px);
}

.panel {
  position: relative;
  background: linear-gradient(135deg, rgba(212, 162, 78, 0.10), rgba(139, 48, 245, 0.06));
  border: 1px solid rgba(245, 246, 248, 0.10);
  box-shadow: var(--shadow-card);
  padding: 1.5rem;
}

.panel--cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.panel--glow {
  overflow: hidden;
}

.panel--glow::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 40%, rgba(0, 212, 255, 0.14), transparent 68%);
  pointer-events: none;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.65rem;
  background: rgba(184, 192, 204, 0.08);
  color: var(--moon);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  border-left: 2px solid var(--fog);
}

.tag--gold {
  background: rgba(212, 162, 78, 0.12);
  color: var(--gold);
  border-left-color: var(--gold);
}

.tag--purple {
  background: rgba(139, 48, 245, 0.14);
  color: var(--cyan);
  border-left-color: var(--purple);
}

.tag--orange {
  background: rgba(255, 107, 0, 0.12);
  color: var(--orange);
  border-left-color: var(--orange);
}

.grid {
  display: grid;
  gap: 1.5rem;
}

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

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

.section {
  padding: 4.5rem 0;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.4rem, 3vw, 2.2rem);
  font-weight: 900;
  color: var(--moon);
  margin: 0 0 1.1rem;
  line-height: 1.15;
}

.section-title::after {
  content: "";
  display: block;
  width: 3.2rem;
  height: 3px;
  margin-top: 0.7rem;
  background: linear-gradient(90deg, var(--gold), var(--orange));
}

.kicker {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  margin-bottom: 0.7rem;
  color: var(--cyan);
  font-weight: 900;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-size: 0.78rem;
}

.kicker::before {
  content: "";
  width: 1.8rem;
  height: 2px;
  background: var(--gold);
}

.page-heading {
  padding: calc(var(--header-h) + 3.5rem) 0 2.5rem;
  position: relative;
}

.page-heading::after {
  content: "";
  display: block;
  width: 4.5rem;
  height: 3px;
  background: linear-gradient(90deg, var(--gold), var(--purple));
  margin-top: 1.5rem;
}

.page-heading__title {
  font-size: clamp(2rem, 5vw, 3.4rem);
  font-weight: 900;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--moon);
}

.page-heading__lead {
  max-width: 68ch;
  color: var(--fog);
  margin-top: 1rem;
  font-size: 1.05rem;
  line-height: 1.8;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.3rem 0.1rem;
  margin: 0 0 2.2rem;
  font-size: 0.85rem;
}

.breadcrumb__link {
  color: var(--fog);
  text-decoration: none;
  font-weight: 700;
  transition: color 0.2s ease;
}

.breadcrumb__link:hover {
  color: var(--gold);
}

.breadcrumb__item {
  color: var(--gold);
  font-weight: 700;
}

.breadcrumb__item::before {
  content: "/";
  margin: 0 0.55rem;
  color: var(--fog);
}

.prose {
  max-width: 72ch;
  color: var(--fog);
  line-height: 1.85;
}

.prose p {
  margin: 0 0 1.4em;
}

.prose h2,
.prose h3 {
  color: var(--moon);
  font-family: var(--font-heading);
  margin: 2.2em 0 0.9em;
  line-height: 1.2;
}

.prose h2 {
  font-size: clamp(1.3rem, 2.2vw, 1.7rem);
}

.prose h3 {
  font-size: 1.2rem;
}

.prose a {
  color: var(--cyan);
  text-decoration-color: var(--gold);
  text-underline-offset: 0.25em;
}

.prose ul,
.prose ol {
  padding-left: 1.1rem;
  margin-bottom: 1.4em;
}

.prose li {
  margin: 0.5em 0;
}

.prose blockquote {
  border-left: 3px solid var(--gold);
  padding-left: 1rem;
  color: var(--moon);
  margin: 1.5em 0;
}

.media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, rgba(212, 162, 78, 0.10), rgba(139, 48, 245, 0.08));
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.media--square {
  aspect-ratio: 1 / 1;
}

.media--wide {
  aspect-ratio: 21 / 9;
}

.media__img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.media:hover .media__img {
  transform: scale(1.02);
}

.toc {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 0 0 2.5rem;
  padding: 0.9rem 1rem;
  background: rgba(245, 246, 248, 0.04);
  border-left: 3px solid var(--gold);
}

.toc__link {
  color: var(--fog);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.85rem;
  padding: 0.4rem 0.8rem;
  border: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.toc__link:hover {
  color: var(--gold);
  border-color: rgba(212, 162, 78, 0.35);
}

.toc__link.is-active {
  color: var(--orange);
  border-color: rgba(255, 107, 0, 0.45);
  background: rgba(255, 107, 0, 0.08);
}

.site-footer {
  position: relative;
  background: var(--black);
  border-top: 1px solid rgba(212, 162, 78, 0.22);
  color: var(--fog);
}

.site-footer::before {
  content: "";
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--gold), var(--orange), var(--purple));
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1.3fr;
  gap: 2.5rem;
  padding: 4rem 0 3rem;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1rem;
}

.footer-trust {
  max-width: 26rem;
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--fog);
  border-left: 2px solid rgba(212, 162, 78, 0.45);
  padding-left: 1rem;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.footer-heading {
  margin: 0;
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
}

.footer-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.footer-link {
  color: var(--fog);
  text-decoration: none;
  transition: color 0.2s ease, padding-left 0.2s ease, text-decoration-color 0.2s ease;
}

.footer-link:hover {
  color: var(--orange);
  padding-left: 0.3rem;
  text-decoration: underline;
  text-decoration-color: var(--orange);
  text-underline-offset: 0.2em;
}

.footer-contact {
  gap: 0.6rem;
}

.footer-contact__item {
  display: flex;
  align-items: flex-start;
  gap: 0.7rem;
}

.footer-contact__label {
  flex: 0 0 auto;
  min-width: 2.4rem;
  padding: 0.15rem 0.4rem;
  background: rgba(212, 162, 78, 0.10);
  color: var(--gold);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  border-left: 2px solid var(--gold);
}

.footer-contact__text {
  color: var(--fog);
  font-size: 0.88rem;
  line-height: 1.6;
  overflow-wrap: anywhere;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem 1.5rem;
  border-top: 1px solid rgba(245, 246, 248, 0.08);
  padding: 1.6rem 0 2.6rem;
}

.footer-meta,
.footer-note {
  margin: 0;
  font-size: 0.8rem;
  color: var(--fog);
}

.footer-note {
  color: rgba(184, 192, 204, 0.65);
}

.return-top {
  position: fixed;
  right: 1.2rem;
  bottom: 1.2rem;
  z-index: 950;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 0.95rem;
  background: var(--gold);
  color: var(--black);
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 0.82rem;
  border: 0;
  border-left: 3px solid var(--orange);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  opacity: 0;
  transform: translateY(0.8rem);
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.return-top.is-visible {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

.return-top:hover {
  background: #E4B962;
}

@media (max-width: 899px) {
  :root {
    --header-h: 66px;
  }

  .site-header__bar {
    height: var(--header-h);
  }

  .site-header.is-scrolled .site-header__bar {
    height: 60px;
  }

  .site-nav {
    display: block;
    flex: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    padding: 0.6rem 1.25rem 1.4rem;
    background: rgba(5, 7, 13, 0.98);
    border-bottom: 2px solid var(--gold);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }

  .site-nav[data-open] {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav__link {
    border-bottom: 1px solid rgba(212, 162, 78, 0.12);
    padding: 0.95rem 0.3rem;
    font-size: 1rem;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    padding: 0.5rem 0.7rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--moon);
    font-weight: 700;
  }

  .nav-toggle__box {
    position: relative;
    width: 22px;
    height: 14px;
  }

  .nav-toggle__bar {
    position: absolute;
    left: 0;
    width: 22px;
    height: 2px;
    background: var(--moon);
    transition: transform 0.25s ease, opacity 0.25s ease, top 0.25s ease;
  }

  .nav-toggle__bar:nth-child(1) {
    top: 0;
  }

  .nav-toggle__bar:nth-child(2) {
    top: 6px;
  }

  .nav-toggle__bar:nth-child(3) {
    top: 12px;
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) {
    top: 6px;
    transform: rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3) {
    top: 6px;
    transform: rotate(-45deg);
  }

  .nav-toggle__label {
    font-size: 0.75rem;
  }

  .header-cta {
    padding: 0.45rem 0.65rem;
    font-size: 0.72rem;
  }

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

  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 780px) {
  .grid--two,
  .grid--three {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 781px) and (max-width: 1080px) {
  .grid--three {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 599px) {
  .container {
    width: min(1180px, 100% - 1.5rem);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 3rem 0 2rem;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    padding: 1.4rem 0 2rem;
  }
}

@media (max-width: 480px) {
  .brand__en {
    display: none;
  }

  .brand__zh {
    font-size: 1rem;
  }

  .brand__mark {
    width: 34px;
    height: 34px;
  }

  .header-cta {
    font-size: 0.68rem;
    padding: 0.4rem 0.55rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}