/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body { min-height: 100vh; }
table { border-collapse: collapse; }
input, select, textarea { font: inherit; color: inherit; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
a { color: inherit; }
img, svg { display: block; max-width: 100%; }
ul, ol { list-style: none; }

:root {
  --color-bg: #0A1A2F;
  --color-bg-deep: #050D18;
  --color-gold: #D4AF37;
  --color-gold-light: #F0D98C;
  --color-accent: #E84A1B;
  --color-text: #F5F7FA;
  --color-text-secondary: #B8BEC9;
  --color-border: #3B4A5D;
  --font-head: "Noto Sans SC", "MiSans", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", sans-serif;
  --font-data: "JetBrains Mono", "Roboto Mono", "SFMono-Regular", Consolas, monospace;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-pill: 999px;
  --transition-speed: 0.3s;
  --container-width: 1320px;
  --header-bg: rgba(10, 26, 47, 0.96);
  --footer-bg: #050D18;
}

body {
  background-color: var(--color-bg);
  background-image:
    linear-gradient(rgba(59, 74, 93, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(59, 74, 93, 0.06) 1px, transparent 1px);
  background-size: 44px 44px;
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--color-gold); color: var(--color-bg-deep); }
:focus-visible { outline: 2px solid var(--color-gold); outline-offset: 3px; border-radius: 4px; }

::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--color-bg-deep); }
::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--color-gold); }

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 { font-family: var(--font-head); line-height: 1.3; font-weight: 700; color: var(--color-text); }
.text-secondary { color: var(--color-text-secondary); }
.font-data { font-family: var(--font-data); }

/* ===== Layout Helpers ===== */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin-inline: auto;
  padding-inline: 24px;
}
.content-container {
  max-width: 720px;
  margin-inline: auto;
  padding-inline: 24px;
  font-size: 15px;
  line-height: 1.8;
}
.content-container h1 { font-size: 36px; margin-bottom: 16px; }
.content-container h2 { font-size: 24px; margin-block: 40px 16px; }
.content-container p { margin-bottom: 16px; color: var(--color-text-secondary); }

.grid-2, .grid-3 {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}
@media (min-width: 768px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
}

.main-column { width: 100%; }
.side-column { width: 100%; }
@media (min-width: 992px) {
  .main-column { width: 70%; padding-right: 40px; }
  .side-column { width: 30%; }
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 16px 0;
  font-size: 13px;
  list-style: none;
}
.breadcrumb a { color: var(--color-gold); text-decoration: none; transition: color var(--transition-speed) ease; }
.breadcrumb a:hover { color: var(--color-gold-light); text-decoration: underline; }
.breadcrumb li + li::before { content: '/'; font-family: var(--font-data); color: var(--color-border); margin-right: 8px; }
.breadcrumb [aria-current="page"] { color: var(--color-text-secondary); }

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 24px;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.4;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color var(--transition-speed) ease,
              box-shadow var(--transition-speed) ease,
              transform var(--transition-speed) ease,
              color var(--transition-speed) ease;
}
.btn:active { transform: translateY(0) scale(0.98); }
.btn-gold {
  background: linear-gradient(135deg, var(--color-gold), var(--color-gold-light));
  color: var(--color-bg-deep);
}
.btn-gold:hover {
  box-shadow: 0 4px 24px rgba(212, 175, 55, 0.35);
  transform: translateY(-1px);
}
.btn-warm {
  background: var(--color-accent);
  color: var(--color-text);
}
.btn-warm:hover {
  background: #c9421a;
  box-shadow: 0 4px 16px rgba(232, 74, 27, 0.28);
  transform: translateY(-1px);
}
.btn-sm { padding: 7px 16px; font-size: 13px; }

/* ===== Skip Link & Scroll Progress ===== */
.skip-link {
  position: fixed;
  top: -100px;
  left: 24px;
  z-index: 9999;
  background: var(--color-gold);
  color: var(--color-bg-deep);
  padding: 10px 24px;
  border-radius: var(--radius-pill);
  font-weight: 600;
  font-size: 14px;
  text-decoration: none;
  box-shadow: 0 4px 20px rgba(212, 175, 55, 0.35);
  transition: top 0.3s ease;
}
.skip-link:focus { top: 16px; }

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0;
  background: linear-gradient(90deg, var(--color-gold), var(--color-gold-light), var(--color-gold));
  z-index: 9999;
  pointer-events: none;
  transition: width 0.08s linear;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 900;
  background-color: var(--header-bg);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.site-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--color-gold) 0%, rgba(212, 175, 55, 0.2) 20%, transparent 40%, transparent 100%);
  z-index: 1;
  pointer-events: none;
}

.frame-corner {
  position: absolute;
  width: 28px;
  height: 28px;
  border: 2px solid var(--color-gold);
  opacity: 0.5;
  pointer-events: none;
  z-index: 2;
}
.frame-corner-tl { top: 3px; left: 4px; border-right: none; border-bottom: none; border-radius: 6px 0 0 0; }
.frame-corner-tr { top: 3px; right: 4px; border-left: none; border-bottom: none; border-radius: 0 6px 0 0; }

.header-main {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px 20px;
  padding-block: 16px;
  position: relative;
  z-index: 1;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}
.brand-mark-diamond {
  width: 14px;
  height: 14px;
  background: linear-gradient(135deg, var(--color-gold), var(--color-gold-light));
  transform: rotate(45deg);
  border-radius: 2px;
  flex-shrink: 0;
  box-shadow: 0 0 12px rgba(212, 175, 55, 0.3);
}
.brand-text { display: flex; flex-direction: column; gap: 2px; }
.brand-name {
  font-family: var(--font-head);
  font-size: 23px;
  font-weight: 800;
  color: var(--color-text);
  letter-spacing: 0.04em;
  line-height: 1.2;
}
.brand-sub {
  font-family: var(--font-data);
  font-size: 11px;
  color: var(--color-text-secondary);
  letter-spacing: 0.08em;
}

.quick-query {
  display: flex;
  align-items: center;
  gap: 8px;
}
.query-label {
  font-family: var(--font-data);
  font-size: 11px;
  color: var(--color-text-secondary);
  letter-spacing: 0.14em;
  white-space: nowrap;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 3px 8px;
}
.query-input {
  width: 190px;
  padding: 8px 16px;
  background: rgba(245, 247, 250, 0.07);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  color: var(--color-text);
  font-family: var(--font-data);
  font-size: 14px;
  transition: border-color var(--transition-speed) ease, background-color var(--transition-speed) ease;
}
.query-input::placeholder { color: var(--color-text-secondary); opacity: 0.7; }
.query-input:focus {
  outline: none;
  border-color: var(--color-gold);
  background: rgba(245, 247, 250, 0.12);
}

.nav-toggle {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 44px;
  height: 44px;
  border: 1px solid var(--color-border);
  border-radius: 14px;
  background: rgba(245, 247, 250, 0.04);
  transition: border-color var(--transition-speed) ease, background-color var(--transition-speed) ease;
  flex-shrink: 0;
}
.nav-toggle:hover { border-color: var(--color-gold); background: rgba(212, 175, 55, 0.06); }
.nav-toggle-line {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease, background-color 0.3s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) { transform: translateY(6px) rotate(45deg); background: var(--color-gold); }
.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) { transform: translateY(-6px) rotate(-45deg); background: var(--color-gold); }

.header-nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-top: 1px solid rgba(59, 74, 93, 0.55);
  position: relative;
  z-index: 1;
}

.site-nav { display: none; }
.site-nav[data-open] {
  display: block;
  animation: navSlideIn 0.3s ease forwards;
}

@keyframes navSlideIn {
  from { opacity: 0; transform: translateY(-12px); }
  to { opacity: 1; transform: none; }
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-block: 8px;
}
.nav-item a {
  position: relative;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  color: var(--color-text-secondary);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  border-radius: 12px;
  transition: color var(--transition-speed) ease, background-color var(--transition-speed) ease;
}
.nav-item a::before {
  content: attr(data-index);
  font-family: var(--font-data);
  font-size: 10px;
  color: var(--color-gold);
  opacity: 0.55;
  letter-spacing: 0.06em;
}
.nav-item a::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 4px;
  width: 0;
  height: 2px;
  background: var(--color-gold);
  transform: translateX(-50%);
  border-radius: 2px;
  transition: width 0.3s ease;
}
.nav-item a:hover { color: var(--color-gold-light); background: rgba(212, 175, 55, 0.08); }
.nav-item a:hover::after { width: 20px; }
.nav-item a[aria-current="page"] {
  color: var(--color-gold-light);
  background: rgba(212, 175, 55, 0.1);
  font-weight: 600;
}
.nav-item a[aria-current="page"]::after { width: 20px; opacity: 1; }

.nav-coordinate {
  font-family: var(--font-data);
  font-size: 11px;
  color: var(--color-text-secondary);
  letter-spacing: 0.08em;
  white-space: nowrap;
  border-left: 1px solid var(--color-border);
  padding-left: 16px;
}

/* ===== Footer ===== */
.site-footer {
  background-color: var(--footer-bg);
  position: relative;
  z-index: 1;
  margin-top: 0;
}
.footer-topline {
  height: 3px;
  background: linear-gradient(90deg, var(--color-bg-deep) 0%, var(--color-gold) 25%, var(--color-gold-light) 50%, var(--color-gold) 75%, var(--color-bg-deep) 100%);
  opacity: 0.75;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  padding-block: 48px 32px;
}

.footer-brand { display: flex; flex-direction: column; gap: 16px; }
.footer-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}
.footer-logo-diamond {
  width: 12px;
  height: 12px;
  border: 2px solid var(--color-gold);
  transform: rotate(45deg);
  border-radius: 2px;
  flex-shrink: 0;
}
.footer-logo-text { display: flex; flex-direction: column; gap: 2px; }
.footer-logo-name {
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: 0.05em;
}
.footer-logo-sub {
  font-family: var(--font-data);
  font-size: 11px;
  color: var(--color-text-secondary);
  letter-spacing: 0.06em;
}
.footer-about {
  font-size: 13px;
  line-height: 1.7;
  color: var(--color-text-secondary);
  max-width: 340px;
}

.footer-heading {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-gold);
  letter-spacing: 0.08em;
  margin-bottom: 14px;
  padding-bottom: 8px;
  position: relative;
}
.footer-heading::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 24px;
  height: 2px;
  background: var(--color-gold);
  border-radius: 2px;
}

.footer-nav {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.footer-nav a {
  color: var(--color-text-secondary);
  font-size: 14px;
  text-decoration: none;
  transition: color var(--transition-speed) ease, padding-left var(--transition-speed) ease;
  padding-left: 0;
}
.footer-nav a:hover { color: var(--color-gold-light); padding-left: 4px; }

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.footer-contact li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text-secondary);
  word-break: break-all;
}
.contact-label {
  flex-shrink: 0;
  font-family: var(--font-data);
  font-size: 11px;
  color: var(--color-gold);
  background: rgba(212, 175, 55, 0.08);
  border: 1px solid rgba(212, 175, 55, 0.2);
  border-radius: 5px;
  padding: 1px 7px;
  margin-top: 2px;
  letter-spacing: 0.08em;
  white-space: nowrap;
}
.footer-contact-note {
  font-size: 12px;
  line-height: 1.7;
  color: var(--color-text-secondary);
  opacity: 0.8;
  margin-top: 4px;
  border-top: 1px solid rgba(59, 74, 93, 0.4);
  padding-top: 10px;
  word-break: normal;
}

.footer-meta {
  border-top: 1px solid rgba(59, 74, 93, 0.55);
  padding-block: 20px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 24px;
}
.footer-legal { display: flex; align-items: center; gap: 10px; }
.footer-legal a {
  color: var(--color-text-secondary);
  font-size: 13px;
  text-decoration: none;
  transition: color var(--transition-speed) ease;
}
.footer-legal a:hover { color: var(--color-gold); }
.legal-divider { color: var(--color-border); font-size: 12px; }
.footer-icp {
  margin-left: auto;
  color: var(--color-text-secondary);
  font-size: 13px;
  font-family: var(--font-data);
  letter-spacing: 0.04em;
}
.footer-trust {
  flex-basis: 100%;
  font-size: 12px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  opacity: 0.75;
  max-width: 860px;
}

/* ===== Image Placeholder ===== */
.img-placeholder {
  position: relative;
  display: block;
  width: 100%;
  min-height: 160px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: linear-gradient(135deg, #0d2035 0%, var(--color-bg) 60%, #152a42 100%);
  isolation: isolate;
}
.img-placeholder::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(59, 74, 93, 0.2) 1px, transparent 1px),
    linear-gradient(90deg, rgba(59, 74, 93, 0.2) 1px, transparent 1px);
  background-size: 28px 28px;
}
.img-placeholder::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1;
  background: radial-gradient(circle at 72% 28%, rgba(212, 175, 55, 0.1) 0%, transparent 42%);
}
.img-placeholder .img-caption {
  position: absolute;
  bottom: 12px;
  left: 12px;
  z-index: 1;
  background: rgba(5, 13, 24, 0.75);
  color: var(--color-text);
  font-size: 12px;
  font-family: var(--font-data);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  letter-spacing: 0.04em;
}
.img-caption {
  background: rgba(5, 13, 24, 0.75);
  color: var(--color-text);
  font-size: 12px;
  font-family: var(--font-data);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  letter-spacing: 0.04em;
  border: 1px solid rgba(212, 175, 55, 0.15);
}
.img-ratio-16x9 { aspect-ratio: 16 / 9; }
.img-ratio-4x3 { aspect-ratio: 4 / 3; }
.img-ratio-1x1 { aspect-ratio: 1 / 1; }

/* ===== Scroll Reveal ===== */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
  will-change: opacity, transform;
}
[data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ===== Responsive ===== */
@media (max-width: 767px) {
  .quick-query {
    order: 3;
    flex-basis: 100%;
  }
  .query-label { display: none; }
  .query-input { flex: 1; width: auto; min-width: 0; }
  .brand-name { font-size: 20px; }
  .brand-sub { display: none; }
  .nav-coordinate { display: none; }
  .footer-grid { padding-block: 36px 24px; gap: 32px; }
  .footer-icp { margin-left: 0; }
  .footer-meta { flex-direction: column; align-items: flex-start; gap: 10px; }
}

@media (max-width: 991px) {
  .site-nav { display: none; }
  .site-nav[data-open] { display: block; }
  .header-nav-wrap { align-items: flex-start; flex-direction: column; }
}

@media (min-width: 992px) {
  .nav-toggle { display: none; }
  .site-nav { display: block; }
  .header-nav-wrap {
    align-items: center;
    flex-direction: row;
    border-bottom: 1px solid rgba(59, 74, 93, 0.55);
  }
  .nav-list {
    flex-direction: row;
    gap: 4px;
    padding-block: 4px;
  }
  .nav-item a { padding: 10px 14px; border-radius: var(--radius-pill); }
  .footer-grid { grid-template-columns: 1.6fr 1fr 1.4fr; gap: 48px; padding-block: 56px 40px; }
}

/* ===== Reduced Motion ===== */
@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;
  }
  .scroll-progress { display: none; }
  [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .site-nav[data-open] { animation: none; }
  .btn:hover { transform: none; }
}