*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
ul, ol { list-style: none; }
a { text-decoration: none; color: inherit; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }
img { max-width: 100%; display: block; }
[hidden] { display: none !important; }

:root {
  --primary: #FFB200;
  --primary-deep: #E59C00;
  --secondary: #0F2A43;
  --black: #0A0A0A;
  --white: #FFFFFF;
  --gray-light: #F5F5F5;
  --gray-mid: #CCCCCC;
  --gray-deep: #333333;
  --cyan: #00C9C8;
  --gradient: linear-gradient(135deg, #FFB200 0%, #0F2A43 100%);
  --font-sans: "Noto Sans SC", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "Roboto Mono", "SF Mono", "Cascadia Mono", Consolas, monospace;
  --header-height: 68px;
  --container: 1240px;
  --gutter: 24px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--black);
  background: var(--white);
  -webkit-font-smoothing: antialiased;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 2001;
  padding: 12px 20px;
  background: var(--black);
  color: var(--white);
  font-weight: 700;
  font-size: 14px;
  transform: translateY(-200%);
  transition: transform 0.25s var(--ease);
}
.skip-link:focus-visible { transform: translateY(0); }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--white);
  border-bottom: 1px solid var(--gray-mid);
}
.site-header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--primary);
  z-index: 1;
}

.header-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--primary);
  transform: scaleX(0);
  transform-origin: left center;
  z-index: 2000;
  pointer-events: none;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  gap: 20px;
  position: relative;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}
.brand-symbol {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: var(--black);
  font-size: 20px;
  font-weight: 900;
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
}
.brand-copy { display: flex; flex-direction: column; line-height: 1.2; gap: 2px; }
.brand-name { font-size: 18px; font-weight: 900; letter-spacing: 0.02em; }
.brand-tagline {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--gray-deep);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 24px;
}
.nav-list { display: flex; align-items: center; gap: 4px; }
.nav-item { position: relative; }
.nav-link {
  position: relative;
  display: block;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 600;
  color: var(--black);
  white-space: nowrap;
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 4px;
  height: 2px;
  background: var(--primary);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.3s var(--ease);
}
.nav-link:hover::after,
.nav-link[aria-current="page"]::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { font-weight: 700; }

.nav-version { position: relative; margin-left: 8px; }
.version-trigger {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 16px;
  background: var(--black);
  color: var(--white);
  font-size: 13px;
  font-weight: 600;
  line-height: 1;
  transition: background 0.2s;
}
.version-trigger:hover { background: var(--secondary); }
.version-caret { width: 10px; height: 8px; flex-shrink: 0; }

.version-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 140px;
  padding: 6px;
  background: var(--white);
  border: 1px solid var(--gray-mid);
  box-shadow: 0 16px 32px rgba(10, 10, 10, 0.08);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: opacity 0.2s var(--ease), visibility 0.2s var(--ease), transform 0.2s var(--ease);
  z-index: 30;
}
.nav-version.is-open .version-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.version-option {
  display: block;
  width: 100%;
  padding: 9px 12px;
  text-align: left;
  font-size: 13px;
  font-weight: 500;
  color: var(--gray-deep);
  background: transparent;
  transition: background 0.2s, color 0.2s;
}
.version-option:hover { background: var(--gray-light); color: var(--black); }
.version-option.is-current { color: var(--black); font-weight: 700; }
.version-option.is-current::before {
  content: "● ";
  color: var(--primary);
  font-size: 10px;
  vertical-align: 2px;
}

.nav-toggle {
  display: none;
  position: relative;
  width: 44px;
  height: 44px;
  border: 1px solid var(--gray-mid);
  background: var(--white);
  flex-shrink: 0;
}
.nav-toggle-line {
  position: absolute;
  left: 10px;
  right: 10px;
  height: 2px;
  background: var(--black);
  transition: top 0.3s var(--ease), transform 0.3s var(--ease), opacity 0.3s;
}
.nav-toggle-line--1 { top: 13px; }
.nav-toggle-line--2 { top: 21px; }
.nav-toggle-line--3 { top: 29px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-line--1 { top: 21px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-line--2 { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-line--3 { top: 21px; transform: rotate(-45deg); }

.site-footer {
  position: relative;
  background-color: var(--secondary);
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 32px 32px;
  color: rgba(255, 255, 255, 0.92);
  font-size: 14px;
  padding-top: 72px;
}
.site-footer::before {
  content: "";
  display: block;
  height: 4px;
  background: var(--primary);
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 56px;
}

.footer-brand-name {
  font-size: 24px;
  font-weight: 900;
  letter-spacing: 0.03em;
  color: var(--white);
  margin-bottom: 14px;
}
.footer-statement {
  font-size: 14px;
  line-height: 1.85;
  color: rgba(255, 255, 255, 0.72);
  max-width: 360px;
}

.footer-title {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 18px;
}

.footer-list li { margin-bottom: 10px; line-height: 1.6; }
.footer-list a {
  color: rgba(255, 255, 255, 0.82);
  transition: color 0.2s;
}
.footer-list a:hover { color: var(--primary); }
.footer-address { color: rgba(255, 255, 255, 0.58); line-height: 1.7; }

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  padding: 20px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: rgba(255, 255, 255, 0.55);
}
.footer-bottom-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 20px;
}
.footer-copy,
.footer-icp { margin: 0; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border: 2px solid var(--black);
  background: transparent;
  color: var(--black);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  transition: background 0.25s var(--ease), color 0.25s var(--ease), border-color 0.25s var(--ease);
}
.btn:hover { background: var(--black); color: var(--white); }
.btn--primary {
  background: var(--primary);
  border-color: var(--primary);
  color: var(--black);
}
.btn--primary:hover { background: var(--secondary); border-color: var(--secondary); color: var(--white); }
.btn--ghost { border-color: var(--gray-mid); }
.btn--ghost:hover { border-color: var(--black); background: transparent; color: var(--black); }

.section { padding: 72px 0; }
.section--light { background: var(--gray-light); }
.section--dark { background: var(--black); color: var(--white); }

.section-heading {
  font-size: 34px;
  font-weight: 900;
  line-height: 1.25;
  margin-bottom: 12px;
}
.section-kicker {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--secondary);
  margin-bottom: 10px;
}
.section-kicker::before {
  content: "";
  display: inline-block;
  width: 18px;
  height: 2px;
  background: var(--primary);
  margin-right: 8px;
  vertical-align: 4px;
}
.chapter-label {
  display: inline-block;
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--gray-deep);
  border-left: 2px solid var(--primary);
  padding-left: 8px;
}

.page-header {
  padding: 64px 0 40px;
  border-bottom: 1px solid var(--gray-mid);
  margin-bottom: 48px;
}
.page-title {
  font-size: 40px;
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: 0.01em;
  margin-bottom: 12px;
}
.lead {
  font-size: 18px;
  line-height: 1.75;
  color: var(--gray-deep);
  max-width: 720px;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--gray-deep);
  margin-bottom: 28px;
}
.breadcrumbs a { color: var(--gray-deep); transition: color 0.2s; }
.breadcrumbs a:hover { color: var(--primary); }
.breadcrumbs-current { color: var(--black); font-weight: 700; }
.breadcrumbs-separator { color: var(--gray-mid); }

.grid { display: grid; gap: 24px; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.card {
  position: relative;
  background: var(--gray-light);
  padding: 28px;
  border-top: 3px solid var(--primary);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}
.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 30px;
  height: 30px;
  background: var(--primary);
  clip-path: polygon(0 0, 100% 0, 0 100%);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 36px rgba(10, 10, 10, 0.08);
}
.card-title { font-size: 18px; font-weight: 800; margin-bottom: 10px; }
.card-content { font-size: 14px; line-height: 1.75; color: var(--gray-deep); }

.stat {
  padding: 24px 0;
  border-bottom: 1px solid var(--gray-mid);
}
.stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--secondary);
}
.stat-label {
  display: block;
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--gray-deep);
  margin-top: 6px;
}

.table-scroll { overflow-x: auto; }
.data-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.data-table th {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-align: left;
  padding: 12px 16px;
  background: var(--gray-light);
  border-bottom: 2px solid var(--black);
}
.data-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--gray-mid);
}
.data-table tbody tr:hover td { background: var(--gray-light); }

[data-reveal] { transition: opacity 0.5s var(--ease), transform 0.5s var(--ease); }
.js [data-reveal="hidden"] { opacity: 0; transform: translateY(18px); }
.js [data-reveal="shown"] { opacity: 1; transform: translateY(0); }

@media (max-width: 920px) {
  .nav-toggle { display: block; }
  .site-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--white);
    flex-direction: column;
    align-items: stretch;
    gap: 28px;
    padding: 28px var(--gutter) 48px;
    overflow-y: auto;
    transform: translateX(100%);
    transition: transform 0.4s var(--ease);
    z-index: 999;
  }
  .site-nav[data-open] { transform: translateX(0); }
  .nav-list { flex-direction: column; align-items: stretch; }
  .nav-link {
    padding: 14px 4px;
    font-size: 18px;
    border-bottom: 1px solid var(--gray-light);
  }
  .nav-link::after { display: none; }
  .nav-version { margin: 0; }
  .version-trigger {
    width: 100%;
    justify-content: space-between;
    padding: 14px 16px;
    background: var(--gray-light);
    color: var(--black);
  }
  .version-trigger:hover { background: var(--gray-mid); color: var(--black); }
  .version-menu {
    position: static;
    min-width: 0;
    width: 100%;
    box-shadow: none;
    border: none;
    border-left: 2px solid var(--primary);
    margin-top: 6px;
    padding: 4px 8px;
    opacity: 1;
    visibility: visible;
    transform: none;
    display: none;
  }
  .nav-version.is-open .version-menu { display: block; }
}

@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 40px; }
  .footer-brand { grid-column: span 2; }
  .section { padding: 56px 0; }
  .section-heading { font-size: 28px; }
  .page-title { font-size: 32px; }
  .grid--3, .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 560px) {
  .container { --gutter: 16px; padding-left: 16px; padding-right: 16px; }
  .brand-tagline { display: none; }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
  .footer-brand { grid-column: auto; }
  .footer-bottom-inner { flex-direction: column; align-items: flex-start; }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: 1fr; }
  .page-header { padding: 40px 0 28px; margin-bottom: 32px; }
  .lead { font-size: 16px; }
  .stat-value { font-size: 32px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  [data-reveal],
  .js [data-reveal="hidden"],
  .js [data-reveal="shown"] {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .header-progress { display: none; }
}