:root {
  --color-primary: #0A1B3D;
  --color-primary-light: #1E3A6D;
  --color-primary-dark: #0D2A4A;
  --color-accent: #FF6A00;
  --color-lime: #C6F24E;
  --color-surface: #F4F6FA;
  --color-surface-alt: #E8EBF0;
  --color-accent-light: #FFD1B0;
  --color-text: #0A1B3D;
  --color-text-inverse: #F4F6FA;
  --font-heading: 'Archivo Black', 'Impact', 'Arial Black', sans-serif;
  --font-body: 'Inter', 'Helvetica Neue', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'Roboto Mono', 'SFMono-Regular', 'Consolas', 'Courier New', monospace;
  --header-height: 72px;
  --container-width: 1280px;
  --transition-fast: 150ms ease;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 400;
  line-height: 1.6;
  letter-spacing: 0.2px;
  color: var(--color-text);
  background: var(--color-surface);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-style: italic;
  font-weight: 900;
  letter-spacing: -0.5px;
  line-height: 1.1;
  color: var(--color-text);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.8rem); }

p { margin-bottom: 1rem; }

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast), padding-left var(--transition-fast);
}

a:hover {
  color: var(--color-primary-light);
}

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

ul, ol { padding-left: 1.5rem; }

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.skip-link {
  position: fixed;
  top: -48px;
  left: 16px;
  z-index: 2000;
  background: var(--color-accent);
  color: #FFFFFF;
  padding: 10px 20px;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: 0;
  box-shadow: 0 2px 12px rgba(255, 106, 0, 0.4);
  transition: top var(--transition-fast);
}

.skip-link:focus-visible {
  top: 12px;
  outline: 2px solid #FFFFFF;
  outline-offset: -2px;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: var(--color-accent);
  z-index: 2001;
  pointer-events: none;
  transition: width 50ms linear;
}

.btn {
  display: inline-block;
  padding: 10px 20px;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast), box-shadow var(--transition-fast), transform var(--transition-fast);
  line-height: 1.4;
}

.btn-primary {
  background: var(--color-primary);
  color: #FFFFFF;
  border-color: var(--color-primary);
}

.btn-primary:hover {
  background: var(--color-primary-light);
  border-color: var(--color-primary-light);
  color: #FFFFFF;
}

.btn-accent {
  background: var(--color-accent);
  color: #FFFFFF;
  border-color: var(--color-accent);
}

.btn-accent:hover {
  background: #E55F00;
  border-color: #E55F00;
  color: #FFFFFF;
  box-shadow: 0 4px 16px rgba(255, 106, 0, 0.3);
}

.btn-feedback {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  padding: 8px 16px;
  border: none;
  border-left: 3px solid var(--color-lime);
  background: var(--color-accent);
  color: #FFFFFF;
  clip-path: polygon(6px 0, 100% 0, calc(100% - 6px) 100%, 0 100%);
}

.btn-feedback::after {
  content: '→';
  margin-left: 6px;
  font-size: 1rem;
  line-height: 1;
}

.btn-feedback:hover {
  background: #E55F00;
  color: #FFFFFF;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: 1000;
  background: transparent;
  transition: background var(--transition-fast), box-shadow var(--transition-fast);
}

.site-header[data-scrolled="true"],
.site-header[data-nav-open] {
  background: rgba(13, 42, 74, 0.96);
  box-shadow: 0 2px 30px rgba(0, 0, 0, 0.25);
}

.header-inner {
  display: flex;
  align-items: center;
  gap: 24px;
  height: 100%;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
  text-decoration: none;
}

.brand-mark {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-lime);
  border: 2px solid var(--color-lime);
  padding: 3px 8px;
  transform: skewX(-8deg);
  display: inline-block;
  letter-spacing: 1px;
  line-height: 1.3;
  background: rgba(10, 27, 61, 0.3);
  flex-shrink: 0;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-name {
  font-family: var(--font-heading);
  font-weight: 900;
  font-style: italic;
  font-size: 1.2rem;
  color: #FFFFFF;
  letter-spacing: -0.5px;
}

.brand-slogan {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--color-lime);
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.site-nav {
  margin-left: auto;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: 2px;
  margin: 0;
  padding: 0;
}

.nav-item {
  list-style: none;
}

.nav-link {
  display: block;
  padding: 8px 14px;
  font-size: 0.875rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.85);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast), background var(--transition-fast);
}

.nav-link:hover {
  color: #FFFFFF;
  background: rgba(255, 106, 0, 0.15);
  border-bottom-color: var(--color-accent);
}

.nav-link[aria-current="page"] {
  color: #FFFFFF;
  border-bottom-color: var(--color-accent);
  background: rgba(255, 106, 0, 0.12);
}

.header-actions {
  display: flex;
  align-items: center;
  flex-shrink: 0;
  margin-left: 8px;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  flex-shrink: 0;
  margin-left: auto;
}

.toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background: #FFFFFF;
  margin: 5px 0;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

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

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

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

.nav-feedback {
  display: none;
}

.site-footer {
  background: var(--color-primary-dark);
  color: rgba(255, 255, 255, 0.75);
  position: relative;
}

.site-footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  height: 4px;
  width: 100%;
  background: repeating-linear-gradient(90deg, var(--color-accent) 0 48px, var(--color-lime) 48px 96px);
  z-index: 1;
}

.footer-main {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.3fr;
  gap: 48px;
  padding-top: 64px;
  padding-bottom: 48px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.footer-brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-brand-name {
  font-family: var(--font-heading);
  font-weight: 900;
  font-style: italic;
  font-size: 1.5rem;
  color: #FFFFFF;
  letter-spacing: -0.5px;
}

.footer-trust {
  font-size: 0.875rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.65);
  max-width: 340px;
}

.footer-col-title {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--color-lime);
  margin-bottom: 16px;
  font-weight: 700;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
  padding-bottom: 8px;
}

.footer-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-list li {
  margin-bottom: 8px;
  font-size: 0.875rem;
  line-height: 1.6;
}

.footer-list a {
  color: rgba(255, 255, 255, 0.75);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.footer-list a:hover {
  color: var(--color-accent);
  padding-left: 4px;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 20px 0;
}

.footer-bottom-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.55);
}

.footer-copyright {
  margin: 0;
}

.footer-icp {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  margin: 0;
}

.page-hero {
  background: var(--color-primary);
  padding: calc(var(--header-height) + 64px) 0 56px;
  position: relative;
  overflow: hidden;
  color: #FFFFFF;
}

.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 24px 24px;
  pointer-events: none;
}

.page-hero::after {
  content: '';
  position: absolute;
  right: -60px;
  top: 30%;
  width: 220px;
  height: 220px;
  border: 3px solid rgba(255, 106, 0, 0.3);
  transform: rotate(12deg);
  border-radius: 4px;
  pointer-events: none;
}

.page-hero-title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  color: #FFFFFF;
  max-width: 800px;
  position: relative;
  z-index: 1;
}

.page-hero-meta {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--color-lime);
  margin-top: 12px;
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
}

.breadcrumb {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  list-style: none;
  padding: 0;
  position: relative;
  z-index: 1;
}

.breadcrumb li + li::before {
  content: '/';
  margin-right: 6px;
  color: var(--color-accent);
}

.breadcrumb a {
  color: rgba(255, 255, 255, 0.75);
  text-decoration: none;
}

.breadcrumb a:hover {
  color: var(--color-accent);
}

.breadcrumb [aria-current="page"] {
  color: var(--color-lime);
}

.section {
  padding: 72px 0;
}

.section + .section {
  border-top: 1px solid var(--color-surface-alt);
}

.section-header {
  margin-bottom: 40px;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--color-accent);
  margin-bottom: 8px;
  display: block;
}

.section-title {
  font-size: clamp(1.5rem, 3vw, 2.5rem);
  color: var(--color-primary);
  margin-bottom: 12px;
}

.section-desc {
  color: #5A6675;
  max-width: 600px;
}

.chapter-label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 2px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.chapter-label::before {
  content: '';
  width: 32px;
  height: 2px;
  background: var(--color-accent);
  display: inline-block;
}

.data-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.data-card {
  background: var(--color-surface);
  border: 1px solid var(--color-surface-alt);
  border-top: 3px solid var(--color-primary-light);
  padding: 24px;
  transition: box-shadow var(--transition-fast), transform var(--transition-fast);
}

.data-card:hover {
  box-shadow: 0 8px 30px rgba(10, 27, 61, 0.1);
  transform: translateY(-2px);
}

.data-card-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--color-accent);
  margin-bottom: 8px;
  display: block;
}

.data-card-value {
  font-family: var(--font-heading);
  font-style: italic;
  font-weight: 900;
  font-size: 2rem;
  color: var(--color-primary);
  line-height: 1.2;
}

@media (max-width: 1024px) {
  .footer-main {
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    padding-top: 48px;
  }

  .brand-slogan {
    display: none;
  }
}

@media (max-width: 900px) {
  :root {
    --header-height: 64px;
  }

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

  .header-inner {
    gap: 8px;
  }

  .brand-mark {
    font-size: 0.95rem;
    padding: 2px 6px;
  }

  .brand-name {
    font-size: 1.05rem;
  }

  .header-actions {
    display: none;
  }

  .site-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    margin-left: 0;
    background: var(--color-primary-dark);
    padding: 20px 24px 28px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.3);
    transform: translateY(-12px);
    visibility: hidden;
    opacity: 0;
    transition: opacity var(--transition-fast), transform var(--transition-fast), visibility var(--transition-fast);
  }

  .site-nav[data-open] {
    transform: translateY(0);
    visibility: visible;
    opacity: 1;
  }

  .nav-list {
    flex-direction: column;
    gap: 0;
  }

  .nav-link {
    padding: 14px 10px;
    font-size: 1rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.07);
    border-left: 3px solid transparent;
    border-radius: 0;
  }

  .nav-link:hover {
    border-left-color: var(--color-accent);
    background: rgba(255, 106, 0, 0.1);
    border-bottom-color: rgba(255, 255, 255, 0.07);
  }

  .nav-link[aria-current="page"] {
    border-left-color: var(--color-lime);
    border-bottom-color: rgba(255, 255, 255, 0.07);
    background: rgba(198, 242, 78, 0.06);
  }

  .nav-feedback {
    display: block;
    margin-top: 20px;
    text-align: center;
    width: 100%;
  }

  .nav-toggle {
    display: block;
  }

  .page-hero {
    padding-top: calc(var(--header-height) + 48px);
    padding-bottom: 40px;
  }
}

@media (max-width: 640px) {
  .container {
    padding-left: 16px;
    padding-right: 16px;
  }

  .footer-main {
    grid-template-columns: 1fr;
    gap: 32px;
    padding-top: 40px;
  }

  .footer-bottom-inner {
    flex-direction: column;
    text-align: center;
  }

  .section {
    padding: 48px 0;
  }

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

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