:root {
  --primary-deep: #0B2447;
  --primary: #1E3A6F;
  --accent: #FF6B35;
  --accent-light: #FFA07A;
  --neutral-light: #F5F7FA;
  --neutral: #D9E2EC;
  --neutral-dark: #33404A;
  --data-green: #00E5A0;
  --data-purple: #9B5CF6;
  --data-cyan: #00B4D8;
  --font-heading: "Noto Serif SC", "Songti SC", "STSong", serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-data: "Roboto Mono", "SFMono-Regular", "Consolas", monospace;
  --radius: 18px;
  --header-top: clamp(0.75rem, 2vw, 1.5rem);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 7rem;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  color: var(--neutral-dark);
  background: var(--neutral-light);
  padding-top: calc(var(--header-top) + 4.75rem);
  -webkit-font-smoothing: antialiased;
}

#main-content {
  scroll-margin-top: 8rem;
  flex: 1;
}

main.site-main {
  flex: 1;
  padding-bottom: clamp(3rem, 8vw, 5rem);
}

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

h1,
h2,
h3,
h4,
p,
ul,
ol {
  margin-top: 0;
}

a {
  color: var(--data-cyan);
}

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

button {
  font: inherit;
  cursor: pointer;
}

:focus-visible {
  outline: 3px solid var(--data-cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

::selection {
  background: rgba(255, 107, 53, 0.25);
}

.skip-link {
  position: fixed;
  top: -100px;
  left: clamp(1rem, 4vw, 2rem);
  z-index: 200;
  padding: 0.75rem 1.2rem;
  border-radius: 999px;
  background: var(--accent);
  color: var(--primary-deep);
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 12px 30px rgba(255, 107, 53, 0.4);
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: var(--header-top);
}

.site-header {
  position: fixed;
  top: var(--header-top);
  left: 50%;
  transform: translateX(-50%);
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 1rem;
  width: min(calc(100% - clamp(1rem, 4vw, 3rem)), 1440px);
  padding: 0.55rem 0.55rem 0.55rem 1.1rem;
  background: linear-gradient(180deg, rgba(11, 36, 71, 0.95), rgba(11, 36, 71, 0.86));
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  box-shadow: 0 24px 70px rgba(11, 36, 71, 0.32), inset 0 1px 0 rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.scroll-progress {
  position: absolute;
  left: 1.6rem;
  right: 1.6rem;
  bottom: 0.45rem;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--accent), var(--accent-light), var(--data-cyan));
  transform: scaleX(0);
  transform-origin: left center;
  pointer-events: none;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-right: auto;
  color: #ffffff;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 1rem;
  background: linear-gradient(135deg, var(--accent), var(--accent-light));
  color: var(--primary-deep);
  font-family: var(--font-data);
  font-weight: 700;
  font-size: 1.25rem;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.2);
}

.brand-text {
  display: grid;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: #ffffff;
}

.brand-sub {
  font-family: var(--font-data);
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  color: var(--data-cyan);
}

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

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  gap: 0.15rem;
}

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

.nav-link {
  position: relative;
  display: inline-block;
  padding: 0.5rem 0.9rem;
  border-radius: 999px;
  color: var(--neutral);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  white-space: nowrap;
  transition: color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.nav-link:hover {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.1);
}

.nav-link[aria-current="page"] {
  color: #ffffff;
  background: rgba(255, 107, 53, 0.18);
  box-shadow: inset 0 0 0 1px rgba(255, 107, 53, 0.55);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.ver-tag {
  font-family: var(--font-data);
  font-size: 0.7rem;
  padding: 0.2rem 0.55rem;
  border: 1px solid rgba(0, 180, 216, 0.5);
  border-radius: 999px;
  color: var(--data-cyan);
  background: rgba(0, 180, 216, 0.08);
  white-space: nowrap;
}

.legacy-toggle {
  font-family: var(--font-data);
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.35rem 0.7rem;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--neutral);
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.legacy-toggle:hover {
  background: rgba(255, 255, 255, 0.14);
  color: #ffffff;
}

.legacy-toggle[aria-pressed="true"] {
  background: var(--accent);
  color: var(--primary-deep);
  border-color: var(--accent);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.45rem;
  padding: 0.5rem 0.9rem;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
}

.nav-toggle-label {
  font-size: 0.82rem;
  font-weight: 600;
}

.nav-toggle-icon {
  position: relative;
  width: 1.1rem;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
  border-radius: 2px;
  transition: transform 0.2s ease, top 0.2s ease;
}

.nav-toggle-icon::before {
  top: -5px;
}

.nav-toggle-icon::after {
  top: 5px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::before {
  top: 0;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-icon::after {
  top: 0;
  transform: rotate(-45deg);
}

.container {
  width: min(100% - clamp(1rem, 4vw, 3rem), 1280px);
  margin-inline: auto;
}

.section {
  padding: clamp(3rem, 7vw, 5.5rem) 0;
}

.section-head {
  max-width: 72ch;
  margin-bottom: 2.5rem;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 3.5vw, 3rem);
  line-height: 1.2;
  color: var(--primary-deep);
  margin: 0.5rem 0 0;
}

.section-sub {
  margin: 0.75rem 0 0;
  color: var(--primary);
  font-size: 1.05rem;
  max-width: 60ch;
}

.eyebrow {
  display: block;
  font-family: var(--font-data);
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--data-purple);
}

.lead {
  font-size: 1.1rem;
  color: var(--primary);
}

.chapter {
  padding: clamp(2rem, 5vw, 4rem) 0;
  border-top: 1px solid var(--neutral);
}

.chapter-index {
  display: block;
  font-family: var(--font-data);
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 700;
  line-height: 1;
  color: rgba(11, 36, 71, 0.16);
  margin-bottom: 0.5rem;
}

.chapter-index[data-index]::before {
  content: attr(data-index);
}

.chapter-title {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3vw, 2.5rem);
  line-height: 1.2;
  color: var(--primary-deep);
  margin: 0 0 0.75rem;
}

.chapter-sub {
  color: var(--primary);
  max-width: 62ch;
}

.card {
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid var(--neutral);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: 0 1px 0 rgba(11, 36, 71, 0.04);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 18px 44px rgba(11, 36, 71, 0.1);
  border-color: rgba(0, 180, 216, 0.35);
}

.card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

.card-body {
  font-size: 0.95rem;
}

.card-title {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: var(--primary-deep);
  margin: 0;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-family: var(--font-data);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  border: 1px solid rgba(0, 180, 216, 0.25);
  background: rgba(0, 180, 216, 0.1);
  color: var(--data-cyan);
  white-space: nowrap;
}

.tag-accent {
  background: rgba(255, 107, 53, 0.12);
  border-color: rgba(255, 107, 53, 0.3);
  color: var(--accent);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.2rem;
  border-radius: 999px;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 700;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.btn-accent {
  background: var(--accent);
  color: var(--primary-deep);
  box-shadow: 0 12px 30px rgba(255, 107, 53, 0.28);
}

.btn-accent:hover {
  background: var(--accent-light);
  color: var(--primary-deep);
}

.btn-ghost {
  background: transparent;
  border-color: var(--primary);
  color: var(--primary);
}

.btn-ghost:hover {
  background: rgba(11, 36, 71, 0.06);
}

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

.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));
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: 2rem;
  align-items: start;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
}

.data-table th,
.data-table td {
  padding: 0.75rem 0.9rem;
  border-bottom: 1px solid var(--neutral);
  text-align: left;
  vertical-align: top;
}

.data-table th {
  font-family: var(--font-data);
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--primary);
  background: rgba(11, 36, 71, 0.045);
}

.data-table tbody tr:hover {
  background: rgba(0, 180, 216, 0.05);
}

.data-number {
  font-family: var(--font-data);
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.data-bar {
  height: 8px;
  border-radius: 999px;
  background: var(--neutral);
  overflow: hidden;
}

.data-bar-fill {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--data-green), var(--data-cyan));
  transform-origin: left center;
}

.heat-strip {
  display: flex;
  gap: 2px;
  height: 38px;
}

.heat-cell {
  flex: 1;
  min-width: 0;
  border-radius: 3px;
  background: var(--neutral);
  transition: filter 0.2s ease;
}

.heat-cell:hover {
  filter: brightness(1.15);
}

.heat-cell[data-level="1"] {
  background: rgba(155, 92, 246, 0.35);
}

.heat-cell[data-level="2"] {
  background: rgba(155, 92, 246, 0.6);
}

.heat-cell[data-level="3"] {
  background: var(--data-purple);
}

.heat-cell[data-level="4"] {
  background: linear-gradient(135deg, var(--data-purple), var(--accent));
}

.media-frame {
  position: relative;
  overflow: hidden;
  min-height: 180px;
  border-radius: var(--radius);
  background: rgba(11, 36, 71, 0.06);
  border: 1px solid var(--neutral);
}

.media-frame[data-ratio="16:9"] {
  aspect-ratio: 16 / 9;
}

.media-frame[data-ratio="4:3"] {
  aspect-ratio: 4 / 3;
}

.media-frame[data-ratio="3:4"] {
  aspect-ratio: 3 / 4;
}

.media-placeholder {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  gap: 0.5rem;
  font-family: var(--font-data);
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  color: var(--primary);
  background:
    radial-gradient(circle at 20% 30%, rgba(255, 107, 53, 0.12), transparent 50%),
    linear-gradient(135deg, rgba(11, 36, 71, 0.1), rgba(0, 180, 216, 0.08));
}

.breadcrumb {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0 0 2rem;
  padding: 0;
  font-size: 0.86rem;
  color: var(--primary);
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--neutral);
}

.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
}

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

.breadcrumb [aria-current="page"] {
  color: var(--neutral-dark);
  font-weight: 600;
}

[data-scrollspy-link] {
  text-decoration: none;
  opacity: 0.75;
  transition: color 0.2s ease, opacity 0.2s ease;
}

[data-scrollspy-link]:hover {
  opacity: 1;
  color: var(--accent);
}

[data-scrollspy-link].is-active {
  opacity: 1;
  color: var(--accent);
  font-weight: 700;
}

.site-footer {
  position: relative;
  margin-top: auto;
  background: var(--primary-deep);
  color: var(--neutral);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 85% 10%, rgba(255, 107, 53, 0.16), transparent 30%),
    radial-gradient(circle at 12% 100%, rgba(0, 180, 216, 0.12), transparent 34%);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  width: min(100% - clamp(1rem, 4vw, 3rem), 1280px);
  margin-inline: auto;
  padding: clamp(2.5rem, 5vw, 4.5rem) 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1.2fr;
  gap: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.footer-brand {
  max-width: 40rem;
}

.footer-tagline {
  font-family: var(--font-heading);
  color: #ffffff;
  font-size: 1.35rem;
  line-height: 1.5;
  margin-bottom: 1rem;
}

.trust-statement {
  color: var(--neutral);
  font-size: 0.92rem;
  line-height: 1.9;
  margin-bottom: 1rem;
}

.footer-note {
  font-size: 0.85rem;
  color: rgba(217, 226, 236, 0.7);
  margin: 0;
}

.footer-column {
  min-width: 0;
}

.footer-title {
  font-family: var(--font-data);
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: #ffffff;
  margin-bottom: 1.1rem;
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.55rem;
}

.footer-links a {
  color: var(--neutral);
  text-decoration: none;
  font-size: 0.92rem;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--accent-light);
}

.footer-contact {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
  font-size: 0.9rem;
  word-break: break-word;
}

.footer-contact span {
  display: block;
}

.footer-contact-label {
  font-family: var(--font-data);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--data-cyan);
  margin-bottom: 0.2rem;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-top: 1.5rem;
}

.footer-legal-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
}

.footer-legal-links a {
  color: var(--data-cyan);
  text-decoration: none;
  font-family: var(--font-data);
  font-size: 0.82rem;
  transition: color 0.2s ease;
}

.footer-legal-links a:hover {
  color: var(--accent-light);
}

.footer-icp {
  margin: 0;
  font-family: var(--font-data);
  font-size: 0.78rem;
  color: rgba(217, 226, 236, 0.7);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  padding-top: 1rem;
  font-size: 0.8rem;
  color: rgba(217, 226, 236, 0.65);
}

.footer-copy {
  margin: 0;
}

.footer-domain {
  margin: 0;
  font-family: var(--font-data);
}

html[data-legacy="true"] .site-header {
  border-radius: 14px;
  box-shadow: 0 8px 30px rgba(11, 36, 71, 0.25);
}

html[data-legacy="true"] .brand-mark {
  border-radius: 4px;
}

html[data-legacy="true"] .nav-link[aria-current="page"] {
  border-radius: 6px;
}

html[data-legacy="true"] .card,
html[data-legacy="true"] .media-frame {
  border-radius: 6px;
  box-shadow: none;
}

html[data-legacy="true"] .btn {
  border-radius: 4px;
}

@media (max-width: 1100px) {
  .grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .nav-link {
    padding-left: 0.7rem;
    padding-right: 0.7rem;
    font-size: 0.85rem;
  }

  .ver-tag {
    display: none;
  }
}

@media (max-width: 960px) {
  body {
    padding-top: calc(var(--header-top) + 4.5rem);
  }

  .site-header {
    flex-wrap: wrap;
    border-radius: 24px;
    padding: 0.65rem 0.65rem 0.65rem 1rem;
  }

  .brand-name {
    font-size: 1rem;
  }

  .site-nav {
    order: 3;
    flex-basis: 100%;
    display: none;
    margin-top: 0.5rem;
    padding: 0.35rem;
    border-radius: 18px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(7, 22, 44, 0.96);
  }

  .site-nav[data-open] {
    display: block;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
  }

  .nav-link {
    display: block;
    text-align: left;
    padding: 0.75rem 1rem;
    border-radius: 12px;
    font-size: 0.9rem;
  }

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

  .grid-3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

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

@media (max-width: 620px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

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

  .footer-brand {
    grid-column: auto;
  }
}

@media (max-width: 560px) {
  .footer-legal {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 420px) {
  .brand-sub {
    display: none;
  }

  .brand-mark {
    width: 2.25rem;
    height: 2.25rem;
    font-size: 1rem;
  }

  .site-header {
    gap: 0.5rem;
  }

  .nav-toggle-label {
    display: none;
  }
}

@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;
  }
}