:root {
  --bg-deep: #0D0F14;
  --bg-card: #1A1D24;
  --accent: #FF6A00;
  --accent-soft: #FF9A3C;
  --blue: #00D4FF;
  --text: #FFFFFF;
  --text-dim: #B0B8C4;
  --dark-blue: #0A1E3F;
  --line: rgba(255, 255, 255, 0.12);
  --line-blue: rgba(0, 212, 255, 0.35);
  --line-orange: rgba(255, 106, 0, 0.45);
  --shadow: 0 16px 40px rgba(0, 0, 0, 0.35);
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'Roboto Mono', 'SFMono-Regular', Consolas, monospace;
  --container: 1280px;
  --gutter: clamp(16px, 4vw, 56px);
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  --text-h1: clamp(2rem, 6vw, 3.375rem);
  --text-h2: clamp(1.5rem, 4.5vw, 2.5rem);
  --text-h3: clamp(1.125rem, 2.5vw, 1.75rem);
  --text-h4: clamp(1rem, 2vw, 1.25rem);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg-deep);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-body);
  font-weight: 900;
  line-height: 1.2;
  color: var(--text);
}

h1 { font-size: var(--text-h1); }
h2 { font-size: var(--text-h2); }
h3 { font-size: var(--text-h3); }
h4 { font-size: var(--text-h4); }

p {
  margin: 0;
}

ul, ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

a {
  color: var(--blue);
  text-decoration: none;
}

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

button {
  font: inherit;
  color: inherit;
  border: 0;
  background: none;
  cursor: pointer;
}

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

::selection {
  background: var(--accent);
  color: var(--bg-deep);
}

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

#main-content {
  display: block;
  outline: none;
}

.site-main {
  display: block;
  padding: clamp(24px, 6vw, 64px) 0 clamp(32px, 8vw, 96px);
}

.container-wide {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container-narrow {
  width: 100%;
  max-width: 960px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  background: var(--accent);
  color: var(--bg-deep);
  font-weight: 800;
  padding: 10px 16px;
  transform: translateY(-220%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 150;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--blue));
  box-shadow: 0 0 12px rgba(255, 106, 0, 0.4);
  pointer-events: none;
}

.site-header {
  position: relative;
  overflow: hidden;
  background:
    linear-gradient(135deg, rgba(0, 212, 255, 0.06) 0%, transparent 32%),
    linear-gradient(115deg, rgba(255, 106, 0, 0.08) 0%, transparent 48%),
    var(--bg-deep);
  border-bottom: 1px solid var(--line);
}

.site-header::before {
  content: "";
  position: absolute;
  top: -40px;
  right: -20px;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

.site-header::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--accent) 0%, transparent 30%, rgba(0, 212, 255, 0.5) 85%, transparent 100%);
  pointer-events: none;
}

.header-shell {
  position: relative;
  padding-top: 18px;
  padding-bottom: 0;
}

.header-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  padding-bottom: 12px;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 12px;
  color: var(--text);
  line-height: 1;
}

.brand:hover {
  color: var(--text);
}

.brand-index {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--accent);
  line-height: 1.1;
  border: 1px solid var(--line-orange);
  padding: 4px 6px;
}

.brand-index-slash {
  color: var(--blue);
  margin: 0 3px;
}

.brand-name {
  font-weight: 900;
  font-size: clamp(20px, 3vw, 28px);
  letter-spacing: 0.02em;
  color: var(--text);
}

.brand:hover .brand-name {
  color: var(--accent-soft);
}

.tagline {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 12px 0 0;
  color: var(--text-dim);
  font-size: 13px;
  letter-spacing: 0.24em;
  white-space: nowrap;
}

.tagline-mark {
  width: 8px;
  height: 8px;
  background: var(--accent);
  transform: rotate(45deg);
  flex: none;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  padding: 8px 14px;
  background: rgba(26, 29, 36, 0.8);
  border: 1px solid var(--line);
  color: var(--text-dim);
  transition: border-color 0.2s, background 0.2s, color 0.2s;
}

.nav-toggle:hover {
  border-color: var(--line-orange);
  color: var(--text);
}

.nav-toggle-icon {
  position: relative;
  display: block;
  width: 18px;
  height: 14px;
  flex: none;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--accent);
}

.nav-toggle-icon::before {
  top: 0;
  box-shadow: 0 6px 0 var(--text);
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), top 0.25s var(--ease);
}

.nav-toggle-icon::after {
  bottom: 0;
  transition: transform 0.25s var(--ease), bottom 0.25s var(--ease);
}

.site-header[data-open] .nav-toggle-icon::before {
  top: 6px;
  transform: rotate(45deg);
  box-shadow: none;
}

.site-header[data-open] .nav-toggle-icon::after {
  bottom: 6px;
  transform: rotate(-45deg);
}

.nav-toggle-label {
  font-size: 13px;
  letter-spacing: 0.1em;
}

.primary-nav {
  display: block;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  pointer-events: none;
  transition: max-height 0.35s var(--ease), opacity 0.25s var(--ease);
}

.site-header[data-open] .primary-nav {
  max-height: min(520px, calc(100vh - 90px));
  overflow: auto;
  opacity: 1;
  pointer-events: auto;
}

.nav-list {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--line);
}

.nav-item + .nav-item {
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.nav-link {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 2px;
  color: var(--text-dim);
  font-weight: 700;
  letter-spacing: 0.04em;
  transition: color 0.2s, background 0.2s;
}

.nav-link:hover {
  color: var(--accent-soft);
}

.nav-link[aria-current="page"] {
  color: var(--text);
}

.nav-link[aria-current="page"]::after {
  content: "";
  display: block;
  width: 8px;
  height: 8px;
  background: var(--accent);
  transform: rotate(45deg);
  flex: none;
}

.nav-note {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 12px 0 0;
  padding: 0 2px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--blue);
}

.nav-note-label {
  display: inline-block;
  padding: 2px 6px;
  color: var(--text-dim);
  border: 1px solid var(--line);
  letter-spacing: 0.08em;
}

@media (min-width: 900px) {
  .header-shell {
    padding-top: 20px;
  }

  .header-top {
    padding-bottom: 10px;
  }

  .nav-toggle {
    display: none;
  }

  .primary-nav {
    max-height: none;
    overflow: visible;
    opacity: 1;
    pointer-events: auto;
    display: flex;
    align-items: flex-end;
    justify-content: space-between;
    border-top: 1px solid var(--line);
    margin-top: 8px;
  }

  .nav-list {
    flex-direction: row;
    border-top: 0;
  }

  .nav-item + .nav-item {
    border-top: 0;
    margin-left: 28px;
  }

  .nav-link {
    padding: 16px 2px 12px;
  }

  .nav-link[aria-current="page"]::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    transform: none;
    background: var(--accent);
  }

  .nav-note {
    margin: 0 0 10px;
    padding: 0;
  }
}

.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: 96px;
  background: linear-gradient(180deg, var(--bg-deep) 0%, var(--dark-blue) 100%);
  border-top: 1px solid var(--line);
}

.site-footer::before {
  content: "";
  display: block;
  height: 3px;
  background: linear-gradient(90deg, var(--accent) 0%, var(--blue) 100%);
}

.site-footer::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(0, 212, 255, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.footer-shell {
  position: relative;
  padding-top: 56px;
  padding-bottom: 24px;
}

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

.footer-brand {
  display: inline-flex;
  margin-bottom: 18px;
}

.footer-brand .brand-name {
  font-size: 24px;
}

.footer-tagline {
  margin: 14px 0 10px;
  color: var(--blue);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.18em;
}

.footer-statement {
  max-width: 34em;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.7;
}

.footer-heading {
  margin: 0 0 14px;
  padding-left: 12px;
  font-size: 14px;
  letter-spacing: 0.2em;
  color: var(--text);
  position: relative;
}

.footer-heading::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.3em;
  width: 4px;
  height: 14px;
  background: var(--accent);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px 16px;
}

.footer-links a {
  color: var(--text-dim);
  font-size: 14px;
  transition: color 0.2s, padding-left 0.2s;
}

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

.footer-contact {
  display: grid;
  gap: 8px;
  color: var(--text-dim);
  font-size: 14px;
}

.footer-contact li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.footer-contact li::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--blue);
  transform: rotate(45deg);
  flex: none;
}

.footer-note {
  margin-top: 14px;
  max-width: 32em;
  color: var(--text-dim);
  opacity: 0.72;
  font-size: 13px;
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: 10px 20px;
  border-top: 1px solid var(--line);
  padding-top: 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-dim);
}

.footer-copy {
  margin: 0;
}

.footer-icp {
  margin: 0;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
}

.footer-legal a {
  color: var(--text-dim);
}

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

@media (min-width: 700px) {
  .footer-bottom {
    flex-direction: row;
    align-items: center;
  }

  .footer-legal {
    margin-left: auto;
  }
}

@media (min-width: 900px) {
  .footer-top {
    grid-template-columns: 1.2fr 0.8fr 1fr;
    gap: 40px;
  }
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 12px 0 24px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-dim);
}

.breadcrumbs a {
  color: var(--blue);
}

.breadcrumbs a[aria-current="page"] {
  color: var(--text);
}

.breadcrumb-separator {
  color: var(--text-dim);
  opacity: 0.7;
}

.section {
  position: relative;
  padding-block: clamp(40px, 8vw, 96px);
}

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

.section-head {
  max-width: 760px;
  margin-bottom: 32px;
}

.section-index {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--accent);
  margin-bottom: 8px;
}

.section-index::before {
  content: "#";
  color: var(--blue);
  margin-right: 4px;
}

.section-title {
  margin: 0 0 12px;
  color: var(--text);
}

.section-caption {
  max-width: 640px;
  color: var(--text-dim);
}

.content-block {
  max-width: 760px;
  color: var(--text-dim);
  line-height: 1.8;
}

.content-block p + p {
  margin-top: 1em;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 260px), 1fr));
  gap: 20px;
}

.card {
  position: relative;
  overflow: hidden;
  padding: 20px;
  background: var(--bg-card);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease);
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--blue));
  opacity: 0;
  transition: opacity 0.25s var(--ease);
}

.card:hover {
  transform: translateY(-2px);
  border-color: var(--line-orange);
}

.card:hover::before {
  opacity: 1;
}

.card-title {
  margin: 0 0 8px;
  font-size: 20px;
}

.card-text {
  color: var(--text-dim);
  font-size: 15px;
  line-height: 1.6;
}

.card-link {
  display: inline-block;
  margin-top: 12px;
  color: var(--blue);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.06em;
}

.card-link::after {
  content: " →";
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid var(--line);
  color: var(--text-dim);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.tag[data-tone="orange"] {
  color: var(--accent-soft);
  border-color: var(--line-orange);
}

.tag[data-tone="blue"] {
  color: var(--blue);
  border-color: var(--line-blue);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: 2px solid transparent;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.06em;
  line-height: 1.2;
  border-radius: 0;
  transition: background 0.2s, color 0.2s, border-color 0.2s, transform 0.2s;
}

.btn:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg-deep);
}

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

.btn-secondary {
  background: rgba(0, 212, 255, 0.04);
  border-color: var(--line-blue);
  color: var(--blue);
}

.btn-secondary:hover {
  background: rgba(0, 212, 255, 0.1);
  border-color: var(--blue);
}

.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--bg-card);
  border: 1px solid var(--line);
  aspect-ratio: 16 / 9;
}

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

.media-frame--portrait {
  aspect-ratio: 3 / 4;
}

.media-frame img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  background: repeating-linear-gradient(135deg, rgba(255, 255, 255, 0.025) 0 1px, transparent 1px 12px);
  pointer-events: none;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 3;
  border: 1px solid rgba(0, 212, 255, 0.1);
  pointer-events: none;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-dim);
  font-size: 13px;
}

.legend-dot {
  width: 8px;
  height: 8px;
  background: var(--accent);
  transform: rotate(45deg);
}

.legend-dot[data-tone="blue"] {
  background: var(--blue);
}

.legend-dot[data-tone="orange"] {
  background: var(--accent);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}

.data-table th,
.data-table td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.data-table th {
  background: var(--bg-card);
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--text);
}

.data-table td {
  color: var(--text-dim);
}

.data-table td:first-child {
  color: var(--text);
  font-weight: 700;
}

.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
}

.js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition: none !important;
    animation: none !important;
  }

  .js [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}