:root {
  --c-bg: #0A192F;
  --c-bg-deep: #060D1A;
  --c-paper: #F5F0E8;
  --c-orange: #FF6B35;
  --c-cyan: #00E5FF;
  --c-ink: #1A1A1A;
  --c-white: #FFFFFF;
  --c-gray: #8A8A8A;
  --c-amber: #F1C40F;
  --c-green: #2ECC71;
  --font-heading: 'Noto Sans SC', 'Helvetica Neue', Arial, sans-serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', 'Courier New', monospace;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;
  --space-8: 64px;
  --space-9: 96px;
  --container: 1200px;
  --container-narrow: 760px;
  --header-h: 64px;
  --border-w: 2px;
  --shadow-hard: 5px 5px 0 rgba(0, 0, 0, 0.35);
  --dur: 280ms;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  color-scheme: dark;
}

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

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-white);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--c-white);
}

h1 { font-size: clamp(32px, 5vw, 56px); }
h2 { font-size: clamp(26px, 3.6vw, 40px); }
h3 { font-size: clamp(20px, 2.2vw, 26px); }
h4 { font-size: 18px; }
h5 { font-size: 16px; }
h6 { font-size: 14px; }

p { text-wrap: pretty; }

ul, ol { padding-left: 1.4em; }

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

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

address { font-style: normal; }

a { color: var(--c-cyan); text-decoration: none; transition: color var(--dur) var(--ease); }
a:hover { color: var(--c-orange); }

main { display: block; }

#main-content { scroll-margin-top: 100px; }

::selection {
  background: var(--c-orange);
  color: var(--c-ink);
}

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

.card-paper a:focus-visible,
.card-paper button:focus-visible {
  outline-color: var(--c-orange);
}

.container-main {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

.container-narrow {
  width: 100%;
  max-width: var(--container-narrow);
  margin: 0 auto;
  padding: 0 var(--space-5);
}

.section { padding: var(--space-8) 0; }
.section-tight { padding: var(--space-5) 0; }

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--c-cyan);
  text-transform: uppercase;
}

.section-tag::before {
  content: "";
  width: 24px;
  height: 3px;
  background: var(--c-orange);
  flex-shrink: 0;
}

.section-title { margin-bottom: var(--space-5); }

.section-sub {
  max-width: 52em;
  color: var(--c-gray);
  font-size: 15px;
  margin-bottom: var(--space-5);
}

.skip-link {
  position: fixed;
  top: 0;
  left: var(--space-4);
  z-index: 3000;
  padding: 10px 20px;
  background: var(--c-orange);
  color: var(--c-ink);
  font-weight: 700;
  text-decoration: none;
  transform: translateY(-200%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
  color: var(--c-ink);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 2500;
  width: 100%;
  height: 3px;
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--c-orange), var(--c-cyan));
  box-shadow: 0 0 12px rgba(0, 229, 255, 0.55);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--c-bg);
  border-bottom: var(--border-w) solid var(--c-orange);
}

.header-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  max-width: var(--container);
  margin: 0 auto;
  padding: 5px var(--space-5);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--c-gray);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.header-strip-text {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--c-cyan);
  white-space: nowrap;
}

.header-strip-text::before {
  content: "";
  width: 8px;
  height: 8px;
  flex-shrink: 0;
  background: var(--c-orange);
  box-shadow: 0 0 8px var(--c-orange);
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.header-strip-meta {
  color: var(--c-gray);
  white-space: nowrap;
}

.header-main {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--space-5);
  height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  flex-shrink: 0;
  text-decoration: none;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  flex-shrink: 0;
  background: var(--c-orange);
  color: var(--c-ink);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 15px;
  border: 2px solid var(--c-ink);
  box-shadow: 3px 3px 0 rgba(0, 0, 0, 0.35);
  transition: transform var(--dur) var(--ease);
}

.brand:hover .brand-mark {
  transform: rotate(-4deg) scale(1.03);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-name {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 20px;
  letter-spacing: -0.02em;
  color: var(--c-white);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--c-gray);
  text-transform: uppercase;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-2);
  padding: 8px 14px;
  border: 2px solid var(--c-white);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  line-height: 1;
  color: var(--c-white);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.nav-toggle-box {
  display: flex;
  flex-direction: column;
  gap: 5px;
  width: 18px;
}

.nav-toggle-bar {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--c-white);
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

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

.nav-toggle:hover .nav-toggle-bar {
  background: var(--c-orange);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

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

.nav-list {
  display: flex;
  align-items: stretch;
  height: 100%;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item {
  display: flex;
  align-items: stretch;
  height: 100%;
  border-left: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-item:first-child {
  border-left: none;
}

.nav-link {
  position: relative;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--c-white);
  white-space: nowrap;
  text-decoration: none;
  transition: background-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.nav-link::before {
  content: attr(data-index);
  font-size: 10px;
  font-weight: 500;
  color: var(--c-cyan);
  opacity: 0.65;
  transition: color var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 0;
  height: 3px;
  background: var(--c-cyan);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}

.nav-link:hover,
.nav-link[aria-current="page"] {
  background: var(--c-orange);
  color: var(--c-ink);
}

.nav-link:hover::before,
.nav-link[aria-current="page"]::before {
  color: var(--c-ink);
  opacity: 1;
}

.nav-link:hover::after,
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
}

.site-footer {
  position: relative;
  background: var(--c-bg-deep);
  border-top: var(--border-w) solid var(--c-orange);
  color: var(--c-white);
  overflow: hidden;
}

.site-footer::before {
  content: "196";
  position: absolute;
  right: -30px;
  bottom: -90px;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 320px;
  line-height: 1;
  color: rgba(255, 255, 255, 0.025);
  pointer-events: none;
}

.footer-top {
  display: grid;
  grid-template-columns: 1.4fr 0.7fr 0.7fr 1.2fr;
  gap: var(--space-7);
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--space-8) var(--space-5) var(--space-7);
  position: relative;
  z-index: 1;
}

.footer-brand-col {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  min-width: 0;
}

.footer-brand {
  margin-bottom: var(--space-4);
}

.footer-tagline {
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 17px;
  color: var(--c-paper);
  margin-bottom: var(--space-3);
}

.footer-trust {
  max-width: 36em;
  font-size: 13px;
  line-height: 1.8;
  color: var(--c-gray);
}

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

.footer-heading {
  position: relative;
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-4);
  font-family: var(--font-heading);
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.14em;
  color: var(--c-orange);
  text-transform: uppercase;
}

.footer-heading::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 28px;
  height: 3px;
  background: var(--c-cyan);
}

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

.footer-list li {
  margin-bottom: 2px;
}

.footer-list a {
  display: inline-block;
  padding: 4px 0;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.85);
  transition: color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.footer-list a::before {
  content: "→ ";
  color: var(--c-gray);
  transition: color var(--dur) var(--ease);
}

.footer-list a:hover {
  color: var(--c-orange);
  transform: translateX(3px);
}

.footer-list a:hover::before {
  color: var(--c-orange);
}

.footer-address {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-gray);
}

.footer-address p {
  margin: 0;
}

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
  max-width: var(--container);
  margin: 0 auto;
  padding: var(--space-4) var(--space-5);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-gray);
  position: relative;
  z-index: 1;
}

.footer-copyright {
  color: var(--c-gray);
}

.footer-icp {
  padding: 2px 10px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  color: var(--c-gray);
  letter-spacing: 0.04em;
}

.grid {
  display: grid;
  gap: var(--space-5);
}

.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)); }
.grid-asym { grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr); }
.grid-asym-right { grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); }

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: var(--space-5);
  border: var(--border-w) solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.03);
  color: var(--c-white);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.card-paper {
  background: var(--c-paper);
  border-color: var(--c-ink);
  color: var(--c-ink);
  box-shadow: var(--shadow-hard);
}

.card-dark {
  background: var(--c-bg);
  border-color: rgba(255, 255, 255, 0.24);
}

.card:hover {
  transform: translate(-2px, -2px);
}

.card-paper:hover {
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.3);
}

.card-dark:hover {
  border-color: var(--c-cyan);
}

.card h3, .card h4 {
  color: inherit;
  margin-bottom: var(--space-2);
}

.card p {
  color: inherit;
  font-size: 14px;
  line-height: 1.7;
}

.card-link {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding-top: var(--space-3);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: inherit;
  text-decoration: none;
}

.card-link::after {
  content: "→";
  transition: transform var(--dur) var(--ease);
}

.card-link:hover::after {
  transform: translateX(4px);
}

.data-num {
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--c-orange);
  margin-bottom: var(--space-2);
}

.data-num[data-accent="cyan"] {
  color: var(--c-cyan);
}

.data-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--c-gray);
  text-transform: uppercase;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 12px 24px;
  border: 2px solid transparent;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--dur) var(--ease);
}

.btn-primary {
  background: var(--c-orange);
  border-color: var(--c-orange);
  color: var(--c-ink);
  box-shadow: var(--shadow-hard);
}

.btn-primary:hover {
  background: var(--c-ink);
  color: var(--c-orange);
  transform: translate(-1px, -1px);
  box-shadow: 7px 7px 0 rgba(0, 0, 0, 0.35);
}

.btn-ghost {
  border-color: rgba(255, 255, 255, 0.45);
  color: var(--c-white);
}

.btn-ghost:hover {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
  background: rgba(0, 229, 255, 0.08);
}

.btn-paper {
  background: var(--c-paper);
  border-color: var(--c-paper);
  color: var(--c-ink);
  box-shadow: var(--shadow-hard);
}

.btn-paper:hover {
  background: var(--c-orange);
  border-color: var(--c-orange);
  color: var(--c-ink);
  transform: translate(-1px, -1px);
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: var(--space-4) 0;
  margin-bottom: var(--space-5);
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-gray);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

.breadcrumbs a:hover {
  color: var(--c-orange);
}

.breadcrumbs .sep {
  color: var(--c-gray);
  opacity: 0.6;
}

.breadcrumbs [aria-current="page"] {
  color: var(--c-orange);
  font-weight: 500;
}

.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--c-bg-deep);
  border: var(--border-w) solid rgba(255, 255, 255, 0.25);
  aspect-ratio: 4 / 3;
}

.img-frame::before {
  content: attr(data-caption);
  position: absolute;
  top: 0;
  left: 0;
  z-index: 2;
  padding: 4px 10px;
  background: var(--c-ink);
  color: var(--c-paper);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  white-space: nowrap;
}

.img-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-frame-wide { aspect-ratio: 16 / 7; }
.img-frame-tall { aspect-ratio: 3 / 4; }

.note-vertical {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--c-gray);
  text-transform: uppercase;
  white-space: nowrap;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
  transition-delay: var(--reveal-delay, 0ms);
}

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

body.nav-open {
  overflow: hidden;
}

@media (max-width: 1080px) {
  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-6);
  }
}

@media (max-width: 860px) {
  :root {
    --header-h: 56px;
  }

  .header-strip-meta {
    display: none;
  }

  .header-main {
    gap: var(--space-3);
  }

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

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 1001;
    height: auto;
    max-height: calc(100dvh - var(--header-h) - 30px);
    overflow-y: auto;
    background: var(--c-bg);
    border-bottom: var(--border-w) solid var(--c-orange);
    box-shadow: 0 16px 32px rgba(0, 0, 0, 0.45);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), visibility var(--dur);
  }

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

  .nav-list {
    flex-direction: column;
    height: auto;
    padding: var(--space-2) 0;
  }

  .nav-item {
    height: auto;
    border-left: none;
  }

  .nav-link {
    height: auto;
    padding: 14px var(--space-5);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    font-size: 15px;
  }

  .nav-link::after {
    left: var(--space-5);
    right: auto;
    width: 24px;
    height: 3px;
  }

  .nav-item:last-child .nav-link {
    border-bottom: none;
  }

  .grid-2,
  .grid-3,
  .grid-4,
  .grid-asym,
  .grid-asym-right {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 640px) {
  .section {
    padding: var(--space-6) 0;
  }

  .container-main,
  .container-narrow {
    padding: 0 var(--space-4);
  }

  .header-strip {
    padding: 4px var(--space-4);
  }

  .header-main {
    padding: 0 var(--space-4);
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: var(--space-6);
    padding: var(--space-6) var(--space-4);
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-4);
  }

  .data-num {
    font-size: 36px;
  }

  .grid-2,
  .grid-3,
  .grid-4,
  .grid-asym,
  .grid-asym-right {
    gap: var(--space-4);
  }
}

@media (max-width: 380px) {
  .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;
  }

  .header-strip-text::before {
    animation: none;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}