/* ===================== Reset & Variables ===================== */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: var(--text-body);
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg-light);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, picture, svg, video { display: block; max-width: 100%; height: auto; }
input, button, textarea, select { font: inherit; color: inherit; }
button { background: none; border: none; cursor: pointer; }
a { color: var(--color-blue-deep); text-decoration: none; transition: color .2s ease; }
a:hover { color: var(--color-brand); }
ul[class], ol[class] { list-style: none; margin: 0; padding: 0; }
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  line-height: 1.3;
  color: var(--color-text);
  font-weight: 700;
  margin-bottom: .5em;
}
h1 { font-size: var(--text-h1); }
h2 { font-size: var(--text-h2); }
h3 { font-size: var(--text-h3); }
h4 { font-size: 1.125rem; }
h5 { font-size: 1rem; }
h6 { font-size: .9375rem; }
p { line-height: 1.85; }
[id] { scroll-margin-top: calc(var(--header-h) + var(--space-3)); }

:root {
  --color-bg-dark: #0A0A0C;
  --color-bg-light: #FFFFFF;
  --color-bg-card: #F4F5F7;
  --color-brand: #FF4D00;
  --color-blue-deep: #1B2A4A;
  --color-text: #1A1A1A;
  --color-text-secondary: #5A5A5A;
  --color-grid: #D1D5DB;
  --color-border-strong: #9CA3AF;
  --color-success: #10B981;
  --font-heading: 'Noto Serif SC', 'Source Han Serif SC', 'Songti SC', serif;
  --font-body: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', sans-serif;
  --font-code: 'JetBrains Mono', 'Courier New', monospace;
  --container-max: 1200px;
  --header-h: 72px;
  --radius-sm: .5rem;
  --radius-md: .875rem;
  --radius-lg: 1.5rem;
  --radius-pill: 999px;
  --space-1: .25rem;
  --space-2: .5rem;
  --space-3: 1rem;
  --space-4: 1.5rem;
  --space-5: 2rem;
  --space-6: 3rem;
  --space-7: 4.5rem;
  --space-8: 6rem;
  --text-display: clamp(2.5rem, 6vw, 4.5rem);
  --text-h1: clamp(2rem, 4vw, 3rem);
  --text-h2: clamp(1.5rem, 3vw, 2.25rem);
  --text-h3: 1.25rem;
  --text-body: 1rem;
  --text-caption: .875rem;
}

/* ===================== Focus & Selection ===================== */
:focus-visible {
  outline: 3px solid var(--color-brand);
  outline-offset: 3px;
  border-radius: 4px;
}
::selection { background: var(--color-brand); color: #fff; }
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-thumb { background: var(--color-border-strong); border-radius: 5px; }
::-webkit-scrollbar-track { background: var(--color-bg-card); }

/* ===================== Utilities ===================== */
.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;
}
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: clamp(1.5rem, 4vw, 2.5rem);
}
.section { padding-block: var(--space-7); }
.section-tight { padding-block: var(--space-5); }

/* ===================== Skip Link ===================== */
.skip-link {
  position: fixed;
  top: -100%;
  left: var(--space-3);
  z-index: 2000;
  background: var(--color-brand);
  color: #fff;
  padding: .75rem 1.25rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: .9375rem;
  transition: top .2s ease;
}
.skip-link:focus { top: var(--space-3); }

/* ===================== Header ===================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: transparent;
  transition: background-color .3s ease, box-shadow .3s ease;
}
.site-header[data-scrolled="true"] {
  background: rgba(10, 10, 12, .92);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  box-shadow: 0 1px 0 rgba(255, 255, 255, .06);
}
.site-header[data-nav-expanded="true"] {
  background: var(--color-bg-dark);
}
.progress-track {
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--color-brand), #FF7A30);
  z-index: 3;
  pointer-events: none;
}
.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  height: var(--header-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
}
.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--color-brand);
  color: #fff;
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: .04em;
  padding: .4375rem .875rem;
  border-radius: var(--radius-sm);
  line-height: 1.2;
  transition: background-color .2s ease;
}
.brand:hover .brand-mark { background: #E64600; }
.brand-badge {
  font-family: var(--font-code);
  font-size: .75rem;
  font-weight: 500;
  color: var(--color-brand);
  border: 1px solid rgba(255, 77, 0, .5);
  background: rgba(255, 77, 0, .08);
  border-radius: var(--radius-pill);
  padding: .125rem .625rem;
  letter-spacing: .08em;
  white-space: nowrap;
}

.main-nav { display: block; }
.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}
.nav-item { margin: 0; }
.nav-link {
  display: inline-flex;
  align-items: center;
  padding: .5rem .875rem;
  border-radius: var(--radius-pill);
  color: rgba(255, 255, 255, .85);
  font-size: .9375rem;
  font-weight: 500;
  letter-spacing: .02em;
  white-space: nowrap;
  transition: background-color .2s ease, color .2s ease;
}
.nav-link:hover { background: rgba(255, 255, 255, .1); color: #fff; }
.nav-link[aria-current="page"] { background: var(--color-brand); color: #fff; }

.nav-toggle {
  display: none;
  width: 2.75rem;
  height: 2.75rem;
  border: 1px solid rgba(255, 255, 255, .28);
  border-radius: var(--radius-sm);
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: .3125rem;
  transition: border-color .2s ease, background-color .2s ease;
}
.nav-toggle:hover { border-color: var(--color-brand); }
.nav-toggle-bar {
  display: block;
  width: 1.125rem;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: transform .25s ease, opacity .25s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(.4375rem) 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(-.4375rem) rotate(-45deg); }

/* ===================== Footer ===================== */
.site-footer {
  position: relative;
  background: var(--color-bg-dark);
  color: rgba(255, 255, 255, .72);
  font-size: .9375rem;
  overflow: hidden;
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, .025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .025) 1px, transparent 1px);
  background-size: 44px 44px;
  pointer-events: none;
}
.footer-inner {
  position: relative;
  z-index: 1;
  padding-top: var(--space-7);
  padding-bottom: var(--space-5);
}
.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, .85fr) minmax(0, 1fr);
  gap: var(--space-5) var(--space-6);
  padding-bottom: var(--space-6);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
}
.footer-brand-link { margin-bottom: var(--space-4); }
.footer-slogan {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: #fff;
  font-weight: 700;
  line-height: 1.5;
  margin-bottom: var(--space-3);
  max-width: 22em;
}
.footer-trust {
  font-size: .875rem;
  color: rgba(255, 255, 255, .55);
  max-width: 34em;
  line-height: 1.8;
}
.footer-col { display: flex; flex-direction: column; }
.footer-heading {
  font-family: var(--font-code);
  font-size: .8125rem;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, .45);
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid rgba(255, 255, 255, .1);
}
.footer-link-list,
.footer-contact-list { display: grid; gap: var(--space-2); }
.footer-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: rgba(255, 255, 255, .68);
  font-size: .9375rem;
  transition: color .2s ease, padding-left .2s ease;
}
.footer-link::before {
  content: "";
  width: .375rem;
  height: .375rem;
  border-radius: 50%;
  background: var(--color-brand);
  flex-shrink: 0;
  transition: transform .2s ease;
}
.footer-link:hover { color: #fff; padding-left: .25rem; }
.footer-link:hover::before { transform: scale(1.35); }
.footer-contact-item {
  display: flex;
  flex-direction: column;
  gap: .0625rem;
  padding-bottom: var(--space-2);
  border-bottom: 1px dashed rgba(255, 255, 255, .08);
}
.footer-contact-label {
  font-family: var(--font-code);
  font-size: .6875rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, .35);
}
.footer-contact-value {
  color: rgba(255, 255, 255, .78);
  font-size: .875rem;
  line-height: 1.6;
}
.footer-note {
  margin-top: var(--space-3);
  font-size: .8125rem;
  color: rgba(255, 255, 255, .4);
  line-height: 1.7;
}
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  padding-top: var(--space-4);
  font-family: var(--font-code);
  font-size: .8125rem;
  color: rgba(255, 255, 255, .45);
}
.footer-coord {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  letter-spacing: .12em;
}
.footer-coord::before {
  content: "";
  width: 1.75rem;
  height: 2px;
  background: var(--color-brand);
  display: inline-block;
}
.footer-copy { letter-spacing: .05em; }
.footer-icp {
  padding: .125rem .5rem;
  border: 1px solid rgba(255, 255, 255, .15);
  border-radius: var(--radius-pill);
  font-size: .75rem;
  letter-spacing: .05em;
}

/* ===================== Buttons ===================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: .75rem 1.5rem;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: .9375rem;
  font-weight: 600;
  line-height: 1.3;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background-color .2s ease, border-color .2s ease, color .2s ease, transform .15s ease;
}
.btn:active { transform: scale(.98); }
.btn-primary { background: var(--color-brand); color: #fff; }
.btn-primary:hover { background: #E64600; color: #fff; }
.btn-outline {
  background: transparent;
  border-color: var(--color-border-strong);
  color: var(--color-text);
}
.btn-outline:hover { border-color: var(--color-brand); color: var(--color-brand); }
.btn-light { background: #fff; color: var(--color-text); }
.btn-light:hover { background: var(--color-bg-card); color: var(--color-text); }
.btn-sm { padding: .5rem 1rem; font-size: .875rem; }

/* ===================== Pills / Tags ===================== */
.pill {
  display: inline-flex;
  align-items: center;
  padding: .25rem .75rem;
  border-radius: var(--radius-pill);
  background: var(--color-bg-card);
  color: var(--color-text-secondary);
  font-size: .8125rem;
  font-weight: 500;
}
.pill--brand { background: var(--color-brand); color: #fff; }
.pill--blue { background: var(--color-blue-deep); color: #fff; }

.index-tag {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-family: var(--font-code);
  font-size: .8125rem;
  font-weight: 600;
  letter-spacing: .1em;
  color: var(--color-brand);
  text-transform: uppercase;
}
.index-tag::before {
  content: "";
  width: 1.5rem;
  height: 1px;
  background: currentColor;
}
.index-tag--box {
  border: 1px solid var(--color-grid);
  border-radius: var(--radius-pill);
  padding: .1875rem .75rem;
  color: var(--color-text-secondary);
  background: var(--color-bg-light);
}
.index-tag--box::before { display: none; }

/* ===================== Cards & Data ===================== */
.card {
  background: var(--color-bg-card);
  border: 1px solid rgba(209, 213, 219, .7);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  position: relative;
  transition: border-color .25s ease, box-shadow .25s ease, transform .25s ease;
}
.card:hover {
  border-color: rgba(255, 77, 0, .45);
  box-shadow: 0 8px 24px rgba(10, 10, 12, .06);
  transform: translateY(-2px);
}
.data-rail {
  border: 1px solid rgba(255, 255, 255, .12);
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, .04);
  padding: var(--space-5);
}
.data-rail-item {
  padding: var(--space-3) 0;
  border-bottom: 1px dashed rgba(255, 255, 255, .12);
}
.data-rail-item:last-child { border-bottom: 0; }
.data-rail-label {
  font-family: var(--font-code);
  font-size: .75rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, .45);
}
.data-rail-value {
  font-family: var(--font-code);
  font-size: 1.5rem;
  color: #fff;
  font-weight: 700;
  line-height: 1.3;
}
.status-dot--live {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-family: var(--font-code);
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--color-success);
}
.status-dot--live::before {
  content: "";
  width: .5rem;
  height: .5rem;
  border-radius: 50%;
  background: var(--color-success);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, .15);
}

/* ===================== Grid ===================== */
.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--space-5);
}
.grid--2 > * { grid-column: span 6; }
.grid--3 > * { grid-column: span 4; }
.grid--4 > * { grid-column: span 3; }

/* ===================== Breadcrumb ===================== */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  list-style: none;
  padding: 0;
  margin: 0 0 var(--space-4);
  font-size: .875rem;
  color: var(--color-text-secondary);
}
.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: var(--space-2);
  color: var(--color-border-strong);
}
.breadcrumb-link { color: var(--color-text-secondary); text-decoration: none; transition: color .2s; }
.breadcrumb-link:hover { color: var(--color-brand); }
.breadcrumb [aria-current="page"] { color: var(--color-text); font-weight: 600; }

/* ===================== Prose ===================== */
.prose {
  max-width: 68ch;
  font-size: 1.0625rem;
  line-height: 1.85;
}
.prose p { margin-bottom: 1.25em; }
.prose strong { font-weight: 600; }
.prose ul { padding-left: 1.25rem; margin-bottom: 1.25em; list-style: disc; }
.prose ol { padding-left: 1.25rem; margin-bottom: 1.25em; list-style: decimal; }
.prose li + li { margin-top: .375rem; }
.prose h2, .prose h3 { margin-top: 1.75em; }
.prose h2:first-child, .prose h3:first-child { margin-top: 0; }
.prose a {
  color: var(--color-blue-deep);
  text-decoration: underline;
  text-underline-offset: .2em;
  text-decoration-color: rgba(27, 42, 74, .3);
}
.prose a:hover { color: var(--color-brand); text-decoration-color: var(--color-brand); }
.prose blockquote {
  border-left: 3px solid var(--color-brand);
  background: var(--color-bg-card);
  padding: var(--space-3) var(--space-4);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin-bottom: 1.25em;
}
.prose code {
  font-family: var(--font-code);
  font-size: .875em;
  background: var(--color-bg-card);
  padding: .15em .4em;
  border-radius: var(--radius-sm);
}

/* ===================== Divider ===================== */
.rule {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--color-grid), transparent);
  margin: var(--space-6) 0;
}
.rule--strong {
  height: 2px;
  background: linear-gradient(90deg, var(--color-brand), rgba(255, 77, 0, .15));
}

/* ===================== Image Frames ===================== */
.image-frame {
  position: relative;
  display: block;
  width: 100%;
  background: var(--color-bg-card);
  border: 1px solid var(--color-grid);
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 16 / 9;
}
.image-frame--widescreen { aspect-ratio: 21 / 9; }
.image-frame--portrait { aspect-ratio: 4 / 5; }
.image-frame--square { aspect-ratio: 1 / 1; }
.image-frame img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.image-frame::before {
  content: attr(data-label);
  position: absolute;
  left: var(--space-3);
  bottom: var(--space-3);
  z-index: 1;
  font-family: var(--font-code);
  font-size: .75rem;
  letter-spacing: .1em;
  color: var(--color-text-secondary);
  background: #fff;
  border: 1px solid var(--color-grid);
  border-radius: var(--radius-pill);
  padding: .1875rem .625rem;
}

/* ===================== Cover Hero ===================== */
.cover {
  position: relative;
  background: var(--color-bg-dark);
  color: #fff;
  padding: calc(var(--header-h) * 2.4) 0 var(--space-7);
  overflow: hidden;
}
.cover--min { padding: calc(var(--header-h) * 1.8) 0 var(--space-6); }
.cover::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, .035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .035) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}
.cover > * { position: relative; z-index: 1; }
.cover-tag {
  display: inline-flex;
  align-items: center;
  gap: .625rem;
  font-family: var(--font-code);
  font-size: .8125rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--color-brand);
  margin-bottom: var(--space-3);
}
.cover-tag::before {
  content: "";
  width: 2rem;
  height: 1px;
  background: currentColor;
}
.cover-title {
  font-size: var(--text-display);
  line-height: 1.15;
  color: #fff;
  margin-bottom: var(--space-4);
  max-width: 12em;
}
.cover-lead {
  font-size: 1.125rem;
  color: rgba(255, 255, 255, .72);
  max-width: 30em;
  line-height: 1.8;
}

/* ===================== Blueprint Grid Decor ===================== */
.blueprint-grid {
  background-image:
    linear-gradient(var(--color-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-grid) 1px, transparent 1px);
  background-size: 32px 32px;
}
.blueprint-grid--dark {
  background-image:
    linear-gradient(rgba(255, 255, 255, .04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .04) 1px, transparent 1px);
  background-size: 32px 32px;
}

/* ===================== Scroll Spy ===================== */
.spy-nav {
  display: grid;
  gap: var(--space-1);
}
.spy-link {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: .4375rem .75rem;
  border-radius: var(--radius-pill);
  font-size: .875rem;
  color: var(--color-text-secondary);
  transition: background-color .2s ease, color .2s ease;
}
.spy-link::before {
  content: "";
  width: .375rem;
  height: .375rem;
  border-radius: 50%;
  background: var(--color-border-strong);
  transition: background-color .2s ease, transform .2s ease;
}
.spy-link[data-active="true"] {
  color: var(--color-brand);
  background: rgba(255, 77, 0, .08);
}
.spy-link[data-active="true"]::before {
  background: var(--color-brand);
  transform: scale(1.3);
}

/* ===================== Reveal ===================== */
.js-enabled [data-reveal] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .6s ease, transform .6s ease;
}
.js-enabled [data-reveal][data-revealed="true"] {
  opacity: 1;
  transform: none;
}

/* ===================== Responsive ===================== */
@media (max-width: 991px) {
  :root { --header-h: 68px; }
  .nav-toggle { display: inline-flex; }
  .main-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(10, 10, 12, .98);
    border-bottom: 1px solid rgba(255, 255, 255, .08);
    padding: var(--space-3) var(--space-4) var(--space-5);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity .28s ease, transform .28s ease, visibility 0s linear .28s;
  }
  .main-nav[data-open="true"] {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
    transition: opacity .28s ease, transform .28s ease, visibility 0s;
  }
  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-1);
  }
  .nav-link {
    display: flex;
    width: 100%;
    padding: .75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 1rem;
  }
  .grid--4 > * { grid-column: span 6; }
  .grid--3 > * { grid-column: span 6; }
  .footer-top { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 575px) {
  :root { --header-h: 64px; }
  .brand-badge { display: none; }
  .grid--2 > *,
  .grid--3 > *,
  .grid--4 > * { grid-column: span 12; }
  .footer-top { grid-template-columns: 1fr; }
  .footer-brand { grid-column: auto; }
  .cover { padding-top: calc(var(--header-h) * 2); }
  .data-rail { padding: var(--space-4); }
}

/* ===================== Reduced Motion ===================== */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    transition-delay: 0ms !important;
  }
  .js-enabled [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}