/* ============ reset & base ============ */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  overflow-x: hidden;
  scroll-behavior: smooth;
}

@supports (overflow-x: clip) {
  html {
    overflow-x: clip;
  }
}

body {
  font-family: "Source Han Sans SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-ice);
  background-color: var(--color-navy);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

ul,
ol {
  list-style: none;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
}

button {
  background: none;
  border: none;
  cursor: pointer;
}

/* ============ CSS variables ============ */
:root {
  --color-navy: #0a1f44;
  --color-navy-light: #1b3a6b;
  --color-navy-deep: #050d1f;
  --color-orange: #ff6b00;
  --color-green: #39ff14;
  --color-paper: #f2e8c9;
  --color-ink: #1a1a1a;
  --color-blue-gray: #b0c4de;
  --color-ice: #e8eaed;

  --font-headline: "Helvetica Neue", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "Source Han Sans SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-data: "Roboto Mono", "Consolas", monospace;

  --container-width: 1200px;
  --header-border-color: rgba(176, 196, 222, 0.15);
}

/* ============ typography ============ */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-headline);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.25;
  text-transform: uppercase;
}

p {
  margin: 0 0 1em;
}

:focus-visible {
  outline: 2px solid var(--color-orange);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ============ layout ============ */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.section {
  padding: 64px 0;
}

.section--tight {
  padding: 32px 0;
}

.section--large {
  padding: 96px 0;
}

.grid {
  display: grid;
  gap: 24px;
}

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

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

.grid--4 {
  grid-template-columns: repeat(4, 1fr);
}

@media (max-width: 1024px) {
  .grid--4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .grid--3 {
    grid-template-columns: 1fr;
  }

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

  .grid--4 {
    grid-template-columns: 1fr;
  }
}

/* ============ accessibility ============ */
.skip-link {
  position: fixed;
  top: -100px;
  left: 0;
  z-index: 1000;
  background: var(--color-orange);
  color: #fff;
  padding: 12px 24px;
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.05em;
  text-decoration: none;
  border-radius: 0 0 4px 4px;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
}

/* ============ scroll progress ============ */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-orange), var(--color-green));
  z-index: 10000;
  transition: width 0.06s linear;
  pointer-events: none;
}

/* ============ buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.04em;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  clip-path: polygon(8px 0, 100% 0, calc(100% - 8px) 100%, 0 100%);
  transition: filter 0.2s ease, transform 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.btn--primary {
  background: var(--color-orange);
  color: #fff;
}

.btn--primary:hover {
  filter: brightness(1.12);
  transform: translateX(2px);
}

.btn--ghost {
  background: transparent;
  border-color: var(--color-blue-gray);
  color: var(--color-blue-gray);
  clip-path: none;
  border-radius: 2px;
}

.btn--ghost:hover {
  border-color: var(--color-ice);
  color: var(--color-ice);
}

/* ============ tags ============ */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
  border-radius: 2px;
  font-family: var(--font-headline);
  text-transform: uppercase;
}

.tag--orange {
  background: rgba(255, 107, 0, 0.12);
  border: 1px solid rgba(255, 107, 0, 0.4);
  color: var(--color-orange);
}

.tag--green {
  background: rgba(57, 255, 20, 0.08);
  border: 1px solid rgba(57, 255, 20, 0.4);
  color: var(--color-green);
}

/* ============ status dot ============ */
.status-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-blue-gray);
  flex: none;
}

.status-dot--live {
  background: var(--color-green);
  animation: status-pulse 1.6s ease-in-out infinite;
}

.status-dot--idle {
  background: var(--color-blue-gray);
  animation: none;
}

@keyframes status-pulse {
  0%,
  100% {
    opacity: 1;
    box-shadow: 0 0 0 0 rgba(57, 255, 20, 0.4);
  }
  50% {
    opacity: 0.7;
    box-shadow: 0 0 0 4px rgba(57, 255, 20, 0);
  }
}

/* ============ header ============ */
.site-header {
  position: relative;
  background-color: var(--color-navy);
  background-image:
    linear-gradient(rgba(176, 196, 222, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(176, 196, 222, 0.045) 1px, transparent 1px),
    radial-gradient(ellipse at 15% 0%, rgba(57, 255, 20, 0.03) 0%, transparent 55%),
    radial-gradient(ellipse at 85% 100%, rgba(255, 107, 0, 0.05) 0%, transparent 55%);
  background-size: 36px 36px, 36px 36px, auto, auto;
  color: var(--color-ice);
  border-bottom: 4px solid var(--color-orange);
}

.site-header__inner {
  padding-top: 8px;
}

/* masthead */
.site-header__masthead {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
  padding: 20px 0 12px;
}

.site-header__masthead-left {
  text-align: left;
}

.site-header__masthead-center {
  text-align: center;
}

.site-header__masthead-right {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
}

.site-header__tagline {
  font-family: var(--font-headline);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.4em;
  color: var(--color-orange);
  text-transform: uppercase;
  line-height: 1.4;
  margin: 0 0 4px;
}

.site-header__coords {
  font-family: var(--font-data);
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--color-blue-gray);
  opacity: 0.55;
  text-transform: uppercase;
  margin: 0;
}

.site-header__brand {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 44px;
  letter-spacing: -0.03em;
  color: var(--color-ice);
  text-decoration: none;
  line-height: 1;
  white-space: nowrap;
  display: inline-block;
  transition: color 0.2s ease;
}

.site-header__brand::before,
.site-header__brand::after {
  content: "/";
  font-family: var(--font-data);
  font-weight: 500;
  font-size: 0.55em;
  color: var(--color-orange);
  margin: 0 6px;
  vertical-align: super;
}

.site-header__brand:hover {
  color: var(--color-paper);
}

/* version badge */
.site-header__version {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border: 1px solid rgba(176, 196, 222, 0.25);
  border-radius: 2px;
  background: rgba(5, 13, 31, 0.5);
  font-family: var(--font-data);
  font-size: 12px;
  color: var(--color-blue-gray);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.site-header__version:hover,
.site-header__version:focus-visible {
  border-color: var(--color-green);
  color: var(--color-green);
  transform: translateY(-1px);
}

.site-header__version-label {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--color-blue-gray);
  opacity: 0.8;
}

.site-header__version-value {
  font-weight: 700;
  letter-spacing: 0.04em;
}

/* navigation */
.site-nav {
  background: transparent;
  border-top: 1px solid var(--header-border-color);
  margin-top: 4px;
}

.site-nav__list {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin: 0;
  padding: 0;
}

.site-nav__item {
  position: relative;
}

.site-nav__link {
  display: block;
  padding: 15px 22px;
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.05em;
  color: var(--color-blue-gray);
  text-decoration: none;
  border-bottom: 3px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  color: var(--color-ice);
  background: rgba(255, 107, 0, 0.06);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-ice);
  border-bottom-color: var(--color-orange);
}

/* nav toggle (desktop hidden) */
.nav-toggle {
  display: none;
}

/* header slant */
.site-header__slant {
  height: 14px;
  width: 108%;
  margin-left: -4%;
  background: linear-gradient(90deg, var(--color-orange) 0%, #ff934a 60%, var(--color-orange) 100%);
  transform: skewY(-0.8deg);
  transform-origin: left;
}

/* ============ footer ============ */
.site-footer {
  position: relative;
  background-color: var(--color-navy-deep);
  background-image:
    linear-gradient(rgba(176, 196, 222, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(176, 196, 222, 0.04) 1px, transparent 1px);
  background-size: 36px 36px;
  color: var(--color-blue-gray);
  margin-top: 80px;
  padding-top: 0;
  border-top: 3px solid var(--color-orange);
}

.site-footer__slant {
  height: 6px;
  width: 108%;
  margin-left: -4%;
  background: linear-gradient(90deg, var(--color-green) 0%, var(--color-orange) 100%);
  transform: skewY(-0.5deg);
  transform-origin: right;
  margin-bottom: 0;
}

.site-footer__inner {
  padding-top: 48px;
  padding-bottom: 32px;
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: 40px;
  margin-bottom: 40px;
}

.site-footer__logo {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 28px;
  letter-spacing: -0.03em;
  color: var(--color-ice);
  line-height: 1;
  display: inline-block;
  margin-bottom: 6px;
}

.site-footer__logo::before,
.site-footer__logo::after {
  content: "/";
  font-family: var(--font-data);
  font-weight: 500;
  font-size: 0.55em;
  color: var(--color-orange);
  margin: 0 4px;
  vertical-align: super;
}

.site-footer__slogan {
  font-family: var(--font-headline);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.35em;
  color: var(--color-orange);
  text-transform: uppercase;
  margin: 0 0 14px;
}

.site-footer__about {
  font-size: 14px;
  line-height: 1.8;
  color: var(--color-blue-gray);
  margin: 0;
  max-width: 30ch;
}

.site-footer__title {
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--color-ice);
  text-transform: uppercase;
  margin: 0 0 16px;
  padding-bottom: 8px;
  position: relative;
}

.site-footer__title::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 28px;
  height: 2px;
  background: var(--color-orange);
}

.site-footer__list {
  margin: 0;
  padding: 0;
}

.site-footer__list li {
  margin-bottom: 10px;
}

.site-footer__list a {
  font-size: 14px;
  color: var(--color-blue-gray);
  text-decoration: none;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.site-footer__list a:hover,
.site-footer__list a:focus-visible {
  color: var(--color-orange);
  padding-left: 4px;
}

.site-footer__contact .site-footer__list li {
  color: var(--color-blue-gray);
  font-size: 14px;
  line-height: 1.7;
}

/* trust panel */
.site-footer__trust {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 20px;
  border: 1px solid rgba(176, 196, 222, 0.15);
  border-left: 3px solid var(--color-green);
  border-radius: 2px;
  background: rgba(27, 58, 107, 0.25);
  margin-bottom: 28px;
}

.site-footer__trust .status-dot {
  margin-top: 8px;
}

.site-footer__trust p {
  font-size: 13px;
  line-height: 1.8;
  color: var(--color-blue-gray);
  margin: 0;
}

/* bottom bar */
.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 32px;
  justify-content: space-between;
  align-items: center;
  padding-top: 20px;
  border-top: 1px solid rgba(176, 196, 222, 0.12);
  font-family: var(--font-data);
  font-size: 12px;
  color: var(--color-blue-gray);
  opacity: 0.75;
}

.site-footer__bottom p {
  margin: 0;
}

/* ============ breadcrumbs ============ */
.breadcrumbs {
  padding: 20px 0;
  font-family: var(--font-data);
  font-size: 12px;
  color: var(--color-blue-gray);
  overflow-x: auto;
  white-space: nowrap;
  scrollbar-width: none;
}

.breadcrumbs::-webkit-scrollbar {
  display: none;
}

.breadcrumbs ol {
  display: flex;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
}

.breadcrumbs li {
  display: flex;
  align-items: center;
}

.breadcrumbs li + li::before {
  content: "/";
  margin: 0 8px;
  color: var(--color-orange);
}

.breadcrumbs a {
  color: var(--color-blue-gray);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

.breadcrumbs [aria-current="page"] {
  color: var(--color-ice);
  font-weight: 700;
}

/* ============ section heading ============ */
.section-heading {
  margin-bottom: 32px;
}

.section-heading__kicker {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--color-orange);
  text-transform: uppercase;
  display: block;
  margin-bottom: 8px;
}

.section-heading__title {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 32px;
  letter-spacing: -0.02em;
  color: var(--color-ice);
  line-height: 1.2;
}

/* ============ panels & data cells ============ */
.panel {
  background: var(--color-navy-light);
  border-left: 3px solid var(--color-orange);
  border-radius: 0 6px 6px 0;
  padding: 20px 24px;
}

.panel__title {
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 16px;
  color: var(--color-ice);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.panel__body {
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-blue-gray);
}

.data-cell {
  background: rgba(5, 13, 31, 0.6);
  border: 1px solid rgba(176, 196, 222, 0.15);
  border-radius: 2px;
  padding: 18px 20px;
}

.data-cell__value {
  font-family: var(--font-data);
  font-size: 36px;
  font-weight: 500;
  color: var(--color-orange);
  line-height: 1;
  letter-spacing: -0.02em;
}

.data-cell__label {
  font-family: var(--font-headline);
  font-size: 12px;
  color: var(--color-blue-gray);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: 8px;
  display: block;
}

/* ============ image frame ============ */
.image-frame {
  position: relative;
  overflow: hidden;
  background: var(--color-navy-light);
  aspect-ratio: 16 / 10;
  border-radius: 2px;
}

.image-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 107, 0, 0.06) 0%, transparent 55%);
  pointer-events: none;
}

.image-frame--portrait {
  aspect-ratio: 4 / 5;
}

.image-frame--square {
  aspect-ratio: 1 / 1;
}

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

/* ============ paper block ============ */
.paper-block {
  background: var(--color-paper);
  color: var(--color-ink);
  border-radius: 4px;
  padding: 28px;
}

.paper-block h2,
.paper-block h3,
.paper-block h4 {
  color: var(--color-ink);
}

.paper-block p {
  color: var(--color-ink);
}

/* ============ data table ============ */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-data);
  font-size: 14px;
}

.data-table th {
  text-align: left;
  padding: 10px 14px;
  border-bottom: 2px solid var(--color-orange);
  color: var(--color-orange);
  text-transform: uppercase;
  font-size: 12px;
  letter-spacing: 0.08em;
  font-weight: 700;
}

.data-table td {
  padding: 10px 14px;
  border-bottom: 1px solid rgba(176, 196, 222, 0.18);
  color: var(--color-ice);
}

.data-table tr:hover td {
  background: rgba(255, 107, 0, 0.05);
}

/* ============ prose ============ */
.prose {
  font-size: 16px;
  line-height: 1.8;
  color: var(--color-blue-gray);
}

.prose p {
  margin-bottom: 18px;
}

.prose h2 {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 24px;
  color: var(--color-ice);
  margin: 44px 0 16px;
}

.prose h3 {
  font-family: var(--font-headline);
  font-weight: 700;
  font-size: 18px;
  color: var(--color-ice);
  margin: 32px 0 12px;
}

.prose a:not(.btn) {
  color: var(--color-orange);
  text-decoration: underline;
  text-decoration-color: rgba(255, 107, 0, 0.35);
  text-underline-offset: 4px;
  transition: text-decoration-color 0.2s ease;
}

.prose a:not(.btn):hover {
  text-decoration-color: var(--color-orange);
}

.prose ul,
.prose ol {
  margin: 0 0 18px;
  padding-left: 24px;
}

.prose ul {
  list-style: square;
}

.prose ol {
  list-style: decimal;
}

.prose li {
  margin-bottom: 8px;
}

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

  .scroll-progress {
    transition: none;
  }

  .skip-link {
    transition: none;
  }
}

/* ============ responsive ============ */
@media (max-width: 1024px) {
  .site-header__brand {
    font-size: 36px;
  }

  .site-nav__link {
    padding: 14px 14px;
    font-size: 13px;
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 768px) {
  .container {
    padding-left: 20px;
    padding-right: 20px;
  }

  .section {
    padding: 48px 0;
  }

  /* header */
  .site-header__masthead {
    grid-template-columns: 1fr auto;
    padding: 14px 0 10px;
  }

  .site-header__masthead-left {
    display: none;
  }

  .site-header__masthead-center {
    text-align: left;
  }

  .site-header__brand {
    font-size: 28px;
  }

  .site-header__version {
    padding: 5px 10px;
    font-size: 11px;
    gap: 6px;
  }

  .site-header__version-label {
    display: none;
  }

  /* nav toggle */
  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    width: 42px;
    height: 42px;
    border: 1px solid rgba(255, 107, 0, 0.45);
    background: rgba(255, 107, 0, 0.1);
    border-radius: 2px;
    padding: 0;
    transition: background 0.2s ease, border-color 0.2s ease;
  }

  .nav-toggle:hover,
  .nav-toggle[aria-expanded="true"] {
    background: rgba(255, 107, 0, 0.18);
    border-color: var(--color-orange);
  }

  .nav-toggle__label {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
  }

  .nav-toggle__bars {
    display: flex;
    flex-direction: column;
    gap: 5px;
    align-items: center;
  }

  .nav-toggle__bar {
    display: block;
    width: 18px;
    height: 2px;
    background: var(--color-orange);
    transition: transform 0.25s ease, opacity 0.25s ease;
  }

  .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);
  }

  /* mobile nav dropdown */
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 100;
    display: none;
    margin: 0;
    background: var(--color-navy-deep);
    border-top: none;
    border-bottom: 3px solid var(--color-orange);
    box-shadow: 0 16px 32px rgba(5, 13, 31, 0.55);
  }

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

  .site-nav__list {
    flex-direction: column;
    padding: 8px 20px 16px;
  }

  .site-nav__link {
    padding: 14px 0;
    border-bottom: 1px solid rgba(176, 196, 222, 0.1);
    border-left: 3px solid transparent;
    font-size: 15px;
  }

  .site-nav__link:hover,
  .site-nav__link:focus-visible {
    background: transparent;
    border-left-color: var(--color-orange);
  }

  .site-nav__link[aria-current="page"] {
    border-bottom-color: transparent;
    border-left-color: var(--color-orange);
    padding-left: 12px;
    background: rgba(255, 107, 0, 0.06);
  }

  /* footer */
  .site-footer {
    margin-top: 56px;
  }

  .site-footer__inner {
    padding-top: 36px;
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .site-footer__trust {
    flex-direction: column;
    gap: 8px;
  }

  .site-footer__bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
}

@media (max-width: 480px) {
  .site-header__brand {
    font-size: 24px;
  }

  .site-header__brand::before,
  .site-header__brand::after {
    margin: 0 3px;
  }

  .section {
    padding: 40px 0;
  }

  .data-cell__value {
    font-size: 28px;
  }

  .paper-block {
    padding: 20px;
  }
}