:root {
  --color-bg: #04101B;
  --color-bg-alt: #071B2F;
  --color-card: #0C2A45;
  --color-line: #123B5C;
  --color-accent: #B7FF00;
  --color-solar: #FF8A00;
  --color-link: #75D3F5;
  --color-heading: #F4F9FF;
  --color-body: #C2D5E3;
  --color-muted: #6E8BA3;
  --font-heading: "Archivo Black", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-num: "Roboto Mono", "SFMono-Regular", Consolas, monospace;
  --header-h: 72px;
  --nav-w: 96px;
  --content-max: 1200px;
  --space-section: clamp(3rem, 7vw, 5.5rem);
  --radius-card: 14px 6px 14px 6px;
  --shadow: 0 8px 24px rgba(0, 0, 0, 0.35);
}

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

* {
  margin: 0;
  padding: 0;
}

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

body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-body);
  background-color: var(--color-bg);
  background-image:
    linear-gradient(to right, rgba(18, 59, 92, 0.18) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(18, 59, 92, 0.18) 1px, transparent 1px);
  background-size: 32px 32px;
  padding: var(--header-h) 0 0 var(--nav-w);
  overflow-wrap: break-word;
  word-break: break-word;
}

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

figure {
  margin: 0;
}

a {
  color: var(--color-link);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}

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

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

h1 { font-size: clamp(2.8rem, 6vw, 4.2rem); }
h2 { font-size: clamp(2rem, 4vw, 3.1rem); }
h3 { font-size: clamp(1.4rem, 2.5vw, 2.2rem); }
h4 { font-size: clamp(1.1rem, 1.5vw, 1.6rem); }

p {
  margin-bottom: 1rem;
}

ul, ol {
  padding-left: 1.25rem;
}

hr {
  border: 0;
  border-top: 1px solid var(--color-line);
  margin: 2rem 0;
}

code, kbd, samp {
  font-family: var(--font-num);
  font-size: 0.92em;
}

pre {
  background: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-card);
  padding: 1rem;
  overflow: auto;
}

[hidden] {
  display: none !important;
}

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

.container {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 32px);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border: 1px solid transparent;
  border-radius: 4px;
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 1rem;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.3);
}

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

.btn--accent:hover {
  background: #c6ff1a;
  color: var(--color-bg);
}

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

.btn--ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: rgba(183, 255, 0, 0.05);
}

.btn--sm {
  padding: 7px 14px;
  font-size: 0.9rem;
}

.site-header {
  position: relative;
}

.skip-link {
  position: fixed;
  top: -100%;
  left: 16px;
  z-index: 200;
  display: inline-block;
  background: var(--color-accent);
  color: var(--color-bg);
  padding: 10px 16px;
  border-radius: 4px;
  font-weight: 700;
  text-decoration: none;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 16px;
}

.site-header__bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  background: rgba(4, 16, 27, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-line);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--color-heading);
  text-decoration: none;
}

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

.site-brand__mark {
  width: 28px;
  height: 28px;
  border-radius: 3px;
  background: var(--color-accent);
  box-shadow: 0 0 12px rgba(183, 255, 0, 0.45);
  position: relative;
}

.site-brand__mark::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  border-style: solid;
  border-width: 8px 8px 0 0;
  border-color: var(--color-bg) transparent transparent transparent;
}

.site-brand__text {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 900;
  letter-spacing: -0.02em;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--color-line);
  border-radius: 6px;
  background: transparent;
  cursor: pointer;
  color: var(--color-heading);
}

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

.nav-toggle__icon,
.nav-toggle__icon::before,
.nav-toggle__icon::after {
  content: "";
  display: block;
  width: 20px;
  height: 2px;
  background: currentColor;
}

.nav-toggle__icon {
  position: relative;
  transition: background-color 0.2s ease;
}

.nav-toggle__icon::before {
  position: absolute;
  top: -6px;
  left: 0;
  transition: transform 0.2s ease, top 0.2s ease;
}

.nav-toggle__icon::after {
  position: absolute;
  bottom: -6px;
  left: 0;
  transition: transform 0.2s ease, bottom 0.2s ease;
}

.nav-toggle[aria-expanded="false"] .nav-toggle__icon {
  background-color: transparent;
}

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

.nav-toggle[aria-expanded="false"] .nav-toggle__icon::after {
  bottom: 0;
  transform: rotate(-45deg);
}

.nav-toggle__text {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.site-nav {
  position: fixed;
  top: var(--header-h);
  left: 0;
  bottom: 0;
  width: var(--nav-w);
  z-index: 99;
  padding: 24px 0;
  background: rgba(7, 27, 47, 0.92);
  border-right: 1px solid var(--color-line);
}

.site-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.site-nav__item {
  margin: 0;
}

.site-nav__link {
  display: block;
  padding: 12px 20px;
  font-weight: 700;
  color: var(--color-body);
  text-decoration: none;
  border-left: 3px solid transparent;
  font-size: 0.95rem;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.site-nav__link:hover {
  color: var(--color-heading);
  background: rgba(183, 255, 0, 0.06);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-heading);
  border-left-color: var(--color-accent);
  background: linear-gradient(90deg, rgba(183, 255, 0, 0.12), transparent 70%);
}

.breadcrumbs {
  padding-block: 1rem;
}

.breadcrumbs__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.875rem;
  color: var(--color-muted);
}

.breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  margin-right: 8px;
  color: var(--color-line);
}

.breadcrumbs__link {
  color: var(--color-link);
  text-decoration: none;
}

.breadcrumbs__link[aria-current="page"] {
  color: var(--color-body);
}

.section {
  padding-block: var(--space-section);
}

.section--alt {
  background: var(--color-bg-alt);
  border-block: 1px solid var(--color-line);
}

.section__heading {
  margin-bottom: 1rem;
}

.section__lead {
  max-width: 65ch;
  margin-bottom: 2rem;
  font-size: 1.1rem;
  color: var(--color-body);
}

.grid {
  display: grid;
  gap: 24px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.card {
  background: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-card);
  padding: 24px;
  box-shadow: var(--shadow);
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--color-accent);
}

.card__title {
  margin-bottom: 0.5rem;
}

.card__text {
  margin-bottom: 1rem;
}

.card__link {
  text-decoration: none;
  font-weight: 700;
  color: var(--color-accent);
}

.card__link:hover {
  color: var(--color-heading);
}

.img-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--color-card);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-card);
}

.img-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(115deg, transparent 20%, rgba(117, 211, 245, 0.2) 45%, rgba(255, 138, 0, 0.15) 55%, transparent 80%);
  opacity: 0.9;
}

.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.35;
  background-image:
    linear-gradient(to right, var(--color-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--color-line) 1px, transparent 1px);
  background-size: 24px 24px;
  pointer-events: none;
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 24px;
}

.filter-btn {
  background: transparent;
  border: 1px solid var(--color-line);
  color: var(--color-body);
  padding: 8px 18px;
  border-radius: 999px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.filter-btn:hover {
  border-color: var(--color-accent);
  color: var(--color-heading);
}

.filter-btn[aria-pressed="true"],
.filter-btn.is-active {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-bg);
}

.filter-item[hidden] {
  display: none;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--color-accent), var(--color-solar));
  z-index: 300;
  pointer-events: none;
  transition: width 0.1s linear;
}

.site-footer {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-line);
  padding-block: 4rem 0;
  margin-top: 4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  padding-block: 2rem 2.5rem;
}

.footer-heading {
  font-family: var(--font-heading);
  font-size: 0.95rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-heading);
  margin-bottom: 1rem;
}

.site-brand--footer .site-brand__text {
  font-size: 1.5rem;
}

.footer-brand {
  display: grid;
  gap: 1rem;
  align-content: start;
}

.footer-brand__tagline {
  color: var(--color-link);
  font-weight: 700;
}

.footer-brand__statement {
  color: var(--color-muted);
  font-size: 0.95rem;
}

.footer-nav__list,
.footer-legal__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.footer-nav__link,
.footer-legal__link {
  color: var(--color-body);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.2s ease;
}

.footer-nav__link:hover,
.footer-legal__link:hover {
  color: var(--color-accent);
}

.footer-nav__link[aria-current="page"],
.footer-legal__link[aria-current="page"] {
  color: var(--color-accent);
}

.footer-contact {
  color: var(--color-body);
}

.footer-contact__line {
  margin-bottom: 0.4rem;
}

.footer-contact__note {
  color: var(--color-muted);
  font-size: 0.875rem;
  margin-top: 0.75rem;
  margin-bottom: 0.75rem;
}

.footer-legal__text {
  color: var(--color-muted);
  display: block;
}

.site-footer__bottom {
  border-top: 1px solid var(--color-line);
  padding-block: 1.25rem;
  text-align: center;
  color: var(--color-muted);
  font-size: 0.875rem;
}

.site-footer__bottom p {
  margin: 0;
}

@media (max-width: 1023px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 767px) {
  body {
    padding: var(--header-h) 0 80px;
  }

  .site-header__bar {
    padding: 0 16px;
  }

  .site-brand__text {
    font-size: 1.15rem;
  }

  .btn--sm {
    padding: 6px 12px;
    font-size: 0.85rem;
  }

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

  .site-nav {
    position: fixed;
    top: auto;
    left: 0;
    right: 0;
    bottom: 0;
    width: auto;
    height: auto;
    padding: 8px 0;
    background: rgba(7, 27, 47, 0.98);
    border-top: 1px solid var(--color-line);
    border-right: 0;
    box-shadow: 0 -8px 24px rgba(0, 0, 0, 0.3);
    transform: translateY(100%);
    transition: transform 0.25s ease;
  }

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

  .site-nav__list {
    flex-direction: row;
    gap: 0;
    justify-content: space-around;
  }

  .site-nav__item {
    flex: 1;
  }

  .site-nav__link {
    padding: 8px 4px;
    font-size: 0.78rem;
    text-align: center;
    border-left: 0;
    border-top: 2px solid transparent;
    background: transparent;
  }

  .site-nav__link[aria-current="page"] {
    border-left: 0;
    border-top-color: var(--color-accent);
    background: transparent;
  }

  .site-nav__link:hover {
    background: rgba(183, 255, 0, 0.08);
  }

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

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

@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;
  }

  .site-nav,
  .scroll-progress {
    transition: none;
  }
}