:root {
  --color-primary: #0A1E3C;
  --color-accent-green: #39FF14;
  --color-accent-orange: #FF6B00;
  --color-secondary: #102A4C;
  --color-light: #F2F6FA;
  --color-text: #E6EDF3;
  --color-text-subtle: #9AB0C0;
  --color-border: #1D3A5F;
  --color-white: #FFFFFF;
  --color-ink: #15202E;
  --color-ink-soft: #64758A;
  --font-headline: "Archivo Black", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, "SF Mono", Consolas, monospace;
}

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

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

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  background: var(--color-primary);
  color: var(--color-text);
  -webkit-font-smoothing: antialiased;
}

main {
  flex: 1;
}

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

ul,
ol {
  list-style: none;
}

a {
  color: inherit;
}

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

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

.fb-container {
  width: min(1200px, 100% - 2rem);
  margin-inline: auto;
}

.fb-skip-link {
  position: fixed;
  top: 0.75rem;
  left: 0.75rem;
  z-index: 9999;
  transform: translateY(calc(-100% - 2rem));
  background: var(--color-accent-green);
  color: var(--color-primary);
  font-weight: 700;
  font-size: 0.875rem;
  padding: 0.625rem 1rem;
  text-decoration: none;
  box-shadow: 0 0 0 4px rgba(10, 30, 60, 0.85);
  transition: transform 0.2s ease;
}
.fb-skip-link:focus {
  transform: translateY(0);
}

.fb-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  padding: 0.5rem 1rem;
  border: 2px solid transparent;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease, color 0.2s ease;
}
.fb-btn--accent {
  background: var(--color-accent-orange);
  color: var(--color-primary);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.3);
}
.fb-btn--accent:hover {
  background: #FF8540;
  transform: translateY(-2px);
  box-shadow: 5px 6px 0 rgba(0, 0, 0, 0.35);
}
.fb-btn--ghost {
  border-color: var(--color-border);
  color: var(--color-text);
  background: transparent;
}
.fb-btn--ghost:hover {
  border-color: var(--color-accent-green);
  color: var(--color-accent-green);
}

.fb-header {
  position: relative;
  z-index: 50;
  background: var(--color-primary);
}
.fb-header__main {
  border-bottom: 1px solid var(--color-border);
}
.fb-header__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1rem;
  padding-block: 1rem;
}
.fb-header__btn {
  font-size: 0.8125rem;
  padding: 0.4375rem 0.75rem;
}

.fb-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
}
.fb-brand__mark {
  display: inline-grid;
  place-items: center;
  width: 2.5rem;
  height: 2.5rem;
  background: var(--color-accent-green);
  color: var(--color-primary);
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 1rem;
  letter-spacing: -0.02em;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 82% 100%, 0 100%);
}
.fb-brand__name {
  font-family: var(--font-headline);
  font-weight: 900;
  font-size: 1.25rem;
  color: var(--color-text);
}

.fb-nav {
  margin-left: auto;
}
.fb-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.125rem;
}
.fb-nav__link {
  display: block;
  position: relative;
  padding: 0.5rem 0.625rem;
  color: var(--color-text);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-decoration: none;
  border-bottom: 3px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}
.fb-nav__link:hover {
  color: var(--color-accent-green);
  border-bottom-color: var(--color-accent-green);
}
.fb-nav__link[aria-current="page"] {
  color: var(--color-accent-orange);
  border-bottom-color: var(--color-accent-orange);
}

.fb-nav-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.625rem;
  background: transparent;
  border: 1px solid var(--color-border);
  color: var(--color-text);
  cursor: pointer;
  line-height: 1;
}
.fb-nav-toggle:hover {
  border-color: var(--color-accent-green);
}
.fb-nav-toggle.is-active {
  border-color: var(--color-accent-green);
}
.fb-nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 1.25rem;
}
.fb-nav-toggle__bar {
  display: block;
  height: 2px;
  background: var(--color-accent-green);
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.fb-nav-toggle.is-active .fb-nav-toggle__bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}
.fb-nav-toggle.is-active .fb-nav-toggle__bar:nth-child(2) {
  opacity: 0;
}
.fb-nav-toggle.is-active .fb-nav-toggle__bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}
.fb-nav-toggle__text {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.fb-header__tags {
  position: relative;
  background: var(--color-secondary);
  border-top: 1px solid var(--color-border);
  border-bottom: 2px solid var(--color-border);
}
.fb-header__tags::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 4px;
  background: var(--color-accent-green);
  pointer-events: none;
}
.fb-header__tags-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding-block: 0.5rem;
  overflow-x: auto;
  scrollbar-width: none;
}
.fb-header__tags-row::-webkit-scrollbar {
  display: none;
}
.fb-header__tags-label {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-text-subtle);
}
.fb-tag {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.25rem 0.625rem;
  background: var(--color-primary);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  font-size: 0.75rem;
  font-weight: 600;
  text-decoration: none;
  transition: border-color 0.2s ease, color 0.2s ease;
}
.fb-tag::before {
  content: "";
  width: 5px;
  height: 5px;
  flex-shrink: 0;
  background: var(--color-accent-green);
  animation: fb-pulse 2s ease-in-out infinite;
}
.fb-tag:hover {
  border-color: var(--color-accent-green);
  color: var(--color-accent-green);
}

@keyframes fb-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

.fb-footer {
  margin-top: 3rem;
  background: var(--color-primary);
}
.fb-footer__signal {
  height: 4px;
  background: linear-gradient(90deg, var(--color-accent-green) 0%, var(--color-secondary) 25%, var(--color-accent-orange) 50%, var(--color-border) 75%, var(--color-primary) 100%);
}
.fb-footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.25fr 1fr;
  gap: 2rem;
  padding: 3rem 0 2.5rem;
}
.fb-footer__col {
  min-width: 0;
}
.fb-footer__col--brand {
  display: grid;
  align-content: start;
  gap: 1rem;
}
.fb-brand--footer .fb-brand__mark {
  width: 2.75rem;
  height: 2.75rem;
}
.fb-brand--footer .fb-brand__name {
  font-size: 1.375rem;
  color: var(--color-white);
}
.fb-footer__desc {
  max-width: 30ch;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--color-text-subtle);
}
.fb-footer__badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.fb-badge {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  background: var(--color-secondary);
  border: 1px solid var(--color-border);
  color: var(--color-accent-green);
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.06em;
}
.fb-footer__heading {
  margin: 0 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text);
  font-family: var(--font-headline);
  font-size: 0.8125rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.fb-footer__heading::before {
  content: "// ";
  color: var(--color-accent-green);
}
.fb-footer__links {
  display: grid;
  gap: 0.625rem;
}
.fb-footer__link {
  display: inline-block;
  color: var(--color-text-subtle);
  font-size: 0.8125rem;
  text-decoration: none;
  transition: color 0.2s ease, transform 0.2s ease;
}
.fb-footer__link:hover {
  color: var(--color-accent-green);
  transform: translateX(3px);
}
.fb-footer__contact {
  display: grid;
  gap: 0.5rem;
}
.fb-footer__contact-item {
  font-size: 0.8125rem;
  line-height: 1.55;
  color: var(--color-text-subtle);
  overflow-wrap: anywhere;
}
.fb-footer__time {
  margin-top: 0.5rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--color-border);
  font-size: 0.75rem;
}
.fb-footer__bottom {
  border-top: 1px solid var(--color-border);
}
.fb-footer__bottom-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.375rem 1rem;
  padding-block: 1rem;
  color: var(--color-text-subtle);
  font-size: 0.75rem;
}
.fb-footer__copy,
.fb-footer__icp {
  margin: 0;
}

.fb-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem 0.375rem;
  padding: 0.875rem 0;
  color: var(--color-ink-soft);
  font-size: 0.75rem;
}
.fb-breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
}
.fb-breadcrumb__item + .fb-breadcrumb__item::before {
  content: "/";
  font-family: var(--font-mono);
  color: var(--color-border);
}
.fb-breadcrumb__link {
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: color 0.2s ease;
}
.fb-breadcrumb__link:hover {
  color: var(--color-accent-orange);
}
.fb-breadcrumb__item[aria-current="page"] {
  color: var(--color-primary);
  font-weight: 600;
}

.fb-section {
  padding: 3.5rem 0;
}
.fb-section--tight {
  padding: 2rem 0;
}
.fb-section__label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
  padding: 0.375rem 0.75rem;
  background: var(--color-secondary);
  border-left: 3px solid var(--color-accent-green);
  color: var(--color-accent-green);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.fb-panel {
  padding: 1.25rem;
  background: var(--color-secondary);
  border: 1px solid var(--color-border);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, 0.18);
}

.fb-frame {
  padding: 1.5rem;
  background: var(--color-secondary);
  border: 2px solid var(--color-border);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.22);
}

.fb-grid {
  display: grid;
  gap: 1.5rem;
}
.fb-grid--2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}
.fb-grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.fb-prose {
  max-width: 68ch;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--color-ink);
}
.fb-prose h1,
.fb-prose h2,
.fb-prose h3,
.fb-prose h4 {
  color: var(--color-primary);
  font-family: var(--font-headline);
  line-height: 1.25;
  margin: 1.4em 0 0.55em;
}
.fb-prose h1 { font-size: 2rem; }
.fb-prose h2 { font-size: 1.5rem; }
.fb-prose h3 { font-size: 1.125rem; }
.fb-prose p { margin-bottom: 1rem; }
.fb-prose a {
  color: #E85C00;
  text-decoration: underline;
  text-underline-offset: 0.15em;
}
.fb-prose a:hover { color: #C24E00; }
.fb-prose ul,
.fb-prose ol {
  margin: 0 0 1rem 1.25rem;
}
.fb-prose ul { list-style: disc; }
.fb-prose ol { list-style: decimal; }
.fb-prose li { margin-bottom: 0.375rem; }
.fb-prose strong { color: var(--color-primary); }
.fb-prose blockquote {
  margin: 1.5rem 0;
  padding: 0.75rem 1rem;
  border-left: 4px solid var(--color-accent-green);
  background: #E4EBF3;
  color: var(--color-primary);
}

.fb-figure {
  position: relative;
  display: block;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background-color: var(--color-secondary);
  background-image: linear-gradient(135deg, rgba(57, 255, 20, 0.06) 25%, transparent 25%), linear-gradient(225deg, rgba(57, 255, 20, 0.06) 25%, transparent 25%);
  background-size: 1.5rem 1.5rem;
  border: 1px solid var(--color-border);
}
.fb-figure::before {
  content: attr(data-caption);
  position: absolute;
  top: auto;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 0.375rem 0.625rem;
  color: transparent;
  background: transparent;
  font-size: 0.6875rem;
  letter-spacing: 0.05em;
}
.fb-figure[data-caption]:not([data-caption=""])::before {
  color: var(--color-text);
  background: rgba(10, 30, 60, 0.88);
  border-top: 1px solid var(--color-border);
}
.fb-figure::after {
  content: "FB";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: var(--color-border);
  font-family: var(--font-headline);
  font-size: 2.5rem;
  letter-spacing: -0.04em;
  opacity: 0.8;
}

.fb-mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

.fb-page--light {
  background: var(--color-light);
  color: var(--color-ink);
}
.fb-page--light h1,
.fb-page--light h2,
.fb-page--light h3,
.fb-page--light h4,
.fb-page--light h5,
.fb-page--light h6 {
  color: var(--color-primary);
}

.fb-scrollprogress {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  z-index: 9998;
  background: linear-gradient(90deg, var(--color-accent-green), var(--color-accent-orange));
  transform-origin: 0 50%;
  transform: scaleX(0);
  pointer-events: none;
  will-change: transform;
}

@media (min-width: 768px) and (max-width: 1023px) {
  .fb-nav__link {
    padding: 0.5rem 0.375rem;
    font-size: 0.8125rem;
    letter-spacing: 0.02em;
  }
  .fb-header__btn {
    padding: 0.4375rem 0.625rem;
    font-size: 0.75rem;
  }
  .fb-footer__grid {
    grid-template-columns: 1fr 1fr;
  }
  .fb-grid--3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 767px) {
  .fb-header__row {
    padding-block: 0.75rem;
    gap: 0.5rem 0.75rem;
  }
  .fb-header__btn {
    margin-left: auto;
  }
  .fb-nav {
    flex-basis: 100%;
    order: 99;
    margin-left: 0;
    max-height: 0;
    overflow: hidden;
    border-top: 1px solid var(--color-border);
    transition: max-height 0.3s ease;
  }
  .fb-nav[data-open] {
    max-height: 22rem;
  }
  .fb-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .fb-nav__item {
    border-bottom: 1px solid var(--color-border);
  }
  .fb-nav__link {
    border-bottom: none;
  }
  .fb-nav__link[aria-current="page"] {
    border-bottom: none;
    border-left: 3px solid var(--color-accent-orange);
    color: var(--color-accent-orange);
  }
  .fb-nav-toggle {
    display: inline-flex;
  }
  .fb-header__tags-label {
    display: none;
  }
  .fb-footer__grid {
    grid-template-columns: 1fr;
    gap: 2.25rem;
    padding: 2.25rem 0 2rem;
  }
  .fb-grid--2,
  .fb-grid--3 {
    grid-template-columns: 1fr;
  }
  .fb-section {
    padding: 2.5rem 0;
  }
}

@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;
  }
}