*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; font-family: var(--font-body); font-size: var(--text-body); line-height: 1.7; color: var(--c-text-body); background: var(--c-light); -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; }
img, svg, video { max-width: 100%; height: auto; display: block; }
button, input, select, textarea { font: inherit; color: inherit; }
:root {
  --c-primary: #0B1B3D;
  --c-accent: #39FF14;
  --c-data: #FF6B35;
  --c-light: #F4F7FB;
  --c-white: #FFFFFF;
  --c-text-dark: #E6EDF7;
  --c-text-dim: #8CA3C0;
  --c-text-body: #10203A;
  --c-text-soft: #3E4E68;
  --c-line-dark: #1F3455;
  --c-line-light: #D6DFEA;
  --font-head: "Noto Serif SC", "Source Han Serif SC", "Songti SC", SimSun, serif;
  --font-body: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --text-h1: clamp(30px, 5vw, 48px);
  --text-h2: clamp(24px, 3.6vw, 32px);
  --text-h3: 24px;
  --text-body: 16px;
  --text-small: 13px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 40px;
  --space-5: 64px;
  --space-6: 96px;
  --header-h: 72px;
  --content-w: 1240px;
}
h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 900;
  line-height: 1.25;
  color: var(--c-primary);
  margin: 0 0 var(--space-2);
}
h1 { font-size: var(--text-h1); line-height: 1.18; }
h2 { font-size: var(--text-h2); }
h3 { font-size: var(--text-h3); }
h4 { font-size: 18px; }
.board--dark h1, .board--dark h2, .board--dark h3, .board--dark h4 { color: var(--c-text-dark); }
a { color: inherit; }
::selection { background: var(--c-accent); color: var(--c-primary); }
:focus-visible { outline: 2px solid var(--c-accent); outline-offset: 3px; }

.skip-link {
  position: fixed;
  top: var(--space-1);
  left: var(--space-1);
  z-index: 310;
  background: var(--c-accent);
  color: var(--c-primary);
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 14px;
  padding: 10px 16px;
  text-decoration: none;
  transform: translateY(-260%);
  transition: transform .15s ease;
}
.skip-link:focus { transform: translateY(0); }

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: var(--c-accent);
  box-shadow: 0 0 8px rgba(57, 255, 20, 0.6);
  z-index: 320;
  pointer-events: none;
}

.back-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 300;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  width: 54px;
  height: 54px;
  padding: 0;
  background: rgba(11, 27, 61, 0.92);
  border: 1px solid var(--c-line-dark);
  color: var(--c-accent);
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.1em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity .18s ease, transform .18s ease, border-color .15s ease, box-shadow .15s ease, visibility 0s linear .18s;
}
.back-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition-delay: 0s;
}
.back-top:hover {
  border-color: var(--c-accent);
  box-shadow: 0 0 16px rgba(57, 255, 20, 0.3);
}
.back-top__arrow { font-size: 18px; line-height: 1; }
.back-top__text { font-size: 9px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background-color: var(--c-primary);
  background-image:
    linear-gradient(rgba(57, 255, 20, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(57, 255, 20, 0.035) 1px, transparent 1px);
  background-size: 32px 32px;
  border-bottom: 1px solid var(--c-line-dark);
  color: var(--c-text-dark);
}
.site-header__inner {
  max-width: var(--content-w);
  margin-inline: auto;
  padding-inline: var(--space-2);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}
.site-header__rule {
  position: relative;
  height: 8px;
  border-top: 1px solid var(--c-line-dark);
  background-image: repeating-linear-gradient(90deg, var(--c-line-dark) 0 1px, transparent 1px 30px);
}
.site-header__rule-signal {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 108px;
  background: var(--c-accent);
  clip-path: polygon(0 0, 76% 0, 42% 100%, 0 100%);
  opacity: 0.9;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--c-white);
  text-decoration: none;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 22px;
  line-height: 1;
  letter-spacing: 0.03em;
  white-space: nowrap;
}
.brand:hover { color: var(--c-white); }
.brand__lamp {
  width: 10px;
  height: 10px;
  background: var(--c-accent);
  border: 1px solid rgba(11, 27, 61, 0.4);
  box-shadow: 0 0 6px rgba(57, 255, 20, 0.9), 0 0 20px rgba(57, 255, 20, 0.35);
}
.brand__name { display: inline-block; }
.brand__domain {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--c-accent);
  margin-left: -4px;
  letter-spacing: 0.06em;
}

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--c-line-dark);
  color: var(--c-text-dark);
  cursor: pointer;
  transition: border-color .15s ease, color .15s ease;
}
.nav-toggle:hover { border-color: var(--c-accent); color: var(--c-accent); }
.nav-toggle__glyph { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.nav-toggle__bar {
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform .2s ease, opacity .2s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1) { transform: translateY(6px) 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(-6px) rotate(-45deg); }

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.site-nav__list { display: flex; align-items: center; gap: 2px; list-style: none; margin: 0; padding: 0; }
.site-nav__item { margin: 0; }
.nav-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 10px 12px;
  color: var(--c-text-dim);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  white-space: nowrap;
  letter-spacing: 0.02em;
}
.nav-link__code {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 700;
  color: var(--c-accent);
  opacity: 0.55;
  letter-spacing: 0.1em;
}
.nav-link__label { display: inline-block; }
.nav-link::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 4px;
  height: 2px;
  background: var(--c-accent);
  box-shadow: 0 0 6px rgba(57, 255, 20, 0.6);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .18s ease;
}
.nav-link:hover { color: var(--c-white); }
.nav-link:hover .nav-link__code { opacity: 1; }
.nav-link:hover::after,
.nav-link[aria-current="page"]::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { color: var(--c-white); }
.nav-link[aria-current="page"] .nav-link__code { opacity: 1; }
.site-nav__status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding-left: var(--space-3);
  border-left: 1px solid var(--c-line-dark);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--c-text-dim);
  white-space: nowrap;
}
.site-nav__status-dot {
  width: 6px;
  height: 6px;
  background: var(--c-accent);
  box-shadow: 0 0 8px rgba(57, 255, 20, 0.8);
}

.site-footer {
  position: relative;
  z-index: 50;
  background-color: var(--c-primary);
  background-image:
    linear-gradient(rgba(57, 255, 20, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(57, 255, 20, 0.03) 1px, transparent 1px);
  background-size: 32px 32px;
  border-top: 1px solid var(--c-line-dark);
  color: var(--c-text-dark);
}
.site-footer__top,
.site-footer__meta,
.site-footer__bar {
  max-width: var(--content-w);
  margin-inline: auto;
  padding-inline: var(--space-2);
}
.site-footer__top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: var(--space-4);
  padding-top: var(--space-5);
  padding-bottom: var(--space-4);
}
.site-footer__col { min-width: 0; }
.site-footer__col--brand { min-width: 0; }
.site-footer__note {
  margin: var(--space-2) 0 var(--space-2);
  padding-left: 10px;
  border-left: 3px solid var(--c-accent);
  color: var(--c-accent);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.6;
}
.site-footer__desc {
  margin: 0;
  max-width: 36ch;
  color: var(--c-text-dim);
  font-size: 13px;
  line-height: 1.7;
}
.site-footer__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--c-accent);
  text-transform: uppercase;
}
.site-footer__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}
.site-footer__list a {
  display: inline-block;
  padding-left: 0;
  color: var(--c-text-dim);
  font-size: 14px;
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color .15s ease, padding-left .15s ease, border-color .15s ease;
}
.site-footer__list a:hover {
  color: var(--c-accent);
  border-left-color: var(--c-accent);
  padding-left: 8px;
}
.site-footer__phone {
  margin: 0 0 2px;
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--c-data);
}
.site-footer__mail {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-text-dim);
}
.site-footer__hour {
  margin: 0;
  font-size: 12px;
  line-height: 1.6;
  color: var(--c-text-dim);
}
.site-footer__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-4);
  border-top: 1px solid var(--c-line-dark);
  padding-top: var(--space-2);
  padding-bottom: var(--space-2);
  font-size: 13px;
  color: var(--c-text-dim);
}
.site-footer__icp,
.site-footer__addr,
.site-footer__meta-note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
}
.site-footer__bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  border-top: 1px solid var(--c-line-dark);
  padding-top: var(--space-2);
  padding-bottom: var(--space-2);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-text-dim);
}
.site-footer__copy,
.site-footer__trust,
.site-footer__health { margin: 0; }
.site-footer__trust { color: var(--c-text-dim); }
.site-footer__health { display: inline-flex; align-items: center; gap: 8px; }
.site-footer__health-dot {
  width: 6px;
  height: 6px;
  background: var(--c-accent);
  box-shadow: 0 0 8px rgba(57, 255, 20, 0.8);
}

.container { width: 100%; max-width: var(--content-w); margin-inline: auto; padding-inline: var(--space-2); }
.container--narrow { max-width: 780px; }
.grid { display: grid; gap: var(--space-3); }
.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)); }
.section { padding: var(--space-5) 0; }
.section--tight { padding: var(--space-3) 0; }
.section--dark { background: var(--c-primary); color: var(--c-text-dark); }

.board {
  position: relative;
  padding: var(--space-4);
  background: var(--c-white);
  border: 1px solid var(--c-line-light);
}
.board--light { background: var(--c-light); border-color: var(--c-line-light); }
.board--dark { background: var(--c-primary); border-color: var(--c-line-dark); color: var(--c-text-dark); }
.board__coord {
  position: absolute;
  top: -1px;
  left: -1px;
  z-index: 1;
  padding: 4px 8px;
  background: var(--c-accent);
  color: var(--c-primary);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
}

.chapter { padding: var(--space-6) 0; }
.chapter__header {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: var(--space-3);
  align-items: start;
  margin-bottom: var(--space-4);
}
.chapter__idx {
  font-family: var(--font-mono);
  font-size: 64px;
  font-weight: 700;
  line-height: 0.9;
  color: var(--c-primary);
}
@supports (-webkit-text-stroke: 1px black) {
  .chapter__idx {
    color: transparent;
    -webkit-text-stroke: 1.5px var(--c-primary);
  }
  .chapter__idx--accent { -webkit-text-stroke-color: var(--c-accent); }
}
.chapter__title { margin: 0 0 8px; }
.chapter__lead {
  margin: 0;
  max-width: 48ch;
  color: var(--c-text-soft);
  font-size: 14px;
  line-height: 1.7;
}

.card {
  padding: var(--space-3);
  background: var(--c-white);
  border: 1px solid var(--c-line-light);
  transition: border-color .15s ease, box-shadow .15s ease, transform .15s ease;
}
.card--dark { background: var(--c-primary); border-color: var(--c-line-dark); color: var(--c-text-dark); }
.card--lg { padding: var(--space-4); }
.card--interactive:hover {
  border-color: var(--c-accent);
  box-shadow: 5px 5px 0 rgba(57, 255, 20, 0.15);
  transform: translate(-2px, -2px);
}
.card__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 900;
}
.card__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}
.card--dark .card__text { color: var(--c-text-dim); }

.stat { display: grid; gap: 4px; }
.stat__value {
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--c-primary);
  font-variant-numeric: tabular-nums;
}
.stat__value--data { color: var(--c-data); }
.stat__value--accent { color: var(--c-accent); }
.stat__label {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-text-soft);
  text-transform: uppercase;
}
.board--dark .stat__value { color: var(--c-text-dark); }
.board--dark .stat__label { color: var(--c-text-dim); }

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding: var(--space-2);
  background: rgba(11, 27, 61, 0.55);
  border: 1px solid var(--c-line-dark);
  border-left: 3px solid var(--c-accent);
}
.legend__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  font-size: 12px;
  color: var(--c-text-dim);
}
.legend__dot {
  width: 8px;
  height: 8px;
  background: var(--c-accent);
  box-shadow: 0 0 4px rgba(57, 255, 20, 0.6);
}
.legend__dot--data { background: var(--c-data); box-shadow: none; }
.legend__dot--line { background: transparent; border: 1px solid var(--c-text-dim); box-shadow: none; }

.coord {
  display: inline-block;
  padding: 4px 8px;
  background: rgba(11, 27, 61, 0.75);
  border: 1px solid var(--c-line-dark);
  color: var(--c-accent);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  background: rgba(11, 27, 61, 0.85);
  border: 1px solid var(--c-line-dark);
  color: var(--c-accent);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 22px;
  border: 1px solid var(--c-accent);
  background: transparent;
  color: var(--c-accent);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: background .15s ease, color .15s ease, border-color .15s ease, box-shadow .15s ease;
}
.btn:hover {
  background: var(--c-accent);
  border-color: var(--c-accent);
  color: var(--c-primary);
  box-shadow: 0 0 14px rgba(57, 255, 20, 0.35);
}
.btn--solid { background: var(--c-accent); border-color: var(--c-accent); color: var(--c-primary); }
.btn--solid:hover {
  background: var(--c-primary);
  border-color: var(--c-primary);
  color: var(--c-accent);
  box-shadow: 0 0 0 1px var(--c-accent);
}
.btn--ghost { border-color: var(--c-line-dark); color: var(--c-primary); }
.btn--ghost:hover {
  background: var(--c-primary);
  border-color: var(--c-primary);
  color: var(--c-accent);
  box-shadow: none;
}

.media {
  position: relative;
  display: grid;
  place-items: center;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background-color: var(--c-primary);
  background-image:
    linear-gradient(rgba(57, 255, 20, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(57, 255, 20, 0.06) 1px, transparent 1px);
  background-size: 28px 28px;
  border: 1px solid var(--c-line-dark);
}
.media--wide { aspect-ratio: 21 / 9; }
.media--square { aspect-ratio: 1 / 1; }
.media--light {
  background-color: var(--c-light);
  border-color: var(--c-line-light);
  background-image:
    linear-gradient(rgba(11, 27, 61, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(11, 27, 61, 0.06) 1px, transparent 1px);
}
.media::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 0%, rgba(255, 107, 53, 0.12) 50%, transparent 100%);
}
.media__placeholder {
  position: relative;
  z-index: 1;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.22em;
  color: var(--c-accent);
  opacity: 0.7;
}
.media--light .media__placeholder { color: var(--c-primary); opacity: 0.45; }
.media img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 1;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: var(--space-2) 0;
  font-size: 13px;
  color: var(--c-text-soft);
}
.breadcrumbs a {
  color: var(--c-text-body);
  text-decoration: underline;
  text-decoration-color: transparent;
  text-underline-offset: 4px;
  transition: color .15s ease, text-decoration-color .15s ease;
}
.breadcrumbs a:hover { color: var(--c-text-body); text-decoration-color: var(--c-accent); }
.breadcrumbs__sep { font-family: var(--font-mono); color: var(--c-line-light); }
.breadcrumbs [aria-current="page"] { color: var(--c-primary); font-weight: 600; }

.prose { max-width: 68ch; }
.prose p { margin: 0 0 1em; }
.prose a {
  color: var(--c-primary);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
  text-decoration-color: var(--c-line-light);
  transition: text-decoration-color .15s ease;
}
.prose a:hover { text-decoration-color: var(--c-accent); }
.board--dark .prose a {
  color: var(--c-accent);
  text-decoration-color: rgba(57, 255, 20, 0.4);
}
.board--dark .prose a:hover { text-decoration-color: var(--c-accent); }

#main-content {
  scroll-margin-top: calc(var(--header-h) + 12px);
}
#main-content:focus { outline: none; }

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

@media (max-width: 920px) {
  .nav-toggle { display: inline-flex; }
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 90;
    display: block;
    padding: var(--space-2);
    background: var(--c-primary);
    border-bottom: 1px solid var(--c-accent);
    box-shadow: 0 24px 40px rgba(2, 8, 20, 0.45);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-6px);
    transition: opacity .18s ease, transform .18s ease, visibility 0s linear .18s;
  }
  .site-nav[data-open] {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
    transition: opacity .18s ease, transform .18s ease;
  }
  .site-nav__list { flex-direction: column; align-items: stretch; gap: 0; }
  .site-nav__item { border-bottom: 1px solid var(--c-line-dark); }
  .site-nav__item:last-child { border-bottom: none; }
  .nav-link { display: flex; justify-content: space-between; align-items: center; padding: 14px 8px; font-size: 15px; }
  .nav-link::after { left: 0; right: 0; bottom: 0; }
  .site-nav__status { display: none; }
  .grid--3,
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .site-footer__top { grid-template-columns: 1fr 1fr; gap: var(--space-4) var(--space-3); }
}

@media (max-width: 620px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: 1fr; }
  .chapter { padding: var(--space-4) 0; }
  .chapter__header { grid-template-columns: 1fr; gap: var(--space-1); }
  .chapter__idx { font-size: 44px; }
  .board { padding: var(--space-3); }
  .site-footer__top { grid-template-columns: 1fr; }
  .site-footer__meta,
  .site-footer__bar { flex-direction: column; align-items: flex-start; }
  .back-top { right: 12px; bottom: 16px; }
}

@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;
  }
  .site-nav, .site-nav[data-open], .back-top, .skip-link { transition: none; }
}