:root {
  --color-moss: #1F3D2D;
  --color-wave: #2E6B5E;
  --color-mist: #6B7A72;
  --color-terracotta: #C4552B;
  --color-cream: #F4EFE6;
  --color-ink: #231A15;
  --color-soft: #D9E5DF;
  --color-alert: #B3372A;
  --color-gold: #D9A441;

  --font-display: "STFangsong", "Kaiti SC", "STKaiti", "KaiTi", "楷体", serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Mono", "Roboto Mono", Menlo, Consolas, monospace;

  --border-w: 1.5px;
  --shadow-hard: 6px 6px 0 rgba(31, 61, 45, 0.25);
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  background: var(--color-cream);
  color: var(--color-ink);
  padding-top: 42px;
  padding-left: 196px;
}

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

a {
  color: var(--color-wave);
}

ul,
ol {
  padding-left: 1.2em;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.25;
  margin-bottom: 0.5em;
}

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

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

.skip-link {
  position: fixed;
  top: 10px;
  left: 206px;
  z-index: 999;
  background: var(--color-terracotta);
  color: var(--color-cream);
  padding: 8px 16px;
  font-size: 14px;
  text-decoration: none;
  font-weight: 500;
  transform: translateY(-200%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus-visible {
  transform: translateY(0);
}

.status-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 42px;
  z-index: 340;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 20px;
  background: var(--color-ink);
  color: rgba(244, 239, 230, 0.82);
  border-bottom: var(--border-w) solid var(--color-wave);
  overflow: hidden;
  font-family: var(--font-mono);
}

.status-bar__season {
  flex-shrink: 0;
  font-size: 12px;
  letter-spacing: 0.4px;
  white-space: nowrap;
}

.status-bar__update {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  letter-spacing: 0.3px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: rgba(244, 239, 230, 0.9);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-gold);
  flex-shrink: 0;
  animation: pulseBreathe 2.4s ease-in-out infinite;
}

.side-nav {
  position: fixed;
  top: 42px;
  left: 0;
  width: 196px;
  height: calc(100vh - 42px);
  z-index: 200;
  display: flex;
  flex-direction: column;
  background: var(--color-moss);
  color: var(--color-cream);
  padding: 28px 14px 16px;
}

.brand-block {
  display: block;
  margin-bottom: 36px;
  padding: 0 8px 18px 10px;
  border-bottom: 1px solid rgba(217, 164, 65, 0.5);
  text-decoration: none;
}

.brand-block__name {
  display: block;
  font-family: var(--font-display);
  font-size: 30px;
  line-height: 1.2;
  letter-spacing: 4px;
  color: var(--color-cream);
}

.brand-block__tag {
  display: block;
  margin-top: 6px;
  font-size: 11px;
  letter-spacing: 0.4em;
  color: var(--color-gold);
  opacity: 0.85;
}

.side-nav__list {
  list-style: none;
  margin: 0;
  padding: 0;
  flex: 1;
  overflow-y: auto;
}

.side-nav__list li {
  margin: 0;
}

.side-nav__list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 12px;
  color: var(--color-soft);
  text-decoration: none;
  font-size: 15px;
  border-left: 2px solid transparent;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.side-nav__list a:hover {
  background: rgba(255, 255, 255, 0.06);
  color: var(--color-cream);
}

.side-nav__list a[aria-current="page"] {
  background: rgba(255, 255, 255, 0.08);
  border-left-color: var(--color-terracotta);
  color: var(--color-cream);
  font-weight: 500;
}

.side-nav__list a[aria-current="page"] .nav-code {
  opacity: 1;
}

.nav-code {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-gold);
  opacity: 0.7;
  letter-spacing: 0.5px;
  flex-shrink: 0;
}

.side-nav__foot {
  padding: 16px 8px 4px;
  border-top: 1px solid rgba(217, 164, 65, 0.4);
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-gold);
  opacity: 0.85;
}

.side-nav__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-terracotta);
  flex-shrink: 0;
  animation: pulseBreathe 2.4s ease-in-out infinite;
}

.nav-toggle {
  position: fixed;
  right: 16px;
  bottom: 24px;
  z-index: 400;
  width: 54px;
  height: 54px;
  border-radius: 50%;
  background: var(--color-terracotta);
  border: var(--border-w) solid var(--color-ink);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.25);
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  color: var(--color-cream);
  padding: 0;
  transition: background 0.2s ease, transform 0.2s ease;
}

.nav-toggle:hover {
  background: #b34a24;
  transform: translateY(-1px);
}

.nav-toggle__bar {
  width: 20px;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}

.nav-toggle__label {
  font-size: 9px;
  letter-spacing: 1px;
  margin-top: 2px;
  font-family: var(--font-body);
}

.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);
}

.brand-float {
  position: fixed;
  top: 50px;
  left: 12px;
  z-index: 320;
  display: none;
  align-items: center;
  gap: 6px;
  background: rgba(31, 61, 45, 0.92);
  border: var(--border-w) solid var(--color-ink);
  box-shadow: 3px 3px 0 rgba(0, 0, 0, 0.18);
  color: var(--color-cream);
  text-decoration: none;
  padding: 4px 10px 4px 8px;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.brand-float__text {
  font-family: var(--font-display);
  font-size: 15px;
  letter-spacing: 2px;
  line-height: 1.2;
}

.brand-float__v4 {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--color-gold);
  border: 1px solid var(--color-gold);
  padding: 1px 4px;
  line-height: 1.4;
}

.main-content {
  min-height: 60vh;
  max-width: 1180px;
  padding: 56px 56px 88px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 18px;
  background: var(--color-terracotta);
  color: var(--color-cream);
  border: var(--border-w) solid var(--color-ink);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.2);
  font-size: 15px;
  font-family: var(--font-body);
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn:hover {
  background: #b34a24;
  transform: translate(-1px, -1px);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, 0.2);
}

.btn--ghost {
  background: transparent;
  border-color: var(--color-moss);
  color: var(--color-moss);
  box-shadow: none;
}

.btn--ghost:hover {
  background: var(--color-soft);
  box-shadow: none;
  transform: none;
}

.section-head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin: 48px 0 24px;
  position: relative;
}

.section-head::before {
  content: "";
  flex: 0 0 48px;
  border-top: var(--border-w) solid var(--color-wave);
}

.section-head__index {
  font-family: var(--font-display);
  font-size: 42px;
  line-height: 1;
  color: var(--color-wave);
}

.section-head__title {
  font-size: 26px;
  font-weight: 600;
  color: var(--color-ink);
}

.section-head__note {
  writing-mode: vertical-rl;
  letter-spacing: 0.3em;
  font-size: 12px;
  color: var(--color-mist);
  margin-left: auto;
}

.window-frame {
  border: var(--border-w) solid var(--color-ink);
  background: var(--color-cream);
  box-shadow: 8px 8px 0 var(--color-moss);
}

.window-frame__bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 14px;
  border-bottom: var(--border-w) solid var(--color-ink);
  background: var(--color-soft);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-mist);
}

.window-frame__body {
  padding: 24px;
}

.card {
  border: var(--border-w) solid var(--color-ink);
  background: var(--color-cream);
  box-shadow: 4px 4px 0 rgba(31, 61, 45, 0.25);
  padding: 20px;
}

.scale-rule {
  height: 10px;
  border-bottom: var(--border-w) solid var(--color-wave);
  background: repeating-linear-gradient(
    to right,
    var(--color-wave) 0,
    var(--color-wave) 1px,
    transparent 1px,
    transparent 12px
  );
  opacity: 0.85;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-mist);
  margin: 8px 0 32px;
  padding-bottom: 14px;
  border-bottom: var(--border-w) solid var(--color-wave);
}

.breadcrumb__item {
  color: var(--color-wave);
  text-decoration: none;
}

.breadcrumb__item:hover {
  text-decoration: underline;
}

.breadcrumb__sep::before {
  content: "·";
  opacity: 0.5;
}

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

.grid--2 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.grid--3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.img-slot {
  position: relative;
  border: var(--border-w) solid var(--color-ink);
  background: var(--color-soft);
  box-shadow: 6px 6px 0 rgba(31, 61, 45, 0.2);
  min-height: 180px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.img-slot::after {
  content: attr(data-caption);
  display: block;
  font-size: 12px;
  color: var(--color-mist);
  letter-spacing: 0.2em;
  padding: 8px;
  text-align: center;
}

.img-slot--tall {
  min-height: 280px;
}

.img-slot--sm {
  min-height: 120px;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.24s ease, transform 0.24s ease;
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

.site-footer {
  background: var(--color-moss);
  color: var(--color-cream);
  padding: 56px 48px 24px;
}

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

.site-footer__logo {
  display: block;
  font-family: var(--font-display);
  font-size: 32px;
  letter-spacing: 4px;
  line-height: 1.2;
  color: var(--color-cream);
}

.site-footer__icp {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--color-mist);
}

.site-footer__desc {
  display: block;
  margin-top: 12px;
  font-size: 13px;
  letter-spacing: 0.4em;
  color: var(--color-gold);
  opacity: 0.85;
}

.site-footer__heading {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.3em;
  color: var(--color-gold);
  margin-bottom: 14px;
}

.site-footer__nav a {
  display: block;
  padding: 4px 0;
  color: var(--color-soft);
  text-decoration: none;
  font-size: 15px;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.site-footer__nav a:hover {
  color: var(--color-gold);
  padding-left: 4px;
}

.site-footer__contact span {
  display: block;
  color: var(--color-soft);
  font-size: 14px;
  padding: 3px 0;
}

.site-footer__route {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--color-gold);
  border-bottom: 1px solid var(--color-gold);
  text-decoration: none;
  font-size: 13px;
  padding-bottom: 2px;
}

.site-footer__route:hover {
  color: var(--color-cream);
  border-color: var(--color-cream);
}

.site-footer__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  padding-top: 20px;
  border-top: 1px solid rgba(217, 164, 65, 0.35);
  font-size: 13px;
}

.site-footer__copy {
  font-family: var(--font-mono);
  color: var(--color-soft);
}

.site-footer__tagline {
  letter-spacing: 0.3em;
  color: var(--color-gold);
  opacity: 0.85;
}

@keyframes pulseBreathe {
  0%,
  100% {
    opacity: 1;
    box-shadow: 0 0 0 0 rgba(217, 164, 65, 0.4);
  }
  50% {
    opacity: 0.75;
    box-shadow: 0 0 0 6px rgba(217, 164, 65, 0);
  }
}

@media (min-width: 768px) and (max-width: 1023px) {
  .grid--3 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .main-content {
    padding: 40px 32px 72px;
  }

  .site-footer {
    padding: 48px 32px 24px;
  }
}

@media (max-width: 1023px) {
  body {
    padding-left: 0;
  }

  .side-nav {
    transform: translateX(-102%);
    transition: transform 0.24s var(--ease), box-shadow 0.24s var(--ease);
    box-shadow: none;
    width: 220px;
  }

  .side-nav[data-open="true"] {
    transform: translateX(0);
    box-shadow: 12px 0 28px rgba(0, 0, 0, 0.28);
  }

  .side-nav[data-open="true"] ~ .brand-float {
    opacity: 0;
    pointer-events: none;
    transform: translateX(-12px);
  }

  .nav-toggle {
    display: flex;
  }

  .brand-float {
    display: flex;
  }

  .skip-link {
    left: 10px;
  }

  .site-footer {
    padding: 44px 24px 20px;
  }

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

@media (max-width: 767px) {
  .status-bar {
    padding: 0 12px;
    gap: 10px;
  }

  .status-bar__season {
    font-size: 11px;
  }

  .status-bar__update {
    font-size: 10px;
  }

  .main-content {
    padding: 32px 20px 72px;
  }

  .grid--2,
  .grid--3 {
    grid-template-columns: 1fr;
  }

  .section-head {
    flex-wrap: wrap;
    gap: 8px 12px;
  }

  .section-head::before {
    flex-basis: 28px;
  }

  .section-head__index {
    font-size: 34px;
  }

  .section-head__title {
    font-size: 22px;
  }

  .section-head__note {
    display: none;
  }

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

@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;
  }

  [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .pulse-dot,
  .side-nav__dot {
    animation: none;
  }
}