:root {
  --color-primary: #0A1F44;
  --color-primary-light: #1E3A8A;
  --color-accent: #FF6B00;
  --color-accent-dark: #E65C00;
  --color-silver: #C0C0C0;
  --color-white: #FFFFFF;
  --color-light-gray: #F5F5F5;
  --color-text: #0A1F44;
  --color-text-secondary: #5A6B8C;
  --color-success: #2E7D32;
  --font-sans: "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: "SF Mono", "Roboto Mono", "Cascadia Code", Consolas, monospace;
  --container-max: 1280px;
  --header-height: 64px;
  --shadow-brutal: 8px 8px 0 rgba(10, 31, 68, 0.18);
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-white);
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 800;
  line-height: 1.25;
  color: var(--color-text);
}

h1 { font-size: clamp(2.25rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); }
h3 { font-size: 1.25rem; }
h4 { font-size: 1rem; }

p { margin-bottom: 1rem; }

ul, ol {
  margin: 0;
  padding: 0;
}

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

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

a {
  color: var(--color-accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: 1.25rem;
}

@media (min-width: 768px) {
  .container {
    padding-inline: 2rem;
  }
}

#main-content {
  flex: 1 0 auto;
  scroll-margin-top: 5rem;
  outline: none;
}

@media (min-width: 960px) {
  #main-content {
    scroll-margin-top: 7rem;
  }
}

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

.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 1000;
  padding: 0.75rem 1.25rem;
  background: var(--color-accent);
  color: var(--color-white);
  font-weight: 700;
  font-size: 0.875rem;
  text-decoration: none;
  border: 2px solid var(--color-white);
  box-shadow: var(--shadow-brutal);
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 1rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-primary);
  color: var(--color-white);
  border-bottom: 3px solid var(--color-accent);
  box-shadow: 0 4px 20px rgba(10, 31, 68, 0.3);
}

.scroll-progress {
  display: block;
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: var(--color-accent);
  z-index: 5;
}

.site-header__inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  min-height: var(--header-height);
  padding-block: 0.375rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--color-white);
}

.brand:hover,
.brand:focus-visible {
  color: var(--color-white);
}

.brand__mark {
  position: relative;
  width: 38px;
  height: 38px;
  flex-shrink: 0;
  background: var(--color-accent);
  transform: rotate(-3deg);
  transition: transform 0.2s ease;
}

.brand__mark::before {
  content: "";
  position: absolute;
  inset: 7px;
  background: var(--color-primary);
  clip-path: polygon(50% 0%, 100% 50%, 50% 100%, 0% 50%);
}

.brand__mark::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 2px solid var(--color-white);
}

.brand:hover .brand__mark,
.brand:focus-visible .brand__mark {
  transform: rotate(-6deg) scale(1.05);
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
  min-width: 0;
}

.brand__name {
  font-size: 1.125rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--color-white);
  white-space: nowrap;
}

.brand__tagline {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.1em;
  color: var(--color-silver);
  text-transform: uppercase;
  white-space: nowrap;
}

.site-header__nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0.625rem;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  background: transparent;
  border: 2px solid var(--color-silver);
  cursor: pointer;
  transition: border-color 0.2s ease;
}

.site-header__nav-toggle:hover,
.site-header__nav-toggle:focus-visible {
  border-color: var(--color-accent);
}

.nav-toggle__bar {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-white);
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.site-header__nav-toggle.is-active .nav-toggle__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.site-header__nav-toggle.is-active .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.site-header__nav-toggle.is-active .nav-toggle__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.site-header__nav {
  display: block;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: 0.125rem;
  list-style: none;
}

.site-header__nav-item {
  list-style: none;
}

.site-header__nav-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.375rem;
  padding: 0.625rem 0.75rem;
  border: 2px solid transparent;
  color: var(--color-white);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
  white-space: nowrap;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.site-header__nav-link:hover,
.site-header__nav-link:focus-visible {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--color-silver);
}

.site-header__nav-link[aria-current="page"] {
  background: rgba(255, 107, 0, 0.12);
  border-color: var(--color-accent);
}

.site-header__nav-link[aria-current="page"] .site-header__nav-index {
  color: var(--color-accent);
  font-weight: 700;
}

.site-header__nav-index {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.05em;
  color: var(--color-silver);
}

.site-header__nav-label {
  display: inline;
}

.site-header__status {
  background: var(--color-primary-light);
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.site-header__status-inner {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.375rem 1.5rem;
  padding-block: 0.375rem;
}

.site-header__status-text {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.08em;
  color: var(--color-silver);
  text-transform: uppercase;
}

.site-header__status-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-success);
  box-shadow: 0 0 6px rgba(46, 125, 50, 0.8);
  animation: status-pulse 2s ease-in-out infinite;
}

@keyframes status-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

@media (max-width: 959px) {
  .site-header__nav-toggle {
    display: flex;
  }

  .site-header__nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    max-height: calc(100vh - var(--header-height));
    overflow-y: auto;
    background: var(--color-primary);
    border-bottom: 3px solid var(--color-accent);
    box-shadow: 0 12px 30px rgba(10, 31, 68, 0.4);
  }

  .site-header__nav[data-open] {
    display: block;
    animation: nav-drop-in 0.25s ease;
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.5rem 0 0.75rem;
  }

  .site-header__nav-item {
    border-bottom: 1px solid rgba(192, 192, 192, 0.15);
  }

  .site-header__nav-link {
    display: flex;
    align-items: baseline;
    gap: 0.75rem;
    padding: 1rem 1.25rem;
    border: 0;
    border-left: 4px solid transparent;
    font-size: 1rem;
  }

  .site-header__nav-link:hover,
  .site-header__nav-link:focus-visible {
    background: rgba(255, 255, 255, 0.06);
    border-left-color: var(--color-silver);
  }

  .site-header__nav-link[aria-current="page"] {
    background: rgba(255, 107, 0, 0.1);
    border-left-color: var(--color-accent);
  }
}

@keyframes nav-drop-in {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 767px) {
  .site-header__status {
    display: none;
  }

  .brand__name {
    font-size: 1rem;
  }
}

@media (max-width: 379px) {
  .brand__tagline {
    display: none;
  }
}

.site-footer {
  margin-top: 4rem;
  background: var(--color-primary);
  color: var(--color-white);
  border-top: 4px solid var(--color-accent);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  padding-block: 3rem 2.5rem;
}

.site-footer__brand {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  max-width: 36ch;
}

.site-footer__trust {
  margin: 0;
  padding-left: 1rem;
  border-left: 3px solid var(--color-accent);
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--color-silver);
}

.site-footer__col {
  display: flex;
  flex-direction: column;
}

.site-footer__contact {
  display: flex;
  flex-direction: column;
}

.site-footer__link-title {
  margin-bottom: 1rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.site-footer__links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.site-footer__link {
  display: inline-block;
  padding: 0.4rem 0;
  color: var(--color-white);
  text-decoration: none;
  font-size: 0.875rem;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease, padding-left 0.2s ease;
}

.site-footer__link:hover,
.site-footer__link:focus-visible {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
  padding-left: 0.375rem;
}

.site-footer__contact-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.875rem;
}

.site-footer__contact-item {
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.site-footer__contact-label {
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-silver);
}

.site-footer__contact-value {
  color: var(--color-white);
  font-size: 0.875rem;
  word-break: break-word;
}

.site-footer__bottom {
  background: rgba(0, 0, 0, 0.25);
  border-top: 1px solid rgba(192, 192, 192, 0.2);
  padding-block: 1rem;
}

.site-footer__bottom-inner {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.75rem;
}

.site-footer__copyright {
  margin: 0;
  font-size: 0.75rem;
  color: var(--color-silver);
}

.site-footer__legal {
  display: flex;
  gap: 1.25rem;
}

.site-footer__legal-link {
  padding-block: 0.25rem;
  color: var(--color-silver);
  text-decoration: none;
  font-size: 0.75rem;
  border-bottom: 1px solid transparent;
}

.site-footer__legal-link:hover,
.site-footer__legal-link:focus-visible {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

.site-footer__icp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-silver);
}

@media (min-width: 768px) {
  .site-footer__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem 2.5rem;
  }

  .site-footer__brand {
    grid-column: 1 / -1;
  }

  .site-footer__contact {
    grid-column: 1 / -1;
  }

  .site-footer__contact-list {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }

  .site-footer__bottom-inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .site-footer__grid {
    grid-template-columns: 1.6fr 1fr 1fr 1.4fr;
  }

  .site-footer__brand,
  .site-footer__contact {
    grid-column: auto;
  }

  .site-footer__contact-list {
    grid-template-columns: 1fr;
    gap: 0.875rem;
  }
}

.page-header {
  padding-block: 3rem 2rem;
  border-bottom: 2px solid var(--color-silver);
  margin-bottom: 2.5rem;
}

.page-header__index {
  display: block;
  margin-bottom: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.page-header__title {
  margin-bottom: 0.75rem;
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.08;
}

.page-header__subtitle {
  max-width: 60ch;
  margin: 0;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.breadcrumb {
  margin-bottom: 1.25rem;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem;
  list-style: none;
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-secondary);
}

.breadcrumb__item:not(:last-child)::after {
  content: "/";
  margin-left: 0.25rem;
  color: var(--color-silver);
}

.breadcrumb__link {
  color: var(--color-text-secondary);
  text-decoration: none;
}

.breadcrumb__link:hover,
.breadcrumb__link:focus-visible {
  color: var(--color-accent);
}

.breadcrumb__current {
  font-weight: 700;
  color: var(--color-text);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 44px;
  padding: 0.625rem 1.5rem;
  border: 2px solid var(--color-primary);
  background: transparent;
  color: var(--color-primary);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.btn--primary {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-white);
  box-shadow: 5px 5px 0 rgba(10, 31, 68, 0.18);
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  box-shadow: 7px 7px 0 rgba(10, 31, 68, 0.22);
  transform: translate(-2px, -2px);
}

.btn--outline {
  border-color: var(--color-silver);
  color: var(--color-text);
}

.btn--outline:hover,
.btn--outline:focus-visible {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.content-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

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

@media (min-width: 768px) {
  .content-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (min-width: 1024px) {
  .content-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  display: flex;
  flex-direction: column;
  padding: 1.5rem;
  background: var(--color-white);
  border: 2px solid var(--color-silver);
  box-shadow: 6px 6px 0 rgba(192, 192, 192, 0.35);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.card:hover,
.card:focus-within {
  border-color: var(--color-accent);
  box-shadow: 8px 8px 0 rgba(255, 107, 0, 0.25);
  transform: translate(-2px, -2px);
}

.card__title {
  margin-bottom: 0.5rem;
  font-size: 1.125rem;
  font-weight: 800;
}

.card__body {
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.card__footer {
  margin-top: auto;
  padding-top: 1rem;
}

.label-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.25rem 0.625rem;
  border: 2px solid var(--color-accent);
  background: var(--color-white);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.exhibit-note {
  position: relative;
  padding: 1.25rem 1.5rem;
  background: var(--color-white);
  border: 2px solid var(--color-primary);
  box-shadow: 6px 6px 0 rgba(10, 31, 68, 0.15);
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.exhibit-note::before {
  content: attr(data-note);
  display: block;
  margin-bottom: 0.375rem;
  font-family: var(--font-mono);
  font-size: 0.625rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.img-frame {
  position: relative;
  display: block;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background-color: var(--color-light-gray);
  background-image:
    linear-gradient(rgba(10, 31, 68, 0.05) 2px, transparent 2px),
    linear-gradient(90deg, rgba(10, 31, 68, 0.05) 2px, transparent 2px),
    linear-gradient(135deg, rgba(10, 31, 68, 0.08) 25%, transparent 25%, transparent 50%, rgba(10, 31, 68, 0.08) 50%, rgba(10, 31, 68, 0.08) 75%, transparent 75%, transparent);
  background-size: 32px 32px, 32px 32px, 64px 64px;
  border: 2px solid var(--color-primary);
  box-shadow: 8px 8px 0 rgba(10, 31, 68, 0.15);
}

.img-frame img {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-frame::after {
  content: attr(data-caption);
  position: absolute;
  left: 0;
  bottom: 0;
  max-width: 100%;
  padding: 0.25rem 0.75rem;
  background: var(--color-primary);
  color: var(--color-white);
  font-family: var(--font-mono);
  font-size: 0.625rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-top: 2px solid var(--color-accent);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.img-frame--4x3 {
  aspect-ratio: 4 / 3;
}

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

.img-frame--tilt {
  transform: rotate(-1.2deg);
}

.index-list {
  list-style: none;
  border-top: 2px solid var(--color-primary);
}

.index-list__item {
  border-bottom: 1px solid var(--color-silver);
}

.index-list__link {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  padding: 0.875rem 0.5rem;
  color: var(--color-text);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.9375rem;
  transition: background-color 0.2s ease, color 0.2s ease, padding-left 0.2s ease;
}

.index-list__link:hover,
.index-list__link:focus-visible {
  background: rgba(255, 107, 0, 0.08);
  color: var(--color-accent);
  padding-left: 1rem;
}

.index-list__num {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--color-accent);
}

.collapse {
  background: var(--color-white);
  border: 2px solid var(--color-silver);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.collapse + .collapse {
  border-top: 0;
}

.collapse[data-open] {
  border-color: var(--color-accent);
  box-shadow: 4px 4px 0 rgba(255, 107, 0, 0.2);
}

.collapse__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  min-height: 44px;
  padding: 0.875rem 1.25rem;
  background: transparent;
  border: 0;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1.4;
  text-align: left;
  color: var(--color-text);
}

.collapse__trigger::after {
  content: "+";
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 400;
  line-height: 1;
  color: var(--color-accent);
  transition: transform 0.2s ease;
}

.collapse[data-open] .collapse__trigger::after {
  transform: rotate(45deg);
}

.collapse__panel {
  display: none;
  padding: 1rem 1.25rem 1.25rem;
  border-top: 1px solid var(--color-silver);
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.collapse[data-open] .collapse__panel {
  display: block;
}

@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;
    scroll-behavior: auto !important;
  }

  .scroll-progress {
    display: none;
  }

  .site-header__status-dot {
    animation: none;
  }
}