:root {
  --paper: #F8F5EF;
  --ink: #1A1A1A;
  --ink-2: #333333;
  --spring: #6BB5A5;
  --summer: #E5544D;
  --autumn: #E8A838;
  --winter: #7B9BB8;
  --glass: rgba(255, 255, 255, 0.7);
  --muted: #716B61;
  --line: rgba(26, 26, 26, 0.12);
  --serif-display: "KaiTi", "Kaiti SC", "STKaiti", "Noto Serif SC", "Source Han Serif SC", serif;
  --serif-text: "Songti SC", "SimSun", "Noto Serif SC", "Source Han Serif SC", serif;
  --sans: "Helvetica Neue", "Inter", "PingFang SC", "Microsoft YaHei", sans-serif;
  --container: 75rem;
  --space: clamp(3rem, 7vw, 5.5rem);
  --shadow: 0 12px 40px rgba(26, 26, 26, 0.08);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif-text);
  font-size: 16px;
  line-height: 1.8;
  text-rendering: optimizeLegibility;
}

#main-content {
  flex: 1 0 auto;
}

h1, h2, h3, h4, h5, h6, p, dl, dd, figure, blockquote {
  margin: 0;
}

ul, ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

a {
  color: inherit;
  text-decoration: inherit;
  transition: color .2s ease, border-color .2s ease, background .2s ease;
}

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

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

::selection {
  background: var(--summer);
  color: var(--paper);
}

:focus-visible {
  outline: 2px solid var(--summer);
  outline-offset: 3px;
  border-radius: 2px;
}

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

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1rem, 4vw, 2.75rem);
}

hr {
  border: 0;
  height: 1px;
  background: var(--line);
  margin: 2rem 0;
}

blockquote {
  margin: 1.5rem 0;
  padding: .2rem 0 .2rem 1.4rem;
  border-left: 3px solid var(--autumn);
  color: var(--muted);
  font-style: italic;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  width: 100%;
  background: rgba(248, 245, 239, 0.94);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  box-shadow: 0 1px 0 var(--line);
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 200;
  padding: .75rem 1.25rem;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--sans);
  font-size: .8rem;
  text-decoration: none;
  border-radius: 0 0 6px 6px;
  transition: top .2s ease;
}

.skip-link:focus {
  top: 0;
  color: #fff;
}

.header-topline {
  background: var(--ink);
  color: rgba(248, 245, 239, 0.72);
  font-family: var(--sans);
  font-size: .72rem;
  letter-spacing: .08em;
}

.header-topline-grid {
  min-height: 2.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.header-quote {
  color: var(--paper);
  display: inline-flex;
  align-items: center;
  gap: .5rem;
}

.header-quote::before {
  content: "";
  width: .45rem;
  height: .45rem;
  border-radius: 50%;
  background: var(--spring);
}

.header-trust {
  color: rgba(248, 245, 239, 0.55);
}

.header-main {
  position: relative;
}

.header-main-grid {
  min-height: 4.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(1rem, 3vw, 2rem);
}

.brand-link {
  display: inline-flex;
  align-items: center;
  text-decoration: none;
  color: var(--ink);
  flex-shrink: 0;
}

.brand-link:hover {
  color: var(--ink);
}

.brand-mark {
  display: inline-grid;
  grid-template-columns: repeat(2, .5em);
  gap: 1px;
  width: 1.2em;
  height: 1.2em;
  margin-right: .6em;
  flex: 0 0 auto;
}

.brand-mark-season {
  display: block;
  border-radius: 1px;
}

.brand-mark-spring {
  background: var(--spring);
}

.brand-mark-summer {
  background: var(--summer);
}

.brand-mark-autumn {
  background: var(--autumn);
}

.brand-mark-winter {
  background: var(--winter);
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--serif-display);
  font-size: 1.9rem;
  font-weight: 700;
  letter-spacing: .04em;
}

.brand-suffix {
  font-family: var(--sans);
  font-size: .62rem;
  font-weight: 600;
  letter-spacing: .28em;
  text-transform: uppercase;
  color: var(--summer);
}

.site-nav {
  margin-left: auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(.2rem, 1.4vw, 1.1rem);
}

.nav-link {
  display: inline-block;
  position: relative;
  padding: .5rem .35rem;
  font-family: var(--sans);
  font-size: .9rem;
  font-weight: 500;
  letter-spacing: .06em;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s, border-color .2s;
}

.nav-link:hover {
  color: var(--summer);
  border-bottom-color: var(--summer);
}

.nav-link[aria-current="page"] {
  color: var(--summer);
  border-bottom-color: var(--summer);
}

.nav-link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -3px;
  width: 5px;
  height: 5px;
  margin-left: -3px;
  border-radius: 50%;
  background: var(--autumn);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: .75rem;
  flex-shrink: 0;
}

.header-contact {
  display: inline-flex;
  align-items: center;
  padding: .4rem .95rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-family: var(--sans);
  font-size: .82rem;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--ink);
  text-decoration: none;
  transition: background .2s, border-color .2s, color .2s;
}

.header-contact:hover {
  background: var(--spring);
  border-color: var(--spring);
  color: var(--ink);
}

.nav-toggle {
  display: none;
  width: 2.75rem;
  height: 2.75rem;
  padding: .55rem;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 3px;
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid var(--line);
  border-radius: 4px;
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 1.1rem;
  height: 2px;
  border-radius: 1px;
  background: currentColor;
  transition: transform .25s ease, opacity .25s ease, background .25s ease;
}

.nav-toggle:hover .nav-toggle-bar {
  background: var(--summer);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(5px) 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(-5px) rotate(-45deg);
}

@media (max-width: 899px) {
  .header-main-grid {
    min-height: 4rem;
  }

  .brand-name {
    font-size: 1.55rem;
  }

  .brand-suffix {
    letter-spacing: .2em;
  }

  .header-contact {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    margin: 0;
    display: none;
    z-index: 120;
    padding: .4rem 0 .8rem;
    background: rgba(248, 245, 239, 0.98);
    -webkit-backdrop-filter: blur(14px);
    backdrop-filter: blur(14px);
    border-top: 1px solid var(--line);
    box-shadow: 0 18px 30px rgba(26, 26, 26, 0.08);
  }

  .site-nav[data-open] {
    display: block;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-link {
    display: block;
    padding: .85rem clamp(1rem, 4vw, 2.5rem);
    border-bottom: 1px solid rgba(26, 26, 26, 0.06);
    border-left: 3px solid transparent;
  }

  .nav-link:hover,
  .nav-link[aria-current="page"] {
    border-left-color: var(--summer);
  }

  .nav-link::after {
    display: none;
  }
}

@media (max-width: 600px) {
  .header-trust {
    display: none;
  }

  .header-topline-grid {
    justify-content: center;
  }
}

.site-footer {
  margin-top: auto;
  background: linear-gradient(135deg, #121212 0%, #252525 100%);
  color: rgba(248, 245, 239, 0.86);
}

.footer-accent {
  height: 4px;
  background: linear-gradient(90deg, var(--spring), var(--summer), var(--autumn), var(--winter));
}

.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, .7fr) minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3.5rem);
  padding-block: var(--space) 2.5rem;
}

.footer-brand .brand-link {
  color: #F8F5EF;
}

.footer-brand .brand-link:hover {
  color: #F8F5EF;
}

.footer-brand .brand-suffix {
  color: var(--autumn);
}

.footer-desc {
  margin-top: 1.1rem;
  max-width: 36ch;
  font-size: .9rem;
  line-height: 1.9;
  color: rgba(248, 245, 239, 0.6);
}

.footer-column {
  min-width: 0;
}

.footer-menu-title {
  font-family: var(--serif-display);
  font-size: 1.1rem;
  letter-spacing: .1em;
  color: #F8F5EF;
  margin-bottom: 1rem;
}

.footer-menu {
  display: flex;
  flex-direction: column;
  gap: .55rem;
}

.footer-link {
  display: inline-block;
  padding: .15rem 0;
  color: rgba(248, 245, 239, 0.62);
  font-family: var(--sans);
  font-size: .9rem;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s, border-color .2s, padding-left .2s;
}

.footer-link:hover {
  color: var(--paper);
  border-bottom-color: var(--summer);
  padding-left: .35rem;
}

.footer-contact {
  font-style: normal;
}

.footer-contact-label {
  display: block;
  font-family: var(--sans);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--autumn);
  margin-bottom: .8rem;
}

.footer-contact p {
  margin-top: .5rem;
  font-size: .88rem;
  line-height: 1.7;
  color: rgba(248, 245, 239, 0.6);
}

.footer-contact strong {
  color: #F8F5EF;
  font-weight: 600;
  margin-right: .4em;
}

.footer-bottom {
  border-top: 1px solid rgba(248, 245, 239, 0.12);
  padding-block: 1.1rem;
}

.footer-bottom-grid {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .35rem 2rem;
  font-family: var(--sans);
  font-size: .76rem;
  letter-spacing: .04em;
  color: rgba(248, 245, 239, 0.48);
}

.footer-copyright {
  color: rgba(248, 245, 239, 0.6);
}

.footer-icp {
  margin-left: auto;
}

@media (max-width: 899px) {
  .footer-inner {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding-top: 3rem;
    padding-bottom: 2rem;
  }

  .footer-bottom-grid {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-icp {
    margin-left: 0;
  }
}

.page-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(3.5rem, 9vw, 7rem) 0 clamp(3rem, 7vw, 5.5rem);
  border-bottom: 1px solid var(--line);
}

.page-hero::after {
  content: "";
  position: absolute;
  right: -4rem;
  top: -4rem;
  width: 16rem;
  height: 16rem;
  border-radius: 50%;
  background: rgba(107, 181, 165, 0.13);
  pointer-events: none;
}

.page-hero-summer::after {
  background: rgba(229, 84, 77, 0.11);
}

.page-hero-winter::after {
  background: rgba(123, 155, 184, 0.16);
}

.page-hero-ink {
  background: linear-gradient(135deg, var(--ink), var(--ink-2));
  color: var(--paper);
  border-bottom-color: rgba(248, 245, 239, 0.1);
}

.page-title {
  font-family: var(--serif-display);
  font-size: clamp(2.75rem, 7vw, 5.5rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: .02em;
}

.page-title small {
  display: block;
  margin-bottom: 1.2rem;
  font-family: var(--sans);
  font-size: clamp(.7rem, 1.6vw, .9rem);
  font-weight: 600;
  letter-spacing: .32em;
  text-transform: uppercase;
  color: var(--summer);
}

.page-hero-ink .page-title small {
  color: var(--autumn);
}

.page-lead {
  margin-top: 1.3rem;
  max-width: 46rem;
  font-size: 1rem;
  line-height: 1.9;
  color: var(--muted);
}

.page-hero-ink .page-lead {
  color: rgba(248, 245, 239, 0.72);
}

.breadcrumb {
  margin-top: 2rem;
}

.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .4rem;
  font-family: var(--sans);
  font-size: .78rem;
  color: #7a746b;
}

.breadcrumb-list li {
  display: inline-flex;
  align-items: center;
}

.breadcrumb-list li + li::before {
  content: "/";
  margin-right: .4rem;
  color: rgba(26, 26, 26, 0.25);
}

.breadcrumb-list a {
  color: var(--spring);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.breadcrumb-list a:hover {
  border-bottom-color: currentColor;
}

.breadcrumb-list [aria-current="page"] {
  color: #7a746b;
}

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

.section-spring {
  background: rgba(107, 181, 165, 0.12);
}

.section-summer {
  background: rgba(229, 84, 77, 0.08);
}

.section-autumn {
  background: rgba(232, 168, 56, 0.1);
}

.section-winter {
  background: rgba(123, 155, 184, 0.12);
}

.section-ink {
  background: linear-gradient(135deg, var(--ink), var(--ink-2));
  color: var(--paper);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 2rem;
  padding-bottom: 1.1rem;
  border-bottom: 1px solid var(--line);
}

.section-index {
  display: inline-flex;
  align-items: center;
  gap: .6rem;
  font-family: var(--sans);
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--summer);
}

.section-index::before {
  content: "";
  width: 1.8rem;
  height: 1px;
  background: var(--summer);
}

.section-title {
  font-family: var(--serif-display);
  font-size: clamp(1.9rem, 4vw, 3rem);
  line-height: 1.15;
}

.section-lead {
  margin-top: .8rem;
  max-width: 62ch;
  color: var(--muted);
}

.section-ink .section-head {
  border-bottom-color: rgba(248, 245, 239, 0.14);
}

.section-ink .section-index {
  color: var(--autumn);
}

.section-ink .section-index::before {
  background: var(--autumn);
}

.section-ink .section-lead {
  color: rgba(248, 245, 239, 0.7);
}

.grid {
  display: grid;
  gap: clamp(1rem, 3vw, 1.75rem);
}

@media (min-width: 640px) {
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .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));
  }
}

.sheet,
.exhibit {
  position: relative;
  padding: 1.6rem;
  background: var(--glass);
  border: 1px solid rgba(26, 26, 26, 0.06);
  border-left: 4px solid var(--spring);
  border-radius: 0 6px 6px 0;
  box-shadow: var(--shadow);
}

.sheet-summer,
.exhibit-summer {
  border-left-color: var(--summer);
}

.sheet-autumn,
.exhibit-autumn {
  border-left-color: var(--autumn);
}

.sheet-winter,
.exhibit-winter {
  border-left-color: var(--winter);
}

.sheet-title,
.exhibit-title {
  font-family: var(--serif-display);
  font-size: 1.25rem;
  margin-bottom: .55rem;
}

.sheet-text,
.exhibit-text {
  color: var(--muted);
  font-size: .95rem;
  line-height: 1.8;
}

.exhibit::before {
  content: attr(data-exhibit-index);
  position: absolute;
  top: 0;
  right: 1rem;
  padding: .25rem .6rem;
  font-family: var(--sans);
  font-size: .7rem;
  letter-spacing: .18em;
  color: rgba(26, 26, 26, 0.35);
  background: rgba(26, 26, 26, 0.04);
  border-bottom: 1px solid var(--line);
}

.exhibit-label,
.specimen-label {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .25rem .7rem;
  margin-bottom: .8rem;
  background: rgba(229, 84, 77, 0.08);
  border-left: 3px solid var(--summer);
  font-family: var(--sans);
  font-size: .7rem;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--summer);
}

.exhibit-note {
  margin-top: 1.2rem;
  padding-top: .8rem;
  border-top: 1px dashed rgba(26, 26, 26, 0.14);
  font-size: .85rem;
  line-height: 1.8;
  color: var(--muted);
}

.note {
  margin: 1.5rem 0;
  padding: 1rem 1.25rem;
  border-left: 4px solid var(--winter);
  background: rgba(123, 155, 184, 0.1);
  border-radius: 0 4px 4px 0;
  font-size: .95rem;
  line-height: 1.8;
}

.note-important {
  border-left-color: var(--summer);
  background: rgba(229, 84, 77, 0.06);
}

.note-title {
  display: block;
  margin-bottom: .35rem;
  font-weight: 600;
}

.badge,
.tag {
  display: inline-flex;
  align-items: center;
  gap: .4em;
  padding: .3em .85em;
  border-radius: 999px;
  font-family: var(--sans);
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .08em;
  line-height: 1.4;
  text-decoration: none;
  border: 1px solid transparent;
}

.badge {
  background: rgba(26, 26, 26, 0.06);
  color: var(--ink);
}

.badge-spring {
  background: rgba(107, 181, 165, 0.15);
  color: #2f6b5f;
}

.badge-summer {
  background: rgba(229, 84, 77, 0.12);
  color: #b43a34;
}

.badge-autumn {
  background: rgba(232, 168, 56, 0.16);
  color: #9a6b13;
}

.badge-winter {
  background: rgba(123, 155, 184, 0.16);
  color: #3d6078;
}

.tag {
  border-radius: 2px;
  border-color: rgba(26, 26, 26, 0.2);
  background: transparent;
  color: var(--ink);
  transition: border-color .2s, color .2s, transform .2s;
}

.tag:hover {
  border-color: var(--summer);
  color: var(--summer);
  transform: translateY(-1px);
}

.tag-group {
  display: flex;
  flex-wrap: wrap;
  gap: .6rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .6rem;
  padding: .8rem 1.5rem;
  border: 1px solid var(--ink);
  border-radius: 999px;
  background: transparent;
  color: var(--ink);
  font-family: var(--sans);
  font-size: .88rem;
  font-weight: 600;
  letter-spacing: .04em;
  text-decoration: none;
  cursor: pointer;
  transition: background .2s, color .2s, border-color .2s, box-shadow .2s, transform .2s;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--summer);
  border-color: var(--summer);
  color: var(--paper);
}

.btn-primary:hover {
  background: #c93d36;
  border-color: #c93d36;
  box-shadow: 0 10px 24px rgba(229, 84, 77, 0.28);
}

.btn-secondary {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

.btn-secondary:hover {
  background: transparent;
  color: var(--ink);
}

.btn-ghost {
  border-color: rgba(248, 245, 239, 0.4);
  color: var(--paper);
}

.btn-ghost:hover {
  background: var(--paper);
  color: var(--ink);
  border-color: var(--paper);
  transform: none;
}

.btn-sm {
  padding: .5rem 1rem;
  font-size: .78rem;
}

.link-more {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  color: var(--summer);
  font-family: var(--sans);
  font-size: .85rem;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.link-more:hover {
  color: var(--ink);
  border-color: var(--ink);
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: .94rem;
}

.table th,
.table td {
  padding: .85rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}

.table thead th {
  background: rgba(26, 26, 26, 0.04);
  font-family: var(--serif-display);
  font-size: 1rem;
  letter-spacing: .04em;
}

.table tbody tr:last-child td {
  border-bottom: 0;
}

.table tbody tr:hover {
  background: rgba(107, 181, 165, 0.06);
}

.media-frame {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, rgba(107, 181, 165, 0.16), rgba(248, 245, 239, 0.5));
  border: 1px solid rgba(26, 26, 26, 0.08);
}

.media-frame::before {
  content: "";
  display: block;
  padding-top: 56.25%;
}

.media-frame-4-3::before {
  padding-top: 75%;
}

.media-frame-1-1::before {
  padding-top: 100%;
}

.media-frame-ph::after {
  content: "四时映象";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--serif-display);
  letter-spacing: .2em;
  color: rgba(26, 26, 26, 0.3);
}

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

[data-reveal] {
  transition: opacity .7s ease, transform .7s ease;
}

[data-reveal][data-state="pending"] {
  opacity: 0;
  transform: translateY(1.5rem);
}

[data-reveal][data-state="shown"] {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }

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