:root {
  --spring-600: #0E6B48;
  --spring-50: #E3F2EB;
  --summer-500: #0E5A8A;
  --summer-50: #E2F0FA;
  --autumn-500: #E8A33D;
  --autumn-700: #B45E1A;
  --winter-400: #9EB7C4;
  --winter-100: #E4EEF3;
  --warm-gray-100: #F5F2EC;
  --ink-900: #17211E;
  --ink-600: #43534D;
  --font-display: 'Noto Sans SC', 'Source Han Sans SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Noto Serif SC', 'Source Han Serif SC', 'Songti SC', 'SimSun', serif;
  --container: 1200px;
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2rem;
  --space-5: 3rem;
  --space-6: 5rem;
  --border-w: 2px;
  --shadow-offset: 4px;
  --radius: 12px;
  --season-color: var(--spring-600);
  color-scheme: light;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 90px;
}

body {
  font-family: var(--font-body);
  background-color: var(--warm-gray-100);
  color: var(--ink-900);
  line-height: 1.8;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

body,
h1,
h2,
h3,
h4,
p,
ul,
ol,
figure,
blockquote,
dl,
dd {
  margin: 0;
  padding: 0;
}

ul,
ol {
  list-style: none;
}

a {
  color: var(--summer-500);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--spring-600);
}

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

button {
  font: inherit;
  border: none;
  background: none;
  cursor: pointer;
  color: inherit;
}

summary {
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 700;
}

:focus-visible {
  outline: 3px solid var(--autumn-500);
  outline-offset: 2px;
  border-radius: 2px;
}

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 24px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 1000;
  background: var(--spring-600);
  color: #fff;
  font-weight: 700;
  padding: 0.75rem 1.5rem;
  border-radius: 0 0 8px 0;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(245, 242, 236, 0.94);
  backdrop-filter: blur(8px);
  border-bottom: var(--border-w) solid var(--ink-900);
}

.header-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 1rem;
  min-height: 72px;
  padding-block: 0.75rem;
  position: relative;
}

.brand-block {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand-link {
  display: inline-flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--ink-900);
}

.brand-mark {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 900;
  letter-spacing: 0.02em;
  line-height: 1.2;
  color: var(--spring-600);
}

.brand-sub {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--ink-600);
  letter-spacing: 0.06em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.status-line {
  font-family: var(--font-display);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink-600);
  background: var(--winter-100);
  border: 1px solid var(--winter-400);
  border-radius: 999px;
  padding: 0.25rem 0.875rem;
  margin-left: auto;
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  margin-left: auto;
  padding: 0.375rem 0.75rem;
  border: var(--border-w) solid var(--ink-900);
  border-radius: 8px;
  background: var(--warm-gray-100);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.9rem;
  box-shadow: 2px 2px 0 var(--ink-900);
}

.nav-toggle-label {
  line-height: 1;
}

.nav-toggle-icon {
  position: relative;
  width: 18px;
  height: 2px;
  background: var(--ink-900);
  display: inline-block;
  transition: background 0.2s;
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--ink-900);
  transition: transform 0.2s;
}

.nav-toggle-icon::before {
  top: -6px;
}

.nav-toggle-icon::after {
  top: 6px;
}

.site-nav[data-open] .nav-toggle-icon {
  background: transparent;
}

.site-nav[data-open] .nav-toggle-icon::before {
  transform: translateY(6px) rotate(45deg);
}

.site-nav[data-open] .nav-toggle-icon::after {
  transform: translateY(-6px) rotate(-45deg);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-list a {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--ink-900);
  text-decoration: none;
  padding: 0.375rem 0.75rem;
  border-radius: 6px;
  white-space: nowrap;
  position: relative;
}

.nav-list a:hover {
  background: var(--spring-50);
  color: var(--spring-600);
}

.nav-list a[aria-current="page"] {
  background: var(--spring-600);
  color: #fff;
  box-shadow: 2px 2px 0 var(--ink-900);
}

.site-header .btn {
  margin-left: 0.25rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.9375rem;
  line-height: 1;
  padding: 0.75rem 1.25rem;
  border-radius: 10px;
  text-decoration: none;
  border: var(--border-w) solid var(--ink-900);
  box-shadow: 3px 3px 0 var(--ink-900);
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
  cursor: pointer;
}

.btn:hover {
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 var(--ink-900);
  color: inherit;
}

.btn:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--ink-900);
}

.btn-primary {
  background: var(--spring-600);
  color: #fff;
}

.btn-primary:hover {
  background: #0B5A3C;
  color: #fff;
}

.btn-outline {
  background: var(--warm-gray-100);
  color: var(--ink-900);
}

.btn-outline:hover {
  background: var(--winter-100);
  color: var(--ink-900);
}

.btn-small {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  border-radius: 8px;
  box-shadow: 2px 2px 0 var(--ink-900);
}

.site-footer {
  background: var(--ink-900);
  color: var(--warm-gray-100);
  margin-top: auto;
  border-top: var(--border-w) solid var(--ink-900);
  padding-top: var(--space-5);
  padding-bottom: var(--space-3);
}

.site-footer a {
  color: var(--winter-400);
}

.site-footer a:hover {
  color: #fff;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(180px, 0.7fr) 2fr;
  gap: var(--space-4);
  align-items: start;
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--winter-400);
}

.footer-brand-name {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.6rem);
  font-weight: 900;
  line-height: 1.1;
  color: var(--autumn-500);
}

.footer-brand-en {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--winter-400);
  margin-top: 0.25rem;
}

.footer-statement {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.7;
  background: var(--warm-gray-100);
  color: var(--ink-900);
  border-left: 5px solid var(--autumn-500);
  padding: var(--space-3) var(--space-4);
  border-radius: 0 12px 12px 0;
  box-shadow: 3px 3px 0 var(--winter-400);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-4);
  padding-block: var(--space-4);
  border-bottom: 1px solid var(--winter-400);
}

.footer-heading {
  font-family: var(--font-display);
  font-size: 0.875rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: var(--autumn-500);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--winter-400);
}

.footer-contact-list li,
.footer-links li {
  font-size: 0.9375rem;
  line-height: 1.8;
  margin-bottom: 0.375rem;
}

.footer-links a {
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.footer-links a:hover {
  border-bottom-color: var(--autumn-500);
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-3);
  font-size: 0.8125rem;
  color: var(--winter-400);
  font-family: var(--font-display);
}

.footer-meta p {
  margin: 0;
}

.footer-icp {
  font-variant-numeric: tabular-nums;
}

/* 通用正文容器 */
.page-main {
  flex: 1;
  width: 100%;
}

.page-container {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: 24px;
  padding-block: var(--space-5);
}

.page-content {
  max-width: 720px;
}

/* 章节与标题 */
.chapter {
  position: relative;
  padding-block: var(--space-4);
}

.chapter-number {
  font-family: var(--font-display);
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 900;
  line-height: 0.85;
  color: var(--season-color, var(--spring-600));
  opacity: 0.2;
  display: block;
  margin-bottom: 0.5rem;
  user-select: none;
}

.chapter-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.6rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 0.75rem;
  color: var(--ink-900);
}

.chapter-intro {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--ink-600);
  max-width: 60ch;
}

/* 卡片 */
.card {
  background: #fff;
  border: var(--border-w) solid var(--ink-900);
  border-radius: var(--radius);
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--ink-900);
  padding: var(--space-4);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.card:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--ink-900);
}

.card-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
}

.card-meta {
  font-size: 0.875rem;
  color: var(--ink-600);
  font-family: var(--font-display);
}

.card-data {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 900;
  color: var(--autumn-700);
  font-variant-numeric: tabular-nums;
}

/* 数据面板 */
.status-panel {
  background: var(--ink-900);
  border: var(--border-w) solid var(--ink-900);
  border-radius: var(--radius);
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--autumn-500);
  color: var(--warm-gray-100);
  padding: var(--space-4);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
}

.status-panel a {
  text-decoration: none;
  color: inherit;
}

.status-item {
  padding: var(--space-2);
  border-radius: 8px;
  transition: background 0.2s;
}

.status-item:hover {
  background: rgba(255, 255, 255, 0.06);
}

.stat-value {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 900;
  line-height: 1;
  color: var(--autumn-500);
  font-variant-numeric: tabular-nums;
}

.stat-label {
  display: block;
  margin-top: 0.375rem;
  font-size: 0.8125rem;
  color: var(--winter-400);
  font-family: var(--font-display);
  letter-spacing: 0.04em;
}

/* 主题筛选 */
.theme-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-block: var(--space-4);
}

.theme-filter button {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.9375rem;
  padding: 0.5rem 1.25rem;
  border: var(--border-w) solid var(--ink-900);
  border-radius: 999px;
  background: var(--warm-gray-100);
  box-shadow: 2px 2px 0 var(--ink-900);
  transition: background 0.15s, box-shadow 0.15s, transform 0.15s;
}

.theme-filter button:hover {
  transform: translate(-1px, -1px);
  box-shadow: 3px 3px 0 var(--ink-900);
}

.theme-filter button[data-filter="spring"].is-active {
  background: var(--spring-600);
  color: #fff;
}

.theme-filter button[data-filter="summer"].is-active {
  background: var(--summer-500);
  color: #fff;
}

.theme-filter button[data-filter="autumn"].is-active {
  background: var(--autumn-500);
  color: var(--ink-900);
}

.theme-filter button[data-filter="winter"].is-active {
  background: var(--winter-400);
  color: var(--ink-900);
}

/* 季节背景和曲线分隔 */
.season-bg {
  --season-color: var(--spring-600);
  background: var(--season-color);
  color: #fff;
  padding-block: var(--space-5);
}

.season-bg[data-season="spring"] {
  --season-color: var(--spring-600);
}

.season-bg[data-season="summer"] {
  --season-color: var(--summer-500);
}

.season-bg[data-season="autumn"] {
  --season-color: var(--autumn-500);
  color: var(--ink-900);
}

.season-bg[data-season="winter"] {
  --season-color: var(--winter-400);
  color: var(--ink-900);
}

.curve-divider {
  display: block;
  width: 100%;
  height: 60px;
  margin-block: var(--space-5);
  overflow: hidden;
  position: relative;
}

.curve-divider svg,
.curve-divider-line {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

/* 图片容器基础规则，供页面阶段使用 */
.image-frame {
  position: relative;
  border: var(--border-w) solid var(--ink-900);
  border-radius: var(--radius);
  background:
    linear-gradient(135deg, rgba(14, 107, 72, 0.08), rgba(14, 90, 138, 0.08)),
    var(--winter-100);
  aspect-ratio: 16 / 10;
  overflow: hidden;
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--ink-900);
}

.image-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.image-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  border: 2px dashed var(--winter-400);
  border-radius: 8px;
  margin: 16px;
  z-index: 1;
}

.image-frame img + * {
  position: relative;
  z-index: 2;
}

/* 表格与数据 */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9375rem;
  background: #fff;
  border: var(--border-w) solid var(--ink-900);
  border-radius: var(--radius);
  box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--ink-900);
  overflow: hidden;
}

.data-table th,
.data-table td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--winter-400);
  text-align: left;
  font-variant-numeric: tabular-nums;
}

.data-table th {
  background: var(--spring-50);
  font-family: var(--font-display);
  font-weight: 700;
}

.data-table td {
  border-right: 1px solid var(--winter-400);
}

/* details 折叠 */
details.accordion {
  background: #fff;
  border: var(--border-w) solid var(--ink-900);
  border-radius: var(--radius);
  box-shadow: 3px 3px 0 var(--ink-900);
  margin-bottom: var(--space-2);
  padding: var(--space-2) var(--space-3);
}

details.accordion summary {
  font-size: 1.0625rem;
  list-style: none;
  position: relative;
  padding-right: 2.5rem;
}

details.accordion summary::-webkit-details-marker {
  display: none;
}

details.accordion summary::after {
  content: "+";
  position: absolute;
  right: 0.25rem;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--summer-500);
  transition: transform 0.2s;
}

details.accordion[open] summary::after {
  transform: translateY(-50%) rotate(45deg);
}

details.accordion .accordion-content {
  padding-top: var(--space-2);
  color: var(--ink-600);
  font-size: 0.9375rem;
}

/* 主体中的链接列表和面包屑 */
.breadcrumb {
  font-family: var(--font-display);
  font-size: 0.875rem;
  margin-bottom: var(--space-4);
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  color: var(--ink-600);
}

.breadcrumb a {
  color: var(--summer-500);
}

.breadcrumb [aria-current="page"] {
  color: var(--spring-600);
  font-weight: 700;
}

/* 移动端状态 */
@media (max-width: 920px) {
  .header-inner {
    gap: 0.5rem;
  }

  .status-line {
    margin-left: 0;
    order: 3;
    width: 100%;
    text-align: center;
  }

  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 24px;
    right: 24px;
    background: var(--warm-gray-100);
    border: var(--border-w) solid var(--ink-900);
    border-radius: 0 0 var(--radius) var(--radius);
    box-shadow: var(--shadow-offset) var(--shadow-offset) 0 var(--ink-900);
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: var(--space-2);
    z-index: 200;
  }

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

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
    gap: 0.25rem;
  }

  .nav-list a {
    display: block;
    padding: 0.75rem 1rem;
    border-radius: 8px;
    font-size: 1rem;
  }

  .nav-list a[aria-current="page"] {
    box-shadow: 2px 2px 0 var(--ink-900);
  }

  .site-header .btn.nav-cta {
    margin: 0.5rem 0 0;
    width: 100%;
  }

  .footer-top {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .footer-meta {
    justify-content: flex-start;
  }
}

@media (max-width: 600px) {
  .container {
    padding-inline: 16px;
  }

  .brand-mark {
    font-size: 1.25rem;
  }

  .brand-sub {
    font-size: 0.6875rem;
  }

  .status-line {
    font-size: 0.75rem;
    padding-inline: 0.625rem;
  }

  .card {
    padding: var(--space-3);
  }

  .status-panel {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }

  .status-item {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
  }

  .stat-value {
    font-size: 1.75rem;
  }

  .theme-filter {
    gap: 0.5rem;
  }

  .theme-filter button {
    padding: 0.375rem 1rem;
    font-size: 0.875rem;
  }
}

/* 打印 */
@media print {
  .site-header,
  .site-footer {
    display: none;
  }
}

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

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }

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

/* 滚动显现基础状态 */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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