/* ==========================================================================
   51大赛 · 全站样式表
   视觉方向：展览目录与实验排版的混合风格
   米色纸面底色、墨色文字与朱红标识
   ========================================================================== */

/* ==========================================================================
   base · 基础变量与重置
   ========================================================================== */

:root {
  --paper: #f6f1e8;
  --ink: #1c1e1c;
  --accent: #d94f35;
  --moss: #5f6f52;
  --plaque: #e8dcc8;
  --paper-deep: #efe7d8;
  --white: #ffffff;
  --ink-soft: #4a4d48;
  --line: #d8cdb8;
  --serif: "Noto Serif SC", "Source Han Serif CN", "Songti SC", "SimSun", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --container: 1200px;
  --radius: 6px;
  --radius-sm: 4px;
  --shadow: 0 2px 12px rgba(28, 30, 28, 0.06);
  --transition: 0.25s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--ink);
  background-color: var(--paper);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--ink);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--accent);
}

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.4;
  color: var(--ink);
}

p {
  margin-bottom: 1em;
}

p:last-child {
  margin-bottom: 0;
}

/* ==========================================================================
   layout · 全站骨架
   ========================================================================== */

.site-body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background-color: var(--paper);
}

.site-main {
  flex: 1 0 auto;
}

/* 内页统一主容器 */
.inner-main {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px 72px;
}

/* ==========================================================================
   layout · 页头与导航
   ========================================================================== */

.site-header {
  background-color: var(--paper);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  gap: 24px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
}

.brand-name {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink);
  line-height: 1.2;
}

.brand-name::after {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  margin-left: 4px;
  vertical-align: middle;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  justify-content: flex-end;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  width: 44px;
  height: 44px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  border-radius: var(--radius-sm);
}

.nav-toggle-line {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--ink);
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: block;
  padding: 8px 14px;
  font-size: 15px;
  color: var(--ink);
  border-radius: var(--radius-sm);
  line-height: 1.5;
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--accent);
  background-color: rgba(217, 79, 53, 0.06);
}

.nav-item.is-current .nav-link,
.nav-link.is-current {
  color: var(--accent);
  font-weight: 600;
}

.nav-item.is-current .nav-link::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 2px;
  height: 2px;
  background-color: var(--accent);
}

.nav-cta {
  display: inline-block;
  margin-left: 8px;
  padding: 10px 22px;
  border: 1.5px solid var(--accent);
  border-radius: var(--radius);
  color: var(--accent);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.5;
  background: transparent;
  transition: background-color var(--transition), color var(--transition);
  white-space: nowrap;
}

.nav-cta:hover {
  background-color: var(--accent);
  color: var(--white);
}

/* ==========================================================================
   layout · 面包屑
   ========================================================================== */

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 28px 0 20px;
  font-size: 14px;
  color: var(--ink-soft);
}

.breadcrumb a {
  color: var(--ink-soft);
}

.breadcrumb a:hover {
  color: var(--accent);
}

.breadcrumb-sep {
  color: var(--moss);
  opacity: 0.6;
}

.breadcrumb-current {
  color: var(--ink);
  font-weight: 500;
}

/* ==========================================================================
   layout · 内页页头标题区
   ========================================================================== */

.page-header {
  padding: 12px 0 36px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 44px;
}

.page-title {
  font-size: 34px;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.3;
  margin-bottom: 12px;
}

.page-description {
  font-size: 16px;
  color: var(--ink-soft);
  max-width: 720px;
  line-height: 1.7;
}

/* ==========================================================================
   layout · 页脚
   ========================================================================== */

.site-footer {
  background-color: var(--ink);
  color: var(--paper);
  margin-top: auto;
}

.footer-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 56px 24px 40px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 48px;
}

.footer-brand-name {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 700;
  color: var(--paper);
  margin-bottom: 14px;
}

.footer-brand-desc {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(246, 241, 232, 0.72);
  max-width: 360px;
}

.footer-col-title {
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 600;
  color: var(--paper);
  margin-bottom: 16px;
  letter-spacing: 0.04em;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  font-size: 14px;
  color: rgba(246, 241, 232, 0.72);
  line-height: 1.6;
}

.footer-links a:hover {
  color: var(--accent);
}

.footer-bottom {
  border-top: 1px solid rgba(246, 241, 232, 0.14);
  padding: 20px 24px;
  text-align: center;
}

.copyright {
  font-size: 13px;
  color: rgba(246, 241, 232, 0.5);
  margin: 0;
}

/* ==========================================================================
   components · 通用区块标题
   ========================================================================== */

.section-title {
  font-size: 26px;
  font-weight: 700;
  color: var(--ink);
  line-height: 1.4;
  margin-bottom: 16px;
}

.section-intro {
  font-size: 16px;
  color: var(--ink-soft);
  max-width: 640px;
  line-height: 1.7;
}

.section-lead {
  font-size: 16px;
  color: var(--ink-soft);
  max-width: 640px;
  margin-bottom: 32px;
}

/* ==========================================================================
   components · 按钮
   ========================================================================== */

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  transition: background-color var(--transition), color var(--transition), border-color var(--transition);
}

.btn-primary {
  background-color: var(--accent);
  color: var(--white);
  border: 1.5px solid var(--accent);
}

.btn-primary:hover {
  background-color: #c4432c;
  border-color: #c4432c;
  color: var(--white);
}

.btn-secondary {
  background-color: transparent;
  color: var(--ink);
  border: 1.5px solid var(--ink);
}

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

/* ==========================================================================
   components · 任务条（页脚上方相关入口）
   ========================================================================== */

.task-strip {
  background-color: var(--paper-deep);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.task-strip:not(.task-strip .task-strip) {
  margin-top: 0;
}

.task-strip-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 32px 24px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

/* 首页任务条 */
.home-main .task-strip {
  max-width: var(--container);
  margin: 64px auto 0;
  padding: 32px 24px;
  background-color: transparent;
  border: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.task-card {
  display: block;
  padding: 24px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.task-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  border-color: var(--accent);
  color: var(--ink);
}

.task-card-label {
  display: inline-block;
  font-size: 13px;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: 0.04em;
}

.task-card-title {
  display: block;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.4;
}

.task-card-desc {
  display: block;
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
}

.task-title {
  display: block;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 8px;
}

.task-desc {
  display: block;
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* 内页任务条链接 */
.task-link {
  display: flex;
  flex-direction: column;
  padding: 20px 24px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.task-link:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  border-color: var(--accent);
  color: var(--ink);
}

.task-link-title {
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 6px;
  line-height: 1.4;
}

.task-link-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* ==========================================================================
   components · 相关链接
   ========================================================================== */

.related-links {
  max-width: var(--container);
  margin: 0 auto;
  padding: 24px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.related-links-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--ink-soft);
  margin-right: 4px;
}

.related-links-item {
  font-size: 14px;
  color: var(--accent);
  border-bottom: 1px solid rgba(217, 79, 53, 0.3);
  padding-bottom: 2px;
}

.related-links-item:hover {
  border-bottom-color: var(--accent);
}

/* ==========================================================================
   pages · 首页
   ========================================================================== */

/* 首屏高密度定位区 */
.hero-tight {
  max-width: var(--container);
  margin: 0 auto;
  padding: 56px 24px 0;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
  position: relative;
}

.hero-copy {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero-kicker {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 20px;
  padding: 6px 14px;
  border: 1px solid rgba(217, 79, 53, 0.35);
  border-radius: 999px;
  background-color: rgba(217, 79, 53, 0.04);
}

.hero-title {
  font-size: 42px;
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 20px;
  max-width: 540px;
}

.hero-lead {
  font-size: 17px;
  color: var(--ink-soft);
  line-height: 1.75;
  margin-bottom: 32px;
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-figure {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.hero-figure img {
  width: 100%;
  height: 380px;
  object-fit: cover;
}

.hero-band {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  gap: 8px 28px;
  flex-wrap: wrap;
  padding: 18px 0;
  border-top: 1px solid var(--line);
  margin-top: 24px;
}

.band-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--moss);
  letter-spacing: 0.05em;
  white-space: nowrap;
}

.band-item {
  font-size: 14px;
  color: var(--ink-soft);
  position: relative;
  padding-left: 14px;
}

.band-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background-color: var(--accent);
}

/* 服务矩阵四象限 */
.service-matrix {
  max-width: var(--container);
  margin: 0 auto;
  padding: 80px 24px 0;
}

.matrix-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 36px;
}

.matrix-item {
  padding: 32px 24px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  position: relative;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.matrix-item:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow);
}

.matrix-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--accent);
  color: var(--white);
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 20px;
}

.matrix-name {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 10px;
}

.matrix-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
}

/* 典型赛事形态展览 */
.exhibition {
  max-width: var(--container);
  margin: 0 auto;
  padding: 80px 24px 0;
}

.exhibit-block {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 32px;
  align-items: center;
  margin-bottom: 48px;
}

.exhibit-block:nth-child(even) {
  grid-template-columns: 0.8fr 1.2fr;
}

.exhibit-block:nth-child(even) .exhibit-figure {
  order: 2;
}

.exhibit-block:nth-child(even) .exhibit-card {
  order: 1;
}

.exhibit-figure {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.exhibit-figure img {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

.exhibit-card {
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 36px 32px;
  position: relative;
}

.exhibit-index {
  display: inline-block;
  font-family: var(--serif);
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}

.exhibit-title {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 14px;
}

.exhibit-desc {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
}

/* 能力摘要区 */
.capability-summary {
  max-width: var(--container);
  margin: 0 auto;
  padding: 80px 24px 0;
}

.capability-summary .section-title {
  max-width: 520px;
  margin-left: 8%;
}

.summary-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  margin-top: 32px;
}

.summary-text {
  font-size: 16px;
  color: var(--ink-soft);
  line-height: 1.75;
}

/* 合作流程缩略 */
.process-preview {
  max-width: var(--container);
  margin: 0 auto;
  padding: 80px 24px 0;
}

.process-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 36px;
}

.process-step {
  padding: 28px 24px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  position: relative;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.process-step:hover {
  border-color: var(--moss);
  box-shadow: var(--shadow);
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--moss);
  color: var(--white);
  font-family: var(--serif);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
}

.step-name {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.step-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
}

.section-link {
  display: inline-block;
  margin-top: 28px;
  font-size: 15px;
  font-weight: 600;
  color: var(--accent);
  border-bottom: 1.5px solid rgba(217, 79, 53, 0.3);
  padding-bottom: 2px;
}

.section-link:hover {
  border-bottom-color: var(--accent);
}

/* ==========================================================================
   pages · 关于页
   ========================================================================== */

.intro-band {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 48px;
  align-items: center;
  margin-bottom: 64px;
}

.intro-copy p {
  font-size: 16px;
  color: var(--ink-soft);
  line-height: 1.75;
  margin-bottom: 1.2em;
}

.intro-media {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.intro-media img {
  width: 100%;
  height: 300px;
  object-fit: cover;
}

.team-role-grid {
  margin-bottom: 64px;
}

.role-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.role-card {
  padding: 28px 24px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.role-card:hover {
  border-color: var(--moss);
  box-shadow: var(--shadow);
}

.role-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--moss);
  color: var(--white);
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 16px;
}

.role-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 10px;
}

.role-card p {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
}

.principles-list {
  margin-bottom: 64px;
}

.principles-items {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.principle-item {
  padding: 24px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.principle-item h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--ink);
}

.principle-item p {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
}

.boundary-note {
  padding: 36px 32px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  margin-bottom: 24px;
}

.boundary-note h2 {
  font-size: 22px;
  margin-bottom: 16px;
}

.boundary-note p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 1em;
}

/* ==========================================================================
   pages · 赛事服务页
   ========================================================================== */

.scope-note {
  padding: 32px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 56px;
}

.scope-note .section-title {
  font-size: 22px;
}

.scope-note p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
  max-width: 800px;
}

.service-category-list {
  margin-bottom: 72px;
}

.service-item {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 40px;
  align-items: center;
  margin-bottom: 56px;
  padding-bottom: 56px;
  border-bottom: 1px solid var(--line);
}

.service-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.service-item:nth-child(even) {
  grid-template-columns: 1.1fr 0.9fr;
}

.service-item:nth-child(even) .service-media {
  order: 2;
}

.service-item:nth-child(even) .service-body {
  order: 1;
}

.service-media {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.service-media img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

.service-name {
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 20px;
}

.service-detail {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.detail-col {
  padding: 20px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.detail-col h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.detail-col p {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
}

.match-suggestion {
  padding: 40px 32px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 24px;
}

.match-intro {
  font-size: 15px;
  color: var(--ink-soft);
  margin-bottom: 24px;
}

.match-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.match-item {
  padding: 24px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.match-item h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 10px;
}

.match-item p {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
}

/* ==========================================================================
   pages · 赛事经验页
   ========================================================================== */

.expo-note {
  padding: 32px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 56px;
}

.expo-note .section-title {
  font-size: 22px;
}

.expo-note p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
  max-width: 800px;
  margin-bottom: 1em;
}

.exhibition-group {
  margin-bottom: 64px;
}

.exhibit-item {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: center;
  margin-bottom: 56px;
  padding-bottom: 56px;
  border-bottom: 1px solid var(--line);
}

.exhibit-item:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.exhibit-item:nth-child(even) {
  grid-template-columns: 0.8fr 1.2fr;
}

.exhibit-item:nth-child(even) .exhibit-figure {
  order: 2;
}

.exhibit-item:nth-child(even) .exhibit-plaque {
  order: 1;
}

.exhibit-figure {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.exhibit-image {
  width: 100%;
  height: 340px;
  object-fit: cover;
}

.exhibit-plaque {
  padding: 36px 32px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.exhibit-number {
  font-family: var(--serif);
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.08em;
  margin-bottom: 12px;
}

.exhibit-title {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 14px;
}

.exhibit-desc {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 20px;
}

.plaque-subtitle {
  font-size: 15px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 10px;
  padding-top: 16px;
  border-top: 1px solid rgba(28, 30, 28, 0.1);
}

.plaque-list {
  margin-bottom: 16px;
}

.plaque-list li {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
  padding-left: 16px;
  position: relative;
  margin-bottom: 6px;
}

.plaque-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background-color: var(--moss);
}

.plaque-note {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
  font-style: italic;
}

.lesson-summary {
  padding: 40px 32px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 24px;
}

.lesson-intro {
  font-size: 15px;
  color: var(--ink-soft);
  margin-bottom: 24px;
}

.lesson-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.lesson-item {
  padding: 24px;
  background-color: var(--paper-deep);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.lesson-item-title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 10px;
  position: relative;
  padding-left: 16px;
}

.lesson-item-title::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.45em;
  width: 6px;
  height: 6px;
  background-color: var(--accent);
  border-radius: 1px;
}

.lesson-item-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
}

/* ==========================================================================
   pages · 合作流程页
   ========================================================================== */

.stage-timeline {
  margin-bottom: 64px;
}

.stage-item {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 32px;
  padding-bottom: 40px;
  margin-bottom: 40px;
  position: relative;
}

.stage-item::before {
  content: "";
  position: absolute;
  left: 79px;
  top: 64px;
  bottom: 0;
  width: 1px;
  background-color: var(--line);
}

.stage-item:last-child::before {
  display: none;
}

.stage-head {
  text-align: right;
  padding-right: 24px;
  position: relative;
}

.stage-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--accent);
  color: var(--white);
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 600;
  position: absolute;
  right: -20px;
  top: 0;
  z-index: 1;
}

.stage-name {
  font-size: 20px;
  font-weight: 600;
  margin-top: 52px;
}

.stage-body {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding-left: 24px;
}

.stage-col {
  padding: 20px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.stage-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--moss);
  letter-spacing: 0.04em;
  margin-bottom: 8px;
  text-transform: uppercase;
}

.stage-text {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
}

.prep-check {
  margin-bottom: 64px;
  padding: 40px 32px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.prep-intro {
  font-size: 15px;
  color: var(--ink-soft);
  margin-bottom: 24px;
}

.prep-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}

.prep-item {
  display: flex;
  gap: 14px;
  padding: 20px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.prep-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--moss);
  color: var(--white);
  font-family: var(--serif);
  font-size: 14px;
  font-weight: 600;
  flex-shrink: 0;
}

.prep-content {
  min-width: 0;
}

.prep-name {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 6px;
}

.prep-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
}

.image-band {
  margin-bottom: 24px;
}

.process-figure {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.process-figure img {
  width: 100%;
  height: 360px;
  object-fit: cover;
}

.process-figure figcaption {
  padding: 14px 20px;
  background-color: var(--ink);
  color: var(--paper);
  font-size: 14px;
  line-height: 1.6;
}

/* ==========================================================================
   pages · 常见问题页
   ========================================================================== */

.faq-group {
  margin-bottom: 56px;
}

.faq-group .section-title {
  font-size: 22px;
}

.content-media {
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 32px;
}

.content-media img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.content-media figcaption {
  padding: 12px 16px;
  background-color: var(--plaque);
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.5;
}

.faq-list {
  border-top: 1px solid var(--line);
}

.faq-item {
  border-bottom: 1px solid var(--line);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 8px;
  font-family: var(--serif);
  font-size: 17px;
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
  transition: color var(--transition);
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-question::after {
  content: "+";
  font-family: var(--sans);
  font-size: 22px;
  font-weight: 400;
  color: var(--accent);
  flex-shrink: 0;
  transition: transform var(--transition);
  line-height: 1;
}

.faq-item[open] .faq-question {
  color: var(--accent);
}

.faq-item[open] .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  padding: 0 8px 24px;
}

.faq-answer p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
}

.tip-note {
  padding: 24px 32px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 24px;
}

.tip-note p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
}

.tip-note a {
  color: var(--accent);
  font-weight: 600;
  border-bottom: 1px solid rgba(217, 79, 53, 0.3);
}

.tip-note a:hover {
  border-bottom-color: var(--accent);
}

/* ==========================================================================
   pages · 合作沟通页
   ========================================================================== */

.prep-list {
  margin-bottom: 64px;
}

.prep-list .section-intro {
  margin-bottom: 32px;
}

.prep-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
}

.prep-item {
  display: flex;
  flex-direction: column;
  padding: 28px 24px;
  background-color: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.prep-item:hover {
  border-color: var(--moss);
  box-shadow: var(--shadow);
}

.prep-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--accent);
  color: var(--white);
  font-family: var(--serif);
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 16px;
}

.prep-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 10px;
}

.prep-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.65;
}

.progress-note {
  margin-bottom: 64px;
}

.progress-layout {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 40px;
  align-items: center;
}

.progress-image {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.media-figure img {
  width: 100%;
  height: 300px;
  object-fit: cover;
}

.progress-content {
  min-width: 0;
}

.progress-text {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.75;
  margin-bottom: 1.2em;
}

.guide-links {
  margin-bottom: 24px;
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.guide-card {
  display: flex;
  flex-direction: column;
  padding: 28px 24px;
  background-color: var(--plaque);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.guide-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
  border-color: var(--accent);
  color: var(--ink);
}

.guide-card-title {
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 8px;
}

.guide-card-desc {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* ==========================================================================
   pages · 404 错误页
   ========================================================================== */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 96px 24px;
  min-height: 60vh;
}

.error-content {
  text-align: center;
  max-width: 560px;
}

.error-code {
  font-family: var(--serif);
  font-size: 72px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 28px;
  margin-bottom: 16px;
}

.error-desc {
  font-size: 16px;
  color: var(--ink-soft);
  margin-bottom: 32px;
}

.error-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.error-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 12px 28px;
  background-color: var(--accent);
  color: var(--white);
  border-radius: var(--radius);
  font-size: 16px;
  font-weight: 600;
}

.error-btn:hover {
  background-color: #c4432c;
  color: var(--white);
}

.error-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 12px 28px;
  border: 1.5px solid var(--ink);
  color: var(--ink);
  border-radius: var(--radius);
  font-size: 16px;
  font-weight: 600;
}

.error-link:hover {
  background-color: var(--ink);
  color: var(--paper);
}

/* ==========================================================================
   responsive · 1024px
   ========================================================================== */

@media (max-width: 1024px) {
  .header-inner {
    padding: 0 20px;
  }

  .nav-link {
    padding: 8px 10px;
    font-size: 14px;
  }

  .nav-cta {
    padding: 9px 16px;
    font-size: 14px;
  }

  .hero-tight {
    gap: 32px;
  }

  .hero-title {
    font-size: 36px;
  }

  .hero-figure img {
    height: 340px;
  }

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

  .exhibit-block {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .exhibit-figure img {
    height: 280px;
  }

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

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

  .service-item {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .service-item:nth-child(even) {
    grid-template-columns: 1fr;
  }

  .service-item:nth-child(even) .service-media {
    order: 1;
  }

  .service-item:nth-child(even) .service-body {
    order: 2;
  }

  .service-media img {
    height: 240px;
  }

  .exhibit-item {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .exhibit-item:nth-child(even) {
    grid-template-columns: 1fr;
  }

  .exhibit-item:nth-child(even) .exhibit-figure {
    order: 1;
  }

  .exhibit-item:nth-child(even) .exhibit-plaque {
    order: 2;
  }

  .exhibit-image {
    height: 300px;
  }

  .stage-item {
    grid-template-columns: 120px 1fr;
    gap: 24px;
  }

  .stage-item::before {
    left: 59px;
  }

  .stage-number {
    right: -20px;
  }

  .stage-body {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .progress-layout {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .guide-grid {
    grid-template-columns: 1fr;
  }

  .match-list {
    grid-template-columns: 1fr;
  }

  .lesson-list {
    grid-template-columns: 1fr;
  }

  .summary-columns {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .principles-items {
    grid-template-columns: 1fr;
  }

  .footer-main {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }

  .intro-band {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .service-detail {
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
  }

  .detail-col {
    padding: 16px;
  }
}

/* ==========================================================================
   responsive · 768px 及以下（手机端）
   ========================================================================== */

@media (max-width: 768px) {
  .header-inner {
    height: 64px;
    padding: 0 16px;
  }

  .brand-name {
    font-size: 22px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    gap: 0;
  }

  .nav-list {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background-color: var(--paper);
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    align-items: stretch;
    padding: 8px 16px 16px;
    gap: 0;
    box-shadow: 0 8px 20px rgba(28, 30, 28, 0.08);
    z-index: 99;
  }

  .nav-list.is-open {
    display: flex;
  }

  .nav-item {
    border-bottom: 1px solid rgba(216, 205, 184, 0.5);
  }

  .nav-item:last-child {
    border-bottom: none;
  }

  .nav-item.is-current .nav-link::after {
    left: 0;
    right: auto;
    width: 3px;
    height: 20px;
    top: 50%;
    transform: translateY(-50%);
    bottom: auto;
  }

  .nav-link {
    padding: 14px 8px;
    font-size: 16px;
    white-space: normal;
  }

  .nav-cta {
    display: none;
  }

  .inner-main {
    padding: 0 16px 56px;
  }

  .breadcrumb {
    padding: 20px 0 16px;
    font-size: 13px;
    flex-wrap: wrap;
  }

  .page-header {
    padding: 8px 0 28px;
    margin-bottom: 32px;
  }

  .page-title {
    font-size: 28px;
  }

  .page-description {
    font-size: 15px;
  }

  /* 首页 */
  .hero-tight {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px 16px 0;
  }

  .hero-copy {
    order: 1;
  }

  .hero-figure {
    order: 2;
  }

  .hero-band {
    order: 3;
    padding: 14px 0;
    gap: 6px 16px;
  }

  .hero-kicker {
    font-size: 13px;
    margin-bottom: 14px;
  }

  .hero-title {
    font-size: 30px;
    margin-bottom: 14px;
  }

  .hero-lead {
    font-size: 16px;
    margin-bottom: 24px;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .btn-primary,
  .btn-secondary {
    width: 100%;
  }

  .hero-figure img {
    height: 240px;
  }

  .service-matrix,
  .exhibition,
  .capability-summary,
  .process-preview {
    padding: 48px 16px 0;
  }

  .matrix-grid {
    grid-template-columns: 1fr;
    gap: 14px;
    margin-top: 24px;
  }

  .matrix-item {
    padding: 24px 20px;
  }

  .exhibit-block {
    grid-template-columns: 1fr;
    gap: 16px;
    margin-bottom: 32px;
  }

  .exhibit-block:nth-child(even) {
    grid-template-columns: 1fr;
  }

  .exhibit-block:nth-child(even) .exhibit-figure {
    order: 1;
  }

  .exhibit-block:nth-child(even) .exhibit-card {
    order: 2;
  }

  .exhibit-figure img {
    height: 220px;
  }

  .exhibit-card {
    padding: 24px 20px;
  }

  .capability-summary .section-title {
    margin-left: 0;
  }

  .process-strip {
    grid-template-columns: 1fr;
    gap: 14px;
    margin-top: 24px;
  }

  .process-step {
    padding: 20px;
  }

  .section-link {
    margin-top: 20px;
  }

  /* 关于页 */
  .intro-band {
    grid-template-columns: 1fr;
    gap: 20px;
    margin-bottom: 48px;
  }

  .intro-media img {
    height: 220px;
  }

  .role-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .principles-items {
    gap: 14px;
  }

  .boundary-note {
    padding: 24px 20px;
  }

  /* 服务页 */
  .scope-note {
    padding: 24px 20px;
    margin-bottom: 40px;
  }

  .service-item {
    gap: 16px;
    margin-bottom: 40px;
    padding-bottom: 40px;
  }

  .service-media img {
    height: 200px;
  }

  .service-name {
    font-size: 22px;
  }

  .service-detail {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .match-suggestion {
    padding: 24px 20px;
  }

  /* 经验页 */
  .expo-note {
    padding: 24px 20px;
    margin-bottom: 40px;
  }

  .exhibit-item {
    gap: 16px;
    margin-bottom: 40px;
    padding-bottom: 40px;
  }

  .exhibit-image {
    height: 220px;
  }

  .exhibit-plaque {
    padding: 24px 20px;
  }

  .lesson-summary {
    padding: 24px 20px;
  }

  /* 流程页 */
  .stage-item {
    grid-template-columns: 1fr;
    gap: 16px;
    padding-bottom: 32px;
    margin-bottom: 32px;
  }

  .stage-item::before {
    display: none;
  }

  .stage-head {
    text-align: left;
    padding-right: 0;
  }

  .stage-number {
    position: static;
    margin-bottom: 8px;
  }

  .stage-name {
    margin-top: 8px;
    font-size: 19px;
  }

  .stage-body {
    grid-template-columns: 1fr;
    gap: 10px;
    padding-left: 0;
  }

  .prep-check {
    padding: 24px 20px;
    margin-bottom: 48px;
  }

  .process-figure img {
    height: 220px;
  }

  /* FAQ 页 */
  .faq-group {
    margin-bottom: 40px;
  }

  .content-media img {
    height: 200px;
  }

  .faq-question {
    font-size: 15px;
    padding: 16px 4px;
  }

  .faq-answer {
    padding: 0 4px 20px;
  }

  .tip-note {
    padding: 20px;
  }

  /* 沟通页 */
  .prep-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .progress-layout {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .media-figure img {
    height: 220px;
  }

  .guide-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .guide-card {
    padding: 24px 20px;
  }

  /* 任务条 */
  .task-strip-inner {
    padding: 24px 16px;
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .home-main .task-strip {
    margin: 40px auto 0;
    padding: 24px 16px;
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .related-links {
    padding: 20px 16px;
    gap: 10px 14px;
  }

  /* 页脚 */
  .footer-main {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 40px 16px 32px;
  }

  .footer-brand {
    grid-column: auto;
  }

  .footer-bottom {
    padding: 16px;
  }

  /* 404 */
  .error-main {
    padding: 64px 16px;
  }

  .error-code {
    font-size: 56px;
  }

  .error-actions {
    flex-direction: column;
    width: 100%;
  }

  .error-btn,
  .error-link {
    width: 100%;
  }
}

/* ==========================================================================
   responsive · 480px 极小屏微调
   ========================================================================== */

@media (max-width: 480px) {
  .hero-title {
    font-size: 26px;
  }

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

  .page-title {
    font-size: 24px;
  }

  .band-item {
    font-size: 13px;
  }

  .hero-band {
    gap: 4px 12px;
  }

  .exhibit-title {
    font-size: 20px;
  }

  .exhibit-index {
    font-size: 13px;
  }

  .matrix-index {
    width: 32px;
    height: 32px;
    font-size: 14px;
  }

  .step-num {
    width: 28px;
    height: 28px;
    font-size: 13px;
  }

  .task-card,
  .task-link {
    padding: 18px 16px;
  }

  .task-card-title,
  .task-title,
  .task-link-title {
    font-size: 17px;
  }

  .footer-brand-name {
    font-size: 20px;
  }
}