/* ============================================================
   base / 基础变量与全局重置
   ============================================================ */
:root {
  --bg: #f7fafc;
  --surface: #ffffff;
  --ink: #1a2a33;
  --muted: #5b6b73;
  --line: #dbe6eb;
  --accent: #0e8a83;
  --accent2: #3b82c4;
  --warn: #d97706;
  --radius: 8px;
  --radius-sm: 4px;
  --font-sans: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  --font-mono: "SFMono-Regular", "Menlo", "Consolas", monospace;
  --header-h: 64px;
  --container: 1200px;
  --content-max: 860px;
  --sidebar-w: 220px;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--accent2);
}

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5 {
  line-height: 1.4;
  font-weight: 700;
}

h1 {
  font-size: 32px;
}

h2 {
  font-size: 24px;
}

h3 {
  font-size: 18px;
}

h4 {
  font-size: 16px;
}

p {
  margin-bottom: 1em;
}

/* ============================================================
   layout / 全站骨架：页头、页脚、主容器
   ============================================================ */

/* 页头 */
.site-header {
  background: var(--surface);
  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;
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-shrink: 0;
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0;
}

.brand-tag {
  font-size: 13px;
  color: var(--muted);
  font-family: var(--font-mono);
}

/* 主导航 */
.main-nav ul {
  display: flex;
  gap: 4px;
}

.main-nav a {
  display: block;
  padding: 8px 14px;
  font-size: 15px;
  color: var(--muted);
  border-radius: var(--radius-sm);
  transition: color 0.2s, background 0.2s;
}

.main-nav a:hover {
  color: var(--accent);
  background: rgba(14, 138, 131, 0.06);
}

.main-nav a.is-current {
  color: var(--accent);
  background: rgba(14, 138, 131, 0.1);
  font-weight: 600;
}

/* 汉堡按钮（桌面隐藏） */
.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--radius-sm);
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 0;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--ink);
  border-radius: 1px;
}

/* 主内容区 */
.site-main {
  min-height: 60vh;
}

.inner-main {
  max-width: var(--container);
  margin: 0 auto;
  padding: 32px 24px 64px;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 24px;
  font-family: var(--font-mono);
}

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

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

.breadcrumb-sep {
  color: var(--line);
}

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

/* 页面标题区 */
.page-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--line);
}

.page-title {
  font-size: 32px;
  color: var(--ink);
}

.page-heading {
  margin-bottom: 32px;
}

.page-lead {
  font-size: 17px;
  color: var(--muted);
  max-width: 720px;
}

.page-title-block {
  margin-bottom: 32px;
}

.page-intro {
  font-size: 17px;
  color: var(--muted);
  max-width: 720px;
}

.page-tag {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 8px;
}

/* 页脚 */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--line);
  margin-top: 64px;
}

.footer-grid {
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px 24px 32px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1.2fr;
  gap: 48px;
}

.footer-brand .footer-logo {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.footer-brand p {
  font-size: 14px;
  color: var(--muted);
  margin-top: 12px;
  max-width: 320px;
}

.footer-links h2,
.footer-boundary h2 {
  font-size: 15px;
  margin-bottom: 16px;
  color: var(--ink);
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-links a {
  font-size: 14px;
  color: var(--muted);
}

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

.footer-boundary p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.7;
}

.footer-bottom {
  border-top: 1px solid var(--line);
  padding: 16px 24px;
  text-align: center;
}

.footer-bottom p {
  font-size: 13px;
  color: var(--muted);
  margin: 0;
}

/* ============================================================
   layout / 侧栏布局（内页统一文档外壳）
   ============================================================ */

/* 内页侧栏布局：桌面侧栏在左，正文在右 */
.sidebar-left {
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  gap: 48px;
  align-items: start;
}

/* 当 body 自身作为布局容器时 */
.site-body.sidebar-left {
  max-width: var(--container);
  margin: 0 auto;
  padding: 32px 24px 64px;
}

.site-body.sidebar-left .site-main {
  min-width: 0;
}

/* 侧栏通用样式 */
.sidebar,
.side-nav,
.aside-inner {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  position: sticky;
  top: calc(var(--header-h) + 24px);
}

.side-nav-label {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 12px;
}

.sidebar h2,
.side-nav h2,
.aside-inner h2 {
  font-size: 14px;
  margin-bottom: 12px;
  color: var(--ink);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.sidebar ul,
.side-nav ul,
.aside-inner ul {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.sidebar a,
.side-nav a,
.aside-inner a {
  display: block;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--muted);
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
}

.sidebar a:hover,
.side-nav a:hover,
.aside-inner a:hover {
  color: var(--accent);
  background: rgba(14, 138, 131, 0.05);
  border-left-color: var(--accent);
}

.sidebar a.is-current,
.side-nav a.is-current,
.aside-inner a.is-current {
  color: var(--accent);
  background: rgba(14, 138, 131, 0.08);
  border-left-color: var(--accent);
  font-weight: 600;
}

/* 侧栏补充说明 */
.aside-note {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--muted);
}

/* 正文区域 */
.observe-content,
.process-content,
.about-content,
.faq-content,
.case-content {
  max-width: var(--content-max);
  min-width: 0;
}

/* ============================================================
   components / 通用卡片、链接、按钮
   ============================================================ */

/* 区块标题 */
.section-head {
  margin-bottom: 32px;
}

.section-head h2 {
  font-size: 24px;
  margin-bottom: 8px;
}

.section-head p {
  font-size: 15px;
  color: var(--muted);
  max-width: 640px;
}

.section-desc {
  font-size: 15px;
  color: var(--muted);
  max-width: 640px;
  margin-bottom: 24px;
}

/* 查看更多链接 */
.section-more {
  margin-top: 24px;
  text-align: right;
}

.section-more a {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
}

.section-more a::after {
  content: "→";
  font-family: var(--font-mono);
}

/* 通用按钮 */
.btn-primary,
.cta-primary,
.error-btn,
.hero-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  background: var(--accent);
  color: #ffffff;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid var(--accent);
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s;
  min-height: 44px;
}

.btn-primary:hover,
.cta-primary:hover,
.error-btn:hover,
.hero-cta:hover {
  background: #0b756f;
  border-color: #0b756f;
  color: #ffffff;
}

.btn-secondary,
.cta-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  background: transparent;
  color: var(--accent);
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 1px solid var(--accent);
  cursor: pointer;
  transition: background 0.2s, color 0.2s;
  min-height: 44px;
}

.btn-secondary:hover,
.cta-secondary:hover {
  background: rgba(14, 138, 131, 0.06);
  color: #0b756f;
}

/* 卡片通用 */
.service-card,
.observe-card,
.case-card,
.stage-card,
.principle-card,
.mode-item,
.article-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}

/* 编号 */
.card-index,
.stage-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  display: block;
  margin-bottom: 8px;
}

/* ============================================================
   components / 首页 hero
   ============================================================ */

.hero {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding: 64px 0 48px;
}

.hero-grid {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 16px;
}

.hero h1 {
  font-size: 36px;
  line-height: 1.3;
  margin-bottom: 20px;
}

.hero-lead {
  font-size: 17px;
  color: var(--muted);
  margin-bottom: 28px;
  max-width: 520px;
}

.hero-visual figure {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg);
}

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

/* 三维度入口 */
.hero-dimensions {
  max-width: var(--container);
  margin: 48px auto 0;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.dimension-group {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}

.dimension-group h2 {
  font-size: 15px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  color: var(--accent);
}

.dimension-group li {
  margin-bottom: 4px;
}

.dimension-group a {
  display: block;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--muted);
  border-radius: var(--radius-sm);
}

.dimension-group a:hover {
  color: var(--accent);
  background: var(--surface);
}

/* ============================================================
   components / 首页服务概览
   ============================================================ */

.service-preview {
  max-width: var(--container);
  margin: 0 auto;
  padding: 64px 24px;
}

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

.service-card h3 {
  margin-bottom: 8px;
}

.service-card p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 16px;
}

.service-card a {
  font-size: 14px;
  font-weight: 600;
}

.service-card a::after {
  content: " →";
  font-family: var(--font-mono);
}

/* ============================================================
   components / 首页案例摘要
   ============================================================ */

.case-preview {
  background: var(--surface);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 64px 0;
}

.case-preview .section-head {
  max-width: var(--container);
  margin: 0 auto 32px;
  padding: 0 24px;
}

.case-columns {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.case-col {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}

.case-col h3 {
  font-size: 16px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
  color: var(--accent);
}

.case-col p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 16px;
}

.case-col a {
  font-size: 14px;
  font-weight: 600;
}

.case-figure {
  max-width: var(--container);
  margin: 32px auto 0;
  padding: 0 24px;
}

.case-figure img {
  width: 100%;
  height: 280px;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
}

.case-preview .section-more {
  max-width: var(--container);
  margin: 32px auto 0;
  padding: 0 24px;
}

/* ============================================================
   components / 首页合作节奏
   ============================================================ */

.stage-archive {
  max-width: var(--container);
  margin: 0 auto;
  padding: 64px 24px;
}

.stage-layout {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 48px;
  align-items: start;
}

.stage-index {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px;
  position: sticky;
  top: calc(var(--header-h) + 24px);
}

.stage-index h2 {
  font-size: 14px;
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.stage-index li {
  margin-bottom: 2px;
}

.stage-index a {
  display: block;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--muted);
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
}

.stage-index a:hover {
  color: var(--accent);
  border-left-color: var(--accent);
  background: rgba(14, 138, 131, 0.05);
}

.stage-groups {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.stage-card h3 {
  margin-bottom: 8px;
}

.stage-card p {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

/* ============================================================
   components / 首页观察列表
   ============================================================ */

.observe-list {
  background: var(--surface);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 64px 0;
}

.observe-list .section-head {
  max-width: var(--container);
  margin: 0 auto 32px;
  padding: 0 24px;
}

.observe-cards {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.observe-cat {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent);
  display: block;
  margin-bottom: 12px;
}

.observe-card h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.observe-card p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 12px;
}

.observe-meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.observe-list .section-more {
  max-width: var(--container);
  margin: 32px auto 0;
  padding: 0 24px;
}

/* ============================================================
   components / 首页 FAQ 预览
   ============================================================ */

.faq-preview {
  max-width: var(--container);
  margin: 0 auto;
  padding: 64px 24px;
}

.faq-accordion {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-accordion details {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.faq-accordion summary {
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

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

.faq-accordion summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--accent);
  flex-shrink: 0;
}

.faq-accordion details[open] summary::after {
  content: "−";
}

.faq-accordion details p {
  margin: 12px 0 0;
  font-size: 14px;
  color: var(--muted);
}

/* ============================================================
   components / 首页底部 CTA
   ============================================================ */

.cta-footer {
  background: var(--surface);
  border-top: 1px solid var(--line);
  padding: 64px 0;
}

.cta-block {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  text-align: center;
}

.cta-block h2 {
  font-size: 28px;
  margin-bottom: 12px;
}

.cta-block p {
  font-size: 16px;
  color: var(--muted);
  max-width: 560px;
  margin: 0 auto 28px;
}

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

/* 相关链接（首页与内页共用） */
.related-links {
  max-width: var(--container);
  margin: 0 auto;
  padding: 32px 24px 0;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.related-links-label {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--muted);
}

.related-links-item {
  font-size: 14px;
  color: var(--accent);
  padding: 6px 12px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
}

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

/* ============================================================
   components / 服务矩阵页
   ============================================================ */

.service-intro {
  margin-bottom: 48px;
}

.service-card-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.service-card .card-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 12px;
}

.card-head h3 {
  font-size: 20px;
}

.card-desc {
  font-size: 15px;
  color: var(--muted);
  margin-bottom: 20px;
}

.card-block {
  margin-bottom: 16px;
}

.card-block h4 {
  font-size: 14px;
  margin-bottom: 8px;
  color: var(--ink);
  font-family: var(--font-mono);
}

.card-block ul {
  list-style: none;
}

.card-block li {
  font-size: 14px;
  color: var(--muted);
  padding: 4px 0 4px 16px;
  position: relative;
}

.card-block li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: var(--accent);
  font-weight: 700;
}

/* 服务详情图文块 */
.service-detail {
  margin-bottom: 48px;
}

.service-detail > h2 {
  margin-bottom: 24px;
}

.detail-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}

.detail-figure {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg);
}

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

.detail-figure figcaption {
  padding: 12px 16px;
  font-size: 13px;
  color: var(--muted);
  font-family: var(--font-mono);
}

.detail-points {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.point-item {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.point-item h3 {
  font-size: 15px;
  margin-bottom: 4px;
}

.point-item p {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

/* 交付标准列表 */
.delivery-list {
  margin-bottom: 48px;
}

.standard-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.standard-list li {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.standard-list h3 {
  font-size: 15px;
  margin-bottom: 4px;
}

.standard-list p {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

/* 服务页底部路径 */
.service-path {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  margin-top: 48px;
}

.service-path p {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

.service-path a {
  display: inline-block;
  margin-right: 16px;
  margin-top: 8px;
  font-weight: 600;
}

/* ============================================================
   components / 案例页
   ============================================================ */

.case-intro {
  margin-bottom: 40px;
}

.case-intro p {
  font-size: 15px;
  color: var(--muted);
}

.case-tags {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

.case-tags a {
  padding: 8px 16px;
  font-size: 14px;
  color: var(--accent);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 999px;
}

.case-tags a:hover {
  border-color: var(--accent);
}

.case-card-list {
  display: flex;
  flex-direction: column;
  gap: 32px;
  margin-bottom: 48px;
}

.case-card-list .section-title {
  font-size: 20px;
  margin-bottom: 8px;
}

.case-card {
  padding: 0;
  overflow: hidden;
}

.case-card-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}

.case-category {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent);
  display: block;
  margin-bottom: 4px;
}

.case-card-header h3 {
  font-size: 20px;
}

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

.case-column {
  padding: 20px 24px;
}

.case-column + .case-column {
  border-left: 1px solid var(--line);
}

.fact-column {
  background: var(--surface);
}

.method-column {
  background: rgba(14, 138, 131, 0.03);
}

.experience-column {
  background: rgba(59, 130, 196, 0.03);
}

.case-column h4 {
  font-size: 14px;
  margin-bottom: 12px;
  color: var(--accent);
  font-family: var(--font-mono);
}

.case-column ul {
  list-style: none;
}

.case-column li {
  font-size: 14px;
  color: var(--muted);
  padding: 4px 0 4px 16px;
  position: relative;
}

.case-column li::before {
  content: "·";
  position: absolute;
  left: 4px;
  color: var(--accent);
}

/* 案例导行 */
.case-path {
  margin-top: 48px;
}

.case-path h2 {
  margin-bottom: 24px;
}

.case-path .case-figure {
  padding: 0;
  margin: 0 0 24px;
}

.case-path .case-figure img {
  height: 240px;
}

.case-path .case-figure figcaption {
  padding: 8px 0;
  font-size: 13px;
  color: var(--muted);
  font-family: var(--font-mono);
}

.case-path p {
  font-size: 15px;
  color: var(--muted);
}

.case-path a {
  font-weight: 600;
}

/* ============================================================
   components / 今日观察页
   ============================================================ */

.observe-intro {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  margin-bottom: 48px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}

.intro-figure {
  border-radius: var(--radius);
  overflow: hidden;
}

.intro-figure img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.intro-text h2 {
  font-size: 20px;
  margin-bottom: 12px;
}

.intro-text p {
  font-size: 14px;
  color: var(--muted);
}

/* 文章分类块 */
.category-block {
  margin-bottom: 48px;
}

.category-block > h2 {
  font-size: 20px;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

.category-desc {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 20px;
}

.article-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.article-card {
  padding: 20px;
}

.article-card h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.article-card p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 12px;
}

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--accent);
  background: rgba(14, 138, 131, 0.06);
  padding: 4px 10px;
  border-radius: 999px;
  margin-right: 8px;
}

.read-time {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 8px;
}

/* 观察页 CTA */
.observe-cta {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px;
  text-align: center;
}

.observe-cta h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.observe-cta p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 20px;
}

.cta-links {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================================
   components / 合作流程页
   ============================================================ */

.process-steps {
  margin-bottom: 48px;
}

.process-steps > h2 {
  margin-bottom: 24px;
}

.stage-card {
  margin-bottom: 24px;
}

.stage-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.stage-header h3 {
  font-size: 20px;
}

.stage-number {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
}

.stage-detail {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.stage-row {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 16px;
  padding: 8px 0;
  border-bottom: 1px solid rgba(219, 230, 235, 0.5);
}

.stage-row:last-child {
  border-bottom: none;
}

.stage-row dt {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
  font-weight: 600;
}

.stage-row dd {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

/* 准备清单 */
.prepare-list {
  margin-bottom: 48px;
}

.prepare-list h2 {
  margin-bottom: 8px;
}

.prepare-list > p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 20px;
}

.check-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.check-list li {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px 16px;
  font-size: 14px;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 10px;
}

.check-list li::before {
  content: "✓";
  font-family: var(--font-mono);
  color: var(--accent);
  font-weight: 700;
  flex-shrink: 0;
}

/* 流程插图 */
.process-illustration {
  margin-top: 48px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}

.process-illustration h2 {
  font-size: 20px;
  margin-bottom: 16px;
}

.illustration-figure {
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 16px;
}

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

.illustration-figure figcaption {
  padding: 8px 0;
  font-size: 13px;
  color: var(--muted);
  font-family: var(--font-mono);
}

.process-illustration p {
  font-size: 14px;
  color: var(--muted);
}

/* ============================================================
   components / 常见问题页
   ============================================================ */

.faq-group {
  margin-bottom: 48px;
}

.faq-group > h2 {
  font-size: 20px;
  margin-bottom: 8px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 20px;
}

.faq-item summary {
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

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

.faq-item summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--accent);
  flex-shrink: 0;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  margin: 12px 0 0;
  font-size: 14px;
  color: var(--muted);
}

/* FAQ 说明图 */
.faq-note {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  margin-top: 48px;
}

.faq-figure {
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-figure img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.faq-note-text h2 {
  font-size: 20px;
  margin-bottom: 12px;
}

.faq-note-text p {
  font-size: 14px;
  color: var(--muted);
}

/* ============================================================
   components / 关于我们页
   ============================================================ */

.brand-position {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: center;
  margin-bottom: 48px;
}

.text-block h2 {
  font-size: 20px;
  margin-bottom: 12px;
}

.text-block p {
  font-size: 15px;
  color: var(--muted);
}

.brand-image {
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--line);
}

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

.brand-image figcaption {
  padding: 8px 16px;
  font-size: 13px;
  color: var(--muted);
  font-family: var(--font-mono);
  background: var(--bg);
}

/* 工作方式 */
.working-mode {
  margin-bottom: 48px;
}

.working-mode > h2 {
  margin-bottom: 8px;
}

.working-mode > p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 24px;
}

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

.mode-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
  color: var(--accent);
  font-family: var(--font-mono);
}

.mode-item p {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

/* 服务原则 */
.principles {
  margin-bottom: 48px;
}

.principles > h2 {
  margin-bottom: 8px;
}

.principles > p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 24px;
}

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

.principle-card h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.principle-card p {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

/* 关于页相关链接 */
.about-content .related-links {
  padding: 0;
  margin-top: 48px;
  display: block;
}

.about-content .related-links h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.about-content .related-links > p {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 16px;
}

.about-content .related-links ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.about-content .related-links a {
  font-size: 14px;
  font-weight: 600;
}

/* ============================================================
   components / 404 页
   ============================================================ */

.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  padding: 48px 24px;
}

.error-panel {
  text-align: center;
  max-width: 480px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 48px 32px;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 64px;
  font-weight: 700;
  color: var(--accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-panel h1 {
  font-size: 24px;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: var(--muted);
  margin-bottom: 24px;
}

/* ============================================================
   responsive / 响应式断点
   ============================================================ */

/* 1024px：平板 */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .hero-visual img {
    height: 260px;
  }

  .hero-dimensions {
    grid-template-columns: 1fr;
    gap: 16px;
  }

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

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

  .case-column + .case-column {
    border-left: none;
    border-top: 1px solid var(--line);
  }

  .observe-cards {
    grid-template-columns: 1fr;
  }

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

  .stage-index {
    position: static;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    padding: 16px;
  }

  .stage-index h2 {
    width: 100%;
    margin-bottom: 8px;
  }

  .stage-index ul {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 4px;
  }

  .stage-index a {
    padding: 6px 12px;
    border-left: none;
    border-radius: 999px;
  }

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

  .sidebar,
  .side-nav,
  .aside-inner {
    position: static;
  }

  .detail-block {
    grid-template-columns: 1fr;
  }

  .observe-intro {
    grid-template-columns: 1fr;
  }

  .article-cards {
    grid-template-columns: 1fr;
  }

  .brand-position {
    grid-template-columns: 1fr;
  }

  .faq-note {
    grid-template-columns: 1fr;
  }

  .mode-list,
  .principle-grid {
    grid-template-columns: 1fr;
  }

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

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

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

/* 768px：手机 */
@media (max-width: 768px) {
  :root {
    --header-h: 56px;
  }

  .header-inner {
    padding: 0 16px;
  }

  .brand-tag {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--line);
    padding: 0 16px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }

  .main-nav.is-open {
    max-height: 400px;
    overflow-y: auto;
  }

  .main-nav ul {
    flex-direction: column;
    padding: 16px 0;
    gap: 4px;
  }

  .main-nav a {
    padding: 12px 16px;
    font-size: 16px;
    min-height: 44px;
    display: flex;
    align-items: center;
  }

  .site-main {
    padding-top: 0;
  }

  .inner-main {
    padding: 24px 16px 48px;
  }

  .page-header {
    margin-bottom: 24px;
    padding-bottom: 16px;
  }

  .page-title {
    font-size: 26px;
  }

  h1 {
    font-size: 26px;
  }

  h2 {
    font-size: 20px;
  }

  .hero {
    padding: 40px 0 32px;
  }

  .hero-grid {
    padding: 0 16px;
  }

  .hero h1 {
    font-size: 28px;
  }

  .hero-lead {
    font-size: 15px;
  }

  .hero-visual img {
    height: 200px;
  }

  .hero-dimensions {
    padding: 0 16px;
    margin-top: 32px;
  }

  .service-preview,
  .stage-archive,
  .faq-preview {
    padding: 48px 16px;
  }

  .case-preview,
  .observe-list {
    padding: 48px 0;
  }

  .case-preview .section-head,
  .case-columns,
  .case-figure,
  .case-preview .section-more,
  .observe-list .section-head,
  .observe-cards,
  .observe-list .section-more {
    padding-left: 16px;
    padding-right: 16px;
  }

  .service-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .service-card {
    padding: 20px;
  }

  .case-columns {
    gap: 16px;
  }

  .case-col {
    padding: 20px;
  }

  .case-figure img {
    height: 200px;
  }

  .stage-groups {
    gap: 16px;
  }

  .stage-card {
    padding: 20px;
  }

  .observe-cards {
    gap: 16px;
  }

  .observe-card {
    padding: 20px;
  }

  .faq-accordion details {
    padding: 14px 16px;
  }

  .faq-accordion summary {
    font-size: 14px;
  }

  .cta-footer {
    padding: 48px 0;
  }

  .cta-block {
    padding: 0 16px;
  }

  .cta-block h2 {
    font-size: 24px;
  }

  .cta-actions {
    flex-direction: column;
    align-items: center;
  }

  .cta-actions a {
    width: 100%;
    max-width: 320px;
  }

  .related-links {
    padding: 24px 16px 0;
    gap: 8px;
  }

  .related-links-label {
    width: 100%;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
    padding: 40px 16px 24px;
  }

  .footer-bottom {
    padding: 12px 16px;
  }

  /* 内页侧栏布局在手机端：正文优先，侧栏在后 */
  .sidebar-left {
    display: flex;
    flex-direction: column;
  }

  .sidebar-left .site-main,
  .sidebar-left > .site-main {
    order: 1;
  }

  .sidebar-left > aside,
  .sidebar-left .sidebar,
  .sidebar-left .side-nav,
  .sidebar-left .observe-nav,
  .sidebar-left .about-nav,
  .sidebar-left .faq-nav,
  .sidebar-left .process-nav,
  .sidebar-left .case-filter,
  .sidebar-left .service-nav {
    order: 2;
    position: static;
    overflow-x: auto;
    white-space: nowrap;
    padding: 12px 16px;
    border-radius: var(--radius);
  }

  .sidebar-left .sidebar ul,
  .sidebar-left .side-nav ul,
  .sidebar-left .observe-nav ul,
  .sidebar-left .about-nav ul,
  .sidebar-left .faq-nav ul,
  .sidebar-left .process-nav ul,
  .sidebar-left .case-filter ul,
  .sidebar-left .service-nav ul {
    flex-direction: row;
    gap: 8px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .sidebar-left .sidebar a,
  .sidebar-left .side-nav a,
  .sidebar-left .observe-nav a,
  .sidebar-left .about-nav a,
  .sidebar-left .faq-nav a,
  .sidebar-left .process-nav a,
  .sidebar-left .case-filter a,
  .sidebar-left .service-nav a {
    border-left: none;
    border-radius: 999px;
    padding: 8px 16px;
    white-space: nowrap;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
  }

  .sidebar-left .sidebar h2,
  .sidebar-left .side-nav h2,
  .sidebar-left .observe-nav h2,
  .sidebar-left .about-nav h2,
  .sidebar-left .faq-nav h2,
  .sidebar-left .process-nav h2,
  .sidebar-left .case-filter h2,
  .sidebar-left .service-nav h2 {
    display: none;
  }

  .sidebar-left .aside-note {
    display: none;
  }

  .side-nav-label {
    display: none;
  }

  /* 内页正文 */
  .observe-content,
  .process-content,
  .about-content,
  .faq-content,
  .case-content {
    max-width: 100%;
  }

  .detail-block {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .detail-figure img {
    height: 200px;
  }

  .service-card-list {
    gap: 16px;
  }

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

  .case-column + .case-column {
    border-left: none;
    border-top: 1px solid var(--line);
  }

  .case-card-header {
    padding: 16px 20px;
  }

  .case-column {
    padding: 16px 20px;
  }

  .observe-intro {
    grid-template-columns: 1fr;
    padding: 16px;
    gap: 16px;
  }

  .intro-figure img {
    height: 180px;
  }

  .article-cards {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .article-card {
    padding: 16px;
  }

  .observe-cta {
    padding: 24px 16px;
  }

  .stage-row {
    grid-template-columns: 1fr;
    gap: 4px;
    padding: 12px 0;
  }

  .stage-row dt {
    margin-bottom: 4px;
  }

  .stage-header {
    margin-bottom: 12px;
  }

  .check-list {
    grid-template-columns: 1fr;
    gap: 8px;
  }

  .check-list li {
    padding: 12px 14px;
  }

  .process-illustration {
    padding: 16px;
  }

  .illustration-figure img {
    height: 200px;
  }

  .faq-group {
    margin-bottom: 32px;
  }

  .faq-item {
    padding: 14px 16px;
  }

  .faq-item summary {
    font-size: 14px;
  }

  .faq-note {
    grid-template-columns: 1fr;
    padding: 16px;
    gap: 16px;
  }

  .faq-figure img {
    height: 180px;
  }

  .brand-position {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .brand-image img {
    height: 220px;
  }

  .mode-list {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .mode-item {
    padding: 16px;
  }

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

  .principle-card {
    padding: 16px;
  }

  .error-code {
    font-size: 48px;
  }

  .error-panel {
    padding: 32px 20px;
  }
}

/* 390px：小屏手机 */
@media (max-width: 390px) {
  .brand-name {
    font-size: 18px;
  }

  .hero h1 {
    font-size: 24px;
  }

  .hero-lead {
    font-size: 14px;
  }

  .hero-visual img {
    height: 180px;
  }

  .service-card {
    padding: 16px;
  }

  .case-col {
    padding: 16px;
  }

  .stage-card {
    padding: 16px;
  }

  .observe-card {
    padding: 16px;
  }

  .cta-block h2 {
    font-size: 22px;
  }

  .cta-actions a {
    max-width: 100%;
  }

  .footer-grid {
    gap: 24px;
  }

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

  .detail-figure img {
    height: 180px;
  }

  .point-item {
    padding: 14px 16px;
  }

  .standard-list li {
    padding: 14px 16px;
  }

  .case-card-header {
    padding: 14px 16px;
  }

  .case-column {
    padding: 14px 16px;
  }

  .article-card {
    padding: 14px;
  }

  .stage-header h3 {
    font-size: 18px;
  }

  .faq-item summary {
    font-size: 13px;
  }

  .brand-image img {
    height: 200px;
  }

  .error-code {
    font-size: 40px;
  }
}