/* ==========================================================================
   牛马 AI 建站 · 全局基础样式
   ========================================================================== */

/* --------------------------------------------------------------------------
   base · 变量与重置
   -------------------------------------------------------------------------- */
:root {
  --color-ink: #1F2A2E;
  --color-bg: #F4F1EB;
  --color-accent: #C8974A;
  --color-white: #FFFFFF;
  --color-muted: #6B7280;
  --color-line: #E3DED5;
  --color-ink-soft: #2E3B40;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --container-w: 1200px;
  --sidebar-w: 240px;
  --content-w: 720px;
  --radius: 8px;
  --radius-sm: 6px;
  --header-h: 72px;
  --transition: 0.25s ease;
}

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

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

body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-ink);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

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

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-ink);
}

h1 {
  font-size: 36px;
}

h2 {
  font-size: 26px;
}

h3 {
  font-size: 19px;
}

p {
  margin-bottom: 1em;
}

/* 视觉隐藏，仅供屏幕阅读器 */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* --------------------------------------------------------------------------
   base · 全局骨架（页头 / 页脚 / 主容器）
   -------------------------------------------------------------------------- */
.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.site-home {
  background-color: var(--color-bg);
}

.site-inner {
  background-color: var(--color-bg);
}

.site-header {
  background-color: var(--color-ink);
  border-bottom: 3px solid var(--color-accent);
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.brand {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  flex-shrink: 0;
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.01em;
}

.brand-tag {
  font-size: 12px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  letter-spacing: 0.08em;
  margin-top: 2px;
}

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

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

.nav-list li {
  position: relative;
}

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

.nav-list a:hover {
  color: var(--color-accent);
  background-color: rgba(255, 255, 255, 0.06);
}

.nav-list a.is-current {
  color: var(--color-accent);
  background-color: rgba(200, 151, 74, 0.12);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-white);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.site-main {
  flex: 1;
  width: 100%;
}

.site-footer {
  background-color: var(--color-ink);
  color: rgba(255, 255, 255, 0.72);
  margin-top: auto;
}

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

.footer-col h4 {
  color: var(--color-white);
  font-size: 16px;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.footer-col p {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.6);
  margin-bottom: 0;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 20px 24px;
  text-align: center;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.45);
}

.footer-bottom p {
  margin-bottom: 0;
}

/* --------------------------------------------------------------------------
   base · 通用组件（按钮 / 面包屑 / 页面标题）
   -------------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  cursor: pointer;
  line-height: 1.4;
  border: 1px solid transparent;
  transition: background-color var(--transition), border-color var(--transition), color var(--transition);
}

.btn-primary {
  background-color: var(--color-accent);
  color: var(--color-ink);
}

.btn-primary:hover {
  background-color: #b9863c;
  color: var(--color-ink);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-white);
  border-color: rgba(255, 255, 255, 0.5);
}

.btn-secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.breadcrumb {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 20px 24px 0;
  font-size: 13px;
  color: var(--color-muted);
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

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

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

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

.breadcrumb-current {
  color: var(--color-ink);
  font-weight: 600;
}

.page-header {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 32px 24px 28px;
}

.page-title {
  font-size: 36px;
  font-weight: 700;
  color: var(--color-ink);
  margin-bottom: 12px;
  line-height: 1.25;
}

.page-description {
  font-size: 16px;
  color: var(--color-muted);
  line-height: 1.7;
  max-width: 760px;
  margin-bottom: 0;
}

/* 相关链接通用样式 */
.related-links {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 48px 24px 64px;
}

.related-links h2,
.related-links h3 {
  font-size: 18px;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-line);
}

.related-links ul {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.related-links li a {
  display: inline-block;
  padding: 8px 18px;
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--color-ink);
  transition: border-color var(--transition), color var(--transition);
}

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

.related-links-item {
  display: inline-block;
  margin-top: 12px;
  font-size: 14px;
  color: var(--color-accent);
  font-weight: 600;
}

.related-title {
  font-size: 18px;
  margin-bottom: 16px;
}

.related-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.related-list li a {
  display: inline-block;
  padding: 8px 18px;
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  font-size: 14px;
}

/* ==========================================================================
   layout · 内页布局外壳
   ========================================================================== */
.inner-main {
  padding-bottom: 40px;
}

.layout-shell {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  gap: 48px;
  align-items: start;
}

.sidebar-left {
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
}

.sidebar-left .page-layout {
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
}

.sidebar-left .page-layout .content-area {
  min-width: 0;
}

/* 内页两栏：侧栏 + 正文 */
.page-layout {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: var(--sidebar-w) minmax(0, 1fr);
  gap: 48px;
  align-items: start;
}

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

/* 侧栏通用 */
.service-index,
.doc-aside,
.topic-sidebar,
.sidebar {
  position: sticky;
  top: calc(var(--header-h) + 24px);
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 20px;
}

.service-index h2,
.doc-aside h2,
.topic-sidebar h2,
.sidebar-title {
  font-size: 16px;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-accent);
}

.index-list li,
.aside-nav li,
.topic-list li,
.step-directory li {
  margin-bottom: 4px;
}

.index-list a,
.aside-nav a,
.topic-list a,
.step-directory a {
  display: block;
  padding: 8px 12px;
  font-size: 14px;
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  color: var(--color-ink);
}

.index-list a:hover,
.aside-nav a:hover,
.topic-list a:hover,
.step-directory a:hover {
  background-color: var(--color-bg);
  color: var(--color-accent);
  border-left-color: var(--color-accent);
}

.index-note,
.sidebar-note {
  font-size: 13px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--color-line);
}

/* ==========================================================================
   components · 首页模块
   ========================================================================== */

/* --- 首屏 hero --- */
.hero-section {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 56px 24px 48px;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.hero-kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.hero-title {
  font-size: 40px;
  line-height: 1.2;
  margin-bottom: 20px;
}

.hero-title .accent {
  color: var(--color-accent);
}

.hero-summary {
  font-size: 16px;
  color: var(--color-muted);
  line-height: 1.8;
  margin-bottom: 28px;
  max-width: 520px;
}

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

.hero-media {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-line);
  background-color: var(--color-white);
}

.hero-media img {
  width: 100%;
  height: 380px;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.hero-media:hover img {
  transform: scale(1.02);
}

.hero-media figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-white);
  border-top: 1px solid var(--color-line);
}

/* --- 服务区（首页） --- */
.services-section {
  background-color: var(--color-white);
  border-top: 1px solid var(--color-line);
  border-bottom: 1px solid var(--color-line);
  padding: 56px 0;
}

.section-title {
  font-size: 28px;
  margin-bottom: 32px;
  position: relative;
  padding-bottom: 14px;
}

.section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 48px;
  height: 3px;
  background-color: var(--color-accent);
}

.services-layout {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: 48px;
  align-items: start;
}

.service-index {
  position: sticky;
  top: calc(var(--header-h) + 24px);
}

.service-details {
  min-width: 0;
}

.service-card {
  padding: 28px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background-color: var(--color-bg);
  margin-bottom: 20px;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.service-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 16px rgba(31, 42, 46, 0.06);
}

.service-number {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--color-accent);
  margin-bottom: 10px;
}

.service-card h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.service-card p {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.7;
}

.service-scene {
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px dashed var(--color-line);
  font-size: 14px;
  color: var(--color-ink);
}

/* --- 案例区（首页） --- */
.cases-section {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 56px 24px;
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  align-items: start;
}

.case-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
}

.case-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(31, 42, 46, 0.08);
}

.case-card-wide {
  grid-column: span 1;
  margin-top: 32px;
}

.case-card-offset {
  margin-top: 32px;
}

.case-card figure {
  position: relative;
  overflow: hidden;
  aspect-ratio: 4 / 3;
}

.case-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.case-card:hover img {
  transform: scale(1.04);
}

.case-card figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 20px 16px 10px;
  background: linear-gradient(to top, rgba(31, 42, 46, 0.7), transparent);
  color: var(--color-white);
  font-size: 13px;
}

.case-info {
  padding: 18px 20px 20px;
}

.case-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-accent);
  margin-bottom: 8px;
}

.case-info h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.case-info p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

.cases-more {
  margin-top: 32px;
  text-align: right;
}

.cases-more a {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  border-bottom: 1px solid var(--color-accent);
  padding-bottom: 2px;
}

/* --- 流程区（首页） --- */
.process-section {
  background-color: var(--color-white);
  border-top: 1px solid var(--color-line);
  border-bottom: 1px solid var(--color-line);
  padding: 56px 0;
}

.process-steps {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.process-step {
  position: relative;
  padding: 24px;
  background-color: var(--color-bg);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
}

.step-number {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.step-content h3 {
  font-size: 17px;
  margin-bottom: 10px;
}

.step-content p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  margin-bottom: 0;
}

.process-more {
  max-width: var(--container-w);
  margin: 28px auto 0;
  padding: 0 24px;
  text-align: right;
}

.process-more a {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  border-bottom: 1px solid var(--color-accent);
  padding-bottom: 2px;
}

/* --- 资料与更新双栏（首页） --- */
.info-section {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 56px 24px;
}

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

.info-col {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 28px;
}

.info-col h3 {
  font-size: 18px;
  margin-bottom: 18px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-accent);
}

.info-list li {
  padding: 10px 0;
  border-bottom: 1px dashed var(--color-line);
}

.info-list li:last-child {
  border-bottom: none;
}

.info-list a {
  display: block;
  font-size: 15px;
  font-weight: 600;
}

.info-list a::after {
  content: "→";
  color: var(--color-accent);
  margin-left: 8px;
  font-family: var(--font-mono);
}

/* --- FAQ 折叠区（首页） --- */
.faq-section {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px 56px;
}

.faq-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-item summary {
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 44px;
  transition: background-color var(--transition);
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--color-accent);
  transition: transform var(--transition);
}

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

.faq-item summary:hover {
  background-color: var(--color-bg);
}

.faq-item p {
  padding: 0 20px 16px;
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 0;
}

.faq-more {
  margin-top: 20px;
  text-align: center;
}

.faq-more a {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  border-bottom: 1px solid var(--color-accent);
  padding-bottom: 2px;
}

/* ==========================================================================
   components · 内页模块
   ========================================================================== */

/* --- 影像服务页 --- */
.service-content {
  min-width: 0;
}

.service-block {
  margin-bottom: 48px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--color-line);
}

.service-block:last-of-type {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.service-head {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.service-no {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
}

.service-head h3 {
  font-size: 24px;
}

.service-lead {
  font-size: 16px;
  color: var(--color-ink);
  line-height: 1.75;
  margin-bottom: 20px;
}

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

.detail-col {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  padding: 18px;
}

.detail-col h4 {
  font-size: 14px;
  margin-bottom: 10px;
  color: var(--color-accent);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

.detail-col ul li {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  padding: 3px 0;
  position: relative;
  padding-left: 14px;
}

.detail-col ul li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--color-accent);
}

.service-figure {
  margin-top: 24px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-line);
}

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

.service-figure figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-white);
  border-top: 1px solid var(--color-line);
}

/* 交付标准 */
.delivery-standard {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 48px 24px 0;
}

.delivery-standard h2 {
  font-size: 24px;
  margin-bottom: 12px;
}

.section-intro {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 28px;
  max-width: 720px;
}

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

.standard-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 24px;
  text-align: left;
}

.standard-no {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--color-accent);
  margin-bottom: 10px;
}

.standard-card h3 {
  font-size: 17px;
  margin-bottom: 10px;
}

.standard-card p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  margin-bottom: 0;
}

/* --- 作品案例页 --- */
.case-feature {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px 40px;
}

.case-feature .section-title {
  font-size: 24px;
}

.featured-card {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.featured-media {
  position: relative;
  min-height: 340px;
}

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

.featured-content {
  padding: 32px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.case-type {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-accent);
  margin-bottom: 12px;
  letter-spacing: 0.06em;
}

.featured-title {
  font-size: 24px;
  margin-bottom: 16px;
}

.featured-desc {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}

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

/* 筛选栏 */
.filter-bar {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px 24px;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

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

.filter-link {
  display: inline-block;
  padding: 8px 18px;
  font-size: 14px;
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: 999px;
  color: var(--color-ink);
  transition: all var(--transition);
}

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

/* 案例网格 */
.case-grid {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px 48px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.case-grid .case-card {
  overflow: hidden;
}

.card-media {
  position: relative;
  aspect-ratio: 4 / 3;
  overflow: hidden;
}

.card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.case-grid .case-card:hover .card-media img {
  transform: scale(1.04);
}

.card-title {
  font-size: 17px;
  margin-bottom: 8px;
}

.card-desc {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 0;
}

/* --- 制作流程页 --- */
.sidebar {
  position: sticky;
  top: calc(var(--header-h) + 24px);
}

.step-directory {
  counter-reset: step-counter;
}

.step-directory a {
  display: flex;
  align-items: center;
  gap: 10px;
}

.step-directory a::before {
  content: counter(step-counter);
  counter-increment: step-counter;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-accent);
  width: 20px;
  flex-shrink: 0;
}

.content-area .section-title {
  font-size: 24px;
}

.process-step {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 28px;
  margin-bottom: 24px;
}

.step-head {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 18px;
}

.step-head .step-number {
  font-size: 26px;
}

.step-head h3 {
  font-size: 22px;
}

.step-body p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-ink);
  margin-bottom: 12px;
}

.step-body strong {
  color: var(--color-accent);
  font-weight: 600;
  margin-right: 6px;
}

.process-media {
  margin-top: 20px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-line);
}

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

.process-media figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-bg);
  border-top: 1px solid var(--color-line);
}

/* 进度提示 */
.progress-indicator {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-top: 32px;
}

.progress-indicator p {
  font-size: 14px;
  color: var(--color-muted);
  margin-bottom: 10px;
}

.progress-bar {
  height: 6px;
  background-color: var(--color-bg);
  border-radius: 3px;
  overflow: hidden;
  margin-bottom: 12px;
}

.progress-fill {
  display: block;
  height: 100%;
  width: 60%;
  background-color: var(--color-accent);
  border-radius: 3px;
}

.progress-tip {
  font-size: 14px;
}

.progress-tip a {
  color: var(--color-accent);
  font-weight: 600;
}

/* 交付说明 */
.deliverable-section {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 48px 24px 0;
}

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

.deliverable-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 24px;
}

.deliverable-card h3 {
  font-size: 16px;
  margin-bottom: 10px;
  color: var(--color-accent);
}

.deliverable-card p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  margin-bottom: 0;
}

/* --- 资料中心页 --- */
.doc-block {
  margin-bottom: 48px;
}

.doc-block h2 {
  font-size: 22px;
  margin-bottom: 8px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--color-accent);
}

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

.doc-item {
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr);
  gap: 20px;
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 16px;
}

.doc-media {
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--color-line);
  aspect-ratio: 4 / 3;
}

.doc-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.doc-body h3 {
  font-size: 17px;
  margin-bottom: 8px;
}

.doc-body p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.6;
  margin-bottom: 10px;
}

.doc-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
  color: var(--color-muted);
  margin-top: 8px;
}

.doc-meta dt {
  display: inline;
  font-weight: 600;
  color: var(--color-ink);
}

.doc-meta dd {
  display: inline;
  margin-left: 4px;
}

/* 获取方式说明 */
.access-note {
  background-color: var(--color-white);
  border-top: 1px solid var(--color-line);
  border-bottom: 1px solid var(--color-line);
  padding: 48px 0;
}

.access-inner {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px;
}

.access-inner h2 {
  font-size: 22px;
  margin-bottom: 16px;
}

.access-inner p {
  font-size: 15px;
  color: var(--color-muted);
  line-height: 1.7;
  max-width: 720px;
}

/* --- 更新记录页 --- */
.version-panel {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 0 24px 32px;
}

.version-card {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.version-banner {
  position: relative;
  min-height: 240px;
}

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

.version-body {
  padding: 28px;
}

.version-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.version-tag {
  display: inline-block;
  padding: 4px 12px;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 12px;
  font-weight: 700;
  border-radius: 999px;
  font-family: var(--font-mono);
}

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

.version-title {
  font-size: 22px;
  margin-bottom: 16px;
}

.change-list li {
  font-size: 15px;
  line-height: 1.6;
  padding: 6px 0;
  padding-left: 18px;
  position: relative;
  color: var(--color-ink);
}

.change-list li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--color-accent);
}

.version-note {
  font-size: 14px;
  color: var(--color-muted);
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px dashed var(--color-line);
}

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

.version-details {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
}

.version-details summary {
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: background-color var(--transition);
}

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

.version-details summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--color-accent);
}

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

.version-details summary:hover {
  background-color: var(--color-bg);
}

.details-date {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-muted);
  font-weight: 400;
}

.details-content {
  padding: 0 20px 16px;
  border-top: 1px solid var(--color-line);
}

.details-content .change-list {
  padding-top: 12px;
}

/* --- 合作咨询页 --- */
.topic-sidebar {
  position: sticky;
  top: calc(var(--header-h) + 24px);
}

.faq-section h2 {
  font-size: 24px;
  margin-bottom: 20px;
}

.content-media-inline {
  margin-bottom: 24px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--color-line);
}

.content-media-inline img {
  width: 100%;
  height: 240px;
  object-fit: cover;
}

.content-media-inline figcaption {
  padding: 10px 16px;
  font-size: 13px;
  color: var(--color-muted);
  background-color: var(--color-white);
  border-top: 1px solid var(--color-line);
}

.faq-topic-block {
  margin-bottom: 36px;
}

.faq-topic-block h3 {
  font-size: 18px;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--color-accent);
}

/* 合作路径 */
.cooperation-path {
  max-width: var(--container-w);
  margin: 0 auto;
  padding: 48px 24px 0;
}

.cooperation-path h2 {
  font-size: 24px;
  margin-bottom: 12px;
}

.cooperation-path > p {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 28px;
}

.path-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.path-steps li {
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 24px;
  position: relative;
}

.path-steps h3 {
  font-size: 17px;
  margin-bottom: 10px;
  padding-top: 28px;
  position: relative;
}

.path-steps h3::before {
  content: attr(data-step);
  position: absolute;
  top: 16px;
  left: 0;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--color-accent);
}

.path-steps p {
  font-size: 14px;
  color: var(--color-muted);
  line-height: 1.65;
  margin-bottom: 14px;
}

.path-steps a {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
  border-bottom: 1px solid var(--color-accent);
  padding-bottom: 2px;
}

/* ==========================================================================
   pages · 404 错误页
   ========================================================================== */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 70vh;
  padding: 48px 24px;
}

.error-content {
  text-align: center;
  max-width: 560px;
  background-color: var(--color-white);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 48px 40px;
}

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

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

.error-desc {
  font-size: 15px;
  color: var(--color-muted);
  margin-bottom: 28px;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.error-btn {
  display: inline-block;
  padding: 12px 28px;
  background-color: var(--color-accent);
  color: var(--color-ink);
  font-weight: 700;
  border-radius: var(--radius-sm);
}

.error-btn:hover {
  background-color: #b9863c;
  color: var(--color-ink);
}

.error-link {
  display: inline-block;
  padding: 12px 24px;
  font-size: 14px;
  color: var(--color-ink);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-sm);
}

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

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

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

  .hero-media img {
    height: 320px;
  }

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

  .service-index {
    position: static;
  }

  .service-index .index-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }

  .service-index .index-list li {
    margin-bottom: 0;
  }

  .service-index .index-list a {
    border-left: none;
    border-bottom: 2px solid transparent;
    padding: 6px 14px;
  }

  .service-index .index-list a:hover {
    border-bottom-color: var(--color-accent);
    background-color: var(--color-bg);
  }

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

  .case-card-wide,
  .case-card-offset {
    margin-top: 0;
  }

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

  .layout-shell,
  .page-layout {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 32px;
  }

  .sidebar-left .page-layout {
    grid-template-columns: 200px minmax(0, 1fr);
  }

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

  .featured-card {
    grid-template-columns: 1fr;
  }

  .featured-media {
    min-height: 280px;
  }

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

  .version-card {
    grid-template-columns: 1fr;
  }

  .version-banner {
    min-height: 200px;
  }

  .doc-item {
    grid-template-columns: 1fr;
  }

  .doc-media {
    max-width: 240px;
  }

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

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

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: var(--header-h);
    left: 0;
    right: 0;
    background-color: var(--color-ink);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    border-bottom: 3px solid var(--color-accent);
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: flex-start;
    padding: 12px 16px;
    gap: 0;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }

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

  .nav-list li {
    width: 100%;
  }

  .nav-list a {
    padding: 12px 10px;
    font-size: 16px;
    border-radius: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  }

  .nav-list a.is-current {
    background-color: transparent;
  }

  .hero-section {
    padding: 40px 16px 36px;
  }

  .hero-title {
    font-size: 32px;
  }

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

  .services-section,
  .cases-section,
  .process-section,
  .info-section,
  .faq-section {
    padding: 40px 0;
  }

  .services-layout,
  .cases-grid,
  .process-steps,
  .info-columns,
  .standard-grid,
  .deliverable-grid,
  .path-steps,
  .footer-columns {
    padding-left: 16px;
    padding-right: 16px;
  }

  .layout-shell,
  .page-layout {
    display: block;
    padding: 0 16px;
  }

  .service-index,
  .doc-aside,
  .topic-sidebar,
  .sidebar {
    position: static;
    margin-bottom: 24px;
  }

  .service-index .index-list,
  .aside-nav,
  .topic-list,
  .step-directory {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }

  .service-index .index-list li,
  .aside-nav li,
  .topic-list li,
  .step-directory li {
    margin-bottom: 0;
  }

  .service-index .index-list a,
  .aside-nav a,
  .topic-list a,
  .step-directory a {
    border-left: none;
    border-bottom: 2px solid transparent;
    padding: 6px 12px;
    background-color: var(--color-bg);
  }

  .service-index .index-list a:hover,
  .aside-nav a:hover,
  .topic-list a:hover,
  .step-directory a:hover {
    border-bottom-color: var(--color-accent);
    background-color: var(--color-bg);
  }

  .step-directory a::before {
    display: none;
  }

  .page-header {
    padding: 24px 16px 20px;
  }

  .page-title {
    font-size: 30px;
  }

  .breadcrumb {
    padding: 16px 16px 0;
  }

  .case-feature {
    padding: 0 16px 32px;
  }

  .filter-bar {
    padding: 0 16px 20px;
  }

  .case-grid {
    padding: 0 16px 40px;
    grid-template-columns: 1fr;
  }

  .service-block {
    margin-bottom: 32px;
    padding-bottom: 28px;
  }

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

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

  .related-links {
    padding: 40px 16px 48px;
  }

  .version-panel {
    padding: 0 16px 24px;
  }

  .access-note {
    padding: 40px 0;
  }

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

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

  .deliverable-section,
  .cooperation-path {
    padding: 40px 16px 0;
  }

  .footer-columns {
    padding: 40px 16px 32px;
  }
}

/* --- 480px --- */
@media (max-width: 480px) {
  :root {
    --header-h: 64px;
  }

  .brand-name {
    font-size: 17px;
  }

  .brand-tag {
    font-size: 11px;
  }

  .hero-section {
    padding: 32px 16px 28px;
  }

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

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

  .hero-cta {
    flex-direction: column;
  }

  .hero-cta .btn {
    width: 100%;
  }

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

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

  .service-card {
    padding: 20px;
  }

  .service-card h3 {
    font-size: 18px;
  }

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

  .process-steps {
    grid-template-columns: 1fr;
  }

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

  .standard-grid,
  .deliverable-grid,
  .path-steps {
    grid-template-columns: 1fr;
  }

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

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

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

  .service-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .service-no {
    font-size: 22px;
  }

  .featured-media {
    min-height: 200px;
  }

  .featured-content {
    padding: 24px;
  }

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

  .doc-item {
    padding: 16px;
  }

  .doc-media {
    max-width: 100%;
  }

  .version-body {
    padding: 20px;
  }

  .version-title {
    font-size: 19px;
  }

  .change-list li {
    font-size: 14px;
  }

  .error-content {
    padding: 32px 24px;
  }

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

  .error-actions {
    flex-direction: column;
  }

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

  .progress-indicator {
    padding: 16px 18px;
  }

  .process-step {
    padding: 20px;
  }

  .step-head h3 {
    font-size: 19px;
  }

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

/* --- 滚动出现动画（不影响初始可见性） --- */
@media (prefers-reduced-motion: no-preference) {
  .case-card,
  .process-step,
  .service-card,
  .standard-card,
  .deliverable-card,
  .doc-item,
  .path-steps li {
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition), opacity var(--transition);
  }
}