/* ============================================================
   base — 基础变量、重置、字体与全局骨架
   ============================================================ */
:root {
  --color-primary: #16a085;
  --color-primary-dark: #117a65;
  --color-primary-light: #e8f6f3;
  --color-dark: #2c3e50;
  --color-dark-2: #34495e;
  --color-text: #2c3e50;
  --color-text-light: #5d6d7e;
  --color-bg: #ffffff;
  --color-bg-light: #ecf0f1;
  --color-border: #d5dbdb;
  --color-border-light: #e8ecef;
  --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  --container-width: 1200px;
  --container-padding: 24px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --shadow-card: 0 1px 4px rgba(44, 62, 80, 0.08);
  --shadow-hover: 0 4px 12px rgba(44, 62, 80, 0.12);
}

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

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

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

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

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

a:hover {
  color: var(--color-primary-dark);
}

ul,
ol {
  list-style: none;
}

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

/* ============================================================
   layout — 全站统一容器、页头、页脚骨架
   ============================================================ */
.site-header {
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border-light);
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-nav {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  position: relative;
}

.brand-logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-dark);
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.brand-logo:hover {
  color: var(--color-primary);
}

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

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-dark);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

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

.nav-list li a {
  display: block;
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.nav-list li a:hover {
  color: var(--color-primary);
  background-color: var(--color-bg-light);
}

.nav-list li a.is-current {
  color: var(--color-primary);
  font-weight: 600;
  background-color: var(--color-primary-light);
}

.site-main {
  min-height: 60vh;
}

.site-footer {
  background-color: var(--color-dark);
  color: #bdc3c7;
  margin-top: 80px;
}

.footer-content {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px var(--container-padding) 24px;
  display: grid;
  grid-template-columns: 1.2fr 2fr;
  gap: 40px;
}

.footer-brand .footer-logo {
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 8px;
}

.footer-brand .footer-tagline {
  font-size: 15px;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.footer-brand .footer-desc {
  font-size: 14px;
  line-height: 1.7;
  color: #aeb6bf;
}

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

.footer-group-title {
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 12px;
}

.footer-group a {
  display: block;
  font-size: 14px;
  color: #aeb6bf;
  padding: 4px 0;
  transition: color var(--transition-fast);
}

.footer-group a:hover {
  color: var(--color-primary);
}

.footer-copyright {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 16px var(--container-padding) 24px;
  font-size: 13px;
  color: #7f8c8d;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  text-align: center;
}

/* ============================================================
   components — 通用组件：按钮、标题、面包屑、页面头部、图
   ============================================================ */
.btn-primary,
.btn-secondary {
  display: inline-block;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.btn-primary {
  background-color: var(--color-primary);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  color: #ffffff;
}

.btn-secondary {
  background-color: var(--color-bg);
  color: var(--color-dark);
  border: 1px solid var(--color-border);
}

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

.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-dark);
  line-height: 1.4;
  margin-bottom: 12px;
}

.section-intro {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 24px;
  max-width: 720px;
}

.text-link {
  display: inline-block;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-primary);
  padding: 8px 0;
  transition: color var(--transition-fast);
}

.text-link:hover {
  color: var(--color-primary-dark);
}

.breadcrumb {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 16px var(--container-padding) 0;
  font-size: 14px;
  color: var(--color-text-light);
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

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

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

.breadcrumb-sep {
  color: #bdc3c7;
  margin: 0 2px;
}

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

.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding) 60px;
}

.page-header {
  padding: 36px 0 28px;
  border-bottom: 1px solid var(--color-border-light);
  margin-bottom: 36px;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-dark);
  line-height: 1.4;
  margin-bottom: 12px;
}

.page-description {
  font-size: 16px;
  color: var(--color-text-light);
  line-height: 1.7;
  max-width: 820px;
}

figure {
  margin: 0;
}

figcaption {
  font-size: 13px;
  color: var(--color-text-light);
  text-align: center;
  padding: 8px 0 4px;
}

/* ============================================================
   pages — 首页
   ============================================================ */
.home-main {
  overflow: visible;
}

/* ---- hero ---- */
.hero-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 56px var(--container-padding) 48px;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 48px;
  align-items: start;
}

.hero-copy h1 {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-dark);
  line-height: 1.35;
  margin-bottom: 16px;
}

.hero-tagline {
  font-size: 17px;
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.hero-description {
  font-size: 16px;
  color: var(--color-text-light);
  line-height: 1.75;
  margin-bottom: 24px;
  max-width: 520px;
}

.hero-copy .btn-primary,
.hero-copy .btn-secondary {
  margin-right: 12px;
  margin-bottom: 12px;
}

.hero-media {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 16px;
}

.hero-figure img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.hero-links {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-top: 16px;
}

.cat-link {
  display: block;
  padding: 10px 14px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-dark);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.cat-link:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.content-media-primary {
  grid-column: 1 / -1;
  margin-top: 24px;
}

.content-media-primary img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  border-radius: var(--radius-md);
}

/* ---- 产品分类导航带 ---- */
.category-strip {
  background-color: var(--color-bg-light);
  padding: 48px 0;
}

.category-strip .section-title,
.category-strip .section-intro {
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

.category-tabs {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.category-tab {
  display: block;
  padding: 20px 16px;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  color: var(--color-dark);
  text-align: center;
  transition: all var(--transition-fast);
}

.category-tab:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  box-shadow: var(--shadow-hover);
}

/* ---- 规格能力展示 ---- */
.capability-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 56px var(--container-padding) 24px;
}

.capability-table {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.cap-row {
  display: grid;
  grid-template-columns: 1fr 1.2fr 1fr;
  border-bottom: 1px solid var(--color-border-light);
}

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

.cap-head {
  background-color: var(--color-dark);
  color: #ffffff;
  font-weight: 600;
  font-size: 14px;
}

.cap-cell {
  padding: 14px 16px;
  font-size: 14px;
  line-height: 1.5;
}

.cap-head .cap-cell {
  color: #ffffff;
}

.cap-row:not(.cap-head) .cap-cell:first-child {
  font-weight: 600;
  color: var(--color-dark);
}

.table-note {
  font-size: 14px;
  color: var(--color-text-light);
  margin-top: 12px;
  line-height: 1.6;
}

.table-note a {
  font-weight: 500;
}

/* ---- 采购流程说明 ---- */
.process-section {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px var(--container-padding) 24px;
}

.process-list {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
}

.process-item {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  position: relative;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 15px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 12px;
}

.step-content h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 6px;
}

.step-content p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.6;
}

.process-more {
  margin-top: 20px;
}

/* ---- 工程配套思路 ---- */
.project-scenarios {
  background-color: var(--color-bg-light);
  padding: 48px 0;
}

.project-scenarios .section-title,
.project-scenarios .section-intro {
  max-width: var(--container-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

.scenario-grid {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.scenario-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  transition: box-shadow var(--transition-fast);
}

.scenario-card:hover {
  box-shadow: var(--shadow-hover);
}

.scenario-card h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 10px;
}

.scenario-card p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 14px;
}

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

/* ---- 交付看板预览 ---- */
.delivery-preview {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 56px var(--container-padding) 24px;
}

.timeline-preview {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 16px;
}

.timeline-item {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  text-align: center;
}

.tl-node {
  display: block;
  width: 12px;
  height: 12px;
  background-color: var(--color-primary);
  border-radius: 50%;
  margin: 0 auto 10px;
}

.tl-desc {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-dark);
  line-height: 1.5;
  display: block;
}

/* ---- FAQ 预览 ---- */
.faq-preview {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px var(--container-padding) 24px;
}

.faq-list {
  max-width: 860px;
}

.faq-item {
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  background-color: var(--color-bg);
}

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

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

.faq-item summary::after {
  content: "+";
  font-size: 20px;
  font-weight: 400;
  color: var(--color-primary);
  transition: transform var(--transition-fast);
}

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

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

.faq-item p a {
  font-weight: 500;
}

/* ============================================================
   pages — 产品目录
   ============================================================ */
.scope-section {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 40px;
}

.scope-section p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.8;
}

.category-section {
  margin-bottom: 48px;
}

.category-section > h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 8px;
}

.section-note {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.category-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.category-card {
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--color-bg);
  transition: box-shadow var(--transition-fast);
}

.category-card:hover {
  box-shadow: var(--shadow-hover);
}

.category-media img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.category-body {
  padding: 20px;
}

.category-body h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 8px;
}

.category-body > p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 10px;
}

.category-usage {
  font-size: 13px;
  color: var(--color-primary);
  background-color: var(--color-primary-light);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  margin-bottom: 12px;
}

.category-body a {
  font-size: 14px;
  font-weight: 600;
}

.custom-range-section {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 28px 24px;
}

.custom-range-section h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 12px;
}

.custom-range-section p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 10px;
}

/* ============================================================
   pages — 选型指南
   ============================================================ */
.guide-intro {
  margin-bottom: 40px;
}

.guide-intro p {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.8;
  max-width: 860px;
}

.usage-groups {
  margin-bottom: 48px;
}

.usage-groups > .section-title {
  margin-bottom: 20px;
}

.usage-card {
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 20px;
  background-color: var(--color-bg);
}

.usage-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 10px;
}

.usage-card > p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 12px;
}

.check-list {
  margin: 12px 0;
  padding-left: 0;
}

.check-list li {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  padding: 4px 0 4px 24px;
  position: relative;
}

.check-list li::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 14px;
  width: 6px;
  height: 6px;
  background-color: var(--color-primary);
  border-radius: 50%;
}

.usage-card .text-link {
  margin-right: 16px;
}

.guide-notes {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  margin-bottom: 40px;
}

.guide-notes .section-title {
  margin-bottom: 16px;
}

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

.note-list li {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  padding: 6px 0;
}

.note-list strong {
  color: var(--color-dark);
  font-weight: 600;
}

.guide-notes > p {
  font-size: 14px;
  color: var(--color-text-light);
}

.guide-figure {
  margin-bottom: 40px;
}

.guide-figure img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.related-guides {
  margin-bottom: 40px;
}

.related-guides > p {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 16px;
}

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

.related-links a {
  font-size: 15px;
  font-weight: 500;
}

/* ============================================================
   pages — 加工定制
   ============================================================ */
.section {
  margin-bottom: 40px;
}

.learning-goal {
  background-color: var(--color-primary-light);
  border-radius: var(--radius-md);
  padding: 24px;
}

.learning-goal p {
  font-size: 15px;
  color: var(--color-text);
  line-height: 1.8;
}

.preparation-list {
  margin-top: 16px;
}

.preparation-list li {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  padding: 8px 0 8px 24px;
  position: relative;
}

.preparation-list li::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 18px;
  width: 6px;
  height: 6px;
  background-color: var(--color-primary);
  border-radius: 50%;
}

.preparation-list strong {
  color: var(--color-dark);
  font-weight: 600;
}

.process-steps .process-list {
  grid-template-columns: repeat(3, 1fr);
}

.process-steps .process-item {
  background-color: var(--color-bg-light);
}

.process-steps .process-item h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 6px;
}

.process-steps .process-item p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.6;
}

.final-check .check-list {
  margin-top: 16px;
}

.media-block {
  margin-bottom: 40px;
}

.media-block img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.related-links[aria-label="相关服务入口"] {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 24px;
}

.related-links[aria-label="相关服务入口"] p {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.related-links[aria-label="相关服务入口"] a {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  margin: 4px 16px 4px 0;
}

/* ============================================================
   pages — 交付说明
   ============================================================ */
.delivery-timeline {
  margin-bottom: 48px;
}

.delivery-timeline > h2,
.time-estimate > h2,
.delivery-notes > h2,
.related-links > h2 {
  font-size: 22px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 12px;
}

.timeline-figure {
  margin-bottom: 24px;
}

.timeline-figure img {
  width: 100%;
  height: 260px;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.timeline-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.timeline-list .timeline-item {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  text-align: left;
  position: relative;
}

.timeline-list .timeline-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 16px;
  right: 16px;
  height: 3px;
  background-color: var(--color-primary);
  border-radius: 0 0 4px 4px;
}

.timeline-list .timeline-item h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 8px;
}

.timeline-list .timeline-item p {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.6;
}

.time-estimate {
  margin-bottom: 48px;
}

.estimate-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.estimate-list li {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 20px;
}

.estimate-list h3 {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-dark);
  margin-bottom: 6px;
}

.estimate-list p {
  font-size: 14px;
  color: var(--color-text-light);
  line-height: 1.6;
}

.delivery-notes {
  background-color: var(--color-bg-light);
  border-radius: var(--radius-md);
  padding: 28px 24px;
  margin-bottom: 40px;
}

.notes-list li {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  padding: 6px 0 6px 24px;
  position: relative;
}

.notes-list li::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 16px;
  width: 6px;
  height: 6px;
  background-color: var(--color-primary);
  border-radius: 50%;
}

.related-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.related-list a {
  display: block;
  font-size: 15px;
  font-weight: 500;
  padding: 12px 16px;
  background-color: var(--color-bg-light);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.related-list a:hover {
  background-color: var(--color-primary-light);
  color: var(--color-primary);
}

/* ============================================================
   pages — 404
   ============================================================ */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  padding: 40px 24px;
}

.error-panel {
  text-align: center;
  max-width: 480px;
}

.error-code {
  font-size: 64px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: 12px;
}

.error-panel h1 {
  font-size: 24px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 24px;
}

.error-back {
  display: inline-block;
  padding: 12px 32px;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: background-color var(--transition-fast);
}

.error-back:hover {
  background-color: var(--color-primary-dark);
  color: #ffffff;
}

/* ============================================================
   responsive — 响应式断点
   ============================================================ */
@media (max-width: 992px) {
  .hero-section {
    grid-template-columns: 1fr;
    gap: 32px;
  }

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

  .process-list {
    grid-template-columns: repeat(3, 1fr);
  }

  .process-list .process-item:nth-child(4),
  .process-list .process-item:nth-child(5) {
    grid-column: span 1;
  }

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

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

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

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

@media (max-width: 768px) {
  .site-nav {
    min-height: 56px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-list {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border-light);
    box-shadow: var(--shadow-card);
    flex-direction: column;
    align-items: stretch;
    padding: 8px 16px 16px;
    display: none;
  }

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

  .nav-list li a {
    padding: 12px 8px;
    border-radius: var(--radius-sm);
  }

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

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

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

  .hero-links {
    grid-template-columns: 1fr 1fr;
  }

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

  .category-strip {
    padding: 32px 0;
  }

  .category-tabs {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .capability-section {
    padding: 32px 16px;
  }

  .cap-row {
    grid-template-columns: 1fr;
  }

  .cap-head {
    display: none;
  }

  .cap-row:not(.cap-head) {
    border: 1px solid var(--color-border-light);
    border-radius: var(--radius-sm);
    padding: 8px 12px;
    margin-bottom: 8px;
  }

  .cap-cell {
    padding: 6px 0;
    font-size: 13px;
  }

  .process-section {
    padding: 32px 16px;
  }

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

  .process-item {
    padding: 16px 12px;
  }

  .project-scenarios {
    padding: 32px 0;
  }

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

  .delivery-preview {
    padding: 32px 16px;
  }

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

  .faq-preview {
    padding: 32px 16px;
  }

  .page-header {
    padding: 24px 0 20px;
    margin-bottom: 24px;
  }

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

  .inner-main {
    padding: 0 16px 48px;
  }

  .breadcrumb {
    padding: 12px 16px 0;
  }

  .category-card .category-media img {
    height: 180px;
  }

  .usage-card {
    padding: 20px 16px;
  }

  .guide-notes {
    padding: 20px 16px;
  }

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

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

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

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

  .footer-content {
    padding: 32px 16px 16px;
  }

  .footer-links {
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
  }
}

@media (max-width: 480px) {
  .category-tabs {
    grid-template-columns: 1fr;
  }

  .hero-links {
    grid-template-columns: 1fr;
  }

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

  .timeline-preview {
    grid-template-columns: 1fr;
  }

  .footer-links {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }

  .btn-primary,
  .btn-secondary {
    display: block;
    text-align: center;
    margin-bottom: 10px;
  }

  .hero-copy .btn-primary,
  .hero-copy .btn-secondary {
    margin-right: 0;
  }
}