/* ============================================================
   base — 基础变量、重置与全站字体
   ============================================================ */
:root {
  --color-primary: #2C3E50;
  --color-accent: #3498DB;
  --color-bg: #ECF0F1;
  --color-white: #FFFFFF;
  --color-text: #2C3E50;
  --color-text-light: #5A6B7B;
  --color-border: #D5DDE2;
  --color-card-bg: #FFFFFF;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  --container-width: 1200px;
  --container-padding: 24px;
  --radius: 8px;
  --transition: 0.2s ease;
  --header-height: 68px;
}

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

html {
  font-size: 16px;
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-bg);
  font-size: 16px;
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

a:hover {
  text-decoration: underline;
}

ul, ol {
  list-style: none;
}

.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;
}

/* ============================================================
   layout — 全站统一布局骨架
   ============================================================ */
.site-header {
  background-color: var(--color-primary);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.logo-area {
  flex-shrink: 0;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  color: var(--color-white);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-link:hover {
  text-decoration: none;
  color: var(--color-white);
}

.brand-name {
  line-height: 1.2;
}

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

.site-nav .nav-list li a {
  display: block;
  padding: 8px 14px;
  color: rgba(255, 255, 255, 0.85);
  font-size: 15px;
  border-radius: 4px;
  transition: background-color var(--transition), color var(--transition);
}

.site-nav .nav-list li a:hover {
  color: var(--color-white);
  background-color: rgba(255, 255, 255, 0.12);
  text-decoration: none;
}

.site-nav .nav-list li a.is-current {
  color: var(--color-white);
  background-color: rgba(255, 255, 255, 0.2);
  font-weight: 600;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
}

.nav-toggle-icon {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-white);
  position: relative;
  transition: background-color var(--transition);
}

.nav-toggle-icon::before,
.nav-toggle-icon::after {
  content: "";
  position: absolute;
  left: 0;
  width: 24px;
  height: 2px;
  background-color: var(--color-white);
}

.nav-toggle-icon::before {
  top: -7px;
}

.nav-toggle-icon::after {
  top: 7px;
}

.site-main {
  flex: 1 0 auto;
  width: 100%;
}

.home-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding) 48px;
}

.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding) 56px;
  width: 100%;
}

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding: 16px 0;
  font-size: 14px;
  color: var(--color-text-light);
}

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

.breadcrumb a:hover {
  text-decoration: underline;
}

.breadcrumb-sep {
  color: var(--color-text-light);
  opacity: 0.7;
}

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

.page-header {
  padding: 20px 0 28px;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: 36px;
}

.page-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.25;
  margin-bottom: 12px;
}

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

/* ============================================================
   components — 通用组件
   ============================================================ */
.section-header {
  margin-bottom: 28px;
}

.section-title {
  font-size: 26px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.3;
  margin-bottom: 10px;
}

.section-intro {
  font-size: 16px;
  color: var(--color-text-light);
  line-height: 1.7;
  max-width: 760px;
}

.text-link {
  display: inline-block;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-accent);
  margin-top: 10px;
}

.text-link:hover {
  text-decoration: underline;
}

/* ============================================================
   components — 首页
   ============================================================ */
.compare-hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
  padding: 48px 0 40px;
}

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

.hero-heading {
  font-size: 34px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.3;
  margin-bottom: 16px;
}

.hero-sub {
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-light);
  margin-bottom: 24px;
  max-width: 520px;
}

.compare-selector {
  display: flex;
  flex-direction: column;
  gap: 14px;
  max-width: 480px;
}

.selector-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.selector-group label {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-primary);
  white-space: nowrap;
  min-width: 70px;
}

.selector-group select {
  flex: 1;
  padding: 10px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background-color: var(--color-white);
  font-size: 15px;
  color: var(--color-text);
  font-family: inherit;
  cursor: pointer;
}

.selector-group select:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 1px;
  border-color: var(--color-accent);
}

.compare-note {
  font-size: 13px;
  color: var(--color-text-light);
  line-height: 1.5;
  padding-top: 4px;
}

.hero-figure {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
}

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

.content-media {
  border-radius: var(--radius);
  overflow: hidden;
  margin-top: 20px;
  background-color: var(--color-white);
}

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

.content-media figcaption {
  padding: 10px 14px;
  font-size: 14px;
  color: var(--color-text-light);
  background-color: var(--color-white);
}

.service-overview {
  padding: 48px 0;
  border-top: 1px solid var(--color-border);
}

.service-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.service-card {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  transition: box-shadow var(--transition), transform var(--transition);
}

.service-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.service-name {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 10px;
}

.service-desc {
  font-size: 14px;
  line-height: 1.65;
  color: var(--color-text-light);
  margin-bottom: 12px;
}

.card-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-accent);
}

.card-link:hover {
  text-decoration: underline;
}

.solutions-preview {
  padding: 48px 0;
  border-top: 1px solid var(--color-border);
}

.solution-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.solution-card {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  transition: box-shadow var(--transition);
}

.solution-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.solution-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.solution-summary {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.cooperation-process {
  padding: 48px 0;
  border-top: 1px solid var(--color-border);
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  counter-reset: step;
}

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

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 16px;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 14px;
}

.step-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.step-desc {
  font-size: 14px;
  line-height: 1.65;
  color: var(--color-text-light);
}

.faq-preview {
  padding: 48px 0;
  border-top: 1px solid var(--color-border);
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 800px;
}

.faq-item {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-item summary {
  padding: 16px 20px;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
  cursor: pointer;
  list-style: none;
  position: relative;
  padding-right: 40px;
  transition: background-color var(--transition);
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  font-weight: 400;
  color: var(--color-accent);
}

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

.faq-item summary:hover {
  background-color: #F5F7F8;
}

.faq-item p,
.faq-item .faq-answer {
  padding: 0 20px 16px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.faq-more {
  margin-top: 20px;
  font-size: 15px;
}

.faq-more a {
  font-weight: 600;
}

/* ============================================================
   components — 服务能力页（service.html）
   ============================================================ */
.service-framework {
  padding: 12px 0 40px;
}

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

.framework-step {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
}

.framework-step .step-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.framework-step .step-title::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  background-color: var(--color-accent);
  border-radius: 2px;
}

.framework-step .step-desc {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.delivery-system {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.delivery-details,
.quality-checks {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  margin-top: 24px;
}

.details-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 16px;
}

.details-list,
.checks-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.details-list li,
.checks-list li {
  padding-left: 20px;
  position: relative;
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.details-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

.checks-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  font-weight: 700;
  color: var(--color-accent);
}

.service-media {
  margin: 40px 0;
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-white);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.service-media .media-image {
  width: 100%;
  height: 360px;
  object-fit: cover;
}

.service-media figcaption {
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-text-light);
  background-color: var(--color-white);
}

.service-boundary {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.boundary-text {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
  max-width: 800px;
}

.boundary-text a {
  font-weight: 600;
  margin-right: 4px;
}

.related-pages {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

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

.related-link {
  display: block;
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px;
  font-size: 15px;
  font-weight: 600;
  color: var(--color-primary);
  transition: box-shadow var(--transition), border-color var(--transition);
}

.related-link:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  border-color: var(--color-accent);
  text-decoration: none;
}

/* ============================================================
   components — 使用指南页（guide.html）
   ============================================================ */
.guide-steps {
  padding: 12px 0 40px;
}

.steps-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 24px;
  max-width: 800px;
}

.steps-list .step-item {
  display: flex;
  gap: 20px;
  align-items: flex-start;
  padding: 24px;
}

.steps-list .step-number {
  flex-shrink: 0;
  margin-bottom: 0;
}

.step-content {
  flex: 1;
  min-width: 0;
}

.step-heading {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.step-content p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.guide-boundary {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.boundary-content {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 32px;
  align-items: start;
  margin-top: 20px;
}

.boundary-content p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.boundary-content p a {
  font-weight: 600;
  margin-right: 4px;
}

.guide-media {
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-white);
}

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

.guide-media figcaption {
  padding: 10px 14px;
  font-size: 14px;
  color: var(--color-text-light);
}

/* ============================================================
   components — 解决方案 A（solution-a.html）
   ============================================================ */
.scenario-section {
  padding: 12px 0 40px;
}

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

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

.scenario-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius);
  background-color: var(--color-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  overflow: hidden;
}

.card-icon img {
  width: 28px;
  height: 28px;
  object-fit: contain;
}

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

.card-text {
  font-size: 14px;
  line-height: 1.65;
  color: var(--color-text-light);
}

.solutions-list {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.solution-items {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 24px;
  max-width: 800px;
}

.solution-item {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
}

.item-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 10px;
}

.solution-item p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.suggestions-section {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.suggestions-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 24px;
  max-width: 800px;
}

.suggestion-item {
  display: flex;
  gap: 16px;
  align-items: flex-start;
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px 24px;
}

.suggestion-label {
  flex-shrink: 0;
  display: inline-block;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 13px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 4px;
}

.suggestion-item p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.suggestion-extra {
  margin-top: 20px;
  padding: 20px 24px;
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.suggestion-extra p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.suggestion-extra p a {
  font-weight: 600;
  margin-right: 4px;
}

.related-links {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.related-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 16px;
}

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

.related-links ul li a {
  display: inline-block;
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.related-links ul li a:hover {
  border-color: var(--color-accent);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  text-decoration: none;
}

/* ============================================================
   components — 解决方案 B（solution-b.html）
   ============================================================ */
.page-figure {
  margin: 0 0 32px;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

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

.page-figure figcaption {
  padding: 12px 16px;
  font-size: 14px;
  color: var(--color-text-light);
  background-color: var(--color-white);
}

.framework-section,
.details-section,
.quality-section {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.framework-section h2,
.details-section h2,
.quality-section h2 {
  font-size: 26px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.framework-section > p,
.details-section > p,
.quality-section > p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
  margin-bottom: 24px;
  max-width: 760px;
}

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

.framework-list li {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  position: relative;
  counter-increment: framework;
}

.framework-list li::before {
  content: counter(framework, decimal-leading-zero);
  display: block;
  font-size: 14px;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 10px;
}

.framework-list li h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 10px;
}

.framework-list li p {
  font-size: 14px;
  line-height: 1.65;
  color: var(--color-text-light);
}

.details-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.details-list li {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px 24px;
}

.details-list li h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
}

.details-list li p {
  font-size: 14px;
  line-height: 1.65;
  color: var(--color-text-light);
}

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

.quality-list li {
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
}

.quality-list li h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.quality-list li h3::before {
  content: "✓";
  color: var(--color-accent);
  font-weight: 700;
}

.quality-list li p {
  font-size: 14px;
  line-height: 1.65;
  color: var(--color-text-light);
}

.related-section {
  padding: 40px 0;
  border-top: 1px solid var(--color-border);
}

.related-section h2 {
  font-size: 22px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.related-section > p {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 20px;
}

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

.related-links li a {
  display: inline-block;
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  transition: border-color var(--transition);
}

.related-links li a:hover {
  border-color: var(--color-accent);
  text-decoration: none;
}

/* ============================================================
   components — 常见问题页（faq.html）
   ============================================================ */
.faq-list {
  padding: 12px 0 40px;
}

.faq-list .faq-item {
  margin-bottom: 12px;
}

.faq-answer {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-light);
}

.faq-more {
  padding: 32px 0;
  border-top: 1px solid var(--color-border);
}

.faq-more h2 {
  font-size: 22px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.faq-more > p {
  font-size: 15px;
  color: var(--color-text-light);
  margin-bottom: 20px;
}

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

.faq-links li a {
  display: inline-block;
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-primary);
  transition: border-color var(--transition);
}

.faq-links li a:hover {
  border-color: var(--color-accent);
  text-decoration: none;
}

.faq-figure {
  margin: 32px 0 0;
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--color-white);
}

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

.faq-figure figcaption {
  padding: 10px 14px;
  font-size: 14px;
  color: var(--color-text-light);
}

/* ============================================================
   components — 404 页
   ============================================================ */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  padding: 48px 24px;
}

.error-content {
  text-align: center;
  max-width: 520px;
}

.error-code {
  font-size: 72px;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: 16px;
}

.error-content h1 {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text-light);
  margin-bottom: 24px;
}

.error-link {
  display: inline-block;
  background-color: var(--color-accent);
  color: var(--color-white);
  font-size: 15px;
  font-weight: 600;
  padding: 12px 28px;
  border-radius: var(--radius);
  transition: background-color var(--transition);
}

.error-link:hover {
  background-color: #2A80B9;
  text-decoration: none;
}

/* ============================================================
   components — 页脚
   ============================================================ */
.site-footer {
  background-color: var(--color-primary);
  color: rgba(255, 255, 255, 0.85);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px var(--container-padding) 24px;
}

.footer-brand {
  margin-bottom: 32px;
}

.footer-site-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: 8px;
}

.footer-desc {
  font-size: 14px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.7);
  max-width: 480px;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  padding: 32px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
}

.footer-col-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 14px;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-col ul li a {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.75);
  transition: color var(--transition);
}

.footer-col ul li a:hover {
  color: var(--color-white);
  text-decoration: none;
}

.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 13px;
  color: rgba(255, 255, 255, 0.6);
}

/* ============================================================
   responsive — 响应式
   ============================================================ */
@media (max-width: 992px) {
  .service-list {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

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

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

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

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

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

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

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

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

@media (max-width: 768px) {
  :root {
    --container-padding: 16px;
  }

  .header-inner {
    height: 60px;
  }

  .nav-toggle {
    display: block;
  }

  .site-nav {
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background-color: var(--color-primary);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  }

  .site-nav .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 8px 16px 16px;
  }

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

  .site-nav .nav-list li a {
    padding: 12px 14px;
    border-radius: 4px;
  }

  .page-header {
    padding: 16px 0 20px;
    margin-bottom: 28px;
  }

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

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

  .hero-heading {
    font-size: 26px;
  }

  .compare-hero {
    padding: 32px 0;
  }

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

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

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

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

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

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

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

  .footer-inner {
    padding-top: 32px;
  }

  .steps-list .step-item {
    flex-direction: column;
    gap: 12px;
  }

  .steps-list .step-number {
    margin-bottom: 0;
  }

  .details-list li,
  .quality-list li {
    padding: 16px;
  }

  .service-media .media-image {
    height: 220px;
  }

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

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

  .content-media img {
    height: 180px;
  }

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

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

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

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

@media (max-width: 480px) {
  .brand-name {
    font-size: 18px;
  }

  .selector-group {
    flex-direction: column;
    align-items: stretch;
    gap: 6px;
  }

  .selector-group label {
    min-width: 0;
  }

  .faq-item summary {
    padding: 14px 16px;
    padding-right: 36px;
    font-size: 15px;
  }

  .faq-item p,
  .faq-item .faq-answer {
    padding: 0 16px 14px;
  }

  .solution-card {
    padding: 20px;
  }

  .service-card {
    padding: 20px;
  }

  .step-item {
    padding: 20px;
  }

  .suggestion-item {
    flex-direction: column;
    gap: 10px;
  }
}