@import url('https://fonts.googleapis.com/css2?family=Anton&family=Epilogue:wght@400;500;600;700&display=swap');

/* ===== 基础重置 ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --black: #000000;
  --white: #ffffff;
  --gray-100: #f5f5f5;
  --gray-200: #e8e8e8;
  --gray-400: #999999;
  --gray-600: #555555;
  --gray-800: #222222;
  --accent: #ffffff;
  --accent-inv: #000000;
  --sidenav-w: 260px;
  --base: 8px;
  --radius: 10px;
  --font-display: 'Anton', 'Impact', sans-serif;
  --font-body: 'Epilogue', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --transition: 0.22s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.6;
  color: var(--black);
  background: var(--white);
  min-height: 100vh;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

ul, ol, menu {
  list-style: none;
}

/* ===== 布局骨架 ===== */
.site-wrapper {
  display: grid;
  grid-template-columns: var(--sidenav-w) 1fr;
  min-height: 100vh;
}

.page-canvas {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  overflow-x: hidden;
}

.page-canvas main {
  flex: 1;
}

/* ===== 侧边导航 ===== */
.sidenav {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidenav-w);
  height: 100vh;
  background: var(--black);
  color: var(--white);
  display: flex;
  flex-direction: column;
  z-index: 100;
  overflow-y: auto;
  border-right: 2px solid var(--gray-800);
}

.sidenav-brand {
  padding: calc(var(--base) * 3) calc(var(--base) * 2.5);
  border-bottom: 1px solid var(--gray-800);
}

.brand-link {
  font-family: var(--font-display);
  font-size: 1.05rem;
  color: var(--white);
  letter-spacing: 0.02em;
  line-height: 1.3;
  display: block;
  transition: opacity var(--transition);
}

.brand-link:hover {
  opacity: 0.7;
}

/* details/summary 导航结构 */
.nav-group {
  flex: 1;
  padding: calc(var(--base) * 2) 0;
}

.nav-group-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: calc(var(--base) * 1.5) calc(var(--base) * 2.5);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--gray-400);
  cursor: pointer;
  user-select: none;
  list-style: none;
  min-height: 40px;
}

.nav-group-label::after {
  content: '▾';
  font-size: 0.8rem;
  transition: transform var(--transition);
}

details[open] .nav-group-label::after {
  transform: rotate(180deg);
}

.nav-group-label::-webkit-details-marker {
  display: none;
}

.nav-menu {
  padding: calc(var(--base)) 0;
}

.nav-menu li {
  margin: 0;
}

.nav-link {
  display: block;
  padding: calc(var(--base) * 1.25) calc(var(--base) * 2.5);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--gray-200);
  transition: background var(--transition), color var(--transition), padding-left var(--transition);
  border-left: 3px solid transparent;
  min-height: 40px;
  line-height: 1.4;
  display: flex;
  align-items: center;
}

.nav-link:hover {
  background: var(--gray-800);
  color: var(--white);
  padding-left: calc(var(--base) * 3);
  border-left-color: var(--white);
}

.nav-link--active {
  color: var(--white);
  background: var(--gray-800);
  border-left-color: var(--white);
  font-weight: 700;
}

.sidenav-cta {
  padding: calc(var(--base) * 2) calc(var(--base) * 2.5);
  border-top: 1px solid var(--gray-800);
}

.btn-cta {
  display: block;
  width: 100%;
  padding: calc(var(--base) * 1.5) calc(var(--base) * 2);
  background: var(--white);
  color: var(--black);
  font-family: var(--font-display);
  font-size: 0.95rem;
  letter-spacing: 0.05em;
  text-align: center;
  border-radius: var(--radius);
  transition: background var(--transition), color var(--transition), transform var(--transition);
  min-height: 44px;
  line-height: 1.2;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-cta:hover {
  background: var(--gray-200);
  transform: translateY(-2px);
}

/* ===== Hero：首页 ===== */
.hero-section {
  position: relative;
  min-height: 70vh;
  background: var(--black);
  color: var(--white);
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  overflow: hidden;
  padding: calc(var(--base) * 6) calc(var(--base) * 6);
}

.hero-inner {
  position: relative;
  z-index: 2;
  max-width: 600px;
}

.hero-eyebrow {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gray-400);
  margin-bottom: calc(var(--base) * 2);
}

.hero-h1 {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5vw, 4rem);
  line-height: 1.05;
  letter-spacing: 0.01em;
  margin-bottom: calc(var(--base) * 2.5);
  color: var(--white);
}

.hero-lead {
  font-size: 1.1rem;
  line-height: 1.7;
  color: var(--gray-200);
  margin-bottom: calc(var(--base) * 4);
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: calc(var(--base) * 2);
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  padding: calc(var(--base) * 1.5) calc(var(--base) * 3);
  background: var(--white);
  color: var(--black);
  font-family: var(--font-display);
  font-size: 1rem;
  letter-spacing: 0.04em;
  border-radius: var(--radius);
  min-height: 44px;
  transition: transform var(--transition), background var(--transition);
}

.btn-primary:hover {
  background: var(--gray-200);
  transform: translateY(-2px);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  padding: calc(var(--base) * 1.5) calc(var(--base) * 3);
  background: transparent;
  color: var(--white);
  font-family: var(--font-display);
  font-size: 1rem;
  letter-spacing: 0.04em;
  border: 2px solid var(--white);
  border-radius: var(--radius);
  min-height: 44px;
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.btn-secondary:hover {
  background: var(--white);
  color: var(--black);
  transform: translateY(-2px);
}

.hero-deco {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  margin-left: calc(var(--base) * 4);
}

.deco-num {
  font-family: var(--font-display);
  font-size: clamp(6rem, 14vw, 12rem);
  line-height: 0.85;
  color: var(--gray-800);
  letter-spacing: -0.05em;
}

.deco-sub {
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gray-600);
  margin-top: calc(var(--base));
}

.hero-slash {
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 80px;
  background: var(--white);
  clip-path: polygon(0 100%, 100% 100%, 100% 0);
  z-index: 3;
}

/* ===== 内页 Hero ===== */
.page-hero {
  background: var(--black);
  color: var(--white);
  padding: calc(var(--base) * 7) calc(var(--base) * 6) calc(var(--base) * 5);
  position: relative;
  overflow: hidden;
}

.page-hero::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  right: 0;
  height: 48px;
  background: var(--white);
  clip-path: polygon(0 100%, 100% 100%, 100% 20%);
}

.page-hero--service { background: var(--black); }
.page-hero--cases { background: var(--gray-800); }
.page-hero--faq { background: var(--black); }
.page-hero--about { background: var(--gray-800); }
.page-hero--contact { background: var(--black); }
.page-hero--privacy { background: var(--gray-800); }

.page-hero-inner {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.breadcrumb {
  font-size: 0.78rem;
  color: var(--gray-400);
  margin-bottom: calc(var(--base) * 2);
  letter-spacing: 0.05em;
  display: flex;
  align-items: center;
  gap: calc(var(--base));
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--gray-400);
  transition: color var(--transition);
}

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

.page-h1 {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 3rem);
  line-height: 1.1;
  letter-spacing: 0.01em;
  color: var(--white);
  margin-bottom: calc(var(--base) * 1.5);
}

.page-meta {
  font-size: 0.82rem;
  color: var(--gray-400);
  letter-spacing: 0.03em;
}

/* ===== 内容区网格 ===== */
.content-section {
  padding: calc(var(--base) * 6) calc(var(--base) * 6);
}

.content-grid {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: calc(var(--base) * 5);
  max-width: 1100px;
}

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

/* ===== 正文排版 ===== */
.prose {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--gray-800);
}

.prose h2 {
  font-family: var(--font-display);
  font-size: 1.6rem;
  color: var(--black);
  margin-top: calc(var(--base) * 4);
  margin-bottom: calc(var(--base) * 1.5);
  letter-spacing: 0.01em;
  line-height: 1.2;
}

.prose h3 {
  font-family: var(--font-body);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--black);
  margin-top: calc(var(--base) * 3);
  margin-bottom: calc(var(--base));
}

.prose p {
  margin-bottom: calc(var(--base) * 2);
}

.prose ul, .prose ol {
  margin-bottom: calc(var(--base) * 2);
  padding-left: calc(var(--base) * 3);
  list-style: disc;
}

.prose ol {
  list-style: decimal;
}

.prose li {
  margin-bottom: calc(var(--base) * 0.75);
  line-height: 1.7;
}

.prose a {
  color: var(--black);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
  transition: opacity var(--transition);
}

.prose a:hover {
  opacity: 0.6;
}

.prose strong {
  font-weight: 700;
}

.prose blockquote {
  border-left: 4px solid var(--black);
  padding-left: calc(var(--base) * 2);
  margin: calc(var(--base) * 3) 0;
  color: var(--gray-600);
  font-style: italic;
}

/* ===== Aside 侧边栏 ===== */
.content-aside {
  display: flex;
  flex-direction: column;
  gap: calc(var(--base) * 2.5);
}

.aside-block {
  padding: calc(var(--base) * 2.5);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: var(--white);
}

.aside-block--dark {
  background: var(--black);
  color: var(--white);
  border-color: var(--black);
}

.aside-block--accent {
  background: var(--gray-100);
  border: 2px solid var(--black);
}

.aside-title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  margin-bottom: calc(var(--base) * 0.5);
  line-height: 1.2;
}

.aside-block--dark .aside-title {
  color: var(--white);
}

.subtitle {
  font-size: 0.82rem;
  color: var(--gray-600);
  margin-bottom: calc(var(--base) * 1.5);
  line-height: 1.5;
}

.aside-block--dark .subtitle {
  color: var(--gray-400);
}

.aside-links {
  display: flex;
  flex-direction: column;
  gap: calc(var(--base) * 0.75);
}

.aside-links li a {
  display: block;
  font-size: 0.88rem;
  font-weight: 500;
  padding: calc(var(--base) * 0.75) 0;
  border-bottom: 1px solid var(--gray-200);
  transition: padding-left var(--transition), color var(--transition);
  min-height: 36px;
  display: flex;
  align-items: center;
}

.aside-block--dark .aside-links li a {
  color: var(--gray-200);
  border-bottom-color: var(--gray-800);
}

.aside-links li a:hover {
  padding-left: calc(var(--base));
  color: var(--black);
}

.aside-block--dark .aside-links li a:hover {
  color: var(--white);
}

.aside-stats {
  display: flex;
  flex-direction: column;
  gap: calc(var(--base));
}

.aside-stats li {
  font-size: 0.88rem;
  color: var(--gray-200);
}

.aside-stats strong {
  font-family: var(--font-display);
  font-size: 1.2rem;
  margin-right: calc(var(--base) * 0.5);
}

.btn-aside {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: calc(var(--base) * 1.25) calc(var(--base) * 2);
  border: 2px solid var(--white);
  color: var(--white);
  font-size: 0.88rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  border-radius: var(--radius);
  min-height: 40px;
  transition: background var(--transition), color var(--transition);
}

.aside-block--dark .btn-aside:hover {
  background: var(--white);
  color: var(--black);
}

.aside-block--accent .btn-aside {
  border-color: var(--black);
  color: var(--black);
}

.aside-block--accent .btn-aside:hover {
  background: var(--black);
  color: var(--white);
}

/* ===== 首页卡片区 ===== */
.cards-section {
  padding: calc(var(--base) * 5) calc(var(--base) * 6);
  background: var(--gray-100);
}

.section-header {
  margin-bottom: calc(var(--base) * 4);
}

.section-header h2 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  letter-spacing: 0.01em;
  margin-bottom: calc(var(--base));
}

.section-header .subtitle {
  color: var(--gray-600);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: calc(var(--base) * 2.5);
  list-style: none;
}

/* 玻璃拟态卡片 */
.glass-card {
  display: flex;
  flex-direction: column;
  padding: calc(var(--base) * 3);
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(0, 0, 0, 0.1);
  border-radius: var(--radius);
  box-shadow: 0 4px 24px rgba(0,0,0,0.06);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  height: 100%;
  color: var(--black);
}

.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 36px rgba(0,0,0,0.14);
  border-color: var(--black);
}

.card-index {
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--gray-200);
  letter-spacing: -0.02em;
  line-height: 1;
  margin-bottom: calc(var(--base) * 1.5);
}

.card-title {
  font-family: var(--font-display);
  font-size: 1.05rem;
  letter-spacing: 0.01em;
  margin-bottom: calc(var(--base));
  line-height: 1.3;
  flex: 1;
}

.card-desc {
  font-size: 0.85rem;
  color: var(--gray-600);
  line-height: 1.6;
  margin-bottom: calc(var(--base) * 1.5);
}

.card-arrow {
  font-size: 1.2rem;
  font-weight: 700;
  align-self: flex-end;
  transition: transform var(--transition);
}

.glass-card:hover .card-arrow {
  transform: translateX(4px);
}

/* ===== 首页统计栏 ===== */
.stats-section {
  padding: calc(var(--base) * 5) calc(var(--base) * 6);
  background: var(--black);
  color: var(--white);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: calc(var(--base) * 3);
  max-width: 800px;
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: calc(var(--base) * 0.5);
}

.stat-num {
  font-family: var(--font-display);
  font-size: 2rem;
  letter-spacing: 0.01em;
  line-height: 1;
  color: var(--white);
}

.stat-label {
  font-size: 0.82rem;
  color: var(--gray-400);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ===== 案例列表 ===== */
.cases-list-wrap {
  margin-top: calc(var(--base) * 5);
  padding-top: calc(var(--base) * 4);
  border-top: 2px solid var(--gray-200);
}

.cases-list-wrap h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  margin-bottom: calc(var(--base) * 0.5);
}

.cases-list {
  margin-top: calc(var(--base) * 3);
  display: flex;
  flex-direction: column;
  gap: calc(var(--base) * 1.5);
  list-style: none;
  counter-reset: cases;
}

.cases-list-item {
  counter-increment: cases;
  display: grid;
  grid-template-columns: 3rem 1fr;
  gap: calc(var(--base) * 2);
  align-items: start;
  padding: calc(var(--base) * 2);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  transition: border-color var(--transition), transform var(--transition);
}

.cases-list-item::before {
  content: counter(cases, decimal-leading-zero);
  font-family: var(--font-display);
  font-size: 1.4rem;
  color: var(--gray-200);
  line-height: 1.2;
}

.cases-list-item:hover {
  border-color: var(--black);
  transform: translateX(4px);
}

.cases-list-item a {
  font-weight: 600;
  font-size: 1rem;
  color: var(--black);
  transition: opacity var(--transition);
}

.cases-list-item a:hover {
  opacity: 0.6;
}

.cases-list-item small {
  display: block;
  font-size: 0.82rem;
  color: var(--gray-600);
  margin-top: calc(var(--base) * 0.5);
  line-height: 1.5;
}

/* ===== FAQ ===== */
.faq-intro {
  margin-bottom: calc(var(--base) * 4);
  padding-bottom: calc(var(--base) * 3);
  border-bottom: 2px solid var(--gray-200);
}

.faq-intro h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  margin-bottom: calc(var(--base) * 0.5);
}

.faq-prose h2 {
  padding-top: calc(var(--base) * 2);
  border-top: 1px solid var(--gray-200);
}

.faq-prose h2:first-child {
  border-top: none;
}

/* ===== 关于页 ===== */
.about-banner {
  background: var(--black);
  color: var(--white);
  padding: calc(var(--base) * 4) calc(var(--base) * 4);
  border-radius: var(--radius);
  margin-bottom: calc(var(--base) * 4);
}

.about-banner-text h2 {
  font-family: var(--font-display);
  font-size: 1.8rem;
  color: var(--white);
  margin-bottom: calc(var(--base) * 0.5);
}

.about-banner-text .subtitle {
  color: var(--gray-400);
  font-size: 0.9rem;
}

/* ===== 联系表单 ===== */
.contact-form-wrap {
  margin-top: calc(var(--base) * 5);
  padding-top: calc(var(--base) * 4);
  border-top: 2px solid var(--gray-200);
}

.contact-form-wrap h2 {
  font-family: var(--font-display);
  font-size: 1.5rem;
  margin-bottom: calc(var(--base) * 0.5);
}

.contact-form {
  margin-top: calc(var(--base) * 3);
  display: flex;
  flex-direction: column;
  gap: calc(var(--base) * 2.5);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: calc(var(--base) * 2.5);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: calc(var(--base) * 0.75);
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--black);
}

.form-group input,
.form-group textarea {
  padding: calc(var(--base) * 1.25) calc(var(--base) * 1.75);
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: 1rem;
  color: var(--black);
  background: var(--white);
  transition: border-color var(--transition);
  min-height: 44px;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--black);
}

.form-group textarea {
  resize: vertical;
  min-height: 140px;
}

.btn-submit {
  align-self: flex-start;
  cursor: pointer;
  border: none;
  font-family: var(--font-display);
  font-size: 1rem;
  padding: calc(var(--base) * 1.5) calc(var(--base) * 4);
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--black);
  color: var(--white);
  margin-top: auto;
}

.footer-top {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: calc(var(--base) * 5);
  padding: calc(var(--base) * 6) calc(var(--base) * 6);
  border-bottom: 1px solid var(--gray-800);
}

.footer-heading {
  font-family: var(--font-display);
  font-size: 1rem;
  letter-spacing: 0.04em;
  color: var(--white);
  margin-bottom: calc(var(--base) * 2);
}

.footer-desc {
  font-size: 0.85rem;
  color: var(--gray-400);
  line-height: 1.7;
  margin-bottom: calc(var(--base) * 2);
}

.footer-address {
  font-style: normal;
  font-size: 0.82rem;
  color: var(--gray-600);
  line-height: 1.7;
}

.footer-address a {
  color: var(--gray-400);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  transition: color var(--transition);
}

.footer-address a:hover {
  color: var(--white);
}

.site-footer ul {
  display: flex;
  flex-direction: column;
  gap: calc(var(--base) * 0.5);
}

.site-footer ul li a {
  display: inline-flex;
  align-items: center;
  font-size: 0.88rem;
  color: var(--gray-400);
  padding: calc(var(--base) * 0.5) 0;
  min-height: 36px;
  transition: color var(--transition), padding-left var(--transition);
}

.site-footer ul li a:hover {
  color: var(--white);
  padding-left: calc(var(--base));
}

.footer-bottom {
  padding: calc(var(--base) * 2.5) calc(var(--base) * 6);
  text-align: center;
}

.footer-bottom p {
  font-size: 0.78rem;
  color: var(--gray-600);
  letter-spacing: 0.03em;
}

/* ===== h2 + p.subtitle 标题装饰 ===== */
h2 + .subtitle,
h2 + p.subtitle,
h2 + p.subhead,
h2 + p.desc,
h2 + p.lead {
  margin-top: calc(var(--base) * -0.5);
  margin-bottom: calc(var(--base) * 2);
}

/* ===== 动效：Stagger ===== */
@media (prefers-reduced-motion: no-preference) {
  .stagger-item {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeUp 0.5s ease forwards;
    animation-delay: calc(var(--i, 0) * 80ms + 100ms);
  }

  @keyframes fadeUp {
    to {
      opacity: 1;
      transform: none;
    }
  }
}

@media (prefers-reduced-motion: reduce) {
  .stagger-item {
    opacity: 1;
    transform: none;
    animation: none;
  }
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  :root {
    --sidenav-w: 220px;
  }

  .content-grid {
    grid-template-columns: 1fr 240px;
  }

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

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

  .footer-top {
    grid-template-columns: 1fr 1fr;
  }

  .footer-top .footer-col:first-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  .site-wrapper {
    grid-template-columns: 1fr;
  }

  .sidenav {
    position: static;
    width: 100%;
    height: auto;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    overflow: visible;
  }

  .sidenav-brand {
    padding: calc(var(--base) * 1.5) calc(var(--base) * 2);
    border-bottom: none;
    border-right: 1px solid var(--gray-800);
    flex: 0 0 auto;
  }

  .nav-group {
    flex: 1;
    padding: 0;
    min-width: 0;
  }

  .nav-group-label {
    padding: calc(var(--base) * 1.5) calc(var(--base) * 2);
    min-height: 44px;
  }

  .nav-menu {
    padding: calc(var(--base) * 0.5) 0;
    background: var(--gray-800);
  }

  .nav-link {
    padding: calc(var(--base) * 1) calc(var(--base) * 2);
    min-height: 44px;
  }

  .sidenav-cta {
    padding: calc(var(--base) * 1) calc(var(--base) * 2);
    border-top: none;
    border-left: 1px solid var(--gray-800);
    flex: 0 0 auto;
  }

  .page-canvas {
    min-height: 0;
  }

  .hero-section {
    grid-template-columns: 1fr;
    min-height: auto;
    padding: calc(var(--base) * 6) calc(var(--base) * 3) calc(var(--base) * 8);
  }

  .hero-deco {
    display: none;
  }

  .page-hero {
    padding: calc(var(--base) * 5) calc(var(--base) * 3) calc(var(--base) * 5);
  }

  .content-section {
    padding: calc(var(--base) * 4) calc(var(--base) * 3);
  }

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

  .content-aside {
    order: -1;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: calc(var(--base) * 2);
  }

  .cards-section {
    padding: calc(var(--base) * 4) calc(var(--base) * 3);
  }

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

  .stats-section {
    padding: calc(var(--base) * 4) calc(var(--base) * 3);
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: calc(var(--base) * 2);
  }

  .footer-top {
    grid-template-columns: 1fr;
    padding: calc(var(--base) * 4) calc(var(--base) * 3);
    gap: calc(var(--base) * 3);
  }

  .footer-bottom {
    padding: calc(var(--base) * 2) calc(var(--base) * 3);
  }

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

  .cases-list-item {
    grid-template-columns: 2.5rem 1fr;
  }
}

@media (max-width: 480px) {
  .hero-h1 {
    font-size: 2rem;
  }

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

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

  .content-aside {
    grid-template-columns: 1fr;
  }

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

/* ===== 工具类 ===== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}