/* =========================================================
   策驰影院 · 完整样式系统
   风格: 现代影视 + 沉浸暗色 + 毛玻璃 + 柔和渐变
   响应式 + 暗色模式 + 微交互
   ========================================================= */

/* ---------- 1. Design Tokens ---------- */
:root {
  /* 浅色主题 */
  --bg-light: #f6f8fc;
  --bg-gradient-light: radial-gradient(circle at 10% 20%, rgba(37, 99, 235, 0.08), transparent 40%),
                       radial-gradient(circle at 90% 10%, rgba(190, 24, 60, 0.06), transparent 35%),
                       linear-gradient(145deg, #f6f8fc, #eef2f9);
  --surface-light: #ffffff;
  --surface-2-light: #f1f5f9;
  --surface-glass-light: rgba(255, 255, 255, 0.72);
  --text-primary-light: #1e293b;
  --text-secondary-light: #475569;
  --text-heading-light: #0f172a;
  --border-light: rgba(15, 23, 42, 0.08);
  --border-strong-light: #cbd5e1;
  --nav-bg-light: rgba(255, 255, 255, 0.85);
  --text-link-light: #1d4ed8;
  --btn-bg-light: #1e3a8a;
  --btn-bg-hover-light: #1e40af;
  --btn-text-light: #ffffff;
  --footer-bg-light: #1e293b;
  --footer-text-light: #cbd5e1;
  --shadow-sm-light: 0 2px 8px rgba(15, 23, 42, 0.04);
  --shadow-md-light: 0 8px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg-light: 0 16px 40px rgba(15, 23, 42, 0.12);
  --scrollbar-thumb-light: #cbd5e1;
  --scrollbar-track-light: transparent;
  --code-bg-light: #f1f5f9;

  /* 暗色主题变量 */
  --bg-dark: #0b1220;
  --bg-gradient-dark: radial-gradient(circle at 15% 15%, rgba(59, 130, 246, 0.12), transparent 45%),
                      radial-gradient(circle at 85% 20%, rgba(190, 24, 60, 0.08), transparent 35%),
                      linear-gradient(145deg, #0b1220, #0f172a);
  --surface-dark: #131c2e;
  --surface-2-dark: #1e293b;
  --surface-glass-dark: rgba(19, 28, 46, 0.75);
  --text-primary-dark: #e2e8f0;
  --text-secondary-dark: #94a3b8;
  --text-heading-dark: #f1f5f9;
  --border-dark: rgba(148, 163, 184, 0.14);
  --border-strong-dark: #475569;
  --nav-bg-dark: rgba(11, 18, 32, 0.85);
  --text-link-dark: #93c5fd;
  --btn-bg-dark: #3b82f6;
  --btn-bg-hover-dark: #2563eb;
  --btn-text-dark: #ffffff;
  --footer-bg-dark: #0f172a;
  --footer-text-dark: #94a3b8;
  --shadow-sm-dark: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md-dark: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg-dark: 0 16px 40px rgba(0, 0, 0, 0.5);
  --scrollbar-thumb-dark: #475569;
  --scrollbar-track-dark: transparent;
  --code-bg-dark: #1e293b;

  /* 通用 */
  --font-sans: system-ui, -apple-system, 'Segoe UI', Roboto, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
  --font-serif: Georgia, 'Times New Roman', serif;
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-pill: 9999px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 1280px;
}

/* ---------- 2. Reset & Base ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-sans);
  line-height: 1.7;
  min-height: 100vh;
  background-color: var(--bg-light);
  background-image: var(--bg-gradient-light);
  background-attachment: fixed;
  color: var(--text-primary-light);
  transition: background-color var(--transition-base), color var(--transition-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 暗色模式 */
html[data-theme="dark"] body {
  background-color: var(--bg-dark);
  background-image: var(--bg-gradient-dark);
  color: var(--text-primary-dark);
}

/* ---------- 3. Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-heading-light);
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.01em;
  transition: color var(--transition-base);
  margin-bottom: 0.8rem;
}

html[data-theme="dark"] h1,
html[data-theme="dark"] h2,
html[data-theme="dark"] h3,
html[data-theme="dark"] h4,
html[data-theme="dark"] h5,
html[data-theme="dark"] h6 {
  color: var(--text-heading-dark);
}

h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); margin-top: 1.5rem; }
h3 { font-size: clamp(1.1rem, 2vw, 1.35rem); margin-top: 1rem; }
h4 { font-size: 1.1rem; }

p {
  margin-bottom: 0.75rem;
  opacity: 1 !important;
}

a {
  color: var(--text-link-light);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

html[data-theme="dark"] a {
  color: var(--text-link-dark);
}

a:hover {
  border-bottom-color: currentColor;
}

small, .small-text {
  font-size: 0.875em;
  color: var(--text-secondary-light);
}

html[data-theme="dark"] small,
html[data-theme="dark"] .small-text {
  color: var(--text-secondary-dark);
}

/* ---------- 4. Layout ---------- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.5rem;
}

/* ---------- 5. Scrollbar ---------- */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--scrollbar-track-light);
}

::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb-light);
  border-radius: var(--radius-pill);
  border: 2px solid transparent;
  background-clip: content-box;
}

html[data-theme="dark"] ::-webkit-scrollbar-track {
  background: var(--scrollbar-track-dark);
}

html[data-theme="dark"] ::-webkit-scrollbar-thumb {
  background: var(--scrollbar-thumb-dark);
}

/* ---------- 6. Selection & Focus ---------- */
::selection {
  background: rgba(37, 99, 235, 0.2);
  color: inherit;
}

html[data-theme="dark"] ::selection {
  background: rgba(59, 130, 246, 0.3);
}

a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid #2f6fed;
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 7. Header / Navbar ---------- */
.site-header {
  background-color: var(--nav-bg-light);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-light);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: background-color var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

html[data-theme="dark"] .site-header {
  background-color: var(--nav-bg-dark);
  border-bottom-color: var(--border-dark);
}

.site-header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding-top: 0.6rem;
  padding-bottom: 0.6rem;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-heading-light);
  letter-spacing: -0.02em;
  transition: color var(--transition-base);
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

html[data-theme="dark"] .logo {
  color: var(--text-heading-dark);
}

.logo span {
  color: #b91c1c;
  font-weight: 900;
}

html[data-theme="dark"] .logo span {
  color: #ef4444;
}

.nav-menu {
  display: flex;
  gap: 1.8rem;
  align-items: center;
  list-style: none;
}

.nav-link {
  color: var(--text-heading-light);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.4rem 0.2rem;
  position: relative;
  transition: color var(--transition-fast);
  border-bottom: none;
}

html[data-theme="dark"] .nav-link {
  color: var(--text-heading-dark);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #1e3a8a, #b91c1c);
  transition: width var(--transition-base);
}

html[data-theme="dark"] .nav-link::after {
  background: linear-gradient(90deg, #3b82f6, #ef4444);
}

.nav-link:hover {
  border-bottom-color: transparent;
}

.nav-link:hover::after {
  width: 100%;
}

/* 主题切换按钮 */
.btn-theme {
  background: var(--btn-bg-light);
  color: var(--btn-text-light);
  border: none;
  border-radius: var(--radius-pill);
  padding: 0.4rem 1rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  white-space: nowrap;
}

html[data-theme="dark"] .btn-theme {
  background: var(--btn-bg-dark);
  color: var(--btn-text-dark);
}

.btn-theme:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(30, 58, 138, 0.3);
}

html[data-theme="dark"] .btn-theme:hover {
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.3);
}

/* ---------- 8. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: var(--btn-bg-light);
  color: var(--btn-text-light);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.6rem 1.4rem;
  border-radius: var(--radius-pill);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  line-height: 1.5;
  box-shadow: 0 2px 8px rgba(30, 58, 138, 0.15);
  white-space: nowrap;
}

html[data-theme="dark"] .btn {
  background: var(--btn-bg-dark);
  color: var(--btn-text-dark);
  box-shadow: 0 2px 8px rgba(59, 130, 246, 0.2);
}

.btn:hover {
  background: var(--btn-bg-hover-light);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(30, 58, 138, 0.25);
  border-bottom-color: transparent;
}

html[data-theme="dark"] .btn:hover {
  background: var(--btn-bg-hover-dark);
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.3);
}

.btn:active {
  transform: translateY(0);
}

.btn-lg {
  padding: 0.85rem 2rem;
  font-size: 1.05rem;
}

.btn-sm {
  padding: 0.4rem 1rem;
  font-size: 0.85rem;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--btn-bg-light);
  color: var(--btn-bg-light);
  box-shadow: none;
}

html[data-theme="dark"] .btn-outline {
  border-color: var(--btn-bg-dark);
  color: var(--btn-bg-dark);
}

.btn-outline:hover {
  background: var(--btn-bg-light);
  color: var(--btn-text-light);
}

html[data-theme="dark"] .btn-outline:hover {
  background: var(--btn-bg-dark);
  color: var(--btn-text-dark);
}

/* ---------- 9. Cards ---------- */
.card,
.article-card,
.faq-item,
.solution-card {
  background: var(--surface-light);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm-light);
  transition: transform var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base), border-color var(--transition-base);
  position: relative;
  overflow: hidden;
}

html[data-theme="dark"] .card,
html[data-theme="dark"] .article-card,
html[data-theme="dark"] .faq-item,
html[data-theme="dark"] .solution-card {
  background: var(--surface-dark);
  border-color: var(--border-dark);
  box-shadow: var(--shadow-sm-dark);
}

.card::before,
.article-card::before,
.solution-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #1e3a8a, #b91c1c, #f59e0b);
  opacity: 0;
  transition: opacity var(--transition-base);
}

html[data-theme="dark"] .card::before,
html[data-theme="dark"] .article-card::before,
html[data-theme="dark"] .solution-card::before {
  background: linear-gradient(90deg, #3b82f6, #ef4444, #f59e0b);
}

.card:hover,
.article-card:hover,
.solution-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-md-light);
}

html[data-theme="dark"] .card:hover,
html[data-theme="dark"] .article-card:hover,
html[data-theme="dark"] .solution-card:hover {
  box-shadow: var(--shadow-md-dark);
}

.card:hover::before,
.article-card:hover::before,
.solution-card:hover::before {
  opacity: 1;
}

/* 毛玻璃卡片 */
.glass-card {
  background: var(--surface-glass-light);
  backdrop-filter: blur(16px) saturate(160%);
  -webkit-backdrop-filter: blur(16px) saturate(160%);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: var(--shadow-md-light);
}

html[data-theme="dark"] .glass-card {
  background: var(--surface-glass-dark);
  border-color: var(--border-dark);
  box-shadow: var(--shadow-md-dark);
}

/* ---------- 10. Hero / Banner ---------- */
.hero-section {
  background: linear-gradient(145deg, #f1f5f9, #e2e8f0);
  padding: 3.5rem 0;
  position: relative;
  overflow: hidden;
  transition: background var(--transition-base);
}

html[data-theme="dark"] .hero-section {
  background: linear-gradient(145deg, #131c2e, #0f172a);
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 60%;
  height: 200%;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.08), transparent 60%);
  pointer-events: none;
}

.hero-section .container {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2rem;
  position: relative;
  z-index: 1;
}

.hero-content {
  flex: 2;
  min-width: 280px;
}

.hero-visual {
  flex: 1;
  min-width: 220px;
  background: var(--surface-light);
  padding: 1.2rem;
  border-radius: var(--radius-xl);
  text-align: center;
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-md-light);
  transition: all var(--transition-base);
}

html[data-theme="dark"] .hero-visual {
  background: var(--surface-dark);
  border-color: var(--border-dark);
  box-shadow: var(--shadow-md-dark);
}

.hero-visual:hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-lg-light);
}

html[data-theme="dark"] .hero-visual:hover {
  box-shadow: var(--shadow-lg-dark);
}

.hero-title {
  font-size: clamp(2rem, 5vw, 2.6rem);
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, #1e3a8a, #b91c1c);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}

html[data-theme="dark"] .hero-title {
  background: linear-gradient(135deg, #60a5fa, #f87171);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  font-weight: 600;
  color: var(--text-primary-light);
  margin-bottom: 0.8rem;
}

html[data-theme="dark"] .hero-subtitle {
  color: var(--text-primary-dark);
}

/* ---------- 11. Section Titles ---------- */
.section-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  margin-top: 2.5rem;
}

.section-title h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin: 0;
  position: relative;
  padding-left: 1rem;
  border-left: 6px solid #b91c1c;
}

html[data-theme="dark"] .section-title h2 {
  border-left-color: #ef4444;
}

/* ---------- 12. Grid Layouts ---------- */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.5rem;
}

/* ---------- 13. Articles ---------- */
.article-card {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.article-card h3 {
  margin-bottom: 0.3rem;
  font-size: 1.15rem;
  line-height: 1.4;
  transition: color var(--transition-fast);
}

.article-card:hover h3 {
  color: var(--text-link-light);
}

html[data-theme="dark"] .article-card:hover h3 {
  color: var(--text-link-dark);
}

.article-card .meta {
  font-size: 0.8rem;
  color: var(--text-secondary-light);
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

html[data-theme="dark"] .article-card .meta {
  color: var(--text-secondary-dark);
}

.article-card p {
  font-size: 0.95rem;
  flex-grow: 1;
}

/* ---------- 14. FAQ ---------- */
.faq-item {
  padding: 0;
  overflow: hidden;
  border-radius: var(--radius-md);
  margin-bottom: 0.5rem;
}

.faq-item summary {
  padding: 1.2rem 1.5rem;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  transition: background-color var(--transition-fast);
  color: var(--text-heading-light);
}

html[data-theme="dark"] .faq-item summary {
  color: var(--text-heading-dark);
}

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

.faq-item summary::after {
  content: '+';
  font-size: 1.5rem;
  font-weight: 300;
  color: var(--text-secondary-light);
  transition: transform var(--transition-base);
  flex-shrink: 0;
}

html[data-theme="dark"] .faq-item summary::after {
  color: var(--text-secondary-dark);
}

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

.faq-item summary:hover {
  background-color: var(--surface-2-light);
}

html[data-theme="dark"] .faq-item summary:hover {
  background-color: var(--surface-2-dark);
}

.faq-item .faq-answer {
  padding: 0 1.5rem 1.2rem;
  font-size: 0.95rem;
  color: var(--text-primary-light);
}

html[data-theme="dark"] .faq-item .faq-answer {
  color: var(--text-primary-dark);
}

/* ---------- 15. Footer ---------- */
.footer {
  background: var(--footer-bg-light);
  color: var(--footer-text-light);
  padding: 2.5rem 0 1.5rem;
  margin-top: 4rem;
  transition: background-color var(--transition-base), color var(--transition-base);
}

html[data-theme="dark"] .footer {
  background: var(--footer-bg-dark);
  color: var(--footer-text-dark);
}

.footer a {
  color: var(--footer-text-light);
  opacity: 0.8;
  transition: opacity var(--transition-fast);
}

html[data-theme="dark"] .footer a {
  color: var(--footer-text-dark);
}

.footer a:hover {
  opacity: 1;
  border-bottom-color: currentColor;
}

.footer .container {
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 1.5rem;
  margin-top: 1rem;
}

html[data-theme="dark"] .footer-bottom {
  border-top-color: rgba(148, 163, 184, 0.1);
}

/* ---------- 16. Back to Top ---------- */
#backTop {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 999;
  background: var(--btn-bg-light);
  color: white;
  border: none;
  border-radius: var(--radius-pill);
  padding: 0.7rem 1.2rem;
  font-size: 1rem;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
  transition: all var(--transition-fast);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
}

html[data-theme="dark"] #backTop {
  background: var(--btn-bg-dark);
}

#backTop.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

#backTop:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

/* ---------- 17. Contact Section ---------- */
.contact-card {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
}

.contact-card > div {
  flex: 1;
  min-width: 200px;
}

.contact-info p {
  margin-bottom: 0.5rem;
}

/* ---------- 18. HowTo ---------- */
.howto-card ol {
  padding-left: 1.5rem;
  margin: 1rem 0;
}

.howto-card ol li {
  margin-bottom: 0.5rem;
  padding-left: 0.5rem;
}

/* ---------- 19. Utility Classes ---------- */
.text-gradient {
  background: linear-gradient(135deg, #1e3a8a, #b91c1c);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

html[data-theme="dark"] .text-gradient {
  background: linear-gradient(135deg, #60a5fa, #f87171);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-muted {
  color: var(--text-secondary-light);
}

html[data-theme="dark"] .text-muted {
  color: var(--text-secondary-dark);
}

.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* ---------- 20. Animations ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes floatY {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

@keyframes shimmer {
  0% { background-position: -1000px 0; }
  100% { background-position: 1000px 0; }
}

/* 滚动动画 */
.scroll-animate {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1), transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.scroll-animate.animate-in {
  opacity: 1;
  transform: translateY(0);
}

/* 图片悬停效果 */
.hover-zoom {
  overflow: hidden;
}

.hover-zoom img {
  transition: transform var(--transition-base);
}

.hover-zoom:hover img {
  transform: scale(1.05);
}

/* ---------- 21. Responsive ---------- */
@media (max-width: 1024px) {
  .container {
    padding: 1rem 1.25rem;
  }
  
  .nav-menu {
    gap: 1.2rem;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0.75rem 1rem;
  }

  .site-header .container {
    flex-wrap: wrap;
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
  }

  .logo {
    font-size: 1.3rem;
  }

  .nav-menu {
    order: 3;
    width: 100%;
    justify-content: center;
    gap: 0.8rem;
    padding-top: 0.5rem;
    flex-wrap: wrap;
  }

  .nav-link {
    font-size: 0.85rem;
    padding: 0.3rem 0.5rem;
  }

  .btn-theme {
    padding: 0.3rem 0.8rem;
    font-size: 0.8rem;
    margin-left: auto;
  }

  .hero-section {
    padding: 2rem 0;
  }

  .hero-content {
    min-width: 100%;
  }

  .hero-visual {
    min-width: 100%;
  }

  .card,
  .article-card,
  .solution-card {
    padding: 1.2rem;
  }

  #backTop {
    bottom: 1.5rem;
    right: 1.5rem;
    padding: 0.6rem 1rem;
    font-size: 0.9rem;
  }

  .footer {
    padding: 2rem 0 1rem;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .hide-mobile {
    display: none !important;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0.5rem 0.75rem;
  }

  h1 { font-size: 1.7rem; }
  h2 { font-size: 1.3rem; }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .btn {
    width: 100%;
  }

  .btn-theme {
    width: auto;
  }

  .faq-item summary {
    padding: 1rem;
    font-size: 0.95rem;
  }

  .faq-item .faq-answer {
    padding: 0 1rem 1rem;
  }

  .hero-title {
    font-size: 1.8rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }
}

/* ---------- 22. Dark Mode Specific ---------- */
html[data-theme="dark"] {
  color-scheme: dark;
}

html[data-theme="dark"] .glass-card {
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
}

html[data-theme="dark"] .site-header {
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
}

/* ---------- 23. Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- 24. Print Styles ---------- */
@media print {
  .site-header,
  .footer,
  #backTop,
  .btn {
    display: none !important;
  }

  body {
    background: white;
    color: black;
  }

  .card,
  .article-card,
  .faq-item {
    box-shadow: none;
    border: 1px solid #ddd;
    break-inside: avoid;
  }
}