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

:root {
  --zoom-blue: #0B5CFF;
  --zoom-blue-hover: #0047CC;
  --zoom-blue-light: #E8F0FE;
  --zoom-blue-bg: #F0F5FF;
  --zoom-orange: #F26D21;
  --zoom-orange-hover: #D95C17;
  --text-primary: #232333;
  --text-secondary: #6E7282;
  --text-tertiary: #9DA2B3;
  --bg-page: #FFFFFF;
  --bg-section: #F7F8FA;
  --bg-dark: #131619;
  --bg-dark-card: #1A1E23;
  --border-color: #E5E7EB;
  --border-light: #F0F1F3;
  --radius-xs: 6px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 9999px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.12);
  --transition: 0.2s ease;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-family);
  color: var(--text-primary);
  background: var(--bg-page);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ========== HEADER ========== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid transparent;
  transition: all 0.3s ease;
}

.site-header.scrolled {
  border-bottom-color: var(--border-color);
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.06);
}

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  height: 64px;
  gap: 8px;
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  flex-shrink: 0;
  margin-right: 16px;
}

.zoom-logo-icon {
  display: block;
  flex-shrink: 0;
}

.header-logo-text {
  font-size: 22px;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.04em;
  line-height: 1;
}

.zoom-logo-svg {
  display: block;
}

.header-nav {
  flex: 1;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.nav-item {
  position: relative;
}

.nav-link {
  display: block;
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
  white-space: nowrap;
}

.nav-link:hover {
  background: var(--bg-section);
  color: var(--zoom-blue);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.nav-download {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background: var(--zoom-blue);
  color: #fff;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: background var(--transition);
  white-space: nowrap;
  margin-left: 4px;
  gap: 6px;
}

.nav-download i { font-size: 13px; opacity: 0.95; }
.nav-download:hover { background: var(--zoom-blue-hover); }

.header-link {
  padding: 8px 12px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
  white-space: nowrap;
}

.header-link:hover {
  background: var(--bg-section);
}

.header-divider {
  width: 1px;
  height: 20px;
  background: var(--border-color);
}

.btn-orange {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background: var(--zoom-orange);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: background var(--transition), transform var(--transition);
  white-space: nowrap;
}

.btn-orange:hover {
  background: var(--zoom-orange-hover);
  transform: translateY(-1px);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: 8px;
  border: none;
  background: none;
  cursor: pointer;
}

.mobile-menu-btn span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all 0.3s ease;
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ========== BUTTONS ========== */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  background: var(--zoom-blue);
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-full);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  box-shadow: 0 2px 8px rgba(11, 92, 255, 0.3);
}

.btn-primary:hover {
  background: var(--zoom-blue-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(11, 92, 255, 0.4);
}

.btn-primary.btn-white {
  background: #fff;
  color: var(--zoom-blue);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.btn-primary.btn-white:hover {
  background: #f0f0f0;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  background: transparent;
  color: var(--zoom-blue);
  font-size: 15px;
  font-weight: 600;
  border: 2px solid var(--zoom-blue);
  border-radius: var(--radius-full);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-secondary:hover {
  background: var(--zoom-blue-light);
}

.btn-large {
  padding: 14px 36px;
  font-size: 16px;
}


/* ========== HERO ========== */
.hero-section {
  padding: 120px 0 60px;
  background: linear-gradient(180deg, #F0F5FF 0%, #FFFFFF 100%);
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: #fff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
}

.hero-badge svg {
  flex-shrink: 0;
}

.hero-title {
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.hero-desc {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

/* dl-btn / dl-item: msn.js 接口对接按钮 */
.dl-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-decoration: none;
  cursor: pointer;
  font-family: inherit;
  font-weight: 500;
  border: none;
  transition: background var(--transition), color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.dl-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.dl-item-info { flex: 1; min-width: 0; }

.dl-item-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  margin-bottom: 4px;
}

.dl-item-meta {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 40px;
  background: var(--zoom-blue);
  color: #fff;
  border: none;
  border-radius: var(--radius-full);
  font-size: 18px;
  font-weight: 500;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.25s ease;
  box-shadow: 0 4px 16px rgba(11, 92, 255, 0.3);
}

.btn-download:hover {
  background: var(--zoom-blue-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 24px rgba(11, 92, 255, 0.4);
}

.hero-dl-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(260px, 1fr));
  gap: 16px 20px;
  max-width: 880px;
  margin: 0 auto;
  width: 100%;
  text-align: left;
}

.hero-dl-item {
  flex-direction: column;
  align-items: stretch;
  background: #fff;
  padding: 20px 20px 18px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
}

.hero-dl-item .btn-download {
  width: 100%;
  justify-content: center;
}

.cta-desc {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.cta-dl-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(260px, 320px));
  gap: 20px;
  justify-content: center;
  margin: 0 auto;
  max-width: 720px;
}

.cta-dl-item {
  flex-direction: column;
  align-items: stretch;
  text-align: left;
  background: var(--bg-page);
  padding: 22px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.cta-dl-item .btn-download {
  width: 100%;
  justify-content: center;
}

/* ========== DOWNLOADS GRID ========== */
.downloads-section {
  padding: 40px 0 80px;
}

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

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

.dl-card:hover {
  border-color: rgba(11, 92, 255, 0.3);
  box-shadow: 0 8px 24px rgba(11, 92, 255, 0.08);
  transform: translateY(-2px);
}

.dl-card-header {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 20px;
}

.dl-card-icon {
  flex-shrink: 0;
}

.dl-card-header h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 4px;
  letter-spacing: -0.01em;
}

.dl-card-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.5;
}

.dl-card-platforms {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.platform-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  background: var(--bg-section);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: all var(--transition);
}

.platform-btn:hover {
  background: var(--zoom-blue-light);
  border-color: var(--zoom-blue);
  color: var(--zoom-blue);
}

/* ========== FEATURES SECTION ========== */
.features-section {
  padding: 80px 0;
  background: var(--bg-section);
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-header h2 {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
  line-height: 1.2;
}

.section-header p {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 540px;
  margin: 0 auto;
  line-height: 1.7;
}

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

.feature-item {
  background: #fff;
  padding: 32px 28px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.feature-item:hover {
  border-color: rgba(11, 92, 255, 0.25);
  box-shadow: 0 12px 32px rgba(11, 92, 255, 0.06);
  transform: translateY(-3px);
}

.feature-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  background: var(--zoom-blue-light);
  border-radius: var(--radius-md);
  margin-bottom: 20px;
}

.feature-item h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.feature-item p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ========== AI BANNER ========== */
.ai-banner {
  padding: 0;
}

.ai-banner .container {
  max-width: 1200px;
}

.ai-banner-inner {
  display: flex;
  align-items: center;
  gap: 60px;
  background: linear-gradient(135deg, #0B5CFF 0%, #0042B3 50%, #002D80 100%);
  border-radius: var(--radius-xl);
  padding: 60px;
  margin: 0 24px;
  overflow: hidden;
  position: relative;
}

.ai-banner-inner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
  border-radius: 50%;
}

.ai-banner-text {
  flex: 1;
  position: relative;
  z-index: 1;
}

.ai-badge {
  display: inline-block;
  padding: 4px 12px;
  background: rgba(255, 255, 255, 0.2);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
}

.ai-banner-text h2 {
  font-size: 32px;
  font-weight: 800;
  color: #fff;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.ai-banner-text p {
  font-size: 15px;
  color: rgba(255, 255, 255, 0.8);
  line-height: 1.7;
  margin-bottom: 28px;
  max-width: 460px;
}

.ai-banner-visual {
  flex-shrink: 0;
  position: relative;
  z-index: 1;
}

/* ========== RESOURCES ========== */
.resources-section {
  padding: 80px 0;
}

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

.resource-card {
  display: flex;
  flex-direction: column;
  padding: 28px 24px;
  background: #fff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition);
}

.resource-card:hover {
  border-color: rgba(11, 92, 255, 0.3);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.resource-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--zoom-blue-light);
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
}

.resource-card h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.resource-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  flex: 1;
  margin-bottom: 16px;
}

.resource-link {
  font-size: 14px;
  font-weight: 600;
  color: var(--zoom-blue);
  display: flex;
  align-items: center;
  gap: 4px;
}

.resource-link span {
  transition: transform var(--transition);
}

.resource-card:hover .resource-link span {
  transform: translateX(3px);
}

/* ========== CTA ========== */
.cta-section {
  text-align: center;
  padding: 80px 24px;
  background: var(--bg-section);
}

.cta-section h2 {
  font-size: clamp(28px, 3.5vw, 40px);
  font-weight: 800;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.cta-section p {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 32px;
}


/* ========== FOOTER ========== */
.site-footer {
  background: var(--bg-dark);
  color: #9DA2B3;
}

.footer-top {
  padding: 56px 0 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(4, 1fr);
  gap: 32px;
}

.footer-brand {
  padding-right: 24px;
}

.footer-logo-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}

.footer-logo-text {
  font-size: 22px;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.04em;
  line-height: 1;
}

.footer-tagline {
  margin-top: 12px;
  font-size: 14px;
  color: #6E7282;
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 700;
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 10px;
}

.footer-col ul a {
  font-size: 13px;
  color: #9DA2B3;
  text-decoration: none;
  transition: color var(--transition);
}

.footer-col ul a:hover {
  color: #fff;
}

.footer-bottom {
  padding: 24px 0;
}

.footer-bottom-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-social {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  color: #6E7282;
  border-radius: var(--radius-xs);
  transition: color var(--transition), background var(--transition);
}

.footer-social a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.footer-legal {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: 12px;
}

.footer-legal-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-legal-links a {
  color: #6E7282;
  text-decoration: none;
  font-size: 12px;
  transition: color var(--transition);
}

.footer-legal-links a:hover {
  color: #fff;
}

.footer-lang .lang-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: 13px;
  color: #9DA2B3;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-family: inherit;
  transition: all var(--transition);
}

.footer-lang .lang-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
}

/* ========== RESPONSIVE ========== */
@media (max-width: 1024px) {
  .downloads-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

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

  .footer-brand {
    grid-column: 1 / -1;
  }

  .ai-banner-inner {
    flex-direction: column;
    text-align: center;
    padding: 48px 32px;
    gap: 32px;
  }

  .ai-banner-text p {
    margin-left: auto;
    margin-right: auto;
  }
}

@media (max-width: 768px) {
  .header-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    padding: 16px;
  }

  .header-nav.open {
    display: block;
  }

  .nav-menu {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .nav-link {
    padding: 12px 16px;
    font-size: 15px;
  }

  .header-actions {
    display: none;
  }

  .mobile-menu-btn {
    display: flex;
    margin-left: auto;
  }

  .hero-section {
    padding: 100px 0 40px;
  }

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

  .hero-dl-grid,
  .cta-dl-grid {
    grid-template-columns: 1fr;
  }

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

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

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

  .ai-banner-inner {
    margin: 0;
    border-radius: 0;
    padding: 40px 24px;
  }

  .ai-banner-visual {
    display: none;
  }

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

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

  .footer-legal-links {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 28px;
  }

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

  .hero-dl-item,
  .cta-dl-item {
    padding: 16px;
  }

  .btn-download {
    padding: 12px 24px;
    font-size: 16px;
  }

  .dl-card {
    padding: 20px;
  }

  .feature-item {
    padding: 24px 20px;
  }

  .resource-card {
    padding: 24px 20px;
  }

  .ai-banner-text h2 {
    font-size: 24px;
  }

  .cta-section h2 {
    font-size: 24px;
  }

  .btn-large {
    padding: 12px 28px;
    font-size: 15px;
  }

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

/* ========== ANIMATIONS ========== */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.hero-badge,
.hero-title,
.hero-desc,
.hero-dl-grid {
  animation: fadeIn 0.6s ease both;
}

.hero-title { animation-delay: 0.1s; }
.hero-desc { animation-delay: 0.2s; }
.hero-dl-grid { animation-delay: 0.3s; }