/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 74px; /* Match fixed navigation height: padding (12*2) + logo (50) = 74px */
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #fff;
  overflow-x: hidden;
}

/* Touch-friendly interactions */
@media (hover: none) and (pointer: coarse) {
  .btn, .nav-link, .mobile-nav-link {
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  
  .mobile-menu-toggle {
    min-height: 44px;
    min-width: 44px;
  }
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Navigation Header */
.nav-header {
  background: rgba(30, 58, 138, 0.95);
  backdrop-filter: blur(10px);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 12px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo-section {
  display: flex;
  align-items: center;
}

.logo {
  height: 50px;
  width: auto;
  max-width: 200px;
  transition: transform 0.3s ease;
}

.logo:hover {
  transform: scale(1.2);
}

.nav-links {
  display: flex;
  gap: 32px;
  align-items: center;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.language-selector {
  display: flex;
  align-items: center;
}

.language-selector select {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: white;
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.3s ease;
}

.language-selector select:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.5);
}

.language-selector select option {
  background: #1e293b;
  color: white;
}

.nav-link {
  color: white;
  text-decoration: none;
  font-weight: 500;
  font-size: 1.2rem;
  transition: color 0.3s ease;
  position: relative;
  padding: 8px 12px;
}

.nav-link:hover {
  color: #60a5fa;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: #60a5fa;
  transition: width 0.3s ease;
}

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

.nav-link.active {
  color: #60a5fa;
}

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

.mobile-nav-link.active {
  color: #60a5fa;
}

.nav-actions {
  display: flex;
  gap: 16px;
  align-items: center;
}

.language-selector {
  position: relative;
}

.language-selector select {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 6px;
  padding: 8px 12px;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6,9 12,15 18,9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 8px center;
  background-size: 16px;
  padding-right: 32px;
  min-width: 100px;
}

.language-selector select:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.5);
}

.language-selector select:focus {
  outline: none;
  background: rgba(255, 255, 255, 0.2);
  border-color: #60a5fa;
}

.language-selector select option {
  background: #1e40af;
  color: white;
  padding: 8px;
}

.mobile-language-selector {
  margin-bottom: 16px;
  width: 100%;
}

.mobile-language-selector select {
  width: 100%;
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 6px;
  padding: 12px 16px;
  font-size: 1.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6,9 12,15 18,9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 12px center;
  background-size: 20px;
  padding-right: 40px;
}

.mobile-language-selector select:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.5);
}

.mobile-language-selector select:focus {
  outline: none;
  background: rgba(255, 255, 255, 0.2);
  border-color: #60a5fa;
}

.mobile-language-selector select option {
  background: #1e40af;
  color: white;
  padding: 12px;
  font-size: 1.9rem;
}

.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  cursor: pointer;
  padding: 27px;
  min-width: 99px;
  min-height: 99px;
  justify-content: center;
}

.hamburger {
  width: 63px;
  height: 8px;
  background-color: white;
  margin: 9px 0;
  transition: 0.3s;
  border-radius: 5px;
}

.mobile-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: rgba(30, 58, 138, 0.98);
  backdrop-filter: blur(10px);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  z-index: 999;
}

.mobile-menu.active {
  display: block;
}

.mobile-menu-content {
  padding: 36px 30px;
}

.mobile-nav-link {
  display: block;
  color: white;
  text-decoration: none;
  padding: 24px 0;
  font-weight: 500;
  font-size: 1.9rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  transition: color 0.3s ease;
}

.mobile-nav-link:hover {
  color: #60a5fa;
}

.mobile-menu-actions {
  margin-top: 30px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

/* Hero Section */
.hero-section {
  background: linear-gradient(135deg, #1e3a8a 0%, #1e40af 100%);
  color: white;
  padding: 160px 0 80px 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  scroll-margin-top: 0; /* Let padding handle the spacing */
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 24px;
}

.hero-description {
  font-size: 1.25rem;
  line-height: 1.6;
  margin-bottom: 40px;
  opacity: 0.9;
}

.hero-buttons {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 16px 32px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition: all 0.3s ease;
  border: none;
  cursor: pointer;
}

.btn-primary {
  background-color: #3b82f6;
  color: white;
}

.btn-primary:hover {
  background-color: #2563eb;
  transform: translateY(-2px);
}

.btn-secondary {
  background-color: rgba(255, 255, 255, 0.1);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.arrow {
  font-style: normal;
  font-size: 1.2em;
}

/* Hero Visual */
.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.video-container {
  position: relative;
  width: 100%;
  max-width: 380px;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

/* Vertical video (9:16 aspect ratio for YouTube Shorts) */
.video-container.vertical-video {
  max-width: 60%; /* Narrower for vertical videos on desktop, responsive percentage */
}

.video-wrapper {
  position: relative;
  width: 100%;
  max-width: 605px; /* Increased by 21% total from 500px */
  padding-bottom: 177.78%; /* 9:16 aspect ratio (16/9 * 100%) */
  height: 0;
  overflow: hidden;
  background: #000;
  border-radius: 12px;
  margin: 0 auto;
}

.video-wrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
  border-radius: 12px;
}

.demo-video {
  width: 100%;
  height: 100%;
  display: block;
  background: #000;
}

.video-caption {
  margin-top: 16px;
  text-align: center;
  color: #fff;
}

.video-caption p {
  font-size: 1rem;
  margin: 0;
  opacity: 0.9;
}

/* About Section */
.about-section {
  padding: 100px 0;
  background-color: #f8fafc;
  scroll-margin-top: 0; /* Let padding handle the spacing */
}

.about-content {
  text-align: center;
  margin-bottom: 60px;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: #1f2937;
}

.section-description {
  font-size: 1.25rem;
  color: #6b7280;
  max-width: 600px;
  margin: 0 auto 40px;
  line-height: 1.6;
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 40px;
  margin-top: 60px;
}

.about-card {
  background: white;
  padding: 40px 30px;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.about-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.about-icon {
  width: 90px;
  height: 90px;
  background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 24px;
  font-size: 32px;
}

.about-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: #1f2937;
}

.about-text {
  font-size: 1rem;
  line-height: 1.6;
  color: #6b7280;
}

/* Downloads Section */
.downloads-section {
  padding: 100px 0;
  background-color: #f8fafc;
  scroll-margin-top: 0; /* Let padding handle the spacing */
}

.downloads-content {
  text-align: center;
  margin-bottom: 60px;
}

/* Utility class for margin-top */
.mt-3 {
  margin-top: 1rem;
}

.downloads-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  margin-top: 60px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.download-item {
  background: white;
  border-radius: 12px;
  padding: 30px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.download-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.download-info {
  display: flex;
  align-items: center;
  gap: 20px;
  flex: 1;
}

.app-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
}

.app-details {
  text-align: left;
}

.app-name {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 4px;
  color: #1f2937;
}

.app-version-date {
  font-size: 0.9rem;
  color: #3b82f6;
  font-weight: 600;
  margin-bottom: 8px;
}

/* 版本信息子元素样式 */
.app-version-date .version-label {
  color: #6b7280; /* 灰色标签 */
  font-weight: 500;
}

.app-version-date .version-number {
  color: #059669; /* 绿色版本号 */
  font-weight: 700;
  font-family: 'Courier New', monospace; /* 等宽字体更清晰 */
}

.app-version-date .date-label {
  color: #6b7280; /* 灰色标签 */
  font-weight: 500;
}

.app-version-date .release-date {
  color: #dc2626; /* 红色发布日期 */
  font-weight: 600;
  font-family: 'Courier New', monospace; /* 等宽字体更清晰 */
}

.app-description {
  font-size: 0.9rem;
  color: #6b7280;
  line-height: 1.4;
}

.download-actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  flex-shrink: 0;
}

.download-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  color: white;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  min-width: 140px;
  justify-content: center;
  flex: 0 0 auto;
}

.download-btn:hover {
  background: linear-gradient(135deg, #1d4ed8 0%, #1e40af 100%);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.download-btn i {
  font-size: 16px;
}


/* Contact Section */
.contact-section {
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  padding: 100px 0;
  scroll-margin-top: 0; /* Let padding handle the spacing */
}

.contact-content {
  text-align: center;
  margin-bottom: 60px;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 40px;
  margin-top: 60px;
}

.contact-person {
  background: white;
  border-radius: 16px;
  padding: 40px 30px;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  text-align: left;
}

.contact-person:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.person-header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 2px solid #f1f5f9;
}

.person-avatar {
  width: 90px;
  height: 90px;
  background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  flex-shrink: 0;
}

.person-info {
  flex: 1;
}

.person-name {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: #1f2937;
}

.person-title {
  font-size: 1rem;
  color: #3b82f6;
  font-weight: 600;
  margin: 0;
}

.contact-details {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 16px;
}

.contact-label {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 120px;
  font-weight: 600;
  color: #374151;
  font-size: 0.95rem;
}

.contact-label i {
  font-size: 18px;
  width: 20px;
  text-align: center;
}

.contact-value {
  flex: 1;
  font-size: 1rem;
  color: #1f2937;
  font-weight: 500;
}

.contact-value.qr-placeholder {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.qr-code {
  width: 180px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.qr-image {
  width: 180px;
  height: 180px;
  border-radius: 12px;
  border: 2px solid #e5e7eb;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.qr-image:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 12px rgba(0, 0, 0, 0.15);
}

.qr-text {
  font-size: 0.85rem;
  color: #6b7280;
  text-align: center;
  line-height: 1.4;
  font-weight: 500;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .container {
    padding: 0 16px;
  }
  
  .hero-title {
    font-size: 3rem;
  }
}

/* 600px 媒体查询中的导航样式已移除 - 这些元素在手机上应该被隐藏 */

@media (max-width: 992px) {
  html {
    scroll-padding-top: 119px; /* Adjusted for larger mobile logo: padding (12*2) + logo (95) = 119px */
  }
  
  .nav-links {
    display: none;
  }
  
  .nav-actions {
    display: none;
  }
  
  .language-selector {
    display: none;
  }
  
  .mobile-menu-toggle {
    display: flex;
  }
  
  /* 增大移动端 Logo 尺寸 */
  .logo {
    height: 95px;
    max-width: 360px;
  }
  
  /* 增大移动端菜单元素尺寸 */
  .mobile-menu-actions .language-selector select {
    padding: 15px 21px;
    font-size: 1.5rem;
    min-height: 66px;
  }

  .mobile-menu-actions .btn {
    padding: 18px 30px;
    font-size: 1.9rem;
    min-height: 72px;
  }
  
  .hero-section {
    padding: 250px 0 60px 0;
  }
  
  .hero-section,
  .about-section,
  .downloads-section,
  .contact-section {
    scroll-margin-top: 0; /* Let padding handle the spacing */
  }
  
  .hero-content {
    grid-template-columns: 1fr;
    gap: 66px;
    text-align: center;
  }
  
  .hero-title {
    font-size: 2.5rem;
    line-height: 1.1;
    margin-bottom: 44px;
  }
  
  .hero-description {
    font-size: 2.0rem;
    margin-bottom: 55px;
  }
  
  .hero-buttons {
    justify-content: center;
    flex-direction: column;
    align-items: center;
    gap: 26px;
    margin-bottom: 10px;
  }
  
  .btn {
    width: 100%;
    max-width: 280px;
    justify-content: center;
    font-size: 2.0rem;
  }
  
  .video-thumbnail p {
    font-size: 1.8rem;
  }
  
  .video-container.vertical-video {
    max-width: 68% !important;
  }
  
  .about-section,
  .downloads-section,
  .contact-section {
    padding-top: 190px;
  }
  
  .section-title {
    font-size: 2.5rem;
  }
  
  .section-description {
    font-size: 2.16rem;
  }
  
  .app-icon {
    width: 90px;
    height: 90px;
  }
  
  .app-icon i {
    font-size: 3.888rem;
  }
  
  .app-name {
    font-size: 1.8rem;
  }
  
  .app-version-date {
    font-size: 1.8rem;
  }
  
  .app-description {
    font-size: 1.8rem;
  }
  
  .about-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  
  .about-card {
    padding: 30px 20px;
  }
  
  .about-icon {
    width: 90px;
    height: 90px;
  }
  
  .about-icon i {
    font-size: 3.888rem;
  }
  
  .about-title {
    font-size: 1.8rem;
  }
  
  .about-text {
    font-size: 1.6rem;
  }
  
  .downloads-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .download-item {
    flex-direction: column;
    text-align: center;
    padding: 24px 20px;
  }
  
  .download-info {
    flex-direction: column;
    text-align: center;
    gap: 16px;
  }
  
  .app-details {
    text-align: center;
  }
  
  .download-actions {
    flex-direction: row;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
  }
  
  .download-btn {
    min-width: 140px;
    font-size: 1.6rem;
    padding: 14px 24px;
    flex: 0 0 auto;
  }
  
  .download-btn i {
    font-size: 1.6rem;
  }
  
  .contact-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  
  .contact-person {
    padding: 30px 20px;
  }
  
  .person-header {
    flex-direction: column;
    text-align: center;
    gap: 16px;
  }
  
  .person-name {
    font-size: 2.0rem;
  }
  
  .person-title {
    font-size: 1.6rem;
  }
  
  .contact-details {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }
  
  .contact-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  
  .contact-item:nth-child(1),
  .contact-item:nth-child(2),
  .contact-item:nth-child(3) {
    padding-left: 60px;
  }
  
  .contact-item:nth-child(4) {
    grid-column: 2;
    grid-row: 1 / 4;
    align-items: center;
    text-align: center;
  }
  
  .qr-code {
    width: 160px;
  }
  
  .qr-image {
    width: 160px;
    height: 160px;
  }
  
  .contact-label {
    min-width: auto;
    font-size: 1.7rem;
  }
  
  .contact-label i {
    font-size: 1.7rem;
  }
  
  .contact-value {
    font-size: 1.7rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
  
  .footer-column.company-info {
    grid-column: 1 / -1;
    text-align: center;
  }
  
  .footer-column.quick-links,
  .footer-column.contact-info {
    text-align: left;
  }
  
  .footer-column.quick-links {
    padding-left: 80px;
  }
  
  .footer-logo {
    height: 83px !important;
    margin-left: auto;
    margin-right: auto;
  }
  
  .footer-description {
    font-size: 1.6rem !important;
  }
  
  .footer-column h4 {
    font-size: 1.87rem !important;
  }
  
  .footer-column ul li a {
    font-size: 1.65rem !important;
  }
  
  .contact-person-title {
    font-size: 1.65rem !important;
  }
  
  .footer-contact-person ul li {
    font-size: 1.65rem !important;
    white-space: nowrap;
  }
  
  .footer-contact-person ul li i {
    font-size: 1.65rem !important;
  }
  
  .footer-bottom p {
    font-size: 1.54rem !important;
  }
}

@media (max-width: 480px) {
  html {
    scroll-padding-top: 126px; /* Adjusted for larger mobile logo: padding (12*2) + logo (102) = 126px */
  }
  
  .container {
    padding: 0 12px;
  }
  
  .nav-header {
    padding: 12px 0;
  }
  
  .logo {
    height: 102px;
    max-width: 327px;
  }
  
  /* .hero-section {
    padding: 90px 0 50px 0;
  } */
  
  .hero-section,
  .about-section,
  .downloads-section,
  .contact-section {
    scroll-margin-top: 0; /* Let padding handle the spacing */
  }
  
  .hero-section {
    padding-top: 260px;
  }
  
  .about-section,
  .downloads-section,
  .contact-section {
    padding-top: 200px;
  }
  
  .hero-title {
    font-size: 2rem;
    margin-bottom: 35px;
  }
  
  .hero-description {
    font-size: 2.0rem;
    margin-bottom: 44px;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
  
  .footer-column.company-info {
    grid-column: 1 / -1;
    text-align: center;
  }
  
  .footer-column.quick-links {
    text-align: left;
  }
  
  .footer-column.contact-info {
    text-align: left;
  }
  
  .hero-buttons {
    gap: 22px;
    margin-bottom: 10px;
  }
  
  .btn {
    padding: 12px 20px;
    font-size: 2.0rem;
  }
  
  .video-container {
    max-width: 100%;
  }
  
  .video-container.vertical-video {
    max-width: 68% !important; /* Limit width on mobile for better layout */
  }
  
  .video-caption p {
    font-size: 1.8rem;
  }
  
  .section-title {
    font-size: 2.2rem;
  }
  
  .section-description {
    font-size: 2.04rem;
  }
  
  .app-icon {
    width: 105px;
    height: 105px;
  }
  
  .app-icon i {
    font-size: 5.04rem;
  }
  
  .app-name {
    font-size: 2.0rem;
  }
  
  .app-version-date {
    font-size: 1.92rem;
  }
  
  .app-description {
    font-size: 1.92rem;
  }
  
  .about-card {
    padding: 24px 16px;
  }
  
  .download-item {
    padding: 20px 16px;
  }
  
  .download-actions {
    flex-direction: column;
    width: 100%;
  }
  
  .download-btn {
    width: 100%;
    min-width: auto;
    font-size: 1.8rem;
    padding: 16px 28px;
  }
  
  .download-btn i {
    font-size: 1.8rem;
  }
  
  .contact-person {
    padding: 24px 16px;
  }
  
  .contact-details {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }
  
  .contact-item:nth-child(4) {
    grid-column: 2;
    grid-row: 1 / 4;
    align-items: center;
    text-align: center;
  }
  
  .about-icon {
    width: 90px;
    height: 90px;
  }
  
  .about-icon i {
    font-size: 3.888rem;
  }
  
  .about-title {
    font-size: 2.0rem;
  }
  
  .about-text {
    font-size: 1.7rem;
  }
  
  .person-avatar {
    width: 90px;
    height: 90px;
    font-size: 32px;
  }
  
  .person-avatar i {
    font-size: 3.888rem;
  }
  
  .person-name {
    font-size: 2.0rem;
  }
  
  .person-title {
    font-size: 1.6rem;
  }
  
  .contact-item {
    gap: 12px;
  }
  
  .contact-item:nth-child(1),
  .contact-item:nth-child(2),
  .contact-item:nth-child(3) {
    padding-left: 45px;
  }
  
  .contact-label {
    font-size: 1.6rem;
  }
  
  .contact-label i {
    font-size: 1.6rem;
  }
  
  .contact-value {
    font-size: 1.6rem;
  }
  
  .qr-code {
    width: 140px;
  }
  
  .qr-image {
    width: 140px;
    height: 140px;
  }
  
  .qr-text {
    font-size: 1.2rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
  
  .footer-column.company-info {
    grid-column: 1 / -1;
    text-align: center;
  }
  
  .footer-column.quick-links,
  .footer-column.contact-info {
    text-align: left;
  }
  
  .footer-column.quick-links {
    padding-left: 80px;
  }
  
  .footer-logo {
    height: 97px !important;
    margin-left: auto;
    margin-right: auto;
  }
  
  .footer-description {
    font-size: 1.6rem !important;
  }
  
  .footer-column h4 {
    font-size: 1.98rem !important;
  }
  
  .footer-column ul li a {
    font-size: 1.76rem !important;
  }
  
  .contact-person-title {
    font-size: 1.76rem !important;
  }
  
  .footer-contact-person ul li {
    font-size: 1.76rem !important;
    white-space: nowrap;
  }
  
  .footer-contact-person ul li i {
    font-size: 1.76rem !important;
  }
  
  .footer-bottom p {
    font-size: 1.65rem !important;
  }
}

/* Extra small devices (phones in portrait) */
@media (max-width: 360px) {
  .container {
    padding: 0 8px;
  }
  
  .hero-title {
    font-size: 1.75rem;
    margin-bottom: 31px;
  }
  
  .hero-description {
    font-size: 2.0rem;
    margin-bottom: 40px;
  }
  
  .btn {
    padding: 10px 16px;
    font-size: 2.0rem;
  }
  
  .video-thumbnail p {
    font-size: 1.8rem;
  }
  
  .video-container.vertical-video {
    max-width: 68% !important;
  }
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
  
  .footer-column.company-info {
    grid-column: 1 / -1;
    text-align: center;
  }
  
  .footer-column.quick-links,
  .footer-column.contact-info {
    text-align: left;
  }
  
  .footer-column.quick-links {
    padding-left: 80px;
  }
  
  .footer-logo {
    height: 91px !important;
    margin-left: auto;
    margin-right: auto;
  }
  
  .footer-description {
    font-size: 1.6rem !important;
  }
  
  .footer-column h4 {
    font-size: 1.87rem !important;
  }
  
  .footer-column ul li a {
    font-size: 1.65rem !important;
  }
  
  .contact-person-title {
    font-size: 1.65rem !important;
  }
  
  .footer-contact-person ul li {
    font-size: 1.65rem !important;
    white-space: nowrap;
  }
  
  .footer-contact-person ul li i {
    font-size: 1.65rem !important;
  }
  
  .footer-bottom p {
    font-size: 1.54rem !important;
  }
}

/* Landscape orientation for mobile */
@media (max-width: 768px) and (orientation: landscape) {
  .hero-section {
    padding: 240px 0 40px 0;
    min-height: auto;
  }
  
  .hero-title {
    font-size: 2rem;
  }
  
  .hero-description {
    font-size: 2.0rem;
  }
  
  
  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
  
  .footer-column.company-info {
    grid-column: 1 / -1;
    text-align: center;
  }
  
  .footer-column.quick-links {
    text-align: left;
  }
  
  .footer-column.contact-info {
    text-align: left;
  }
  
  .footer-column ul {
    display: flex;
    flex-direction: column;
  }
  
}


/* Footer */
.footer {
  background: #1e293b;
  color: #e2e8f0;
  padding: 60px 0 20px 0;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-column h4 {
  color: white;
  margin-bottom: 20px;
  font-size: 1.1rem;
  font-weight: 600;
}

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

.footer-column ul li {
  margin-bottom: 12px;
}

.footer-column ul li a {
  color: #94a3b8;
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-column ul li a:hover {
  color: #3b82f6;
}

.footer-column ul li .icon {
  margin-right: 8px;
  font-size: 1rem;
}

.footer-logo {
  height: 40px;
  margin-bottom: 15px;
}

.footer-description {
  color: #94a3b8;
  line-height: 1.6;
  font-size: 0.95rem;
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,0.1);
  color: #64748b;
  font-size: 0.9rem;
}

/* Footer contact person styles */
.footer-contact-person {
  margin-bottom: 20px;
}

.footer-contact-person:last-child {
  margin-bottom: 0;
}

.contact-person-title {
  color: #60a5fa;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.footer-contact-person ul {
  list-style: none;
  padding-left: 0;
}

.footer-contact-person ul li {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  color: #94a3b8;
  font-size: 0.9rem;
}

.footer-contact-person ul li i {
  color: #60a5fa;
  font-size: 1rem;
  flex-shrink: 0;
}

/* High DPI displays */
@media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
  .logo {
    image-rendering: -webkit-optimize-contrast;
    image-rendering: crisp-edges;
  }
}

/* Font Awesome 图标优化 */
.fas, .fab, .far {
  font-size: inherit;
  line-height: inherit;
}

/* 应用图标容器 */
.app-icon i {
  font-size: 2.5rem;
  color: white;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 下载按钮图标 */
.download-btn i {
  font-size: 1.2rem;
}

/* 品牌颜色图标 - 可用状态 */
.download-btn .fa-android {
  color: #3ddc84; /* Android 绿色 */
}

.download-btn .fa-apple {
  color: #ffffff; /* Apple 白色（在蓝色背景上） */
}

.download-btn .fa-windows {
  color: #00a4ef; /* Windows 蓝色 */
}

.download-btn .fa-globe {
  color: #60a5fa; /* 浅蓝色 */
}

.download-btn .fa-chart-line {
  color: #10b981; /* 绿色 */
}

.download-btn .fa-screwdriver-wrench {
  color: #f59e0b; /* 橙色 */
}

/* 联系人头像图标 */
.person-avatar i {
  font-size: 3.888rem;
  color: white;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 联系信息图标 */
.contact-label i {
  font-size: 1.2rem;
  margin-right: 8px;
  color: #3b82f6;
}

/* 关于卡片图标 */
.about-icon i {
  font-size: 3.888rem;
  color: white;
  margin: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 页脚图标 */
.footer li i {
  margin-right: 8px;
  color: #60a5fa;
}

/* 播放按钮图标 */
.play-icon {
  font-size: 2rem;
  color: white;
}

/* 移动端图标优化 */
@media (max-width: 992px) {
  .app-icon i {
    font-size: 3.888rem;
  }
  
  .person-avatar i {
    font-size: 3.888rem;
  }
  
  .about-icon i {
    font-size: 3.888rem;
  }
}

@media (max-width: 480px) {
  .app-icon i {
    font-size: 4.536rem;
  }
  
  .person-avatar {
    width: 105px;
    height: 105px;
  }
  
  .person-avatar i {
    font-size: 4.536rem;
  }
  
  .about-icon {
    width: 105px;
    height: 105px;
  }
  
  .about-icon i {
    font-size: 4.536rem;
  }
  
  .contact-label i {
    font-size: 1rem;
  }
}

/* 禁用的下载按钮样式 */
.download-btn-disabled {
  background: #e5e7eb !important;
  color: #9ca3af !important;
  border-color: #d1d5db !important;
  cursor: not-allowed !important;
  opacity: 0.6;
  pointer-events: none;
  /* 确保与可用按钮大小一致 */
  padding: 12px 20px !important;
  font-size: 0.9rem !important;
  font-weight: 600 !important;
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 8px !important;
  min-width: 140px;
  border-radius: 8px;
  text-align: center;
  flex: 0 0 auto !important;
}

.download-btn-disabled:hover {
  background: #e5e7eb !important;
  color: #9ca3af !important;
  transform: none !important;
  box-shadow: none !important;
}

.download-btn-disabled i {
  color: #9ca3af !important;
  font-size: 1.2rem;
}

/* 开发中徽章 */
.badge-dev {
  font-size: 0.85em;
  font-weight: normal;
  opacity: 0.8;
  font-style: italic;
}

/* Download button cooling state - simplified */
.download-btn.download-btn-cooling {
  background: #9ca3af !important;
  cursor: not-allowed !important;
  pointer-events: none !important;
  opacity: 0.6 !important;
}

.download-btn.download-btn-cooling i {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

/* 移动端优化 */
@media (max-width: 992px) {
  .badge-dev {
    font-size: 1.2em;
  }
  
  .download-btn-disabled {
    opacity: 0.5;
    min-width: 140px !important;
    font-size: 1.6rem !important;
    padding: 14px 24px !important;
    flex: 0 0 auto !important;
  }
  
  .download-btn-disabled i {
    font-size: 1.6rem !important;
  }
}

@media (max-width: 480px) {
  .badge-dev {
    font-size: 1.3em;
    display: block;
    margin-top: 4px;
  }
  
  .download-btn-disabled {
    width: 100% !important;
    min-width: auto !important;
    font-size: 1.8rem !important;
    padding: 16px 28px !important;
  }
  
  .download-btn-disabled i {
    font-size: 1.8rem !important;
  }
}