/* Variables */
:root {
  /* Colors */
  --color-primary: #0055ff;
  --color-primary-light: #4d8bff;
  --color-primary-dark: #003cb3;
  --color-secondary: #00c9ff;
  --color-accent: #ff9500;
  --color-success: #28a745;
  --color-warning: #ffc107;
  --color-danger: #dc3545;
  --color-info: #17a2b8;
  
  --color-dark: #162447;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-text-lighter: #999999;
  --color-bg: #ffffff;
  --color-bg-light: #f8f9fa;
  --color-bg-dark: #1b1e4b;
  
  /* Typography */
  --font-main: 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
  --font-size-base: 16px;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-bold: 700;
  
  /* Spacing */
  --spacing-xs: 8px;
  --spacing-sm: 16px;
  --spacing-md: 24px;
  --spacing-lg: 32px;
  --spacing-xl: 48px;
  --spacing-xxl: 64px;
  
  /* Border radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  
  /* Shadows */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.1);
  
  /* Animation */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

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

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.5;
  overflow-x: hidden;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

ul, ol {
  list-style: none;
}

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

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
  line-height: inherit;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  font-weight: var(--font-weight-medium);
  transition: all var(--transition-normal);
  text-align: center;
  min-width: 120px;
}

.btn-primary {
  background-color: var(--color-primary);
  color: white;
  box-shadow: 0 4px 6px rgba(0, 85, 255, 0.2);
}

.btn-primary:hover {
  background-color: var(--color-primary-dark);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0, 85, 255, 0.3);
}

.btn-outline {
  background-color: transparent;
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
}

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

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background-color: transparent;
  transition: background-color var(--transition-normal);
  padding: var(--spacing-md) 0;
}

.header.scrolled {
  background-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  padding: var(--spacing-sm) 0;
}

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

.logo img {
  height: 50px;
  width: auto;
  transition: height var(--transition-normal);
}

.header.scrolled .logo img {
  height: 40px;
}

.menu {
  display: flex;
  gap: var(--spacing-md);
}

.menu a {
  color: white;
  font-weight: var(--font-weight-medium);
  position: relative;
  padding: var(--spacing-xs) 0;
}

.menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: white;
  transition: width var(--transition-normal);
}

.menu a:hover::after,
.menu a.active::after {
  width: 100%;
}

.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
}

.mobile-toggle span {
  display: block;
  width: 25px;
  height: 3px;
  background-color: white;
  border-radius: 3px;
  transition: all var(--transition-normal);
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-bg-dark) 100%);
  color: white;
  padding: calc(var(--spacing-xxl) * 2) 0 var(--spacing-xl);
  position: relative;
}

.hero .container {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
  position: relative;
  z-index: 1;
}

.hero-content {
  flex: 1;
}

.hero h1 {
  font-size: 3rem;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
  font-weight: var(--font-weight-bold);
}

.hero .subtitle {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-lg);
  opacity: 0.9;
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-md);
}

.hero-image {
  flex: 1;
  position: relative;
}

.hero-image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  transform: perspective(1000px) rotateY(-5deg);
  max-width: 100%;
}

.wave-separator {
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  line-height: 0;
  overflow: hidden;
}

/* Features Section */
.features {
  padding: var(--spacing-xxl) 0;
  background-color: var(--color-bg);
}

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--spacing-xl);
}

.section-header h2 {
  font-size: 2.5rem;
  color: var(--color-dark);
  margin-bottom: var(--spacing-sm);
}

.section-header p {
  font-size: 1.125rem;
  color: var(--color-text-light);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
}

.feature-card {
  background-color: white;
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  text-align: center;
}

.feature-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  margin-bottom: var(--spacing-md);
  display: flex;
  justify-content: center;
}

.feature-card h3 {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.feature-card p {
  color: var(--color-text-light);
}

/* Showcase Section */
.showcase {
  padding: var(--spacing-xxl) 0;
  background-color: var(--color-bg-light);
}

.showcase-container {
  background-color: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.showcase-tabs {
  display: flex;
  background-color: var(--color-primary);
  padding: var(--spacing-sm);
  gap: var(--spacing-xs);
}

.tab-btn {
  padding: var(--spacing-sm) var(--spacing-md);
  color: white;
  opacity: 0.7;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  font-weight: var(--font-weight-medium);
}

.tab-btn.active,
.tab-btn:hover {
  opacity: 1;
  background-color: rgba(255, 255, 255, 0.1);
}

.tab-content {
  display: none;
  padding: var(--spacing-lg);
}

.tab-content.active {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-lg);
}

.showcase-image {
  flex: 1;
  min-width: 300px;
}

.showcase-image img {
  border-radius: var(--radius-md);
  width: 100%;
}

.showcase-info {
  flex: 1;
  min-width: 300px;
}

.showcase-info h3 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary);
}

.showcase-info p {
  margin-bottom: var(--spacing-md);
}

.showcase-info ul {
  list-style: disc;
  padding-left: var(--spacing-lg);
}

.showcase-info li {
  margin-bottom: var(--spacing-xs);
}

/* Testimonials Section */
.testimonials {
  padding: var(--spacing-xxl) 0;
  background-color: var(--color-bg);
}

.testimonial-carousel {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.testimonial-item {
  background-color: white;
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-md);
  margin: 0 auto;
}

.testimonial-content {
  margin-bottom: var(--spacing-md);
  font-style: italic;
  color: var(--color-text);
  font-size: 1.125rem;
  line-height: 1.6;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.testimonial-author img {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  object-fit: cover;
}

.testimonial-author h4 {
  font-size: 1.125rem;
  margin-bottom: 2px;
}

.testimonial-author p {
  color: var(--color-text-light);
  font-size: 0.875rem;
}

.testimonial-controls {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.testimonial-control {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: white;
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.testimonial-control:hover {
  background-color: var(--color-primary);
  color: white;
}

.testimonial-control span {
  font-size: 1.5rem;
  line-height: 1;
}

/* Download Section */
.download {
  padding: var(--spacing-xxl) 0;
  background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-primary) 100%);
  color: white;
}

.download .section-header h2,
.download .section-header p {
  color: white;
}

.download-options {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-lg);
  justify-content: center;
  margin-bottom: var(--spacing-xl);
}

.download-card {
  background-color: white;
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: var(--shadow-lg);
  flex: 1;
  min-width: 280px;
  max-width: 350px;
  text-align: center;
  color: var(--color-text);
  transition: transform var(--transition-normal);
}

.download-card:hover {
  transform: translateY(-10px);
}

.download-icon {
  margin-bottom: var(--spacing-md);
  display: flex;
  justify-content: center;
}

.download-card h3 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.download-card p {
  margin-bottom: var(--spacing-md);
}

.download-btn {
  display: inline-block;
  margin-bottom: var(--spacing-sm);
}

.mobile-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-sm);
}

.version {
  color: var(--color-text-lighter);
  font-size: 0.875rem;
}

.download-info {
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  max-width: 800px;
  margin: 0 auto;
}

.download-info h3 {
  text-align: center;
  margin-bottom: var(--spacing-lg);
  font-size: 1.5rem;
}

.installation-steps {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-lg);
  justify-content: space-around;
}

.step {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.step-number {
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background-color: white;
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: var(--font-weight-bold);
}

/* About Section */
.about {
  padding: var(--spacing-xxl) 0;
  background-color: var(--color-bg);
}

.about-content {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
  align-items: center;
}

.about-image {
  flex: 1;
  min-width: 300px;
}

.about-image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.about-text {
  flex: 1;
  min-width: 300px;
}

.about-text h3 {
  font-size: 1.75rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary);
}

.about-text p {
  margin-bottom: var(--spacing-md);
  line-height: 1.7;
}

.company-stats {
  display: flex;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-lg);
}

.stat {
  text-align: center;
}

.stat h4 {
  font-size: 1.75rem;
  color: var(--color-primary);
  margin-bottom: 5px;
}

.stat p {
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* Contact Section */
.contact {
  padding: var(--spacing-lg) 0;
  background-color: var(--color-bg-light);
}

.contact-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
}

.contact-info {
  flex: 1;
  min-width: 300px;
}

.contact-info h3 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary);
}

.contact-info ul {
  margin-bottom: var(--spacing-md);
}

.contact-info li {
  margin-bottom: var(--spacing-sm);
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.social-links {
  display: flex;
  gap: var(--spacing-sm);
}

.social-links a {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-fast);
}

.social-links a:hover {
  background-color: var(--color-primary-dark);
}

.newsletter {
  flex: 1;
  min-width: 300px;
}

.newsletter h3 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

.newsletter p {
  margin-bottom: var(--spacing-md);
}

.newsletter-form {
  display: flex;
  gap: var(--spacing-sm);
}

.newsletter-form input {
  flex: 1;
  padding: 12px var(--spacing-sm);
  border: 1px solid #ddd;
  border-radius: var(--radius-md);
}

/* Footer */
.footer {
  background-color: var(--color-bg-dark);
  color: white;
  padding: var(--spacing-xl) 0 var(--spacing-lg);
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  padding-bottom: var(--spacing-xl);
}

.footer-brand {
  flex: 1;
  min-width: 250px;
}

.footer-brand img {
  margin-bottom: var(--spacing-sm);
}

.footer-brand p {
  opacity: 0.7;
}

.footer-links {
  flex: 2;
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xl);
}

.footer-group h4 {
  color: white;
  margin-bottom: var(--spacing-md);
  font-size: 1.125rem;
}

.footer-group ul li {
  margin-bottom: var(--spacing-xs);
}

.footer-group ul li a {
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--transition-fast);
}

.footer-group ul li a:hover {
  color: white;
}

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

.footer-bottom p {
  opacity: 0.7;
}

.language-selector select {
  background-color: transparent;
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.3);
  padding: 5px 10px;
  border-radius: var(--radius-sm);
}

/* Back to Top Button */
.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 40px;
  height: 40px;
  background-color: var(--color-primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-md);
  z-index: 99;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--color-primary-dark);
  transform: translateY(-5px);
}

/* Icons */
.icon-email, .icon-phone, .icon-address, 
.icon-wechat, .icon-weibo, .icon-linkedin {
  width: 20px;
  height: 20px;
  background-color: var(--color-primary-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}