:root {
  --primary-color: #4F46E5;
  --primary-hover: #4338ca;
  --bg-color: #ffffff;
  --bg-secondary: #f9fafb;
  --text-main: #111827;
  --text-muted: #4b5563;
  --border-color: #e5e7eb;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --radius-full: 9999px;
  --max-width: 1200px;
}

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

html {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  color: var(--text-main);
  background-color: var(--bg-color);
  scroll-behavior: smooth;
}

body {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-image: url('shanyue_global_bg.png');
  background-size: cover;
  background-attachment: fixed;
  background-position: center top;
}

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

ul {
  list-style: none;
}

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

/* Layout */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

section {
  padding: 4rem 0;
}

section:nth-child(even) {
  background-color: rgba(249, 250, 251, 0.65);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 2rem;
  font-weight: 600;
  font-size: 1.125rem;
  border-radius: var(--radius-full);
  transition: all 0.3s ease;
  cursor: pointer;
  text-align: center;
  border: none;
}

.btn-primary {
  background-color: var(--primary-color);
  color: #ffffff;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

/* Header & Nav */
header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

.nav-links a {
  font-weight: 600;
  color: var(--text-muted);
  transition: color 0.2s;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--primary-color);
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary-color);
  letter-spacing: -0.025em;
}

/* Hero Section */
.hero {
  padding: 6rem 0 4rem;
  background: linear-gradient(135deg, rgba(243, 244, 246, 0.6) 0%, rgba(255, 255, 255, 0.8) 100%);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.hero .container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3rem;
}

.hero-content {
  text-align: center;
  flex: 1;
}

.hero-image-wrapper {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
}

.hero-image {
  max-width: 100%;
  border-radius: var(--radius-lg);
  box-shadow: 0 20px 40px -10px rgba(79, 70, 229, 0.2);
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  background: linear-gradient(to right, var(--text-main), var(--primary-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.125rem;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

@media (min-width: 992px) {
  .hero .container {
    flex-direction: row;
    text-align: left;
    justify-content: space-between;
  }
  
  .hero-content {
    text-align: left;
    padding-right: 2rem;
  }
  
  .hero p {
    margin-left: 0;
    margin-right: 0;
  }
}

/* Section Headers */
.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-header h2 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

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

/* Section Images */
.section-image-wrapper {
  margin: 0 auto 3rem;
  max-width: 800px;
  text-align: center;
}

.section-image {
  border-radius: var(--radius-lg);
  box-shadow: 0 10px 30px -5px rgba(0, 0, 0, 0.1), 0 0 20px rgba(79, 70, 229, 0.1);
  width: 100%;
}

/* Grid Layouts for features, pricing etc */
.grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: 1fr; /* Mobile first: single column */
}

/* Features */
.feature-card {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  padding: 2rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  text-align: center;
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  display: inline-block;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

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

/* Promo Banner */
.promo-banner {
  background: linear-gradient(135deg, rgba(79, 70, 229, 0.08) 0%, rgba(129, 140, 248, 0.08) 100%);
  border: 1px dashed var(--primary-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  margin: -1rem auto 3rem;
  max-width: 800px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  text-align: center;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.promo-icon {
  font-size: 2rem;
}

.promo-title {
  font-size: 1.25rem;
  color: var(--text-main);
  margin-bottom: 0.25rem;
  font-weight: 700;
}

.promo-title strong {
  color: var(--primary-color);
  font-size: 1.5rem;
}

.promo-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.promo-code-box {
  background: rgba(255, 255, 255, 0.9);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  border: 1px solid rgba(79, 70, 229, 0.3);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: all 0.3s ease;
}

.promo-code-box:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--primary-color);
}

.copy-icon {
  color: var(--primary-color);
  opacity: 0.5;
  transition: opacity 0.3s ease;
}

.promo-code-box:hover .copy-icon {
  opacity: 1;
}

.promo-label {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.promo-code {
  font-family: 'Courier New', Courier, monospace;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--primary-color);
  letter-spacing: 1px;
}

@media (min-width: 768px) {
  .promo-banner {
    flex-direction: row;
    text-align: left;
    justify-content: space-between;
  }
  
  .promo-content {
    flex: 1;
    padding: 0 1rem;
  }
}

/* Pricing */
.pricing-card {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  text-align: center;
  position: relative;
  display: flex;
  flex-direction: column;
}

.pricing-card.popular {
  border-color: var(--primary-color);
  box-shadow: var(--shadow-lg);
  transform: scale(1.02);
}

.popular-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--primary-color);
  color: white;
  padding: 0.25rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
}

.pricing-name {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.pricing-price {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1.5rem;
}

.pricing-price span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
}

.pricing-features {
  margin-bottom: 2rem;
  flex-grow: 1;
}

.pricing-features li {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-muted);
}

.pricing-features li:last-child {
  border-bottom: none;
}

/* Reviews */
.review-card {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
}

.review-stars {
  color: #fbbf24;
  margin-bottom: 1rem;
}

.review-text {
  font-style: italic;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.review-author-wrapper {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.review-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--border-color);
}

.review-author {
  font-weight: 600;
  margin: 0;
}

/* FAQ */
.faq-item {
  border-bottom: 1px solid var(--border-color);
  padding: 1.5rem 0;
}

.faq-item h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.faq-item p {
  color: var(--text-muted);
}

/* Footer */
footer {
  background-color: var(--text-main);
  color: #d1d5db;
  padding: 4rem 0 2rem;
  text-align: center;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 2rem;
}

.footer-links a {
  transition: color 0.2s;
}

.footer-links a:hover {
  color: white;
}

.footer-copyright {
  font-size: 0.875rem;
  color: #9ca3af;
}

/* Page Content (for about, terms, privacy) */
.page-content {
  padding: 4rem 0;
  min-height: calc(100vh - 200px);
}

.content-box {
  background: white;
  padding: 3rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

.content-box h1 {
  font-size: 2rem;
  margin-bottom: 2rem;
  color: var(--text-main);
}

.content-box h2 {
  font-size: 1.5rem;
  margin-top: 2rem;
  margin-bottom: 1rem;
}

.content-box p {
  margin-bottom: 1rem;
  color: var(--text-muted);
}

.content-box ul {
  list-style: disc;
  margin-left: 1.5rem;
  margin-bottom: 1rem;
  color: var(--text-muted);
}

/* Responsive (Tablet & Desktop) */
@media (min-width: 768px) {
  .hero h1 {
    font-size: 3.5rem;
  }
  
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-links {
    flex-direction: row;
    justify-content: center;
    gap: 2rem;
  }
}

@media (min-width: 1024px) {
  .grid {
    grid-template-columns: repeat(3, 1fr);
  }
  
  .faq-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .hero {
    padding: 8rem 0 5rem;
  }
}

/* High-tech Grid Cards */
.tech-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-top: 3rem;
}

@media (min-width: 768px) {
  .tech-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .tech-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.tech-card {
  position: relative;
  background: #ffffff;
  border-radius: var(--radius-lg);
  padding: 2rem;
  overflow: hidden;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  border: 1px solid rgba(79, 70, 229, 0.3);
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  height: 100%;
  color: var(--text-main);
  text-decoration: none;
}

.tech-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(79, 70, 229, 0.05) 0%, transparent 100%);
  opacity: 0;
  transition: opacity 0.4s ease;
  z-index: 0;
}

.tech-card:hover {
  transform: translateY(-8px);
  border-color: rgba(79, 70, 229, 0.8);
  box-shadow: var(--shadow-lg);
}

.tech-card:hover::before {
  opacity: 1;
}

.tech-card-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.tech-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-main);
  line-height: 1.4;
}

.tech-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.tech-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: auto;
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
}

.tech-card-tag {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #818cf8;
  font-weight: 600;
}