* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}
:root {
  --primary: #2563eb;
  --secondary: #7c3aed;
  --dark: #1e293b;
  --light: #f8fafc;
  --gray: #94a3b8;
  --accent: #ff3b30;
  --card-bg: #ffffff;
  --section-padding: 2.5rem;
  --border-radius: 12px;
  --box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
}
body {
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  color: var(--dark);
  line-height: 1.6;
  padding-bottom: 2rem;
}
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}
.header {
  background: linear-gradient(to right, var(--primary), var(--secondary));
  color: white;
  padding: 1.5rem 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}
.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  font-size: 1.8rem;
  font-weight: 700;
  display: flex;
  align-items: center;
}
.logo i {
  margin-right: 0.5rem;
  color: #fff;
}
.nav-links {
  display: flex;
  gap: 2rem;
}
.nav-links a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
}
.nav-links a:hover {
  color: rgba(255, 255, 255, 0.8);
}
.breadcrumb {
  padding: 1rem 0;
  font-size: 0.9rem;
  color: var(--gray);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
}
.breadcrumb i {
  font-size: 0.7rem;
}
.main {
  background: white;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  margin-top: 2rem;
  overflow: hidden;
}
.intro {
  padding: var(--section-padding);
  background: linear-gradient(rgba(37, 99, 235, 0.03), rgba(37, 99, 235, 0.05));
  text-align: center;
}
.intro h1 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  color: var(--dark);
  line-height: 1.2;
}
.intro-content {
  font-size: 1.1rem;
  max-width: 800px;
  margin: 0 auto;
}
.highlight {
  background: linear-gradient(
    120deg,
    rgba(255, 237, 0, 0.3) 0%,
    rgba(255, 237, 0, 0.7) 100%
  );
  color: var(--dark);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-weight: 600;
}
.intro-image {
  width: 100%;
  display: flex;
  justify-content: center;
  margin: 1.5rem 0;
}
.intro-image img {
  width: 85%;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: transform 0.3s ease;
}
.intro-image img:hover {
  transform: scale(1.01);
}
.content-section {
  padding: var(--section-padding);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}
.content-section:last-child {
  border-bottom: none;
}
.content-section h2 {
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.content-section h2 i {
  background: var(--primary);
  color: white;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}
.content-section p {
  margin-bottom: 1.2rem;
  font-size: 1.05rem;
}
.content-section ul {
  margin-left: 1.5rem;
  margin-bottom: 1.5rem;
}
.content-section li {
  margin-bottom: 0.8rem;
  position: relative;
}
.content-section li:before {
  content: "•";
  color: var(--primary);
  font-weight: bold;
  display: inline-block;
  width: 1em;
  margin-left: -1em;
}
.models-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}
.model-card {
  background: var(--card-bg);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  box-shadow: var(--box-shadow);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  border: 1px solid rgba(0, 0, 0, 0.05);
  text-align: center;
}
.model-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}
.model-card h3 {
  color: var(--primary);
  margin-bottom: 1rem;
  font-size: 1.3rem;
}
.model-card p {
  color: var(--dark);
  font-size: 0.95rem;
}
.specs-highlight {
  background: var(--light);
  border-left: 4px solid var(--primary);
  padding: 1.5rem;
  border-radius: 4px;
  margin: 1.5rem 0;
}
.specs-highlight h3 {
  color: var(--primary);
  margin-bottom: 1rem;
}
.specs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  margin: 1.5rem 0;
}
.spec-item {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.spec-icon {
  width: 50px;
  height: 50px;
  background: var(--light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-size: 1.5rem;
}
.spec-content h4 {
  margin-bottom: 0.5rem;
  color: var(--dark);
}
.upgrade-reasons {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}
.reason-card {
  background: var(--light);
  padding: 1.5rem;
  border-radius: var(--border-radius);
  border-left: 4px solid var(--secondary);
}
.reason-card h4 {
  color: var(--secondary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.footer {
  background: var(--dark);
  color: white;
  padding: 3rem 0;
  margin-top: 3rem;
}
.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}
.footer-section h3 {
  margin-bottom: 1.5rem;
  font-size: 1.3rem;
}
.footer-links {
  list-style: none;
}
.footer-links li {
  margin-bottom: 0.8rem;
}
.footer-links a {
  color: var(--gray);
  text-decoration: none;
  transition: color 0.3s ease;
}
.footer-links a:hover {
  color: white;
}
.social-links {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
}
.social-links a {
  color: white;
  background: rgba(255, 255, 255, 0.1);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.3s ease;
}
.social-links a:hover {
  background: var(--primary);
}
.copyright {
  text-align: center;
  padding-top: 2rem;
  margin-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--gray);
  font-size: 0.9rem;
}
@media (max-width: 768px) {
  .nav-container {
    flex-direction: column;
    gap: 1rem;
  }
  .nav-links {
    gap: 1.5rem;
  }
  .intro h1 {
    font-size: 2rem;
  }
  .content-section h2 {
    font-size: 1.5rem;
  }
  .models-grid,
  .specs-grid,
  .upgrade-reasons {
    grid-template-columns: 1fr;
  }
}