:root {
  --primary-color: #1E90FF;
  --accent-color: #FFA500;
  --success-color: #32CD32;
  --background-color: #F5F5F5;
  --text-color: #333;
  --card-bg: #fff;
  --shadow: 0 4px 20px rgba(0,0,0,0.08);
}

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

@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;700&family=Open+Sans:wght@400;600&display=swap');

body {
  font-family: 'Open Sans', sans-serif;
  background-color: var(--background-color);
  color: var(--text-color);
  line-height: 1.6;
  overflow-x: hidden;
}

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

/* Header & Navigation */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: linear-gradient(135deg, var(--primary-color), #0066CC);
  color: white;
  padding: 15px 0;
  z-index: 1000;
  box-shadow: 0 2px 15px rgba(0,0,0,0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-family: 'Roboto', sans-serif;
  font-weight: 700;
  font-size: 24px;
  margin-left: 30px;
  letter-spacing: 1px;
}

.nav-menu {
  display: flex;
  gap: 25px;
  margin-right: 30px;
}

.nav-menu a {
  color: white;
  text-decoration: none;
  font-weight: 600;
  position: relative;
  padding: 5px 0;
  transition: all 0.3s ease;
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--accent-color);
  transition: width 0.3s ease;
}

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

/* Hero Section */
.hero {
  height: 500px;
  background: linear-gradient(rgba(0,0,0,0.3), rgba(0,0,0,0.3)), 
              url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  margin-top: 70px;
  position: relative;
  overflow: hidden;
}

.hero-content {
  max-width: 800px;
  padding: 30px;
  background-color: rgba(255,255,255,0.9);
  border-radius: 15px;
  box-shadow: var(--shadow);
  transform: translateY(20px);
  opacity: 0;
  animation: fadeInUp 1s forwards 0.5s;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.hero h1 {
  font-size: 42px;
  margin-bottom: 20px;
  color: var(--primary-color);
  font-family: 'Roboto', sans-serif;
}

.hero p {
  font-size: 18px;
  margin-bottom: 30px;
}

/* Main Content */
.main-content {
  padding: 80px 0;
}

.section {
  margin-bottom: 80px;
  background-color: var(--card-bg);
  border-radius: 12px;
  padding: 40px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}

.section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 5px;
  height: 100%;
  background: linear-gradient(to bottom, var(--primary-color), var(--accent-color));
}

.section h2, .section h3 {
  font-family: 'Roboto', sans-serif;
  margin-bottom: 20px;
  color: var(--primary-color);
  position: relative;
  padding-left: 15px;
}

.section h2 {
  font-size: 32px;
}

.section h3 {
  font-size: 24px;
}

.section p {
  margin-bottom: 20px;
  font-size: 16px;
}

/* Code Blocks */
pre {
  background-color: #282c34;
  color: #abb2bf;
  padding: 20px;
  border-radius: 8px;
  margin: 25px 0;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 14px;
  line-height: 1.5;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

code {
  font-family: 'Courier New', monospace;
  background-color: #f0f0f0;
  padding: 2px 5px;
  border-radius: 3px;
  font-size: 14px;
}

/* Image Gallery */
.image-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 25px;
  margin: 40px 0;
}

.gallery-item {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 25px rgba(0,0,0,0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.gallery-item:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0,0,0,0.15);
}

.gallery-item img {
  width: 100%;
  height: 220px;
  object-fit: cover;
  border-radius: 12px 12px 0 0;
}

.gallery-caption {
  padding: 15px;
  background-color: var(--card-bg);
}

/* Footer */
.footer {
  background: linear-gradient(135deg, var(--primary-color), #0066CC);
  color: white;
  padding: 40px 0;
  text-align: center;
}

.footer p {
  margin-bottom: 10px;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
  .header {
    flex-direction: column;
    padding: 15px 0;
  }
  
  .logo {
    margin: 0 0 15px 0;
  }
  
  .nav-menu {
    margin: 0;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .hero h1 {
    font-size: 32px;
  }
  
  .section {
    padding: 30px 20px;
  }
  
  .image-gallery {
    grid-template-columns: 1fr;
  }
}

/* Floating Elements */
.floating {
  position: absolute;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}

/* Tooltip */
.tooltip {
  position: relative;
  display: inline-block;
  border-bottom: 1px dotted #666;
  cursor: help;
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 200px;
  background-color: #333;
  color: #fff;
  text-align: center;
  border-radius: 6px;
  padding: 5px;
  position: absolute;
  z-index: 1;
  bottom: 125%;
  left: 50%;
  margin-left: -100px;
  opacity: 0;
  transition: opacity 0.3s;
}

.tooltip:hover .tooltiptext {
  visibility: visible;
  opacity: 1;
}

/* Notification */
.notification {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background-color: var(--primary-color);
  color: white;
  padding: 15px 25px;
  border-radius: 8px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.2);
  transform: translateX(150%);
  transition: transform 0.4s ease;
  z-index: 1000;
}

.notification.show {
  transform: translateX(0);
}

/* Scroll Indicator */
.scroll-indicator {
  position: fixed;
  top: 0;
  left: 0;
  height: 5px;
  background: linear-gradient(to right, var(--primary-color), var(--accent-color));
  z-index: 1000;
  transition: width 0.1s;
}