:root {
  --primary: #0A2342;
  --secondary: #1E90FF;
  --accent: #8A2BE2;
  --highlight: #FF7F50;
  --light: #F8F9FA;
  --dark: #212529;
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

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

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

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(10, 35, 66, 0.9);
  backdrop-filter: blur(10px);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  padding: 15px 0;
  transition: var(--transition);
}

.header.scrolled {
  padding: 10px 0;
}

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

.logo {
  color: white;
  font-size: 1.5rem;
  font-weight: 700;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 30px;
}

.nav-link {
  color: white;
  text-decoration: none;
  font-weight: 500;
  position: relative;
  padding: 5px 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--highlight);
  transition: var(--transition);
}

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

.hero {
  height: 600px;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  margin-top: 70px;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  opacity: 0.8;
  z-index: -1;
}

.hero-content {
  max-width: 600px;
  color: white;
}

.hero-title {
  font-size: 3rem;
  margin-bottom: 20px;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.2rem;
  margin-bottom: 30px;
  opacity: 0.9;
}

.notice {
  background: rgba(255, 255, 255, 0.2);
  padding: 15px;
  border-radius: 8px;
  margin: 30px 0;
  text-align: center;
  font-weight: 500;
}

.main {
  padding: 80px 0;
}

.section {
  margin-bottom: 80px;
  position: relative;
}

.section-title {
  font-size: 2.2rem;
  color: var(--primary);
  margin-bottom: 40px;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 60px;
  height: 4px;
  background: var(--highlight);
  border-radius: 2px;
}

.article {
  background: white;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
  padding: 40px;
  margin-bottom: 60px;
}

.article h2 {
  font-size: 2rem;
  color: var(--primary);
  margin-bottom: 20px;
}

.article h3 {
  font-size: 1.5rem;
  color: var(--primary);
  margin: 30px 0 15px;
}

.article p {
  margin-bottom: 20px;
  font-size: 1.1rem;
}

.code-block {
  background: #282c34;
  color: #abb2bf;
  padding: 20px;
  border-radius: 8px;
  margin: 25px 0;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
  line-height: 1.5;
}

.code-block code {
  display: block;
  white-space: pre;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.image-card {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  transition: var(--transition);
  position: relative;
}

.image-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
}

.image-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.footer {
  background: var(--primary);
  color: white;
  padding: 50px 0 20px;
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 30px;
  margin-bottom: 30px;
}

.footer-link {
  color: white;
  text-decoration: none;
  transition: var(--transition);
}

.footer-link:hover {
  color: var(--highlight);
}

.copyright {
  opacity: 0.7;
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .hero-title {
    font-size: 2.2rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
  
  .article {
    padding: 25px;
  }
  
  .section-title {
    font-size: 1.8rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn 1s ease-out forwards;
}

.delay-1 {
  animation-delay: 0.2s;
}

.delay-2 {
  animation-delay: 0.4s;
}

.delay-3 {
  animation-delay: 0.6s;
}

/* Parallax effect */
.parallax {
  background-attachment: fixed;
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

/* Button styles */
.button {
  display: inline-block;
  background: var(--highlight);
  color: white;
  padding: 12px 30px;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(255, 127, 80, 0.3);
}

.button:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(255, 127, 80, 0.4);
}

/* Color classes */
.primary-color {
  color: var(--primary);
}

.secondary-color {
  color: var(--secondary);
}

.accent-color {
  color: var(--accent);
}

.highlight-color {
  color: var(--highlight);
}

/* Tooltip */
.tooltip {
  position: relative;
  display: inline-block;
  border-bottom: 1px dotted var(--primary);
  cursor: help;
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 200px;
  background-color: var(--primary);
  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;
}

/* Accordion */
.accordion {
  background-color: #f8f9fa;
  color: var(--dark);
  cursor: pointer;
  padding: 18px;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 1rem;
  transition: 0.4s;
  border-radius: 8px;
  margin-bottom: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.active, .accordion:hover {
  background-color: #e9ecef;
}

.accordion::after {
  content: '+';
  font-size: 1.2rem;
  color: var(--primary);
}

.active::after {
  content: '-';
}

.panel {
  padding: 0 18px;
  background-color: white;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.2s ease-out;
  margin-bottom: 20px;
  border-radius: 0 0 8px 8px;
}

/* Floating elements */
.floating {
  animation: floating 3s ease-in-out infinite;
}

@keyframes floating {
  0% { transform: translateY(0px); }
  50% { transform: translateY(-15px); }
  100% { transform: translateY(0px); }
}