:root {
  --forest-green: #347C17;
  --earth-brown: #964B00;
  --modern-gray: #D3D3D3;
  --electric-blue: #0074D9;
  --orange: #FFA500;
  --white: #FFFFFF;
  --dark-gray: #333333;
  --light-gray: #F5F5F5;
}

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

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

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

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: linear-gradient(135deg, var(--forest-green), var(--earth-brown));
  padding: 15px 0;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  z-index: 1000;
  display: flex;
  justify-content: center;
}

.navbar-inner {
  width: 100%;
  max-width: 1200px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
}

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

.nav-links a {
  color: var(--white);
  text-decoration: none;
  font-weight: 500;
  font-size: 16px;
  transition: all 0.3s ease;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--orange);
  transition: width 0.3s ease;
}

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

.hero {
  padding: 150px 0 80px;
  background: linear-gradient(135deg, rgba(52,124,23,0.1), rgba(150,75,0,0.1));
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center/cover;
  opacity: 0.1;
  z-index: -1;
}

.hero h1 {
  font-size: 48px;
  color: var(--forest-green);
  margin-bottom: 20px;
  font-weight: 700;
}

.hero p {
  font-size: 20px;
  color: var(--earth-brown);
  max-width: 800px;
  margin: 0 auto 40px;
}

.notice {
  background-color: var(--electric-blue);
  color: var(--white);
  padding: 10px 20px;
  border-radius: 5px;
  display: inline-block;
  margin-bottom: 40px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.content-section {
  padding: 80px 0;
}

.content-section:nth-child(even) {
  background-color: var(--white);
}

.content-section:nth-child(odd) {
  background-color: var(--light-gray);
}

.article-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 20px;
}

article h2 {
  font-size: 32px;
  color: var(--forest-green);
  margin-bottom: 30px;
  position: relative;
  padding-bottom: 15px;
}

article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100px;
  height: 3px;
  background: linear-gradient(90deg, var(--electric-blue), var(--orange));
}

article p {
  font-size: 17px;
  margin-bottom: 25px;
  color: var(--dark-gray);
}

article strong {
  color: var(--earth-brown);
}

pre {
  background-color: #2d2d2d;
  color: #f8f8f2;
  padding: 20px;
  border-radius: 8px;
  margin: 30px 0;
  overflow-x: auto;
  box-shadow: 0 10px 20px rgba(0,0,0,0.2);
  position: relative;
}

pre::before {
  content: 'CSS';
  position: absolute;
  top: 0;
  left: 0;
  background-color: var(--electric-blue);
  color: white;
  padding: 3px 10px;
  border-radius: 0 0 5px 0;
  font-size: 14px;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin: 50px 0;
}

.card {
  background-color: var(--white);
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.15);
}

.card-img {
  height: 200px;
  overflow: hidden;
}

.card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.card:hover .card-img img {
  transform: scale(1.1);
}

.card-content {
  padding: 25px;
}

.card-content h3 {
  font-size: 20px;
  color: var(--forest-green);
  margin-bottom: 15px;
}

.card-content p {
  font-size: 15px;
  color: var(--dark-gray);
  margin-bottom: 20px;
}

.back-to-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--electric-blue), var(--orange));
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 5px 15px rgba(0,0,0,0.2);
  transition: all 0.3s ease;
  opacity: 0;
  visibility: hidden;
}

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

.back-to-top:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.3);
}

.footer {
  background: linear-gradient(135deg, var(--forest-green), var(--earth-brown));
  color: var(--white);
  padding: 50px 0;
  text-align: center;
}

.footer p {
  margin-bottom: 20px;
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 36px;
  }
  
  .hero p {
    font-size: 18px;
  }
  
  article h2 {
    font-size: 28px;
  }
  
  .nav-links {
    gap: 15px;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 28px;
  }
  
  .hero p {
    font-size: 16px;
  }
  
  article h2 {
    font-size: 24px;
  }
  
  .nav-links {
    display: none;
  }
  
  .card-grid {
    grid-template-columns: 1fr;
  }
}