:root {
  --primary-green: #81C784;
  --primary-brown: #A1887F;
  --primary-beige: #FFF3E0;
  --primary-dark-gray: #616161;
  --primary-blue: #2196F3;
  --accent-gold: #FFD700;
}

body {
  background: linear-gradient(135deg, var(--primary-beige), white);
  color: var(--primary-dark-gray);
  font-family: 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
}

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

.header {
  background: linear-gradient(45deg, var(--primary-green), var(--primary-blue));
  padding: 60px 0;
  text-align: center;
  border-radius: 0 0 20px 20px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
  margin-bottom: 40px;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('https://images.gptkong.com/demo/sample3.png') center/cover no-repeat;
  opacity: 0.15;
  z-index: 0;
}

.header h1 {
  color: white;
  font-size: 3rem;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
  position: relative;
  z-index: 1;
}

.design-notice {
  background: white;
  color: var(--primary-dark-gray);
  padding: 15px;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  margin: 20px auto;
  max-width: 600px;
  text-align: center;
  font-weight: bold;
}

article {
  background: white;
  border-radius: 12px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  padding: 40px;
  margin-bottom: 40px;
}

h2 {
  color: var(--primary-green);
  font-size: 2rem;
  margin-top: 40px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--primary-brown);
}

h3 {
  color: var(--primary-blue);
  font-size: 1.5rem;
  margin-top: 30px;
}

p {
  font-size: 1.1rem;
  margin: 20px 0;
}

pre {
  background: #f8f8f8;
  border-left: 4px solid var(--primary-blue);
  border-radius: 4px;
  padding: 15px;
  overflow-x: auto;
  margin: 20px 0;
}

code {
  font-family: 'Courier New', monospace;
  color: var(--primary-dark-gray);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  box-shadow: 0 2px 3px rgba(0,0,0,0.1);
}

th, td {
  padding: 12px 15px;
  text-align: left;
  border-bottom: 1px solid #ddd;
}

th {
  background-color: var(--primary-green);
  color: white;
}

tr:nth-child(even) {
  background-color: #f2f2f2;
}

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

.image-card {
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 16px rgba(0,0,0,0.15);
}

.image-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.image-card:hover img {
  transform: scale(1.05);
}

.nav-tabs {
  display: flex;
  flex-wrap: wrap;
  margin: 30px 0;
  padding: 0;
  list-style: none;
  border-bottom: 1px solid #ddd;
}

.nav-tabs li {
  margin-right: 10px;
}

.nav-tabs a {
  display: block;
  padding: 10px 20px;
  background: #f5f5f5;
  color: var(--primary-dark-gray);
  text-decoration: none;
  border-radius: 5px 5px 0 0;
  transition: all 0.3s ease;
}

.nav-tabs a:hover {
  background: var(--primary-green);
  color: white;
}

.nav-tabs a.active {
  background: var(--primary-blue);
  color: white;
}

.tab-content {
  display: none;
  padding: 20px;
  background: white;
  border-radius: 0 0 5px 5px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.tab-content.active {
  display: block;
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  article {
    padding: 20px;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

@keyframes float {
  0% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
  100% { transform: translateY(0px); }
}

.floating {
  animation: float 3s ease-in-out infinite;
}

.highlight-box {
  background: linear-gradient(135deg, rgba(129, 199, 132, 0.1), rgba(33, 150, 243, 0.1));
  border-left: 4px solid var(--primary-green);
  padding: 20px;
  margin: 30px 0;
  border-radius: 0 8px 8px 0;
}

.highlight-box h3 {
  color: var(--primary-green);
  margin-top: 0;
}

.accordion {
  margin: 30px 0;
}

.accordion-item {
  margin-bottom: 10px;
  border-radius: 5px;
  overflow: hidden;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.accordion-header {
  background: var(--primary-green);
  color: white;
  padding: 15px 20px;
  cursor: pointer;
  font-weight: bold;
  transition: background 0.3s ease;
}

.accordion-header:hover {
  background: var(--primary-blue);
}

.accordion-content {
  background: white;
  padding: 0;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.accordion-content.active {
  padding: 20px;
  max-height: 1000px;
}