:root {
  --primary-blue: #1A237E;
  --primary-violet: #673AB7;
  --electric-blue: #03A9F4;
  --coral-orange: #FF5722;
  --neutral-gray: #757575;
  --white: #FFFFFF;
  --black: #000000;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: var(--black);
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  padding: 0;
  margin: 0;
}

.header {
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-violet) 100%);
  color: var(--white);
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow);
}

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

.header-content {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.header p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto 2rem;
}

.notice {
  background-color: var(--electric-blue);
  color: var(--white);
  padding: 0.5rem;
  border-radius: 4px;
  display: inline-block;
  font-size: 0.9rem;
  margin-top: 1rem;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

.main-container {
  max-width: 1200px;
  margin: 3rem auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
}

.article-container {
  background-color: var(--white);
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 3rem;
  position: relative;
  overflow: hidden;
}

.article-container::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 200px;
  height: 200px;
  background: linear-gradient(45deg, var(--electric-blue), var(--coral-orange));
  clip-path: circle(50% at 100% 0);
  z-index: 0;
  opacity: 0.1;
}

.article-content {
  position: relative;
  z-index: 1;
}

article h2 {
  color: var(--primary-blue);
  font-size: 1.8rem;
  margin: 2rem 0 1.5rem;
  position: relative;
  padding-bottom: 0.5rem;
}

article h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--electric-blue), var(--coral-orange));
}

article h3 {
  color: var(--primary-violet);
  font-size: 1.4rem;
  margin: 1.5rem 0 1rem;
}

article p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
  line-height: 1.7;
}

article strong {
  color: var(--electric-blue);
}

pre {
  background: linear-gradient(135deg, #2c3e50 0%, #1a1a2e 100%);
  color: #f8f8f2;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  position: relative;
}

pre::before {
  content: "CSS";
  position: absolute;
  top: 0;
  left: 0;
  background: var(--coral-orange);
  color: var(--white);
  padding: 0.2rem 0.8rem;
  border-radius: 0 0 4px 0;
  font-size: 0.8rem;
  font-weight: bold;
}

code {
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  box-shadow: 0 2px 3px rgba(0, 0, 0, 0.1);
}

table th {
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-violet) 100%);
  color: var(--white);
  padding: 0.8rem;
  text-align: left;
}

table td {
  padding: 0.8rem;
  border-bottom: 1px solid #eee;
}

table tr:nth-child(even) {
  background-color: #f9f9f9;
}

.image-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.gallery-item {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.gallery-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.gallery-item img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.3s ease;
}

.gallery-item:hover img {
  transform: scale(1.05);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 2rem 0;
}

.nav-link {
  background: linear-gradient(135deg, var(--electric-blue) 0%, var(--coral-orange) 100%);
  color: var(--white);
  padding: 0.8rem 1.5rem;
  border-radius: 30px;
  text-decoration: none;
  font-weight: bold;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.nav-link:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.footer {
  background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-violet) 100%);
  color: var(--white);
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .header p {
    font-size: 1rem;
  }
  
  .article-container {
    padding: 2rem 1.5rem;
  }
  
  article h2 {
    font-size: 1.6rem;
  }
  
  article h3 {
    font-size: 1.3rem;
  }
  
  .image-gallery {
    grid-template-columns: 1fr;
  }
}

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

.content-block {
  animation: fadeIn 0.8s ease-out forwards;
}

.content-block:nth-child(1) { animation-delay: 0.1s; }
.content-block:nth-child(2) { animation-delay: 0.2s; }
.content-block:nth-child(3) { animation-delay: 0.3s; }
.content-block:nth-child(4) { animation-delay: 0.4s; }
.content-block:nth-child(5) { animation-delay: 0.5s; }
.content-block:nth-child(6) { animation-delay: 0.6s; }
.content-block:nth-child(7) { animation-delay: 0.7s; }
.content-block:nth-child(8) { animation-delay: 0.8s; }