:root {
  --primary: #0F2045;
  --secondary: #7A3CA9;
  --accent: #3DDC84;
  --light: #ffffff;
  --dark: #1a1a1a;
  --gray: #f5f5f5;
}

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

@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@700&family=Roboto:wght@400;500&display=swap');

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

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

/* Header Styles */
.header {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: var(--light);
  padding: 40px 0;
  text-align: center;
  margin-bottom: 60px;
  position: relative;
  overflow: hidden;
}

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

.header h1 {
  font-family: 'Poppins', sans-serif;
  font-size: 2.8rem;
  margin-bottom: 20px;
  position: relative;
  z-index: 1;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.header p {
  max-width: 700px;
  margin: 0 auto;
  font-size: 1.1rem;
  position: relative;
  z-index: 1;
}

.notice {
  background-color: var(--accent);
  color: var(--light);
  padding: 15px;
  text-align: center;
  font-weight: 500;
  margin-bottom: 40px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

/* Navigation */
.nav-container {
  background-color: var(--primary);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.nav {
  display: flex;
  justify-content: center;
  padding: 15px 0;
}

.nav a {
  color: var(--light);
  text-decoration: none;
  margin: 0 20px;
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

.nav a:hover {
  color: var(--accent);
}

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

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

/* Main Content */
.main-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 60px;
  margin-bottom: 80px;
}

.article {
  background-color: var(--light);
  border-radius: 10px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  padding: 40px;
  position: relative;
  overflow: hidden;
}

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

.article h2 {
  font-family: 'Poppins', sans-serif;
  font-size: 1.8rem;
  color: var(--primary);
  margin-bottom: 20px;
  position: relative;
}

.article h2::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 50px;
  height: 3px;
  background-color: var(--accent);
}

.article h3 {
  font-family: 'Poppins', sans-serif;
  font-size: 1.4rem;
  color: var(--secondary);
  margin: 30px 0 15px;
}

.article p {
  margin-bottom: 20px;
  font-size: 1.05rem;
}

.article span {
  color: var(--secondary);
  font-weight: 500;
}

/* Code Blocks */
pre {
  background-color: #2d2d2d;
  border-radius: 8px;
  padding: 20px;
  margin: 25px 0;
  overflow: auto;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

code {
  font-family: 'Courier New', monospace;
  color: #f8f8f2;
  font-size: 0.9rem;
}

.language-css {
  color: #66d9ef;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 25px 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);
  color: var(--light);
  font-weight: 500;
}

tr:nth-child(even) {
  background-color: var(--gray);
}

tr:hover {
  background-color: rgba(61, 220, 132, 0.1);
}

/* Image Gallery */
.image-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin: 40px 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;
  position: relative;
}

.gallery-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.gallery-item img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.5s ease;
}

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

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

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

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

.footer-links a {
  color: var(--light);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-links a:hover {
  color: var(--accent);
}

/* Responsive Design */
@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .nav {
    flex-wrap: wrap;
    gap: 15px;
  }
  
  .article {
    padding: 30px 20px;
  }
  
  .image-gallery {
    grid-template-columns: 1fr;
  }
}

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

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

/* Button Styles */
.button {
  display: inline-block;
  background-color: var(--accent);
  color: var(--light);
  padding: 12px 25px;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  border: none;
  cursor: pointer;
}

.button:hover {
  background-color: #2eb77d;
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

/* Highlight Box */
.highlight-box {
  background: linear-gradient(135deg, rgba(15, 32, 69, 0.1), rgba(122, 60, 169, 0.1));
  border-left: 4px solid var(--accent);
  padding: 20px;
  margin: 30px 0;
  border-radius: 0 8px 8px 0;
}

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

.tooltip .tooltiptext {
  visibility: hidden;
  width: 200px;
  background-color: var(--dark);
  color: var(--light);
  text-align: center;
  border-radius: 6px;
  padding: 10px;
  position: absolute;
  z-index: 1;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  opacity: 0;
  transition: opacity 0.3s;
}

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