:root {
  --primary: linear-gradient(135deg, #0D47A1, #8E24AA);
  --secondary: rgba(13, 71, 161, 0.8);
  --accent: linear-gradient(45deg, #FFC107, #FF5722);
  --text: #FFFFFF;
  --card-bg: #FFFFFF;
  --shadow: 0 4px 6px rgba(0,0,0,0.1);
}

body {
  background: var(--primary);
  font-family: 'Roboto', sans-serif;
  color: var(--text);
  margin: 0;
  padding: 0;
  min-height: 100%;
  display: flex;
  flex-direction: column;
}

.header {
  text-align: center;
  padding: 40px 20px;
  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') center/cover no-repeat;
  opacity: 0.2;
  z-index: -1;
}

.navbar {
  position: sticky;
  top: 0;
  width: 100%;
  background: var(--secondary);
  display: flex;
  justify-content: center;
  padding: 20px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.3);
  z-index: 100;
}

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

.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  padding: 10px 15px;
  border-radius: 25px;
  transition: all 0.3s ease;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--text);
  transition: width 0.3s ease;
}

.nav-links a:hover::after {
  width: 70%;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
  gap: 40px;
}

.article {
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(10px);
  border-radius: 20px;
  padding: 30px;
  box-shadow: var(--shadow);
  transition: transform 0.3s ease;
}

.article:hover {
  transform: translateY(-5px);
}

h1, h2, h3, h4 {
  font-weight: 700;
  margin-top: 0;
  position: relative;
}

h1 {
  font-size: 2.5rem;
  background: linear-gradient(90deg, #FFFFFF, #FFC107);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 20px;
}

h2 {
  font-size: 1.8rem;
  margin-bottom: 20px;
  padding-bottom: 10px;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100px;
  height: 3px;
  background: var(--accent);
}

h3 {
  font-size: 1.5rem;
  margin-bottom: 15px;
}

p {
  font-size: 1.1rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

mark {
  background: rgba(255, 193, 7, 0.3);
  padding: 2px 5px;
  border-radius: 3px;
}

.code-container {
  background: rgba(0,0,0,0.3);
  border-radius: 10px;
  padding: 20px;
  margin: 20px 0;
  overflow-x: auto;
}

pre {
  margin: 0;
}

code {
  font-family: 'Courier New', monospace;
  color: #FFC107;
}

.card {
  background: var(--card-bg);
  border-radius: 15px;
  padding: 20px;
  margin: 20px 0;
  box-shadow: var(--shadow);
  color: #333;
  transition: all 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 15px rgba(0,0,0,0.2);
}

.button {
  display: inline-block;
  background: var(--accent);
  color: white;
  padding: 12px 25px;
  border-radius: 25px;
  text-decoration: none;
  font-weight: 500;
  margin: 10px 0;
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.button:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 12px rgba(0,0,0,0.2);
}

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.gallery img {
  width: 100%;
  height: auto;
  border-radius: 10px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  transition: all 0.3s ease;
}

.gallery img:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 15px rgba(0,0,0,0.3);
}

.notice {
  background: rgba(255,255,255,0.2);
  border-left: 4px solid #FFC107;
  padding: 15px;
  margin: 20px 0;
  border-radius: 0 5px 5px 0;
}

.footer {
  text-align: center;
  padding: 30px;
  background: rgba(0,0,0,0.2);
  margin-top: 50px;
}

@media (max-width: 768px) {
  .container {
    grid-template-columns: 1fr;
    padding: 20px;
  }
  
  .nav-links {
    flex-direction: column;
    gap: 10px;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
}

@keyframes float {
  0% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(180deg); }
  100% { transform: translateY(0) rotate(360deg); }
}

.floating {
  animation: float 6s infinite ease-in-out;
}

.floating:nth-child(1) { animation-delay: 0s; }
.floating:nth-child(2) { animation-delay: 2s; }
.floating:nth-child(3) { animation-delay: 4s; }