:root {
  --primary-color: #0f2027;
  --secondary-color: #203a43;
  --accent-color: #ff7e5f;
  --text-color: #333;
  --light-bg: #f8f9fa;
  --dark-bg: #121212;
  --card-shadow: 0 10px 30px rgba(0,0,0,0.1);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.8;
  color: var(--text-color);
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
  margin: 0;
  padding: 0;
  overflow-x: hidden;
}

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

.header {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: white;
  padding: 2rem 0;
  position: relative;
  overflow: hidden;
  box-shadow: var(--card-shadow);
}

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

.header-content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 2rem;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background: rgba(15, 32, 39, 0.9);
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
  padding: 0.5rem 0;
}

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

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

.main-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  padding: 2rem 0;
}

@media (min-width: 992px) {
  .main-content {
    grid-template-columns: 2fr 1fr;
  }
}

.article-container {
  background: white;
  border-radius: 12px;
  padding: 2rem;
  box-shadow: var(--card-shadow);
  transition: var(--transition);
}

.article-container:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.15);
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.sidebar-card {
  background: white;
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--card-shadow);
  transition: var(--transition);
}

.sidebar-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.15);
}

.visual-element {
  width: 100%;
  height: 200px;
  border-radius: 8px;
  object-fit: cover;
  margin: 1rem 0;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  transition: var(--transition);
}

.visual-element:hover {
  transform: scale(1.02);
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

h1, h2, h3, h4 {
  color: var(--primary-color);
  margin-top: 0;
  line-height: 1.3;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

h2 {
  font-size: 1.8rem;
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent-color);
}

h3 {
  font-size: 1.5rem;
  margin: 1.5rem 0 1rem;
  color: var(--secondary-color);
}

p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
}

pre {
  background: #2d2d2d;
  color: #f8f8f2;
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
  box-shadow: inset 0 0 10px rgba(0,0,0,0.5);
}

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

.notice {
  background: rgba(255, 126, 95, 0.1);
  border-left: 4px solid var(--accent-color);
  padding: 1rem;
  margin: 2rem 0;
  border-radius: 0 8px 8px 0;
}

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

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

.grid-item {
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: var(--transition);
}

.grid-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.15);
}

.grid-item img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.grid-content {
  padding: 1.5rem;
}

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

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

@media (max-width: 768px) {
  .navbar {
    flex-direction: column;
    padding: 1rem;
  }
  
  .nav-links {
    flex-direction: column;
    gap: 1rem;
    margin-top: 1rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
}