:root {
  --primary-color: #1E3A8A;
  --background-color: #E0E7FF;
  --accent-color: #F97316;
  --text-color: #1E1E2E;
  --light-gray: #F8FAFC;
  --medium-gray: #E2E8F0;
  --dark-gray: #64748B;
  --success-color: #10B981;
  --warning-color: #F59E0B;
  --danger-color: #EF4444;
}

@font-face {
  font-family: 'Roboto';
  src: url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700&display=swap');
}

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

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

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

.header {
  background: linear-gradient(135deg, var(--primary-color) 0%, #0F172A 100%);
  color: white;
  padding: 2rem 0;
  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-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 2rem;
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  font-weight: 700;
  background: linear-gradient(to right, white, #E0E7FF);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header p {
  font-size: 1.2rem;
  max-width: 800px;
  margin-bottom: 2rem;
  color: rgba(255,255,255,0.9);
}

.notice {
  background-color: rgba(255,255,255,0.2);
  padding: 1rem;
  border-radius: 8px;
  margin-top: 2rem;
  font-size: 0.9rem;
  backdrop-filter: blur(5px);
}

.main-content {
  padding: 3rem 0;
}

.grid-layout {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 2rem;
}

.article-container {
  grid-column: span 8;
}

.sidebar {
  grid-column: span 4;
}

article {
  background-color: white;
  padding: 2.5rem;
  border-radius: 12px;
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  margin-bottom: 2rem;
}

article h2 {
  font-size: 1.8rem;
  color: var(--primary-color);
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--medium-gray);
}

article h3 {
  font-size: 1.5rem;
  color: var(--primary-color);
  margin: 2rem 0 1rem;
}

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

article pre {
  background-color: #1E1E2E;
  color: #E0E7FF;
  padding: 1.5rem;
  border-radius: 8px;
  overflow: auto;
  margin: 1.5rem 0;
  font-family: 'Roboto Mono', monospace;
  font-size: 0.9rem;
  line-height: 1.5;
}

article code {
  font-family: 'Roboto Mono', monospace;
  background-color: rgba(30, 58, 138, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9rem;
}

.sidebar-card {
  background-color: white;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  margin-bottom: 2rem;
}

.sidebar-card h3 {
  color: var(--primary-color);
  margin-bottom: 1rem;
  font-size: 1.3rem;
}

.sidebar-card ul {
  list-style: none;
}

.sidebar-card li {
  margin-bottom: 0.8rem;
}

.sidebar-card a {
  color: var(--text-color);
  text-decoration: none;
  transition: color 0.3s ease;
  display: block;
  padding: 0.5rem 0;
}

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

.image-gallery {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}

.gallery-image {
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.gallery-image:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
}

.gallery-image img {
  width: 100%;
  height: auto;
  display: block;
}

.button {
  display: inline-block;
  background: linear-gradient(to right, var(--accent-color), #EA580C);
  color: white;
  padding: 0.8rem 1.5rem;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 500;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  box-shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
}

.button:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
}

.footer {
  background-color: var(--primary-color);
  color: white;
  padding: 3rem 0;
  text-align: center;
}

.footer p {
  margin-bottom: 1rem;
  opacity: 0.8;
}

@media (max-width: 1024px) {
  .grid-layout {
    grid-template-columns: 1fr;
  }
  
  .article-container, .sidebar {
    grid-column: span 1;
  }
}

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

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

.animated {
  animation: fadeIn 0.6s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

.highlight {
  background: linear-gradient(120deg, rgba(249,115,22,0.3) 0%, rgba(249,115,22,0) 100%);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
}

.tooltip {
  position: relative;
  display: inline-block;
  border-bottom: 1px dotted var(--dark-gray);
  cursor: help;
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 200px;
  background-color: var(--text-color);
  color: white;
  text-align: center;
  border-radius: 6px;
  padding: 0.5rem;
  position: absolute;
  z-index: 1;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  opacity: 0;
  transition: opacity 0.3s;
  font-size: 0.9rem;
}

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

.collapsible {
  background-color: white;
  color: var(--text-color);
  cursor: pointer;
  padding: 1rem;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 1.1rem;
  margin: 0.5rem 0;
  border-radius: 6px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  transition: background-color 0.3s ease;
}

.collapsible:hover {
  background-color: var(--light-gray);
}

.collapsible:after {
  content: '+';
  float: right;
  margin-left: 0.5rem;
}

.active:after {
  content: '-';
}

.content {
  padding: 0 1rem;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out;
  background-color: white;
  border-radius: 0 0 6px 6px;
  margin-bottom: 1rem;
}

.content-inner {
  padding: 1rem 0;
}