:root {
  --primary: #0F3C61;
  --secondary: #1A73E8;
  --accent: #ECEFF1;
  --text: #333;
  --light: rgba(255,255,255,0.8);
}

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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  background-attachment: fixed;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

.header {
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
}

.header::after {
  content: "";
  display: block;
  width: 100px;
  height: 4px;
  background: var(--secondary);
  margin: 1.5rem auto;
  border-radius: 2px;
}

h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--accent);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }

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

.notice {
  background: rgba(255,255,255,0.1);
  padding: 1rem;
  border-left: 4px solid var(--secondary);
  margin-bottom: 2rem;
  font-size: 0.9rem;
  color: var(--accent);
}

.card {
  background: rgba(255,255,255,0.1);
  backdrop-filter: blur(10px);
  border-radius: 12px;
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
  transition: transform 0.3s ease;
}

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

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.img-container {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
  margin: 1rem 0;
}

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

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

pre {
  background: rgba(0,0,0,0.2);
  border-radius: 8px;
  padding: 1.5rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  color: #f8f8f2;
  position: relative;
}

code {
  font-family: 'Courier New', monospace;
  background: rgba(0,0,0,0.2);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-size: 0.9rem;
}

ol, ul {
  margin-left: 2rem;
  margin-bottom: 1.5rem;
}

li {
  margin-bottom: 0.5rem;
}

.nav {
  display: flex;
  justify-content: center;
  margin: 2rem 0;
  flex-wrap: wrap;
}

.nav a {
  color: var(--accent);
  text-decoration: none;
  margin: 0 1rem;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  transition: all 0.3s ease;
  font-weight: 500;
}

.nav a:hover {
  background: rgba(255,255,255,0.1);
}

.footer {
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
  color: var(--accent);
  font-size: 0.9rem;
}

.fade-in {
  opacity: 0;
  animation: fadeIn 1s forwards;
}

@keyframes fadeIn {
  to { opacity: 1; }
}

@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  h3 { font-size: 1.5rem; }
  
  .grid {
    grid-template-columns: 1fr;
  }
  
  .nav {
    flex-direction: column;
    align-items: center;
  }
  
  .nav a {
    margin: 0.5rem 0;
  }
}

.particles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  opacity: 0.1;
  background: url('https://images.gptkong.com/demo/sample1.png');
  animation: moveParticles 20s linear infinite;
}

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

.button {
  display: inline-block;
  background: var(--secondary);
  color: white;
  padding: 0.8rem 1.5rem;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  margin: 1rem 0;
  border: none;
  cursor: pointer;
}

.button:hover {
  background: var(--primary);
  transform: scale(1.05);
  box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.highlight {
  position: relative;
}

.highlight::before {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 30%;
  background: rgba(26, 115, 232, 0.2);
  z-index: -1;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 0.3s ease;
}

.highlight:hover::before {
  transform: scaleX(1);
  transform-origin: left;
}

.tooltip {
  position: relative;
  display: inline-block;
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 200px;
  background-color: var(--primary);
  color: #fff;
  text-align: center;
  border-radius: 6px;
  padding: 5px;
  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;
}