:root {
  --primary: #0d1b2a;
  --secondary: #1b263b;
  --accent: #00c6ff;
  --highlight: #0072ff;
  --text: #e0e1dd;
  --font-main: 'Roboto', sans-serif;
  --font-heading: 'Futura', sans-serif;
  --shadow: 0 10px 30px rgba(0,0,0,0.3);
  --transition: all 0.3s ease;
}

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

body {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: var(--text);
  font-family: var(--font-main);
  line-height: 1.6;
  margin: 0;
  padding: 0;
  min-height: 100%;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}

header {
  text-align: center;
  padding: 60px 0;
  position: relative;
  overflow: hidden;
}

.header-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample1.png') center/cover;
  opacity: 0.2;
  z-index: -1;
  border-radius: 0 0 40px 40px;
}

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  color: white;
  margin-top: 0;
}

h1 {
  font-size: 3rem;
  background: linear-gradient(45deg, var(--accent), var(--highlight));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 20px;
}

h2 {
  font-size: 2.2rem;
  margin-bottom: 30px;
  position: relative;
  display: inline-block;
}

h2::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), transparent);
}

h3 {
  font-size: 1.8rem;
  margin: 40px 0 20px;
}

p {
  font-size: 1.1rem;
  margin-bottom: 25px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
  gap: 40px;
  margin: 60px 0;
}

.card {
  background: rgba(29, 53, 87, 0.5);
  border-radius: 20px;
  padding: 30px;
  box-shadow: var(--shadow);
  transition: var(--transition);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.1);
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.4);
}

.img-container {
  display: flex;
  justify-content: center;
  margin: 30px 0;
  flex-wrap: wrap;
  gap: 20px;
}

.img-container img {
  width: 320px;
  height: 320px;
  object-fit: cover;
  border-radius: 15px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
  transition: var(--transition);
}

.img-container img:hover {
  transform: scale(1.05);
  box-shadow: 0 10px 25px rgba(0,198,255,0.4);
}

pre {
  background: rgba(13, 27, 42, 0.8);
  border-radius: 10px;
  padding: 20px;
  overflow-x: auto;
  font-family: monospace;
  font-size: 0.9rem;
  line-height: 1.5;
  margin: 30px 0;
  border-left: 4px solid var(--accent);
  box-shadow: inset 0 0 10px rgba(0,0,0,0.5);
}

code {
  color: var(--accent);
}

.notice {
  background: rgba(0,198,255,0.1);
  border-left: 4px solid var(--accent);
  padding: 20px;
  margin: 40px 0;
  border-radius: 0 10px 10px 0;
}

.notice p {
  margin: 0;
  font-weight: bold;
}

@media (max-width: 768px) {
  .grid {
    grid-template-columns: 1fr;
  }
  
  h1 {
    font-size: 2.2rem;
  }
  
  h2 {
    font-size: 1.8rem;
  }
  
  .img-container img {
    width: 100%;
    height: auto;
  }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-20px); }
}

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

.decorative {
  position: absolute;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, rgba(0,198,255,0.2), transparent 70%);
  border-radius: 50%;
  z-index: -1;
}

.decorative:nth-child(1) {
  top: 10%;
  left: 5%;
  animation: float 8s ease-in-out infinite;
}

.decorative:nth-child(2) {
  bottom: 15%;
  right: 5%;
  animation: float 7s ease-in-out infinite 2s;
}