body { margin: 0; font-family: 'Open Sans', sans-serif; background: linear-gradient(135deg, #121E3F, #00A2FF); color: white; line-height: 1.6; overflow-x: hidden; }
h1, h2, h3 { font-family: 'Roboto', sans-serif; font-weight: bold; }
.container { max-width: 1400px; margin: auto; padding: 20px; display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
header { position: fixed; top: 0; left: 0; width: 100%; background: rgba(18, 30, 63, 0.9); z-index: 1000; }
nav ul { display: flex; justify-content: space-around; align-items: center; list-style: none; padding: 15px 0; margin: 0; }
nav a { color: white; text-decoration: none; font-size: 18px; transition: color 0.3s ease; }
nav a:hover { color: #4BC5C4; }
.hero { height: calc(100vh - 80px); background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center/cover; position: relative; display: flex; align-items: center; justify-content: center; text-align: center; }
.hero h1 { font-size: 48px; text-shadow: 2px 2px 10px rgba(0, 0, 0, 0.7); }
.card { background: rgba(255, 255, 255, 0.1); border-radius: 10px; padding: 20px; box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2); transition: transform 0.3s ease, box-shadow 0.3s ease; }
.card:hover { transform: translateY(-10px); box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3); }
.button { background-color: #00A2FF; color: white; padding: 15px 30px; border: none; border-radius: 5px; cursor: pointer; transition: all 0.3s ease; }
.button:hover { background-color: #4BC5C4; transform: scale(1.1); }
pre { background: rgba(0, 0, 0, 0.5); padding: 15px; border-radius: 5px; overflow-x: auto; }
@media (max-width: 768px) { nav ul { flex-direction: column; } .hero h1 { font-size: 36px; } .container { grid-template-columns: 1fr; } }
@media (min-width: 1200px) { .container { grid-template-columns: repeat(3, 1fr); } }