body {
  margin: 0;
  font-family: 'Roboto', sans-serif;
  background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  color: #ffffff;
  overflow-x: hidden;
}
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(0, 0, 0, 0.8);
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 20px;
}
header .logo {
  font-size: 24px;
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 2px;
}
header nav ul {
  list-style: none;
  display: flex;
  gap: 20px;
}
header nav ul li a {
  color: #fff;
  text-decoration: none;
  font-size: 16px;
  transition: color 0.3s ease;
}
header nav ul li a:hover {
  color: #00ffcc;
}
@media (max-width: 768px) {
  header nav ul {
    display: none;
    flex-direction: column;
    background: rgba(0, 0, 0, 0.9);
    position: absolute;
    top: 60px;
    right: 0;
    width: 200px;
    padding: 10px;
  }
  header nav.active ul {
    display: flex;
  }
}
header .menu-toggle {
  display: none;
  font-size: 24px;
  cursor: pointer;
}
@media (max-width: 768px) {
  header .menu-toggle {
    display: block;
  }
}
.container {
  max-width: 1200px;
  margin: 80px auto 20px;
  padding: 0 20px;
}
.hero {
  height: 400px;
  background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center/cover, linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  position: relative;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}
.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
}
.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding-top: 100px;
}
.hero-content h1 {
  font-size: 48px;
  font-weight: bold;
  margin-bottom: 20px;
}
.hero-content p {
  font-size: 18px;
  line-height: 1.6;
  margin-bottom: 30px;
}
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  margin-top: 40px;
}
.feature-card {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  padding: 20px;
  text-align: center;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.feature-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.3);
}
.feature-card img {
  width: 100px;
  height: 100px;
  object-fit: cover;
  border-radius: 50%;
  margin-bottom: 15px;
}
.feature-card h3 {
  font-size: 20px;
  margin-bottom: 10px;
}
.feature-card p {
  font-size: 14px;
  line-height: 1.4;
}
.content-section {
  margin-top: 60px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
}
@media (min-width: 768px) {
  .content-section {
    grid-template-columns: 1fr 1fr;
  }
}
.content-block {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}
.content-block img {
  width: 100%;
  height: auto;
  border-radius: 10px;
  margin-bottom: 20px;
}
.content-block h2 {
  font-size: 24px;
  margin-bottom: 15px;
}
.content-block p {
  font-size: 16px;
  line-height: 1.6;
}
.footer {
  background: #0f2027;
  color: #fff;
  text-align: center;
  padding: 20px;
  margin-top: 60px;
}
.footer p {
  font-size: 14px;
}
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
.fade-in {
  animation: fadeIn 1s ease-in-out;
}