body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: #0f1115;
  color: white;
}
.main-header {
  position: fixed;
  width: 100%;
  top: 0;
  background: #14161a;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 5%;
  z-index: 10;
  box-shadow: 0 2px 10px rgba(0,0,0,0.6);
}
.logo {
  font-size: 1.5rem;
  font-weight: bold;
}
.nav-links a {
  margin-left: 20px;
  text-decoration: none;
  color: #eee;
  font-weight: 500;
}
.nav-links a:hover {
  color: #66ccff;
}
.video-section video {
  width: 100%;
  height: auto;
  display: block;
  margin-top: 70px; /* below header */
}
.hero {
  padding: 100px 5% 120px;
  text-align: center;
}
.hero h1 {
  font-size: 3rem;
}
.hero p {
  font-size: 1.25rem;
  margin-top: 10px;
}
.content-section {
  background: rgba(10,10,10,0.85);
  padding: 100px 10%;
  text-align: center;
}
.content-section.alt {
  background: rgba(25,25,30,0.85);
}
.content-section h2 {
  font-size: 2.5rem;
  margin-bottom: 20px;
}
.content-section p {
  font-size: 1.1rem;
  max-width: 800px;
  margin: 0 auto 20px;
}
.content-section img {
  max-width: 80%;
  border-radius: 8px;
  box-shadow: 0 0 20px rgba(0,0,0,0.8);
  margin-top: 30px;
}
.download-button {
  display: inline-block;
  margin-top: 30px;
  padding: 15px 30px;
  background: #66ccff;
  color: #000;
  font-weight: bold;
  border-radius: 5px;
  text-decoration: none;
  transition: background 0.3s;
}
.download-button:hover {
  background: #4ab8e6;
}