/* Reset & base */
*{margin:0;padding:0;box-sizing:border-box;}
html,body{height:100%;font-family:'Orbitron',sans-serif;background:#000;color:#fff;scroll-behavior:smooth;}
a{text-decoration:none;color:inherit;}

/* Header */
header{
  position:fixed;top:0;width:100%;padding:20px 50px;
  display:flex;justify-content:space-between;align-items:center;z-index:1000;
  background:rgba(0,0,0,0.6);
}
header .logo{font-size:32px;color:#ffffff;text-shadow:none;}
header nav a{margin-left:30px;font-weight:700;position:relative;color:#fff;}
header nav a::after{content:"";position:absolute;left:0;bottom:-4px;width:0;height:2px;background:#00ffff;transition:0.3s;}
header nav a:hover::after{width:100%;}
header nav a:hover{color:#00ffff;}

/* Hero */
.hero{
  position:relative;width:100%;height:100vh;display:flex;justify-content:center;align-items:center;overflow:hidden;
}
.hero video{
  position:absolute;
  top:0;
  left:0;
  width:100%;
  height:100%;
  object-fit:cover;
  filter:brightness(0.7);
  z-index:0;
}
.hero::after{
  content:"";position:absolute;inset:0;background:rgba(0,0,0,0);z-index:1;
}
.hero .content{position:relative;z-index:2;text-align:center;display:flex;flex-direction:column;align-items:center;gap:20px;}
.hero .content h1{font-size:72px;color:#fff;text-shadow:none;}
.hero .content p{font-size:20px;margin-bottom:40px;opacity:0.8;text-shadow:none;}

/* Download button */
.btn-download{
  display:flex;align-items:center;gap:10px;padding:20px 50px;
  background:#8000ff;color:#fff;font-weight:700;font-size:22px;border-radius:16px;
  box-shadow:0 4px 10px rgba(0,0,0,0.3);cursor:pointer;transition:0.3s;z-index:2;
}
.btn-download svg{width:28px;height:28px;fill:#fff;}
.btn-download:hover{
  transform:translateY(-2px) scale(1.03);
  box-shadow:0 0 20px #9b59ff,0 0 40px #9b59ff;
}

/* OS Buttons */
@keyframes fadeIn {
  from {opacity:0; transform:translateY(20px);}
  to {opacity:1; transform:translateY(0);}
}
.os-section{
  display:none;
  padding:40px 0;
  justify-content:center;
  gap:20px;
  flex-wrap:wrap;
  opacity:0;
}
.os-section.show{
  display:flex;
  animation:fadeIn 0.6s ease forwards;
}
.os-section a{
  display:flex;align-items:center;gap:10px;
  padding:15px 25px;
  background:#8000ff;color:#fff;font-weight:700;font-size:18px;
  border-radius:12px;transition:0.3s;box-shadow:0 4px 10px rgba(0,0,0,0.3);
}
.os-section a svg{width:20px;height:20px;fill:#fff;}
.os-section a:hover{transform:translateY(-2px) scale(1.05);}
.file-info{text-align:center;opacity:0.7;font-size:14px;margin-top:10px;}

/* Content sections */
section{padding:80px 10% 80px 10%;background:#111;color:#fff;}
section h2{font-size:40px;text-align:center;margin-bottom:20px;}
section p{font-size:18px;line-height:1.6;text-align:center;margin-bottom:20px;}
section ul{list-style:none;margin:20px auto;max-width:800px;padding-left:0;}
section ul li{margin-bottom:10px;font-size:17px;display:flex;align-items:center;gap:10px;justify-content:center;}
section ul li span.icon{font-size:20px;color:#00ffff;}

/* Scroll to top button */
#scrollTopBtn{
  position:fixed;bottom:30px;right:30px;width:50px;height:50px;
  background:#8000ff;color:#fff;font-size:28px;border:none;border-radius:50%;
  cursor:pointer;box-shadow:0 4px 10px rgba(0,0,0,0.5);display:none;align-items:center;justify-content:center;
  z-index:1000;transition:0.3s;
}
#scrollTopBtn:hover{transform:scale(1.1);box-shadow:0 0 20px #9b59ff,0 0 40px #9b59ff;}

/* Footer */
footer{padding:20px;text-align:center;font-size:13px;opacity:0.6;background:#000;}

/* Responsive */
@media(max-width:768px){
  .hero .content h1{font-size:42px;}
  .hero .content p{font-size:16px;}
  header{padding:15px 25px;}
  header nav a{margin-left:15px;}
  .btn-download{font-size:18px;padding:16px 35px;}
  section h2{font-size:32px;}
  section p, section ul li{font-size:16px;}
  .os-section a{font-size:16px;padding:12px 20px;}
}