.hero {
  height: 38vh;

  /* BG image + dark overlay */
  background:
    linear-gradient(rgba(0,0,0,0.75), rgba(0,0,0,0.75)),
    url("../img/space-bg.jpg");

  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;

  color: white;

  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;

  margin-top: 56px;

  position: relative;
  overflow: hidden;
}


/* center content stack */
.hero-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  z-index: 2;
}

/* satellite icon */
.satellite {
  width: 55px;
  margin-bottom: 16px;
  opacity: 0.85;

  animation: float 6s ease-in-out infinite;
  filter: drop-shadow(0 0 10px rgba(255,255,255,0.3));
}

/* floating animation */
@keyframes float {
  0%,100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* mobile adjustments */
@media (max-width: 768px) {
  .hero {
    height: 25vh;
  }

  .satellite {
    width: 32px;
    margin-bottom: 10px;
  }
}

.hero h1 {
  text-shadow: 0 0 25px rgba(255,255,255,0.25);
}


.silambam-img {
  max-height: 350px;
  width: 100%;
  object-fit: cover;
}

#courses .btn {
  border-radius: 30px;
  padding: 12px 28px;
  transition: all 0.3s ease;
}

#courses .btn:hover {
  transform: translateY(-2px);
}

.hero p.small {
  letter-spacing: 0.5px;
}

#youtube {
  background: linear-gradient(180deg, #ffffff 0%, #f8f9fa 100%);
}

#youtube .btn {
  border-radius: 30px;
  padding: 12px 28px;
  font-weight: 600;
  transition: 0.3s;
}

#youtube .btn:hover {
  transform: translateY(-2px);
}
.hero {
  margin-top: 56px;
}
html {
  scroll-behavior: smooth;
}

#about img {
  box-shadow: 0 8px 25px rgba(0,0,0,0.2);
}
#topBtn {
  position: fixed;

  bottom: 30px;
  right: 30px;      /* force right side */

  display: none;

  width: 48px;
  height: 48px;

  border-radius: 50%;
  border: none;

  background: #212529;
  color: white;

  font-size: 20px;
  font-weight: bold;

  cursor: pointer;

  box-shadow: 0 6px 16px rgba(0,0,0,0.35);

  z-index: 9999;

  transition: all 0.25s ease;
}

#topBtn:hover {
  transform: translateY(-4px);
  background: #0d6efd;
}

/* Mobile navbar icon alignment */
@media (max-width: 991px) {

  .navbar-nav {
    text-align: center;
  }

  .navbar-nav .nav-item {
    margin: 8px 0;
  }

  .navbar-nav .nav-link {
    display: inline-block;
  }

}
.navbar .bi {
  font-size: 1.2rem;
}
.navbar .nav-item i {
  margin: 0 6px;
  font-size: 1.2rem;
}
.navbar-collapse {
  transition: height 0.25s ease;
}