body {
  background: linear-gradient(135deg, #0d0d0d, #1a1a1a);
  color: #ffffff;
  font-family: 'Roboto', sans-serif;
  margin: 0;
}

.hero {
  height: 100vh;
  background: url('https://source.unsplash.com/random/1920x1080?technology') center/cover;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  position: relative;
}

.hero h1 {
  font-size: 4rem;
  color: #00ff99;
  text-shadow: 0 0 20px #00ff99;
}

.activities-section {
  padding: 4rem 2rem;
  background: #111111;
  text-align: center;
}

.activity {
  margin-bottom: 3rem;
  background: rgba(0, 0, 0, 0.6);
  padding: 1.5rem;
  border-radius: 10px;
  transition: transform 0.3s;
}

.activity:hover {
  transform: scale(1.05);
}

.activity h3 {
  font-size: 1.8rem;
  color: #00ff99;
}

.activity ul {
  list-style-type: disc;
  text-align: left;
  margin: auto;
  padding-left: 2rem;
}

.video-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

.btn {
  display: inline-block;
  padding: 0.8rem 1.5rem;
  border: 2px solid #00ff99;
  color: #00ff99;
  text-decoration: none;
  transition: background 0.3s;
}

.btn:hover {
  background: #00ff99;
  color: #0d0d0d;
}