@import url('https://fonts.googleapis.com/css2?family=Roboto+Slab&display=swap');

body {
  margin: 0;
  font-family: 'Roboto Slab', serif;
  background: url('https://images.pexels.com/photos/256381/pexels-photo-256381.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=750&w=1260') no-repeat center center fixed;
  background-size: cover;
  color: #222;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 50px 20px;
}

.container {
  background: rgba(255, 255, 255, 0.9);
  max-width: 850px;
  padding: 35px 45px;
  border-radius: 15px;
  box-shadow: 0 10px 35px rgba(0, 0, 0, 0.25);
  animation: popIn 1.3s ease forwards;
}

header {
  text-align: center;
  margin-bottom: 25px;
}

h1 {
  font-size: 3rem;
  color: #444;
  margin-bottom: 8px;
  letter-spacing: 1.5px;
}

.back-link {
  font-size: 1.1rem;
  color: #444;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-bottom 0.3s ease;
}
.back-link:hover {
  border-bottom: 1px solid #444;
}

h2 {
  color: #666;
  font-size: 2rem;
  border-bottom: 2px solid #ccc;
  padding-bottom: 7px;
  margin-top: 30px;
  margin-bottom: 18px;
}

.definition p {
  font-size: 1.2rem;
  line-height: 1.65;
}

.video iframe {
  display: block;
  margin: 20px auto;
  width: 100%;
  max-width: 560px;
  height: 315px;
  border-radius: 14px;
  box-shadow: 0 8px 22px rgba(0, 0, 0, 0.2);
}

.types ul {
  list-style-type: circle;
  padding-left: 24px;
  font-size: 1.15rem;
  max-width: 700px;
  margin: 0 auto;
}

.types li {
  margin-bottom: 10px;
}

/* Animation */
@keyframes popIn {
  0% {
    opacity: 0;
    transform: scale(0.85);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}