@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;700&display=swap');

body {
  margin: 0;
  font-family: 'Open Sans', sans-serif;
  background: linear-gradient(rgba(20, 20, 30, 0.85), rgba(10, 10, 20, 0.85)),
    url('https://images.pexels.com/photos/256370/pexels-photo-256370.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=750&w=1260') no-repeat center center fixed;
  background-size: cover;
  color: #eee;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  padding: 60px 20px;
}

.container {
  background-color: rgba(35, 40, 55, 0.9);
  max-width: 900px;
  padding: 40px 50px;
  border-radius: 16px;
  box-shadow: 0 0 40px rgba(0, 0, 0, 0.7);
  animation: fadeZoomIn 1.4s ease forwards;
}

header {
  text-align: center;
  margin-bottom: 28px;
}

h1 {
  font-weight: 700;
  font-size: 3rem;
  letter-spacing: 1.7px;
  margin-bottom: 10px;
  color: #f0c987;
  text-shadow: 0 0 15px #d19c2b;
}

.back-link {
  font-weight: 600;
  font-size: 1.15rem;
  color: #f0c987;
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: border-color 0.3s ease;
  display: inline-block;
  margin-top: 10px;
}
.back-link:hover {
  border-bottom: 2px solid #f0c987;
}

h2 {
  color: #f7d385;
  border-bottom: 2px solid #d1a84d;
  padding-bottom: 6px;
  margin-top: 30px;
  margin-bottom: 18px;
  font-weight: 700;
}

.definition p,
.key-points ul {
  font-size: 1.2rem;
  line-height: 1.7;
  max-width: 720px;
  margin: 0 auto;
}

.key-points ul {
  list-style-type: disc;
  padding-left: 24px;
}

.key-points li {
  margin-bottom: 12px;
}

.video iframe {
  display: block;
  margin: 25px auto;
  width: 100%;
  max-width: 560px;
  height: 315px;
  border-radius: 16px;
  box-shadow: 0 0 30px #d1a84dcc;
}

/* Animations */
@keyframes fadeZoomIn {
  0% {
    opacity: 0;
    transform: scale(0.9);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}