* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Helvetica Neue', sans-serif;
}

body {
  color: #333;
  line-height: 1.6;
}

header {
  background: url('https://source.unsplash.com/1600x600/?nature') no-repeat center center/cover;
  height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 3em;
  text-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
}

nav {
  background: #fff;
  padding: 1em;
  display: flex;
  justify-content: center;
  gap: 2em;
  border-bottom: 1px solid #eee;
  position: sticky;
  top: 0;
  z-index: 100;
}

nav a {
  color: #333;
  text-decoration: none;
  font-weight: bold;
}

section {
  padding: 4em 10%;
}

section h2 {
  font-size: 2em;
  margin-bottom: 0.5em;
  border-left: 4px solid #333;
  padding-left: 0.5em;
}

section p {
  font-size: 1.1em;
}

footer {
  background: #333;
  color: #fff;
  text-align: center;
  padding: 2em;
}

/* フェードインアニメーション */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: none;
}