body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f4f4f4;
}

header {
  background: #222;
  color: white;
  padding: 15px;
}

nav a {
  color: white;
  margin-right: 15px;
  text-decoration: none;
}

.hero {
  position: relative;
  height: 75vh;
  display: flex;
  align-items: center;
  flex-direction: column;
  justify-content: center;
  text-align: center;
  color: white;

  /* 背景画像 */
  background: url("img/hero.jpg") center/cover no-repeat;
}

/* 文字を見やすくするための暗いオーバーレイ */
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.45);
}

.hero h1, .hero p {
  position: relative;
  z-index: 1;
}

h2 {
  display: inline-block;
  padding-bottom: 8px;
  margin-bottom: 20px;

  /* グラデーション線 */
  background: linear-gradient(to right, #6a1b9a, #cccccc);
  background-repeat: no-repeat;
  background-size: 100% 4px;   /* 線の長さと太さ */
  background-position: left bottom;
}

.cards {
  padding: 40px;
}

.card-container {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.card {
  background: white;
  padding: 20px;
  border-radius: 10px;
  width: 250px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.card a {
  display: inline-block;
  margin-top: 10px;
  color: #0077ff;
}

.blog {
  padding: 40px;
}

article {
  background: white;
  padding: 20px;
  margin-bottom: 20px;
  border-radius: 10px;
}

.date {
  color: gray;
  font-size: 0.9em;
}

.about {
  padding: 40px;
}