/* ===== 基本 ===== */
body {
  font-family: "Segoe UI", "ヒラギノ角ゴ ProN", sans-serif;
  background-color: #f0f4f8;
  margin: 0;
  padding: 0;
  color: #333;
}
/* ===== ヘッダー ===== */
header {
  background-color: #4a90e2;
  color: white;
  padding: 20px;
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

header h1 {
  margin: 0;
  font-size: 1.8em;
}
#menu-toggle {
  background: none;
  border: none;
  color: white;
  font-size: 28px;
  cursor: pointer;
  user-select: none;
  padding: 0;
  line-height: 1;
  position: absolute;
  top: 22px;
  right: 20px;
  z-index: 1100;
}

/* ===== ナビゲーションメニュー（ハンバーガー） ===== */
nav ul.menu-bar {
  list-style: none;
  position: absolute;
  top: 60px;
  right: 20px;
  width: 180px;
  background-color: #4a90e2;
  border-radius: 6px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  display: none;
  flex-direction: column;
  z-index: 1000;
  padding: 10px 0;
  margin: 0;
}

nav ul.menu-bar.show {
  display: flex;
}

nav ul.menu-bar li {
  border-bottom: 1px solid rgba(255,255,255,0.3);
}

nav ul.menu-bar li:last-child {
  border-bottom: none;
}

nav ul.menu-bar li a {
  color: white;
  text-decoration: none;
  font-weight: bold;
  padding: 12px 15px;
  display: block;
}

nav ul.menu-bar li a:hover {
  background-color: #357ab8;
  border-radius: 4px;
}

/* ===== カード ===== */
.card-container {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  max-width: 900px;
  margin: 20px auto;
  padding: 0;
}

.card {
  background-color: white;
  border-radius: 12px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
  padding: 12px;
  flex: 0 1 calc(33.333% - 10.666px); /* 3列に収まるよう調整 */
  box-sizing: border-box; /* paddingやborderを幅に含める */
  text-align: center;
  transition: transform 0.2s;
  text-decoration: none;
  color: #333;
}

@media (max-width: 768px) {
  .card {
    flex: 0 1 calc(50% - 8px); /* 2列に切り替え */
  }
}

@media (max-width: 480px) {
  .card {
    flex: 0 1 100%; /* 1列 */
  }
}