.achievements {
  width: 70%;
  		justify-content: center;
		/* 水平方向の中央寄せ */
		align-items: center;
		/* 垂直方向の中央寄せ */
		margin-left: auto;
		margin-right: auto;
}

.kaitori-category-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 20px;
  margin-top: 40px;
}

.kaitori-category-buttons .cat-btn {
  background: #f0f0f0;
  border: none;
  padding: 8px 16px;
  border-radius: 20px;
  cursor: pointer;
  transition: 0.2s;
}

.kaitori-category-buttons .cat-btn.active {
  background: #0073aa;
  color: #fff;
}

.kaitori-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

@media (max-width: 1024px) {
  .kaitori-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .kaitori-grid {
    grid-template-columns: 1fr;
  }
}

.kaitori-thumb {
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: #f8f8f8;
}

.kaitori-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.kaitori-card {
  background: #fff;
  border: 1px solid #ddd;
  border-radius: 10px;
  overflow: hidden;
  transition: 0.2s;
}

.kaitori-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 3px 8px rgba(0,0,0,0.1);
}

.kaitori-title {
  font-size: 1.1em;
  text-align: center;
  padding: 1em;
  color: #333;
}