@media screen and (max-width: 768px) {
  .profile-header {
    flex-direction: row;
    align-items: flex-start;
    height: auto;
    gap: 12px;
    padding: 12px;
    text-align: center;
    margin-top: 110px;
  }

  .user-icon-area {
    flex-shrink: 0;
  }

  .user-icon-area .user_icon {
    font-size: 80px;
    margin-left: 0;
  }

  .username {
    font-size: 18px;
    margin-bottom: 6px;
  }

  .user-stats {
    display: none;
  }

  .user-stats-mobile {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    flex-wrap: nowrap;
    gap: 10px;
    width: 100%;
    max-width: 320px;
  }

  .user-stats-mobile .stat-item {
    flex: 1 1 0;
    min-width: 0;
    text-align: center;
    white-space: nowrap;
    overflow: visible;
    text-overflow: ellipsis;
  }

  .stat-value {
    font-size: 16px;
  }

  .stat-label {
    font-size: 11px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 4px;
  }

  .stat-label i {
    font-size: 0.9em;
  }

  .tabs-pc{
    display: none;
  }

  .tabs-mobile {
  flex-direction: row;
  display: flex;
  height: auto;
  background-color: #fff;
  justify-content: center;
  align-items: center;
  padding: 10px;
  border: 3px solid #555;
  border-radius: 6px;
  box-shadow: 2px 2px 0 #555;
  gap: 1px;
  margin:20px 0px 0px 5px;
}

.tabs-mobile i {
  font-size: 0.8rem;
  color: #888;
  cursor: pointer;
  transition: color 0.3s ease, transform 0.2s ease;
}

.tabs-mobile i:hover {
  color: #687888;
  transform: translateY(-2px);
}
.tabs-mobile i.active {
  color: #000;
}

  .read-filters {
    flex-wrap: wrap;
    gap: 8px;
  }

  .read-filters .filter-btn {
    font-size: 12px;
    padding: 4px 8px;
  }

  /* 本リストの列数変更 */
  .book-list {
    gap: 10px;
    margin: 0 4px;
    box-sizing: border-box;
    text-align: center;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
  }

  .book-list li {
    width: calc(33.333% - 10px);
    box-sizing: border-box;
    text-align: center;
  }

  .cover {
    width: 100%;
    max-width: 90px;
    height: auto;
  }

  .meta h3, .info h3 {
    font-size: 12px;
  }

  .meta p, .info p {
    font-size: 10px;
  }

}