* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont, system-ui, Roboto, "Helvetica Neue", "Segoe UI", "Apple SD Gothic Neo", "Noto Sans KR", "Malgun Gothic", "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", sans-serif;
      background: #f9f9f9;
      color: #333;
      transition: background 0.3s ease, color 0.3s ease;
    }

    header, .profile-info, .post, .media-item, .follower-card {
      transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
    }

    /* 스크롤바의 폭 너비 */
    ::-webkit-scrollbar {
    width: 5px;  
    }

    ::-webkit-scrollbar-thumb {
    background: lightgray; /* 스크롤바 색상 */
    border-radius: 10px; /* 스크롤바 둥근 테두리 */
    }

    ::-webkit-scrollbar-track {
    background: transparent;  /*스크롤바 뒷 배경 색상*/
    }
    ::-webkit-scrollbar-button {
    display: none;
    }

    img {
        width: 100%;
    }

    .wrap{
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
    }

    .inner{
      max-width: 900px;
      width: 100%;
      border: 1px solid #ddd;
    }

    /*헤더*/
    .profile-header {
      position: relative;
      width: 100%;
      height: 200px;
      /* 수정: 닫는 괄호 추가 */
      background: url('https://images.unsplash.com/photo-1506318137071-a8e063b4bec0?q=80&w=1493&auto=format&fit=crop&ixlib=rb-4.1.0&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D') center/cover no-repeat;
    }

    .profile-info {
      background: #fff;
      padding: 0.2rem 1.5rem;
      margin-top: -60px;
      border-bottom: 1px solid #ddd;
      z-index: 10;
      position: relative;
    }
    .profile-top {
      display: flex;
      gap: 1rem;
      align-items: center;
      flex-wrap: nowrap;
    }
    .profile-img {
      width: 120px;
      height: 120px;
      border-radius: 50%;
      border: 4px solid #fff;
    }
    .profile-details {
      padding-top: 10px;
    }
    .profile-details h2 {
      font-size: 1.5rem;
      margin-bottom: 2px;
    }
    .username {
      color: #555;
      font-size: 0.95rem;
    }
    .profile-meta {
      margin-top: 10px;
      color: #555;
      font-size: 0.9rem;
      line-height: 1.5;
    }
    .profile-meta a {
      color: #1da1f2;
      text-decoration: none;
    }
    .follow-info {
      margin-top: 10px;
      margin-bottom: 10px;
      font-size: 0.9rem;
    }
    .follow-info span {
      margin-right: 15px;
    }
    header {
      background: #fff;
      border-bottom: 1px solid #ddd;
      padding: 0.8rem 2rem;
      position: sticky;
      top: 0;
      z-index: 1000;
    }
    header nav {
      display: flex;
      gap: 20px;
      align-items: center;
    }
    header nav a {
      color: #555;
      text-decoration: none;
      font-weight: 600;
      padding-bottom: 6px;
    }
    header nav a.active {
      border-bottom: 3px solid #1da1f2;
      color: #1da1f2;
    }
    header nav a:hover {
      color: #1da1f2;
    }
    .container {
      padding: 1rem 2rem;
    }
    .tab-content {
      display: none;
      margin-top: 1rem;
    }
    .tab-content.active {
      display: block;
    }
    .tab-content h2 {
      font-size: 1.4rem;
      margin-bottom: 1.5rem;
    }
    .post {
      background: white;
      padding: 15px 20px;
      border-radius: 15px;
      margin-bottom: 10px;
      border: 1px solid #ddd;
    }
    .post-header {
      display: flex;
      align-items: center;
      margin-bottom: 10px;
    }
    .post-header img {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      margin-right: 10px;
    }
    .post-header .name {
      font-weight: bold;
      font-size: 1.1rem;
    }
    .post-date {
      font-size: 0.85rem;
      color: #888;
    }
    .post img {
      margin-top: 10px;
      max-width: 100%;
      border-radius: 10px;
    }
    .post p {
      line-height: 1.6;
    }
    .media-grid {
      column-count: 2;
      column-gap: 15px;
    }
    .media-item {
      display: inline-block;
      width: 100%;
      margin-bottom: 15px;
      border: 1px solid #ddd;
      padding: 0;
      border-radius: 10px;
      background: white;
      overflow: hidden;
    }
    .media-item img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      display: block;
      filter: grayscale(100%);
      transition: filter 0.3s ease;
    }
    .media-item:hover img,
    .media-item:active img {
      filter: grayscale(0%);
    }
    #guestbook iframe {
      width: 100%;
      height: 600px;
      border: none;
      overflow: hidden;
    }
    .modal {
      display: none;
      position: fixed;
      z-index: 10000;
      left: 0;
      top: 0;
      width: 100%;
      height: 100%;
      background-color: rgba(0,0,0,0.9);
      align-items: center;
      justify-content: center;
      padding: 20px;
    }
    .modal-content-wrapper {
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .modal-content {
      display: block;
      max-width: 90%;
      max-height: 90%;
      animation: fadeIn 0.3s;
    }
    @keyframes fadeIn {
      from { opacity: 0; }
      to { opacity: 1; }
    }
    @media (max-width: 768px) {
      .profile-top {
        flex-direction: row;
        align-items: center;
        text-align: left;
      }
      .profile-img {
        width: 100px;
        height: 100px;
      }
      .container {
        padding: 1rem;
      }
      header nav {
        flex-wrap: wrap;
        justify-content: center;
      }
      .media-grid {
        column-count: 2;
        column-gap: 8px;
      }
      .media-item {
        margin-bottom: 8px;
      }
    }
    .follower-cards {
      display: flex;
      flex-direction: column;
      gap: 10px;
      margin-top: 1rem;
    }
    .follower-card {
      display: flex;
      align-items: center;
      background: white;
      padding: 10px 15px;
      border: 1px solid #ddd;
      border-radius: 8px;
      text-decoration: none;
      color: inherit;
      transition: background 0.2s ease-in-out;
    }
    .follower-card:hover {
      background-color: #f0f8ff;
    }
    .follower-avatar {
      width: 50px;
      height: 50px;
      border-radius: 50%;
      margin-right: 12px;
    }
    .follower-info {
      flex: 1;
    }
    .follower-info .follower-name {
      font-weight: bold;
      font-size: 1rem;
      margin: 0;
    }
    .follower-info .follower-username {
      font-size: 0.9rem;
      color: #777;
      margin: 0;
    }
    .follow-btn {
      background-color: #1da1f2;
      border: none;
      border-radius: 16px;
      color: white;
      padding: 6px 12px;
      cursor: pointer;
      font-size: 0.9rem;
      transition: background 0.2s ease-in-out;
    }
    .follow-btn:hover {
      background-color: #0d8dd6;
    }

    ul {
    margin-left: 1em;
    line-height: 1.6;
    }

    li::marker {
    font-size: 0.9em;
    }

details > summary {
    cursor: pointer;
    transition: background 0.5s;
    line-height: 1.6;
}

details > div {
    margin-left: 1em;
    line-height: 1.6;
    }

details > summary::-webkit-details-marker {
    transform: rotate3d(0, 0, 1, 90deg);
    transition: transform 0.25s;
}
 
details[open] > summary::-webkit-details-marker {
    transform: rotate3d(0, 0, 1, 180deg);
}
 
details[open] > summary ~ * {
    animation: reveal 0.5s;
}
 

@keyframes reveal {
    from {
        opacity: 0;
        transform: translate3d(0, -10px, 0);
    }
 
    to {
        opacity: 1;
        transform: translate3d(0, 0, 0);
    }
}