/* 푸터 스타일 */
  footer {
    margin-top: 40px;
    padding: 20px 0;
    width: 100%;
    background-color: rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    text-align: center;
    color: white;
  }

  .footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
  }

  .social-links {
    display: flex;
    gap: 15px;
  }

  .social-links a {
    color: white;
    font-size: 1.5rem;
    transition: opacity 0.3s ease;
  }

  .social-links a:hover {
    opacity: 0.7;
  }

  .footer-menu {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 20px;
    margin: 20px 0;
  }

  .footer-menu a {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s ease;
  }

  .footer-menu a:hover {
    opacity: 0.7;
  }

  .copyright-container {
    font-size: 0.9rem;
    opacity: 0.8;
  }

  /* URL 복사 알림 */
  .url-copy-notification {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 10px 20px;
    border-radius: 50px;
    z-index: 1000;
    animation: fadeIn 0.3s ease-out;
    transition: opacity 0.5s ease;
  }

  .url-copy-notification.error {
    background-color: rgba(220, 53, 69, 0.9);
  }

  @keyframes fadeIn {
    from { opacity: 0; transform: translate(-50%, -20px); }
    to { opacity: 1; transform: translate(-50%, 0); }
  }/* 기본 스타일 및 리셋 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Poppins", "Noto Sans KR", sans-serif;
  }
  
  body {
    background: linear-gradient(135deg, #ff9d6c, #bb4e75);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: #333;
  }
  
  /* 헤더 부분 */
  .header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
    width: 100%;
  }

  .header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    width: 100%;
    max-width: 800px;
    margin: 0 auto 20px;
    padding: 0 15px;
  }

  .back-button {
    display: flex;
    align-items: center;
    color: white;
    text-decoration: none;
    font-weight: bold;
    padding: 8px 15px;
    border-radius: 50px;
    background: rgba(0, 0, 0, 0.2);
    transition: background 0.3s ease;
  }

  .back-button:hover {
    background: rgba(0, 0, 0, 0.3);
  }

  .header-buttons {
    display: flex;
    gap: 10px;
  }

  .language-button,
  .copy-url-button {
    background: rgba(0, 0, 0, 0.2);
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 5px;
    transition: background 0.3s ease;
  }

  .language-button:hover,
  .copy-url-button:hover {
    background: rgba(0, 0, 0, 0.3);
  }

  .language-dropdown {
    display: none;
    background: white;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    overflow: hidden;
  }

  .language-dropdown.active {
    display: block;
  }

  .language-option {
    padding: 10px 20px;
    cursor: pointer;
    color: #333;
    transition: background 0.3s ease;
  }

  .language-option:hover {
    background: #f5f5f5;
  }
  
  .header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
  }
  
  .header p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
  }
  
  /* 게임 영역 */
  .game-container {
    background: rgba(255, 255, 255, 0.9);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
    width: 100%;
    max-width: 400px;
    position: relative;
  }
  
  /* 카드 스타일 */
  .card-container {
    perspective: 1000px;
    width: 100%;
    aspect-ratio: 3/4;
    margin-bottom: 20px;
  }
  
  #card {
    width: 100%;
    height: 100%;
    position: relative;
    cursor: pointer;
    transform-style: preserve-3d;
    transition: transform 0.5s ease-out;
  }
  
  .card-text {
    width: 100%;
    position: absolute;
    text-align: center;
    padding: 10px;
  }
  
  .top-text {
    top: 10px;
    transform: rotate(180deg);
  }
  
  .bottom-text {
    bottom: 10px;
  }
  
  .card-front,
  .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
  }
  
  .card-front {
    background: linear-gradient(45deg, #6b5de6, #8857e9);
    color: white;
    font-size: 2rem;
    transform: rotateY(0deg);
  }
  
  .card-back {
    background: linear-gradient(45deg, #ff7e5f, #feb47b);
    color: white;
    font-size: 1.8rem;
    transform: rotateY(180deg);
    padding: 10px;
    text-align: center;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
  }
  
  /* 카운트다운 스타일 */
  #countdown-container {
    width: 100%;
    text-align: center;
    margin-top: 10px;
    margin-bottom: 10px;
    height: 80px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    z-index: 10;
  }
  
  #countdown {
    font-size: 3.5rem;
    color: #ff4d4d;
    font-weight: bold;
    display: none;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 100;
  }
  
  /* 지시사항 */
  .instructions {
    background: rgba(255, 255, 255, 0.8);
    border-radius: 15px;
    padding: 20px;
    margin-top: 30px;
    text-align: center;
    max-width: 400px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  }
  
  .instructions h3 {
    margin-bottom: 10px;
    color: #6b5de6;
  }
  
  .instructions ol {
    text-align: left;
    padding-left: 25px;
    margin-top: 10px;
  }
  
  .instructions li {
    margin-bottom: 8px;
  }
  
  /* 애니메이션 */
  @keyframes float {
    0% {
      transform: translateY(0px) rotateY(0deg);
    }
  
    50% {
      transform: translateY(-10px) rotateY(0deg);
    }
  
    100% {
      transform: translateY(0px) rotateY(0deg);
    }
  }
  
  .floating {
    animation: float 3s ease-in-out infinite;
  }
  
  /* 회전 애니메이션이 적용될 때 float 애니메이션 제거 */
  .rotating {
    animation: none !important;
  }
  
  /* 반응형 스타일 */
  @media (max-width: 480px) {
    .header h1 {
      font-size: 2rem;
    }
  
    .header p {
      font-size: 1rem;
    }
  
    .card-front {
      font-size: 2rem;
    }
  
    .card-back {
      font-size: 1.3rem;
    }
  
    #countdown {
      font-size: 3.5rem;
    }
  
    .game-container {
      padding: 20px;
    }
  }
  
  /* 버블 배경 애니메이션 */
  .bubbles {
    position: fixed;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
    top: 0;
    left: 0;
  }
  
  .bubble {
    position: absolute;
    bottom: -100px;
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    opacity: 0.5;
    animation: rise 8s infinite ease-in;
  }
  
  .bubble:nth-child(1) {
    width: 40px;
    height: 40px;
    left: 10%;
    animation-duration: 8s;
  }
  
  .bubble:nth-child(2) {
    width: 20px;
    height: 20px;
    left: 20%;
    animation-duration: 5s;
    animation-delay: 1s;
  }
  
  .bubble:nth-child(3) {
    width: 50px;
    height: 50px;
    left: 35%;
    animation-duration: 7s;
    animation-delay: 2s;
  }
  
  .bubble:nth-child(4) {
    width: 80px;
    height: 80px;
    left: 50%;
    animation-duration: 11s;
    animation-delay: 0s;
  }
  
  .bubble:nth-child(5) {
    width: 35px;
    height: 35px;
    left: 55%;
    animation-duration: 6s;
    animation-delay: 1s;
  }
  
  .bubble:nth-child(6) {
    width: 45px;
    height: 45px;
    left: 65%;
    animation-duration: 8s;
    animation-delay: 3s;
  }
  
  .bubble:nth-child(7) {
    width: 25px;
    height: 25px;
    left: 75%;
    animation-duration: 7s;
    animation-delay: 2s;
  }
  
  .bubble:nth-child(8) {
    width: 80px;
    height: 80px;
    left: 80%;
    animation-duration: 10s;
    animation-delay: 1s;
  }
  
  @keyframes rise {
    0% {
      bottom: -100px;
      transform: translateX(0);
    }
  
    50% {
      transform: translate(100px, -500px);
    }
  
    100% {
      bottom: 1080px;
      transform: translateX(-200px);
    }
  }
  
  /* 아이콘 스타일 */
  .icon {
    font-size: 2rem;
    margin-right: 10px;
    vertical-align: middle;
  }
  
  /* 푸터 스타일 */
  footer {
    margin-top: 40px;
    padding: 20px 0;
    width: 100%;
    background-color: rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    text-align: center;
    color: white;
  }

  .footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
  }

  .social-links {
    display: flex;
    gap: 15px;
  }

  .social-links a {
    color: white;
    font-size: 1.5rem;
    transition: opacity 0.3s ease;
  }

  .social-links a:hover {
    opacity: 0.7;
  }

  .footer-menu {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 20px;
    margin: 20px 0;
  }

  .footer-menu a {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s ease;
  }

  .footer-menu a:hover {
    opacity: 0.7;
  }

  .copyright-container {
    font-size: 0.9rem;
    opacity: 0.8;
  }

  /* URL 복사 알림 */
  .url-copy-notification {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background-color: rgba(0, 0, 0, 0.8);
    color: white;
    padding: 10px 20px;
    border-radius: 50px;
    z-index: 1000;
    animation: fadeIn 0.3s ease-out;
    transition: opacity 0.5s ease;
  }

  .url-copy-notification.error {
    background-color: rgba(220, 53, 69, 0.9);
  }

  @keyframes fadeIn {
    from { opacity: 0; transform: translate(-50%, -20px); }
    to { opacity: 1; transform: translate(-50%, 0); }
  }