@media screen and (max-width: 768px) {
  .mobile-menu {
    display: block;
    position: relative;
    z-index: 999;
  }
  /* メニューアイコン（右上に固定） */
  .menu-button {
    position: fixed;
    top: 3vw;
    right: 5vw;
    width: 44px;
    height: 30px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    cursor: pointer;
    z-index: 1001;
  }
  .menu-button span {
    height: 4px;
    background: #999;
    border-radius: 1vw;
    transition: all 0.2s ease;
  }
  #menu-toggle {
    display: none;
  }
  /* ハンバーガー → × 変形 */
  #menu-toggle:checked + .menu-button span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 10px);
    background: #565656;
  }
  #menu-toggle:checked + .menu-button span:nth-child(2) {
    opacity: 0;
    background: #565656;
  }
  #menu-toggle:checked + .menu-button span:nth-child(3) {
    transform: rotate(-45deg) translate(8px, -10px);
    background: #565656;
  }
  /* メニューオーバーレイ */
  .menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(255, 255, 255, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    opacity: 0;
    pointer-events: none;
    transform: scale(1.05);
    transition: opacity 0.4s ease, transform 0.4s ease;
    z-index: 1000;
  }
  #menu-toggle:checked ~ .menu-overlay {
    opacity: 1;
    pointer-events: auto;
    transform: scale(1);
  }
  #sp_menu_logo {
    clear: both;
    width: 80%;
    margin: 0px auto 3.0vh;
  }
  #sp_logo_ma {
    display: block;
    width: 40%;
    margin: 0px auto 2.0vh;
  }
    
    #sp_sns_list {
        clear: both;
        width: 100%;
        display: flex;
        text-align: center;
        justify-content: center;
        margin: 0px auto 4.0vh;
    }
    #sp_sns_list li {
     display: inline-block; 
        width: 9vw;
        margin: 0px 1.8vw 0px;
    }
    
  .menu-overlay ul {
    list-style: none;
    padding: 0;
    margin: 0;
    text-align: center;
  }
  .menu-overlay li {
    margin: 5vw 0;
  }
  .menu-overlay a {
    text-decoration: none;
    font-size: 5.0vw;
    color: #565656;
    line-height: 1.4em;
    transition: color 0.3s;
  }
  .menu-overlay a:hover {
    color: #007bff;
  }
}