*, *::before, *::after {
    box-sizing: inherit;
  }
  
  header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    height: 10vh;
    background-color: #c9f2ff;
    opacity: 1;
    padding: 0 25px;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 500;
    box-sizing: border-box;
  }




  .title-header {
    margin-right: auto;
    font-size: 24px;
    font-weight: bold;
    color: #000;
    text-decoration: none;
  }
   
  .menu-header {
    list-style: none;
    display: flex;
    margin: 0;
    padding: 0;
  }
  
  .menubutton-header {
    margin-left: 20px;
    padding: 10px;
  }
  
  .menubutton-header a {
    text-decoration: none;
    color: #000;
    font-size: 18px;
  }

  /* ハンバーガーメニューアイコンのスタイル */
.hamburger-menu {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 30px;
    height: 25px;
    cursor: pointer;
    z-index: 501;
  }
  
  .hamburger-menu .bar {
    width: 100%;
    height: 4px;
    background-color: #000;
    
    transition: transform 0.3s ease, opacity 0.3s ease;
  }
  

/* ハンバーガーメニューのアニメーション */
.hamburger-menu.open .bar:nth-child(1) {
  transform-origin: center center 0;
  transform: translateY(9px) rotate(-135deg);
}

.hamburger-menu.open .bar:nth-child(2) {
  transform-origin: center center 0;
  opacity: 0;
}

.hamburger-menu.open .bar:nth-child(3) {
  transform-origin: center center 0;
  transform: translateY(-8px) rotate(135deg);
}



  /* モバイル表示用のスタイル */
  @media (max-width: 768px) {
    header{
      height: 10vh;
    }
  
    .menu-header {
        position: absolute;
        top: 60px;
        right: 0;
        width: 100%;
        height: 0;
        background-color: rgba(201, 242, 255, 0.95);
        flex-direction: column;
        align-items: center;
        overflow: hidden;
        transition: height 0.3s ease;
    }
  
    .menu-header.open {
        height: 265px; /* メニューが開いたときの高さ */
    }
  
    .menubutton-header {
        margin: 10px 0;
    }
  
    .hamburger-menu {
        display: flex;
    }
  }