/* ハンバーガーアイコン（左上固定） */
.hamburger {
  padding: 8px 8px 8px 8px;
    display: none;
  width: 30px;
  height: 25px;
  flex-direction: column;
  justify-content: space-between;
  cursor: pointer;
  position: absolute;
  top: 0px;
  left: 0px;
  z-index: 1101;
    background-color: #0f3d67;
}
.hamburger span {
  display: block;
  height: 3px;
  background: #ffffff;
  border-radius: 2px;
  transition: 0.3s ease;
}

/* アニメーション（アイコン） */
.main-nav.open .hamburger span:nth-child(1) {
  transform: translateY(11px) rotate(45deg);
}
.main-nav.open .hamburger span:nth-child(2) {
  opacity: 0;
}
.main-nav.open .hamburger span:nth-child(3) {
  transform: translateY(-11px) rotate(-45deg);
}

/* オーバーレイ背景 */
.nav-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.4);
  z-index: 1100;
  opacity: 0;
  transition: opacity 0.3s ease;
}
.main-nav.open + .nav-overlay {
  display: block;
  opacity: 1;
}

/* メニュー本体（スライドイン） */
@media screen and (max-width: 768px) {
  .main-nav ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: 60px 20px 20px;
    background: #fff;
    position: fixed;
    top: 0;
    left: 0;
    width: 80%;
    max-width: 300px;
    height: 100%;
    z-index: 1102;
    transform: translateX(-100%);
    opacity: 0;
    transition: transform 0.4s ease, opacity 0.3s ease;
  }
  .main-nav.open ul {
    transform: translateX(0);
    opacity: 1;
  }
  .hamburger {
    display: flex;
  }
}