/* 全ページ共通のメニュー。色は各ページで --menu-color と --menu-bg を指定する */
.menu-button {
  position: fixed;
  top: 16px;
  right: 16px;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
  z-index: 11;
}
.menu-button span {
  display: block;
  width: 26px;
  height: 2px;
  margin: 6px auto;
  background: var(--menu-color, #111);
  transition: transform 0.2s, opacity 0.2s;
}
.menu-button[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}
.menu-button[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.menu-button[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}
.menu {
  position: fixed;
  top: 64px;
  right: 16px;
  display: none;
  flex-direction: column;
  gap: 12px;
  min-width: 160px;
  padding: 16px 20px;
  text-align: right;
  background: var(--menu-bg, #fff);
  border-radius: 12px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
  z-index: 10;
}
.menu.open {
  display: flex;
}
.menu a {
  color: var(--menu-color, #111);
  font-family: "Helvetica Neue", Arial, sans-serif;
  font-size: 18px;
  line-height: 1.6;
  text-decoration: none;
}
.menu a:hover {
  text-decoration: underline;
}