body{
    text-align:center;
    line-height:2;
}

h1 {
    color: blue;
    font-size; 100pt;
    border-bottom:2px solid blue;
}

.goback{
    margin-top:50px;
    text-align:center;
}

.font-red{
    color:red;
    font-weight:bold;
}

.menu a{
    text-decoration: none;
    font-size: 1.2rem;
}

/* メニューが横並びになる条件 */
@media screen and (min-width: 768px) {
  .global-nav .menu {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 600px;
  }
  .global-nav .menu a {
    margin-right: 1em;
  }
  .global-nav .hamburger-menu {
    display: none;
  }
}

/* メニューが縦並びになる条件 */
@media screen and (max-width: 767px) {
  .global-nav .menu {
    display: none;
    position: absolute;
    top: 3em;
    left: 0;
    width: 100%;
    background-color: #fff;
    border-bottom: 1px solid #ccc;
  }
  .global-nav .menu a {
    display: block;
    padding: 1em;
    border-bottom: 1px solid #ccc;
  }
  .global-nav .hamburger-menu {
    display: block;
    position: relative;
    z-index: 1;
    background-color: transparent;
    border: none;
    cursor: pointer;
  }
  .global-nav .hamburger-icon {
    display: block;
    width: 24px;
    height: 2px;
    background-color: #333;
    position: relative;
    top: 50%;
    transform: translateY(-50%);
    transition: all 0.3s;
  }
  .global-nav .hamburger-icon::before,
  .global-nav .hamburger-icon::after {
    content: "";
    display: block;
    width: 100%;
    height: 2px;
    background-color: #333;
    position: absolute;
    left: 0;
    transition: all 0.3s;
  }
  .global-nav .hamburger-icon::before {
    top: -6px;
  }
  .global-nav .hamburger-icon::after {
    bottom: -6px;
  }
  .global-nav .hamburger-menu.active .hamburger-icon {
    background-color: transparent;
  }
  .global-nav .hamburger-menu.active .hamburger-icon::before {
    transform: rotate(45deg);
    top: 0;
  }
  .global-nav .hamburger-menu.active .hamburger-icon::after {
    transform: rotate(-45deg);
    bottom: 0;
  }

  .global-nav .menu.active {
    display: block;
  }
}

/* 共通のスタイル */
.global-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1em;
  background-color: #fff;
  border-bottom: 1px solid #ccc;
}