:root {
  --main-color: #448483;
  --text-color: #111;
  --bg-color: #ffffff;
}

body {
  margin: 0;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
}

/* CSS部分 */
header {
  background-color: var(--main-color);
  color: white;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  position: relative;
}

header h1 {
  margin: 0;
  font-size: 1.5rem;
}

header h1 a {
  color: white;
  text-decoration: none;  
}


.menu-icon {
  display: none;
  font-size: 2rem;
  cursor: pointer;
  position: absolute;
  top: 1rem;
  right: 1.5rem;
}

#menu-toggle {
  display: none;
}

nav ul.menu {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
  margin: 0;
  padding: 0;
}

nav ul.menu li {
  margin-left: 1rem;
}

nav ul.menu li a {
  color: white;
  text-decoration: none;
  font-size: 0.9rem;
}