header {
  display: block;
  position: sticky;
  z-index: 999;
  top: 0;
  left: 0;
  width: 100%;
  padding: 20px 40px;
  background: #fff;
  box-sizing: border-box;
}

header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

header .logo {
  width: 200px;
}

header .navi {
  width: 60%;
  display:flex;
}

@media (max-width: 768px) {
  header {
    padding: 10px 16px;
  }

  header .logo {
    width: 28%;
  }

  header .navi {
    width: 60%;
    display:flex;
    gap: 5px;
  }
}

.qa {
  max-width: 780px;
  margin: auto;
}