.content {
  border: 1px solid #ccc;
  padding: 20px;
  margin: 20px auto;
  max-width: 500px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
}

th, td {
  border: 1px solid #666;
  padding: 6px;
}

button {
  margin: 5px;
  padding: 10px 20px;
  font-size: 16px;
}

#yesNoButtons {
  font-family: sans-serif;
  text-align: center;
}

#resetButton {
  font-family: sans-serif;
  text-align: center;
}

.head{
  display: flex; 
  position: sticky;
  top: 0;
  z-index:1;/*最前面固定*/
  background: #3b82c4;
  }

.nav_menu{
  display: flex; 
  }

.nav_menu_item{
  color: #3b82c4;
  margin-lift: 40px;
  margin-right: 40px;
  }

.nav_url{text-decoration: none;
  color: #fff;
}

.flowchart{
  border-width: thin;
  border-style: solid;
}

.button_SWAN{
  font-size: 1rem;
  background: #3aacad;
  color: #fff;
  border-radius: 5px;
  padding: 18px 32px;
}

.button_SWAN:hover{
  background: #808080;
}

.answer{
  background: #f6f0cc;
}