body {
 background: #ffffff;
 text-align: center;
    }
     
.box {
 width: 500px;
 height: 50px;
 background: black;
 justify-content: center;
 align-items: center;
 cursor: pointer;
 display: block;
 border: 1px solid white;
 margin: auto;
    }
     
.box p {
  color: white;  
  font-weight: bold;
  font-size: 24px;
  margin: auto;
    }
     
#message {
  font-size: 200%;
  margin-top: 20px;
}

button {
  padding: 0;
  font-family: inherit;
  cursor: pointer;
  background-color: transparent;
  border: none;
  display: block;
  margin: auto;
}

/* ボタンのスタイル */
.buttonOutline {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 320px;
  height: 64px;
  font-family: sans-serif;
  font-size: 16px;
  color: #6fa24a;
  text-align: center;
  background-color: transparent;
  border: 2px solid #6fa24a;
}

@media (any-hover: hover) {
  .buttonOutline {
    transition: background-color 0.2s;
  }

  .buttonOutline:hover {
    background-color: #dcedd2;
  }
}