body {
  font-family: "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  line-height: 1.8;
  background-color: #e0f7fa; /* 背景 */
  color: #333;
  max-width: 700px;
  margin: 40px auto;
  padding: 0 20px;
}

h1 {
  color: #444;
  border-bottom: 2px solid #ccc;
  padding-bottom: 5px;
}

.date {
  color: #888;
  font-size: 0.9em;
  margin-bottom: 20px;
}

p {
  margin-bottom: 1em;
}

.back-button {
  display: inline-block;
  padding: 10px 20px;
  background-color: #ffe4e1;
  color: #333;
  border: 2px solid #ffb6c1;
  border-radius: 12px;
  font-family: "Hiragino Maru Gothic Pro", "Rounded Mplus 1c", sans-serif;
  font-size: 16px;
  text-decoration: none;
  transition: all 0.3s ease;
  box-shadow: 2px 2px 5px rgba(0,0,0,0.1);
}

.back-button:hover {
  background-color: #ffb6c1;
  color: white;
}

.diary-title {
  font-weight: bold;
  font-size: 18px;
  color: #333;
}

@media screen and (max-width: 600px) {
  body {
    font-size: 16px;
    line-height: 1.8;
    padding: 0 15px;
  }

  h1 {
    font-size: 22px;
  }

  .diary-title {
    font-size: 18px;
  }
}

.diary-title {
  word-break: keep-all;
  white-space: normal;
}