body {
  font-family: sans-serif;
  background: #f5f5f5;
  margin: 0;
  padding: 0;
  font-size: 16px;
  line-height: 1.6;
}

.container {
  max-width: 720px;
  margin: 40px auto;
  padding: 30px;
  background: #fff;
  box-sizing: border-box;
}

h1 {
  margin-top: 0;
  font-size: 26px;
  line-height: 1.4;
}

label {
  display: block;
  margin-top: 20px;
  font-weight: bold;
}

input,
select,
textarea {
  width: 100%;
  padding: 12px;
  margin-top: 6px;
  box-sizing: border-box;
  font-size: 16px;
  border: 1px solid #ccc;
  border-radius: 4px;
}

textarea {
  resize: vertical;
}

button,
.button {
  display: inline-block;
  width: auto;
  margin-top: 25px;
  padding: 12px 24px;
  border: none;
  background: #333;
  color: #fff;
  font-size: 16px;
  cursor: pointer;
  text-decoration: none;
  border-radius: 4px;
  box-sizing: border-box;
}

button:hover,
.button:hover {
  opacity: 0.8;
}

.confirm-box {
  background: #fafafa;
  padding: 20px;
  border: 1px solid #ddd;
  box-sizing: border-box;
  word-break: break-all;
}

.error {
  color: red;
  font-weight: bold;
}

/* スマホ対応 */
@media screen and (max-width: 600px) {
  body {
    background: #fff;
    font-size: 16px;
  }

  .container {
    width: 100%;
    margin: 0;
    padding: 20px 16px;
    box-shadow: none;
  }

  h1 {
    font-size: 22px;
    margin-bottom: 24px;
  }

  label {
    margin-top: 18px;
    font-size: 15px;
  }

  input,
  select,
  textarea {
    font-size: 16px;
    padding: 14px 12px;
  }

  select {
    min-height: 48px;
  }

  textarea {
    min-height: 120px;
  }

  button,
  .button {
    width: 100%;
    padding: 15px;
    font-size: 17px;
    text-align: center;
  }

  .confirm-box {
    padding: 16px;
    font-size: 15px;
  }

  .confirm-box p {
    margin: 0 0 14px;
  }
}