main {
    margin: 0 auto;
    max-width: 1200px;
    padding: 0px 20px;
}

h3 {
    border-bottom: 2px solid #9e5f009c;
    margin-top: 3rem;
}

.top_message {
    align-items: center;
    display: flex;
    flex-direction: column;
    padding: 10px;
}

#chatch_copy {
    font-size: 2em;
    font-weight: 700;
    margin: 5px;
}

.app_item {
    background: #ddd;
    border-radius: 10px;
    padding: 20px;
    margin-left: 20px;
    margin-right: 20px;
    max-width: 500px;
}

.app_info_top {
    display: flex;
}

.app_icon {
    width: 90px;
    height: 90px;
}

.app_content {
    display: flex;
    flex-direction: column;
}

.app_title {
    font-size: 1.1rem;
    font-weight: 700;
    margin: 2px 0 0 14px;
}

.app_description {
    color: #666;
    font-size: .9rem;
    margin: 3px 0 0 14px;
}

.app_info_bottom {
    display: flex;
    margin-top: 10px;
}

.play_store_banner {
    margin-left: -1px;
    margin-top: -6px;
    margin-right: 10px;
}

/* フォームデザイン */
/*
 * INPUT
 */
 input,
 textarea,
 .field {
   display: block;
   margin-bottom: 0.7em;
   border: 0;
   width: 95%;
   border-radius: 3px;
   background-color: #eff1f5;
   box-shadow: none;
   color: rgba(0, 0, 0, 0.7);
   font-size: 1.1em;
   line-height: 1.5;
   transition: ease;
 }
 input:user-invalid,
 textarea:user-invalid {
    border: 2px solid red
 }
 textarea#contact_content {
   max-width: 100%;
   min-height: 200px;
   line-height: 1.5em;
   padding: 0.5em;
   overflow: auto;
   font-family: "Helvetica Neue",
      Arial,
      "Hiragino Kaku Gothic ProN",
      "Hiragino Sans",
      Meiryo,
      sans-serif;
 }

 #send-form, #submit-btn {
    color: #fff;
    cursor: pointer;
    background-color: #212222;
    border: 0;
    font-weight: bold;
    padding: 7px 5px;
    text-align: center;
    border-radius: 5px;
    width: 250px;
    display:inline-block;
}

#back-btn {
    color: #212222;
    cursor: pointer;
    background-color: #fff;
    border: 1px solid #212222;
    font-weight: bold;
    padding: 7px 5px;
    text-align: center;
    border-radius: 5px;
    width: 250px;
    display:inline-block;
}

.pre_wrap {
    white-space: pre-wrap;
}

.error_message {
    display: block;
    color: red;
    font-size: 12px;
  }