.form {
  max-width: 800px;
  margin: 30px auto;
}

.contact_box,
.thanks_box {
  width: min(80%, 800px);
  margin: 30px auto;
}

.form_item {
  border-top: 1px solid #ddd;
  padding: 24px 0;
  width: 100%;
  display: flex;
  align-items: center;
}

.form_item:first-child {
  border-top: none;
}

.form_item_label {
  width: 100%;
  max-width: 248px;
  letter-spacing: 0.05em;
  font-weight: bold;
  font-size: 1rem;
}

.form_item_label.isMsg {
  margin-top: 8px;
  margin-bottom: auto;
}

.form_item_label_required,
.form_item_label_optional {
  border-radius: 6px;
  margin-right: 8px;
  padding: 8px;
  width: 48px;
  display: inline-block;
  text-align: center;
  font-size: 0.8rem;
  color: #fff;
}

.form_item_label_required {
  background: #00569d;
}

.form_item_label_optional {
  background: #9e9e9e;
}

.form_item_input,
.form_item_textarea,
.contact_type {
  border: 1px solid #ddd;
  border-radius: 6px;
  margin-left: 40px;
  padding: 0 1em;
  flex: 1;
  width: 100%;
  max-width: 410px;
  background: #eaedf2;
  font-size: 0.9rem;
  color: #000;
  font-family: inherit;
}

.form_item_input,
.contact_type {
  height: 48px;
}

.form_item_textarea {
  padding: 1em;
  height: 216px;
  resize: vertical;
}

.form_item_input:focus,
.form_item_textarea:focus,
.contact_type:focus {
  border-color: #00569d;
  outline: none;
}

.form_item_input.is-invalid,
.form_item_textarea.is-invalid,
.contact_type.is-invalid {
  border-color: #dc3545;
}

.form_error {
  color: #dc3545;
  font-size: 0.8rem;
  margin-top: 8px;
  margin-left: calc(248px + 40px);
}

.btn_area {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
}

.form_btn {
  border-radius: 6px;
  margin: 32px auto 0;
  padding: 10px 0;
  width: 200px;
  display: block;
  letter-spacing: 0.05em;
  background: #00569d;
  color: #fff;
  font-weight: bold;
  font-size: 1rem;
  cursor: pointer;
}

.form_btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.form_btn.back {
  background: #9e9e9e;
}

.confirm_area,
.thanks_area {
  margin: 150px 0;
}

.confirm_value {
  flex: 1;
  margin-left: 40px;
  font-size: 0.9rem;
  line-height: 1.8;
  white-space: pre-wrap;
}

.thanks_box_text {
  line-height: 1.8;
  text-align: center;
}

.form_status {
  text-align: center;
  margin-top: 16px;
  font-size: 0.9rem;
}

.form_status.is-error {
  color: #dc3545;
}

.form_status.is-success {
  color: #00569d;
}

@media screen and (max-width: 780px) {
  .contact_box,
  .thanks_box {
    width: 100%;
    padding: 10px;
  }

  .form {
    margin: 10px auto;
  }

  .form_item {
    padding: 16px 14px;
    flex-wrap: wrap;
  }

  .form_item_label {
    max-width: inherit;
    font-size: 0.9rem;
  }

  .form_item_label_required,
  .form_item_label_optional {
    padding: 4px;
    width: 32px;
    font-size: 10px;
  }

  .form_item_input,
  .form_item_textarea,
  .contact_type {
    margin-left: 0;
    margin-top: 18px;
    max-width: 100%;
    font-size: 0.8rem;
  }

  .form_item_input,
  .contact_type {
    height: 40px;
  }

  .form_item_textarea {
    height: 200px;
  }

  .form_error,
  .confirm_value {
    margin-left: 0;
  }

  .form_btn {
    width: 160px;
    font-size: 0.9rem;
  }

  .thanks_area .title br {
    display: block;
  }
}