.shadow {
  padding: 10px;
  color: #CCC;
  font-weight: bold;
  font-size: 30px;
  margin: 0;
  text-shadow:
    3px 3px 0px #000, -3px -3px 0px #000,
    -3px 3px 0px #000, 3px -3px 0px #000,
    3px 0px 0px #000, -3px 0px 0px #000,
    0px 3px 0px #000, 0px -3px 0px #000;
}

body {
  background-image: url('/static/kabe1.jpg');
  background-size: cover;
  background-position: center center;
  background-attachment: fixed;
  margin: 0;
}

textarea {
  resize: none;
}

img {
  width: 300px;
  max-width: 90%;
}

.header-img {
  width: 150px;   /* 好きなサイズ */
  max-width: 80%;
}

form {
  margin-bottom: 15px;
}

@media screen and (max-width: 600px) {
  img {
    width: 200px;
  }

  button {
    font-size: 14px;
    padding: 6px 10px;
  }
}