* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ヘッダー全体の設定 */
.header-content {
  position: relative;
  width: 100%;
  text-align: left;
}

.header-img {
  width: 100%;
  height: auto;
  min-height: 280px;
  max-height: 500px;
  object-fit: cover;
  object-position: center;
  display: block;
}

.foreground-img {
  position: absolute;
  top: 25%;
  left: 65%;
  width: clamp(170px, 25vw, 270px);
  height: auto;
  max-height: 90%;
  object-fit: contain;
  z-index: 0;
}

/* ヘッダーメッセージのスタイリングと配置 */
.header-title {
  font-family: Source Sans Pro, OpenSans;
  position: absolute;
  left: 10%;
  top: 15%;
  color: white;
  font-size: 32px;
  max-width: 480px;
  z-index: 1;
  white-space: nowrap;
  overflow: hidden;
}

/* ヘッダーメッセージのスタイリングと配置 */
.header-message {
  position: absolute;
  left: 10%;
  top: 32%;
  transform: translateY(0);
  color: white;
  padding: 10px 20px;
  border-radius: 5px;
  max-width: 480px;
  z-index: 1;
  font-size: 18px;
}

.download-button {
  position: absolute;
  left: 10%;
  top: 65%;
  transform: translateY(-50%);
}

.patent-notice {
  position: absolute;
  left: 10%;
  color: rgba(255, 255, 255, 0.9);
  font-size: 13px;
  z-index: 1;
}

.button-logo {
  height: 20px;
  margin-right: 5px;
  vertical-align: middle;
  transition: height 0.2s ease;
}

button {
  background-color: #666;
  color: White;
  border: 5px;
  padding: 10px 20px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: clamp(12px, 1.2vw, 16px);
  margin: 10px 2px;
  cursor: pointer;
  border-radius: 4px;
  position: relative;
  overflow: visible;
  transition: transform 0.2s ease;
}

button span {
  vertical-align: middle;
}

/* 小規模の画面（スマートフォン） */
@media (max-width: 767px) {
  .header-title {
    left: 6%;
  }
  .header-message {
    left: 6%;
  }
  .download-button {
    left: 6%;
  }
  .foreground-img {
    left: auto;
    right: 5%;
    top: auto;
    bottom: 8%;
  }
}