.gold-plating-banner {
  width: 100%;
  max-width: 750px;
  margin: 4em 0;
  height: 360px;
  box-sizing: border-box;
  display: flex;
  align-items: center;
  overflow: hidden;
  position: relative;
  background-image: linear-gradient(90deg, rgba(255, 255, 255, 0.96) 0%, rgba(255, 255, 255, 0.88) 55%, rgba(255, 255, 255, 0.18) 100%), url('../images/gold-medal_bg.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  border-top: 3px solid #d7ac45;
  border-bottom: 3px solid #d7ac45;
}

.gold-plating-banner::before {
  content: "";
  position: absolute;
  left: -50px;
  bottom: -85px;
  width: 500px;
  height: 140px;
  border-radius: 50%;
  border-top: 1px solid rgba(52, 136, 190, 0.18);
  transform: rotate(-4deg);
}

.gold-plating-content {
  position: relative;
  z-index: 2;
  width: 66%;
  padding: 28px 8px 24px 34px;
  box-sizing: border-box;
}

#main-contents .gold-plating-content h3 {
  font-family: 'Yu Mincho', 'Hiragino Mincho ProN', serif;
  margin: 0 0 8px;
  color: #123b91;
  font-size: 28px;
  line-height: 1.45;
  font-weight: 600;
  clear: none;
  padding: 0;
  border: 0;
  background: transparent;
}

#main-contents .gold-plating-content h3::after {
  content: "";
  display: block;
  width: 100%;
  height: 1px;
  margin-top: 12px;
  background: #d8aa3d;
}

#main-contents .gold-plating-content p {
  font-family: 'Yu Mincho', 'Hiragino Mincho ProN', serif;
  margin: 0;
  color: #333;
  font-size: 15px;
  line-height: 1.95;
  font-weight: 500;
}


.gold-plating-content .gold-accent {
  color: #c99616;
}

.gold-plating-content .blue-accent {
  color: #123b91;
  font-size: 1.08em;
}
.gold-plating-content strong {
  font-weight: 600;
}

.gold-plating-image {
  width: 34%;
  height: 100%;
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: center;
}

.gold-plating-image img {
  display: block;
  width: 84%;
  height: auto;
  max-height: 82%;
  object-fit: contain;
  object-position: center;
}

.gold-plating-banner.image-unavailable .gold-plating-content {
  width: 100%;
  padding-right: 24px;
}

.gold-plating-banner.image-unavailable .gold-plating-image {
  display: none;
}

/* スマホ対応 */
@media (max-width: 780px) {
  .gold-plating-banner {
    width: 100%;
    height: auto;
    min-height: 300px;
  }

  .gold-plating-content {
    width: 70%;
    padding-left: 16px;
  }

  .gold-plating-image {
    width: 30%;
  }

  #main-contents .gold-plating-content h3 {
  font-family: 'Yu Mincho', 'Hiragino Mincho ProN', serif;
    font-size: clamp(20px, 4.5vw, 25px);
  }

  #main-contents .gold-plating-content p {
  font-family: 'Yu Mincho', 'Hiragino Mincho ProN', serif;
    font-size: clamp(11px, 2.6vw, 14px);
  }
}
/* 真鍮素材紹介 */
.brass-feature {
  position: relative;
  margin: 22px 0 30px;
  padding: 26px 30px 24px;
  overflow: hidden;
  box-sizing: border-box;
  border-top: 3px solid #c99a24;
  border-bottom: 1px solid #d9b85e;
  background: linear-gradient(120deg, #fff 0%, #f7fbfe 58%, #edf7fc 100%);
  box-shadow: 0 8px 22px rgba(20, 63, 112, 0.08);
}

.brass-feature::after {
  content: "";
  position: absolute;
  right: -65px;
  bottom: -90px;
  width: 260px;
  height: 180px;
  border: 1px solid rgba(201, 154, 36, 0.2);
  border-radius: 50%;
  transform: rotate(-12deg);
}

.brass-feature-label {
  position: relative;
  z-index: 1;
  margin-bottom: 6px;
  color: #b48113;
  font-family: Georgia, serif;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.18em;
}

#main-contents .brass-feature-title {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 0;
  border: 0;
  background: transparent;
  color: #173f73;
  font-family: 'Yu Mincho', 'Hiragino Mincho ProN', serif;
  font-size: 23px;
  line-height: 1.5;
  font-weight: 600;
}

#main-contents .brass-feature-title span {
  color: #b98512;
}

.brass-feature-line {
  position: relative;
  z-index: 1;
  width: 120px;
  height: 2px;
  margin: 12px 0 16px;
  background: linear-gradient(90deg, #c4911d, rgba(196, 145, 29, 0));
}

.brass-feature-text {
  position: relative;
  z-index: 1;
}

#main-contents .brass-feature-text p {
  margin: 0 0 8px;
  color: #333;
  font-size: 14px;
  line-height: 1.9;
  text-align: justify;
}

#main-contents .brass-feature-summary {
  position: relative;
  z-index: 1;
  margin: 15px 0 0;
  padding: 11px 14px;
  border-left: 3px solid #c4911d;
  background: rgba(255, 255, 255, 0.8);
  color: #173f73;
  font-size: 14px;
  line-height: 1.7;
  font-weight: 700;
}

.brass-feature-summary span {
  display: inline-block;
  margin-right: 8px;
  color: #a8740c;
}

@media (max-width: 599px) {
  .brass-feature {
    margin: 18px 0 24px;
    padding: 20px 18px;
  }

  #main-contents .brass-feature-title {
    font-size: 20px;
  }

  #main-contents .brass-feature-text p,
  #main-contents .brass-feature-summary {
    font-size: 14px;
  }
}