.fv {
  position: relative;
  max-width: 1440px;
  width: 100%;
  height: 416px;
  margin: 0 auto;
  margin-top: var(--header-height, 80px); /* ヘッダーの高さに合わせる */
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
  isolation: isolate;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 10;
}

/* 背景画像を <img> ではなく背景扱いに */
.fv .top-frame-bottom-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover; /* 背景coverと同じ効果 */
  z-index: -1;       /* 背景に回す */
}

/* オーバーレイを追加 */
.fv::after {
  content: "";
  position: absolute;
  inset: 0; /* top, right, bottom, left をまとめて指定 */
  background-color: #29778a;
  mix-blend-mode: multiply;
  z-index: 0;
}

.fv_box {
  position: relative; /* 背景とオーバーレイの上に載せる */
  z-index: 1;
  text-align: left;
  color: #fff;
}

.fv_box .btns {
  margin-top: 1rem;
}

.fv_box2 {
  padding: 80px 10px 20px;
  justify-content: flex-start;
  align-content: center;
  display: flex;
  text-align: left;
  margin: 0 auto;
}

.fv_left {
  padding-right: 2rem;
}

.fv_box h1 {
  position: absolute;
  font-weight: bold;
  font-size: 44px;
  margin-top: 137px;
  margin-left: 65px;
  letter-spacing: 0.08em;
  color: #ffffff;
  z-index: 30;
}

.fv_box h2 {
  position: absolute;
  font-weight: 500; /* CSSでは Medium = 500 相当 */
  font-size: 22px;
  margin-top: 199px;
  margin-left: 65px;
  color: #ffffff;
  z-index: 30;
}


.fv_box2 h1 {
  font-size: 1.6rem;
  font-weight: 600;
  letter-spacing: .6rem;
}

.fv_box2 h2 {
  font-size: 1rem;
  margin-top: 1rem;
}

@media screen and (max-width: 480px) {

  .fv {
    width: 100vw;
    height: 145px;
  }
  .fv_box h1,
  .fv_box2 h1 {
    font-size: 1.5rem;
    line-height: 1.6;
  }

  .fv_box h2,
  .fv_box2 h2 {
    font-size: .9rem;
  }

}

@media screen and (max-width: 375px) {

  .fv_box h1,
  .fv_box2 h1 {
    font-size: 1.6rem;
    line-height: 1.6;

    font-weight: 600;

  }

  .fv_box h2,
  .fv_box2 h2 {
    font-size: .9rem;
  }

  .fv_box,
  .fv_box2 {
    padding: 80px 10px;
  }

}



.fv_left>.btns {
  margin: 3rem 0 0;
  display: flex;
  flex-direction: row;
  justify-content: flex-start;
  padding: 0;
  text-align: center;
}

.fv_left>.btns .blbtn {
  margin-left: 2rem;
}

@media screen and (max-width: 768px) {
  .fv_box2 {
    flex-direction: column-reverse;
  }

  .fv_left {
    padding: 1rem;

  }

  .fv_right img {
    width: 60%;
    margin: 0 20%;
  }

}