.exp_sec .bg-image{
  background-image:
    linear-gradient(rgb(255 248 239 / 70%), rgb(255 248 239 / 70%)),
    url("/upload/tenant_1/119c0dca384519b71a78a189f7497fd1.jpg");
  background-size: auto, contain;   /* 上(色)はautoでOK / 下(画像)はcontain */
  background-repeat: repeat, repeat;
  background-position: center, center;
  /* background-blend-mode: lighten; ← これは不要 */
}