/* below 1408x */
@media (max-width: 88em) {
  .chap-01-pic {
    left: 3%;
  }
}

/* below 1200px */
@media (max-width: 75em) {
  html {
    font-size: 56.25%;
  }
  .hero-flex-start {
    margin-top: 3.2rem;
  }
  .hero-title {
    display: none;
  }
  .hero-title-md {
    display: block;
  }
  .hero-title-img-md {
    width: 43rem;
  }
  .chap-01-pic {
    left: 1%;
  }
  .chap-content-box-bb {
    padding-left: 4.6rem;
    padding-right: 4.6rem;
  }
}

/* below 1040px */
@media (max-width: 65em) {
  .promotion {
    margin-bottom: 3.2rem;
  }
}

/* below 944px */
@media (max-width: 59em) {
  html {
    font-size: 50%;
  }
}

/* below 848px */
@media (max-width: 53em) {
  .section-chap-01 {
    padding-top: 33rem;
  }
  .section-chap-02 {
    padding-top: 80rem;
  }
  .section-chap-03 {
    padding-top: 26rem;
  }
  .section-chap-04 {
    padding-top: 26rem;
  }
  .section-chap-05 {
    padding-top: 47rem;
  }
  .chap-01-pic {
    right: auto;
    left: 50%;
    transform: translateX(-50%);
  }
  .chap-title-flex-end {
    display: flex;
    justify-content: center;
  }
  .chap-title-box {
    text-align: center;
  }
  .chap-content-box-flex-end {
    width: 100%;
  }
  .chap-content-box-01 {
    padding: 2.4rem;
  }
  .lecture-bn-img {
    width: 100%;
  }
}

/* below 752px */
@media (max-width: 47em) {
  .hero-flex-start {
    margin-top: 0;
  }
}

/* below 656px */
@media (max-width: 41em) {
  .section-hero {
    background-image: url("images/bg-hero-md.jpg");
    padding-top: 30rem;
    padding-bottom: 8rem;
  }
}

/* below 560px */
@media (max-width: 35em) {
}

/* below 544px */
@media (max-width: 34em) {
  .main-container {
    padding: 0 2.4rem;
  }
  .hero-flex-start {
    align-items: center;
    margin-left: auto;
  }
  .hero-subtitle {
    padding-left: 0;
  }
  .hero-title-img {
    width: 100%;
  }
  .section-chap-01 {
    padding-top: 27rem;
  }
  .section-chap-02 {
    padding-top: 73rem;
  }
  .section-chap-03 {
    padding-top: 20rem;
  }
  .section-chap-04 {
    padding-top: 20rem;
  }
  .section-chap-05 {
    padding-top: 37rem;
  }
  .chap-01-pic-img,
  .chap-03-pic-img,
  .chap-04-pic-img,
  .chap-05-pic-img {
    width: 50rem;
  }
  .chap-02-pic-img {
    width: 48rem;
  }
  .chap-title {
    font-size: 5rem;

    margin-bottom: 1rem;
  }
  .chap-title-b {
    font-size: 4.8rem;
  }
  .chap-subtitle {
    font-size: 3rem;
  }
  .chap-content-box-bb {
    padding-left: 3.2rem;
    padding-right: 3.2rem;
  }
  .lecture-bn-sm {
    display: block;
    margin-top: 2.4rem;
  }
  .lecture-bn {
    display: none;
    margin-top: 2.4rem;
  }
  .lecture-bn-img-sm {
    width: 34rem;
  }
}

/* below 448px */
@media (max-width: 28em) {
  .section-hero {
    background-image: url("images/bg-hero-md.jpg");
    padding-top: 25rem;
  }
  .chap-01-pic-img,
  .chap-02-pic-img,
  .chap-03-pic-img,
  .chap-04-pic-img,
  .chap-05-pic-img {
    width: 39rem;
  }
  .section-chap-01 {
    padding-top: 20rem;
  }
  .section-chap-02 {
    padding-top: 58rem;
  }
  .section-chap-03 {
    padding-top: 13rem;
  }
  .section-chap-04 {
    padding-top: 15rem;
  }
  .section-chap-05 {
    padding-top: 28rem;
  }
  .chap-intro {
    margin-bottom: 0;
  }
}