* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: "微軟正黑體";
  background-color: #eef7ff;
}
a {
  text-decoration: none;
}
header {
  text-align: center;
  background-color: #ececec;
}
.logo img {
  transform: scale(0.7);
}
nav {
  background-color: #1d1d1d;
  padding: 8px 0;
}
nav ul {
  display: flex;
  gap: 20px;
  justify-content: center;
}
nav ul li {
  list-style: none;
}
li a {
  transition: all 0.2s ease-in;
  border-bottom: 2px solid transparent; /* 預設為透明 */
}
li a:link {
  color: #fff;
}
nav ul li a {
  color: #fff;
}
li a:hover {
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.7);
}
main {
  position: relative;
  max-width: 850px;
  width: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  background-color: rgba(46, 112, 75, 0.2);
}

.cover {
  z-index: 99;
  width: 100%;
  aspect-ratio: 850 / 585; /* 或直接填 16 / 9, 4 / 3 等比例 */
  background-image: url(../images/cover-bg.jpg);
  background-size: cover;
  background-position: center;
  color: #fff;
  padding: 100px 50px;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 50px;
  transition: all 0.1s ease-in;
}
.cover:link,
.cover:visited {
  opacity: 1;
}

.cover:hover,
.cover:active {
  opacity: 0.95;
}
.cover h1 {
  font-size: 30px;
  text-align: end;
  text-decoration: underline 2px solid;
  text-underline-offset: 7px; /* 調整底線與文字的距離 */
  margin-top: 20px;
  line-height: 1.5;
}
.cover h3 {
  font-weight: 500;
  font-size: 16px;
  word-break: break-all;
  max-width: 225px;
  text-align: right;
}
.content {
  position: relative;
  width: 100%;
  background-image: url(../images/main-bg.jpg);
  background-repeat: no-repeat;
  padding: 30px 12% 0px 12%;
}
.ad-text {
  position: absolute;
  bottom: 10px;
  right: 25px;
  color: #878787;
}
.content .title {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
}
.title img {
  max-width: 400px;
}
.title span {
  display: inline-block;
  font-size: 36px;
  line-height: 36px;
  font-weight: 600;
  color: #2e704b;
  border: #2e704b 1px solid;
  padding: 3px;
  padding-bottom: 4px;
}
.course-card {
  font-family: "Noto Sans TC";
  display: flex;
  flex-direction: column;
  background-color: #173980;
  margin: 20px 0px 40px 0;
  gap: 12px;
  padding: 35px 50px;
}
.course-card:nth-child(odd) {
  background-color: #0f5ca4;
}
.reverse {
  flex-direction: row-reverse;
}
.course-info {
  display: flex;
  gap: 30px;
  flex: 1;
}
.course-sort {
  display: flex;
  color: #065d82;
  line-height: 1;
  align-items: flex-start;
  gap: 10px;
}
.right-side {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.slash {
  width: 2px;
  height: 28px;
  background-color: #ffbb00;
  transform: rotate(20deg);
}

.course-title {
  position: relative;
  left: -16px;
  font-size: 24px;
  font-weight: 400;
  letter-spacing: 1px;
  background-color: #ffffff7e;
  display: inline-block;
  border-radius: 50px;
  padding: 5px 20px;
  align-self: flex-start;
  text-align: justify;
}
.course-describe {
  color: #fff;
  font-weight: 400;
  line-height: 1.25;
  font-size: 15px;
  letter-spacing: 1px;
  text-align: justify;
}
.course-info ul {
  line-height: 1.2;
  list-style-position: inside;
}
.course-info ul li {
  list-style: none;
  line-height: 1.1rem;
  font-size: 14px;
  margin-bottom: 8px;
  text-align: justify;
  position: relative;
  padding-left: 1rem;
}

.course-sidebar {
  flex: 1;
  display: flex;
  justify-content: space-between;
}
.img-box {
  flex: 0 0 45%;
  width: 100%;
}
.img-box img {
  width: 100%;
}
.course-heading {
  display: flex;
  align-items: center;
  gap: 14px;
  color: #fff;
  font-size: 24px;

  font-family: "sans-serif";
}
.no {
  font-family: "Inter";
  font-style: italic;
  font-size: 42px;
  color: #dadada;
}
.course-name {
  letter-spacing: 2px;
}
.smaller-fontSize {
  font-size: 22px;
}
.signUp-btn {
  background-color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  align-self: flex-end;
  gap: 10px;
  color: #000;
  border-radius: 4px;
  padding: 16px 24px;
  transition: all 0.2s ease-in;
  box-shadow: 0 0px 8px rgba(0, 0, 0, 0.1);
}
.signUp-btn:hover {
  background-color: #ecad00;
}
.secondary-heading {
  background-color: #12389a;
  padding: 12px 0;
}
.secondary-heading p {
  text-align: center;
  color: #fff;
  letter-spacing: 1px;
}
.back-cover {
  position: relative;
  width: 100%;
}
.back-cover img {
  width: 100%;
}
.more-btn {
  width: 200px;
  height: 45px;
  position: absolute;
  background-image: url(../images/btn-more.svg);
  background-repeat: no-repeat;
  background-size: contain;
  background-position: center;
  color: #fff;
  display: block;
  bottom: 10%;
  right: 3%;
  cursor: pointer;
  transition: all 0.2s ease;
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.15));
}
.more-btn:hover {
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.35));
}
footer {
  position: relative;
  top: -5px;
  background-color: #ccc;
}
.social-links {
  display: flex;
  gap: 20px;
  background-color: #000;
  color: #fff;
  font-size: 14px;
  letter-spacing: 2px;
  justify-content: center;
  padding: 0 30%;
}

.social-link {
  text-align: center;
  padding: 15px 0;
  flex: 1;
}
.social-link svg,
p {
  transition: all 0.1s ease-in;
}
.social-link p {
  margin-top: 8px;
  color: #fff;
}
.social-link:hover p {
  color: #ccc;
}
.social-link:hover svg path {
  fill: #ccc;
}
.company-info {
  background-color: #ececec;
  padding: 20px;
  text-align: center;
  font-size: 13px;
  letter-spacing: 2px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.company-info p a {
  color: #12389a;
  font-weight: 600;
}

/* RWD start*/
@media (max-width: 820px) {
  main {
    width: 100%;
  }
  .cover {
    padding: 100px 50px;
  }
  .content {
    padding: 20px 15% 0 15%;
  }
  .course-card {
    padding: 24px 40px;
    gap: 24px;
  }
  .course-describe {
    font-size: 14px;
  }
  .no {
    font-size: 36px;
  }
  .course-heading {
    font-size: 19px;
  }
  .signUp-btn {
    padding: 12px 18px;
  }
  .signUp-btn p {
    font-size: 14px;
  }
  .smaller-fontSize {
    font-size: 17px;
  }
  .title img {
    max-width: 300px;
  }
  .social-links {
    padding: 0 15%;
  }
  .more-btn {
    width: 150px;
    height: 35px;
  }
}
@media (max-width: 768px) {
  .course-card {
    flex-direction: column-reverse;
  }
  .course-describe {
    font-size: 16px;
  }
  .course-info {
    flex-direction: column;
    gap: 16px;
  }
  .img-box {
    width: 80%;
    margin: 0 auto;
  }
  .course-sidebar {
    flex-direction: column;
    gap: 16px;
  }
  .signUp-btn {
    align-self: center;
  }
  .course-heading {
    justify-content: center;
    font-size: 24px;
  }
  .smaller-fontSize {
    font-size: 21px;
  }
  .course-card:nth-child(odd) .course-heading {
    flex-direction: row-reverse;
  }
  .right-side {
    padding: 0 15%;
  }
}

@media (max-width: 680px) {
}

@media (max-width: 430px) {
  .cover {
    width: 100%;
    background-size: cover;
    padding: 45px 25px;
    background-image: url(../images/cover-bg.jpg);
    display: inline-block;
    /* gap: 25px; */
  }

  .content {
    padding: 20px 10% 0 10%;
  }
  .ad-text {
    font-size: 13px;
  }
  .course-card {
    padding: 14px;
    gap: 14px;
  }
  .course-heading {
    flex-direction: column-reverse;
    gap: 0;
  }
  .course-card:nth-child(odd) .course-heading {
    flex-direction: column;
  }
  .signUp-btn {
    padding: 8px 12px;
  }
  .no {
    font-size: 24px;
  }
  .slash {
    margin: 0 auto;
    height: 14px;
  }
  .course-name {
    text-align: center;
    font-size: 16px;
  }
  .secondary-heading p {
    font-size: 13px;
  }
  .right-side {
    padding: 0 10%;
    gap: 8px;
  }
  .course-describe {
    font-size: 13px;
    line-height: 1.5;
  }
  .img-box {
    width: 80%;
  }
  .more-btn {
    width: 100px;
    height: 25px;
  }
}