/* 基础样式 */
body {
  font-family: "Muli", sans-serif;
  color: rgb(52, 58, 64);
}

/* 字体大小类 */
.f20,
.f-20 {
  font-size: 20px;
}

.f18,
.f-18 {
  font-size: 18px;
}

.f16,
.f-16 {
  font-size: 16px;
}

.f14,
.f-14 {
  font-size: 14px;
}

.f12,
.f-12 {
  font-size: 12px;
}

.mr-20 {
  margin-right: 20px;
}

.mr-10 {
  margin-right: 10px;
}

/* 页脚样式 */
.footer {
  margin-top: 200px;
  padding: 80px 0;
  position: relative;
  background-color: #2a254d;
}

.footer .container {
  display: flex;
  justify-content: center;
}

.row-main {
  display: flex;
  justify-content: space-between;
  width: 100%;
}

.footer-sub-menu li {
  font-size: 16px;
  margin-bottom: 5px;
}

.footer-sub-menu li a:hover {
  color: #f57005;
  text-decoration: none;
  transition: all 0.3s ease;
}

.main-footer {
  background-color: var(--eduact-black);
  position: relative;
  padding: 132px 0 120px;
}

.copyright {
  position: relative;
  background-color: #1f1944;
  padding: 27px 0 28px;
}

.copyright__text {
  color: #697585;
  margin: 0;
  font-family: var(--eduact-font);
  font-size: 16px;
  line-height: 25px;
  font-weight: 400;
}

.copyright__text a {
  color: #f57005;
}

.copyright__text a:hover {
  color: #f57005;
}

/* 响应式容器 */
@media (min-width: 1400px) {
  .container {
    padding: 0 18px;
    max-width: 1356px;
  }
}

/* 头部样式 */
.main-header {
  position: relative;
  width: 100%;
  /* height: 800px; */
}

/* 主导航菜单 */
.main-menu {
  background: #f8f9fa;
  width: 100%;
}

.main-menu .container {
  height: 100px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
}

.main-menu__logo {
  display: flex;
  align-items: center;
  position: relative;
}

.main-menu__list {
  display: flex;
  justify-content: center;
  gap: 35px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.main-menu__list a {
  color: #2c3e50;
  font-size: 16px;
  font-weight: 500;
  text-decoration: none;
  padding: 16px 30px;
  border-radius: 6px;
  transition: all 0.3s ease;
  position: relative;
}

.main-menu__list a:hover {
  color: #fff;
  background-color: #3498db;
  box-shadow: 0 4px 15px rgba(52, 152, 219, 0.3);
  transform: translateY(-2px);
  text-decoration: none;
}

.main-menu__list a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background-color: #3498db;
  transition: all 0.3s ease;
  transform: translateX(-50%);
}

.main-menu__list a:hover::after {
  width: 80%;
}

/* 轮播图样式 */
.banner-content {
  position: absolute;
  top: 65%;
  left: 35%;
  transform: translate(-50%, -50%);
  color: #fff;
  display: flex;
  flex-direction: column;
}

.banner-title {
  font-size: 4em;
  font-weight: 600;
  margin-bottom: 10px;
}

.banner-desc {
  font-size: 2em;
  font-weight: 400;
  width: 750px;
}

.banner-slider {
  width: 100%;
  height: 86vh;
  overflow: hidden;
  position: relative;
}

.banner-container {
  width: 100%;
  height: 100%;
}

.banner-slide {
  display: block;
  width: 100%;
  height: 100%;
}

.banner-slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  /* 关键：等比缩放并铺满 */
  display: block;
}

/* 固定导航 */
.sticky-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: #fff;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  z-index: 1000;
  padding: 10px 0;
}

.sticky-nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.sticky-nav__logo {
  display: flex;
  align-items: center;
  position: relative;
}

.sticky-nav__menu ul {
  display: flex;
  justify-content: center;
  gap: 30px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.sticky-nav__menu ul li a {
  text-decoration: none;
  font-size: 16px;
  transition: color 0.3s;
}

/* 轮播动画 */
@keyframes slide {
  0%,
  33% {
    transform: translateX(0);
  }

  34%,
  66% {
    transform: translateX(-33.33%);
  }

  67%,
  100% {
    transform: translateX(-66.66%);
  }
}

/* 顶部栏 */
.topbar-one {
  background: #3492ed;
}

.topbar-one .container {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.topbar-one .container a {
  color: #fff;
}

.topbar-one .container .topbar-one__info {
  display: flex;
  align-items: center;
  gap: 20px;
}

.topbar-one .container ul {
  display: flex;
  align-items: center;
  margin: 10px 0;
  padding: 0;
}

.topbar-one .container ul li {
  margin-right: 10px;
}

/* 主要内容区 */
.main-content {
  max-width: 1250px;
  margin: 0 auto;
  padding: 0 15px;
}

.core-block {
  margin-top: 80px;
}

.module-header {
  display: flex;
  justify-content: space-between;
  border-bottom: 1px solid #efefef;
  margin-bottom: 20px;
  padding-bottom: 15px;
}

.ModuleTitle_titleWrapper {
  display: flex;
}

.ModuleTitle_title {
  margin-right: 24px;
  font-size: 22px;
  font-weight: 600;
  color: #404040;
}

.tab-header {
  display: flex;
  align-items: center;
  gap: 20px;
}

.tab-header .active {
  color: #f57005;
}

.tab-content {
  display: none;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.tab-content.active {
  opacity: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: flex-start;
}

.tab-item {
  cursor: pointer;
}

.product-item {
  transition: transform 0.3s ease;
}

.product-item:hover {
  transform: translateY(-5px);
  transition: transform 0.5s ease;
}

.ModuleTitle_subtitle {
  font-size: 16px;
  color: #888;
}

.more-btn {
  padding: 3px 15px;
  font-size: 14px;
  color: #7f848c;
  line-height: 30px;
  cursor: pointer;
}

.product-list {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  justify-content: flex-start;
}

.product-item {
  cursor: pointer;
}

.opencourse {
  width: 280px;
  height: 300px;
  background: #fff;
  box-shadow: 0 4px 30px 0 rgba(238, 242, 245, 0.8);
  border-radius: 8px;
  cursor: pointer;
  transition: box-shadow 0.2s linear;
  padding: 15px;
  overflow: hidden;
}

.opencourse:hover .title {
  color: #fa8919;
}

.video {
  position: relative;
  background: #eee;
  border-radius: 8px;
  overflow: hidden;
  width: 250px;
  height: 140px;
}

.video img {
  width: 100%;
  object-fit: cover;
}

.introduction {
  margin: 12px 12px 0 10px;
}

.bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin: 16px 12px 0 10px;
}

.bottom .desc,
.bottom .author,
.bottom .views,
.publishdate {
  font-weight: 400;
  color: #b2b2b2;
  font-size: 14px;
  line-height: 20px;
}

.publishdate {
  margin-top: 10px;
}

.bottom .btn {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 92px;
  height: 28px;
  background: #fbf5ee;
  border-radius: 14px;
  font-weight: 500;
  color: #fa8919;
  cursor: pointer;
  font-size: 14px;
  line-height: 20px;
}

.introduction .title {
  height:50px;
  font-size: 17px;
  font-weight: 500;
  color: #404040;
  line-height: 25px;
  transition: color 0.2s ease;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.introduction .subtitle {
  height: 45px;
  margin-top: 4px;
  font-size: 15px;
  font-weight: 400;
  color: #888;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}