/* === 全局变量定义 === */
:root {
  --primary-blue: #104066;
  --primary-red: #dc3545;
  --gold: #ffc107;
  --light-gray: #e9ecef;
  --medium-gray: #6c757d;
  --dark-gray: #343a40;
  --off-white: #f8f9fa;
  --white: #ffffff;
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-hover: 0 8px 15px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
  --border-radius: 8px;
}

/* === 基础重置和全局样式 === */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Open Sans', sans-serif;
  color: var(--dark-gray);
  line-height: 1.6;
  background-color: var(--white);
}

h1, h2, h3, h4, h5, h6 {
  font-family: 'Montserrat', sans-serif;
  font-weight: 700;
  line-height: 1.2;
  color: var(--primary-blue);
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}
.container h2 {
  color: white;
  font-size: 36px;
  margin-bottom: 20px;
}

/* === PAGE HERO === */
.page-hero {
  padding: 160px 0 80px;
  background: linear-gradient(
          135deg,
          rgba(16, 64, 102, 0.05) 0%,
          rgba(248, 249, 250, 1) 100%
  );
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 40%;
  height: 100%;
  background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 400 400"><path fill="%23104066" fill-opacity="0.03" d="M200,0 C310.46,0 400,89.54 400,200 C400,310.46 310.46,400 200,400 C89.54,400 0,310.46 0,200 C0,89.54 89.54,0 200,0 Z M200,50 C118.43,50 50,118.43 50,200 C50,281.57 118.43,350 200,350 C281.57,350 350,281.57 350,200 C350,118.43 281.57,50 200,50 Z"></path></svg>')
  center/contain no-repeat;
  opacity: 0.5;
  pointer-events: none;
}

.page-hero h1 {
  font-size: 48px;
  margin-bottom: 20px;
  position: relative;
  z-index: 2;
}

.page-hero p {
  font-size: 20px;
  color: var(--medium-gray);
  max-width: 800px;
  margin: 0 auto 30px;
  position: relative;
  z-index: 2;
}

/* === STATS SECTION === */
.stats {
  display: flex;
  justify-content: center;
  gap: 50px;
  margin-top: 40px;
  position: relative;
  z-index: 2;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 42px;
  font-weight: 700;
  color: var(--primary-red);
  margin-bottom: 5px;
}

.stat-label {
  font-size: 16px;
  color: var(--medium-gray);
}

/* === LEARNING CATEGORIES === */
.learning-categories {
  padding: 80px 0;
  background-color: var(--white);
}

.section-title {
  text-align: center;
  margin-bottom: 60px;
}

.section-title h2 {
  font-size: 36px;
  margin-bottom: 15px;
}

.section-title p {
  color: var(--medium-gray);
  max-width: 700px;
  margin: 0 auto;
  font-size: 18px;
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.category-card {
  background-color: var(--off-white);
  border-radius: var(--border-radius);
  padding: 30px;
  border-top: 4px solid var(--primary-blue);
  transition: var(--transition);
  box-shadow: var(--shadow);
}

.category-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-hover);
}

.category-icon {
  width: 50px;
  height: 50px;
  background-color: rgba(16, 64, 102, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--primary-blue);
  font-size: 24px;
}

.category-title {
  font-size: 20px;
  margin-bottom: 15px;
}

.category-description {
  color: var(--medium-gray);
  margin-bottom: 15px;
  font-size: 14px;
  line-height: 1.6;
}

.category-resources {
  font-size: 13px;
  color: var(--medium-gray);
  background-color: rgba(16, 64, 102, 0.05);
  padding: 5px 15px;
  border-radius: 20px;
  display: inline-block;
}

/* === EXPERT VIDEO LIBRARY === */
.expert-video-library {
  padding: 80px 0;
  background-color: var(--white);
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.video-card {
  background-color: var(--off-white);
  border-radius: var(--border-radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.video-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.video-thumbnail {
  height: 180px;
  background-color: var(--light-gray);
  position: relative;
  background: linear-gradient(
          135deg,
          var(--primary-blue) 0%,
          var(--dark-blue) 100%
  );
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 48px;
}

.video-play-button {
  width: 60px;
  height: 60px;
  background-color: var(--primary-red);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 24px;
}

.video-duration {
  position: absolute;
  bottom: 10px;
  right: 10px;
  background-color: rgba(0, 0, 0, 0.5);
  color: white;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 12px;
}

.video-info {
  padding: 20px;
}

.video-category {
  font-size: 12px;
  color: var(--primary-red);
  text-transform: uppercase;
  margin-bottom: 10px;
}

.video-title {
  font-size: 18px;
  margin-bottom: 10px;
}

.video-description {
  color: var(--medium-gray);
  margin-bottom: 15px;
  font-size: 14px;
  line-height: 1.6;
}

.video-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--medium-gray);
}

/* === DOWNLOADABLE PPT RESOURCES === */
.ppt-resources {
  padding: 80px 0;
  background-color: var(--white);
}

.resources-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.resource-card {
  background-color: var(--off-white);
  border-radius: var(--border-radius);
  padding: 30px;
  border-left: 4px solid var(--primary-red);
  transition: var(--transition);
  box-shadow: var(--shadow);
}

.resource-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.resource-icon {
  width: 50px;
  height: 50px;
  background-color: rgba(220, 53, 69, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--primary-red);
  font-size: 24px;
}

.resource-title {
  font-size: 20px;
  margin-bottom: 15px;
}

.resource-description {
  color: var(--medium-gray);
  margin-bottom: 20px;
  font-size: 14px;
  line-height: 1.6;
}

.resource-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--medium-gray);
  margin-bottom: 20px;
}

.download-btn {
  display: inline-block;
  background-color: var(--primary-red);
  color: white;
  padding: 10px 20px;
  text-decoration: none;
  border-radius: 4px;
  font-weight: 600;
  transition: var(--transition);
}

.download-btn:hover {
  background-color: #bd2130;
}

/* === SIMPLE LEARNING PATH === */
.learning-path {
  padding: 80px 0;
  background-color: var(--off-white);
}

.path-steps {
  display: flex;
  justify-content: center;
  gap: 60px;
  margin-top: 40px;
}

.step {
  width: 250px;
  position: relative;
  padding-left: 60px;
}

.step:before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 2px;
  height: 100%;
  background-color: var(--light-gray);
}

.step:first-child:before {
  display: none;
}

.step-number {
  position: absolute;
  left: 0;
  top: 0;
  width: 40px;
  height: 40px;
  background-color: var(--primary-red);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  font-weight: 700;
}

.step-title {
  font-size: 18px;
  margin-bottom: 15px;
}

.step-description {
  color: var(--medium-gray);
  font-size: 14px;
  line-height: 1.6;
}

/* === WHY LEARN WITH US === */
.why-learn {
  padding: 80px 0;
  background-color: var(--white);
}

.benefits-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.benefit-card {
  text-align: center;
  padding: 30px;
  border-radius: var(--border-radius);
  background-color: var(--off-white);
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.benefit-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.benefit-icon {
  width: 50px;
  height: 50px;
  background-color: rgba(16, 64, 102, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--primary-blue);
  font-size: 24px;
}

.benefit-title {
  font-size: 20px;
  margin-bottom: 15px;
}

.benefit-description {
  color: var(--medium-gray);
  font-size: 14px;
  line-height: 1.6;
}

/* === CTA SECTION === */
.cta-section {
  padding: 80px 0;
  background: linear-gradient(135deg,
  var(--primary-blue) 0%,
  var(--dark-blue) 100%);
  color: white;
  text-align: center;
}

.cta-title {
  font-size: 36px;
  margin-bottom: 20px;
}

.cta-description {
  font-size: 18px;
  margin-bottom: 30px;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.cta-btn {
  display: inline-block;
  background-color: var(--gold);
  color: var(--primary-blue);
  padding: 14px 32px;
  text-decoration: none;
  border-radius: 4px;
  font-weight: 700;
  font-size: 16px;
  transition: var(--transition);
}

.cta-btn:hover {
  background-color: #e0a800;
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

/* === 响应式设计 === */
@media (max-width: 1024px) {
  .categories-grid,
  .video-grid,
  .resources-grid,
  .benefits-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .page-hero {
    padding: 140px 0 60px;
  }

  .page-hero h1 {
    font-size: 36px;
  }

  .page-hero p {
    font-size: 18px;
  }

  .stats {
    flex-direction: column;
    gap: 30px;
  }

  .path-steps {
    flex-direction: column;
    gap: 30px;
    align-items: center;
  }

  .step {
    width: 100%;
    padding-left: 0;
    text-align: center;
  }

  .step:before {
    display: none;
  }

  .step-number {
    left: 50%;
    transform: translateX(-50%);
  }

  .video-grid,
  .resources-grid,
  .benefits-grid {
    grid-template-columns: 1fr;
  }

  .modal-content {
    width: 95%;
    margin: 20px auto;
  }

  .modal-body {
    padding: 20px;
  }
}

@media (max-width: 480px) {
  .page-hero h1 {
    font-size: 32px;
  }

  .section-title h2 {
    font-size: 28px;
  }

  .stats {
    gap: 20px;
  }
}