:root {
  --primary-color: #FFD700; /* Gold */
  --secondary-color: #000080; /* Dark Blue */
  --text-dark: #333333;
  --text-light: #ffffff;
  --bg-light: #f8f8f8;
  --bg-dark: #1a1a1a; /* Adjusted for better contrast with light text */
  --border-color: #e0e0e0;
}

.page-index {
  font-family: 'Arial', sans-serif;
  line-height: 1.6;
  color: var(--text-dark); /* Default text color for light body background */
  background-color: #ffffff; /* Explicitly set for clarity, assuming shared.css doesn't set body bg */
}

/* HERO 主图区域样式 */
.page-index__hero-section {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 20px;
  padding-top: var(--header-offset, 120px); /* Fixed header offset */
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%); /* Using brand colors */
  color: var(--text-light); /* Light text for dark/gradient background */
}

.page-index__hero-container {
  position: relative;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.page-index__hero-image {
  width: 100%;
  margin-bottom: 30px;
  max-width: 1000px; /* Limit hero image width on large screens for better composition */
}

.page-index__hero-image img {
  width: 100%;
  height: auto;
  max-width: 100%;
  display: block;
  border-radius: 12px;
  object-fit: cover;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.page-index__hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  width: 100%;
}

.page-index__hero-title {
  font-size: 3.2em;
  margin-bottom: 20px;
  font-weight: bold;
  color: var(--text-light);
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.page-index__hero-description {
  font-size: 1.3em;
  margin-bottom: 40px;
  color: #f0f0f0;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.page-index__hero-cta-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap; /* Allow buttons to wrap on smaller screens */
}

.page-index__cta-button {
  display: inline-block;
  padding: 15px 40px;
  background: var(--primary-color);
  color: var(--text-light);
  text-decoration: none;
  border-radius: 50px;
  font-size: 1.1em;
  font-weight: bold;
  transition: all 0.3s ease;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  border: none;
  cursor: pointer;
  min-width: 180px;
  box-sizing: border-box; /* Crucial for responsive buttons */
}

.page-index__cta-button--primary {
  background: var(--primary-color);
  color: var(--text-light);
}

.page-index__cta-button--secondary {
  background: var(--secondary-color);
  color: var(--text-light);
}

.page-index__cta-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
  opacity: 0.9;
}

/* Common Section Styles */
.page-index__container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}

.page-index__section-title {
  font-size: 2.5em;
  font-weight: bold;
  text-align: center;
  margin-bottom: 20px;
  color: var(--secondary-color);
}

.page-index__section-title--light {
  color: var(--primary-color);
}

.page-index__section-description {
  font-size: 1.1em;
  text-align: center;
  margin-bottom: 50px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
  color: var(--text-dark);
}

.page-index__section-description--light {
  color: #f0f0f0;
}

.page-index__light-bg {
  background-color: var(--bg-light);
  color: var(--text-dark);
}

.page-index__dark-bg {
  background-color: var(--secondary-color); /* Use dark blue as dark bg */
  color: var(--text-light);
}

/* Module 1: Introduction */
.page-index__introduction-section {
  padding: 80px 0;
}

.page-index__content-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: center;
}

.page-index__text-block p {
  margin-bottom: 15px;
  font-size: 1.1em;
}