/* =================================================================== */
/*                                                                     */
/*                 STYLESHEET FOR INDEX.HTML (EnvMolBench)             */
/*                 Optimized & Refactored Version                      */
/*                                                                     */
/* =================================================================== */

/* ============================================= */
/* ==              CSS VARIABLES              == */
/* ============================================= */

:root {
  /* Colors */
  --color-primary: #4f46e5;
  --color-primary-light: #6366f1;
  --color-primary-dark: #3730a3;
  --color-text-header: #1e293b;
  --color-text-body: #374151;
  --color-text-muted: #6b7280;
  --color-border: #e2e8f0;
  --color-background-light: #f8fafc;
  --color-background-card: linear-gradient(
    135deg,
    #ffffff 0%,
    var(--color-background-light) 100%
  );
  --color-gradient-primary: linear-gradient(
    90deg,
    var(--color-primary),
    var(--color-primary-light),
    #8b5cf6
  );
  --color-gradient-text: linear-gradient(
    135deg,
    var(--color-text-header),
    var(--color-primary)
  );

  /* Dark Mode Colors */
  --dark-color-background: #111827;
  --dark-color-card: #1f2937;
  --dark-color-border: #374151;
  --dark-color-text-header: #f3f4f6;
  --dark-color-text-body: #9ca3af;

  /* Sizing & Spacing */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 20px;
  --image-container-height: 200px;

  /* Shadows */
  --shadow-sm: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
  --shadow-interactive: 0 8px 25px -8px rgba(99, 102, 241, 0.4);

  /* Transitions */
  --index-transition-base: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================= */
/* ==       GENERAL PAGE & HERO STYLES        == */
/* ============================================= */

/* ============================================= */
/* ==            SECTION TITLES               == */
/* ============================================= */

#overview-section-title,
.interactive-chapter h2 {
  background: var(--color-gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 800;
  position: relative;
  text-align: center;
  width: 100%;
}

#overview-section-title {
  font-size: 3rem;
  margin-bottom: 4rem !important;
  /* Ensure spacing */
  padding-top: 40px;
  padding-bottom: 20px;
  /* FIX: Provide space for pseudo-element */
}

.interactive-chapter h2 {
  font-size: 2.5rem;
  margin-bottom: 3rem !important;
  display: block;
  /* FIX: Use block for proper width and layout */
  padding-bottom: 20px;
  /* FIX: Provide space for pseudo-element */
}

/* Decorative Underline */
#overview-section-title::after,
.interactive-chapter h2::after {
  content: "";
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-gradient-primary);
  border-radius: 3px;
}

#overview-section-title::after {
  bottom: 0;
  /* Position relative to padding */
  width: 120px;
  height: 6px;
}

.interactive-chapter h2::after {
  bottom: 0;
  /* Position relative to padding */
  width: 80px;
  height: 4px;
}

.interactive-chapter {
  margin-bottom: 4rem;
  animation: fadeInUp 0.6s ease-out;
}

.interactive-chapter:last-child {
  margin-bottom: 2rem;
}

/* ============================================= */
/* ==         CARD STYLES (UNIFIED)           == */
/* ============================================= */

/* Base styles for all cards on the index page */
.overview-card,
.interactive-card-static {
  background: var(--color-background-card);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease,
    border-color 0.3s ease;

  /* 2. 告诉浏览器这个元素会变形，提前分配 GPU 图层 */
  will-change: transform, box-shadow;

  /* 3. 确保 z-index 在悬浮时正确，防止渲染层级打架 */
  position: relative;
  z-index: 1;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  padding: 1.5rem;
  animation: fadeInUp 0.6s ease-out;
}

.overview-card {
  border-radius: var(--radius-md);
}

.interactive-card-static {
  border-radius: var(--radius-lg);
  height: 100%;
}

/* Hover effects for all cards */
.overview-card:hover,
.interactive-card-static:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary-light);
}

.interactive-card-static:hover {
  transform: translateY(-8px) scale(1.02);
}

/* Decorative top border animation for overview cards */
.overview-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--color-gradient-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s ease;
}

.overview-card:hover::before {
  transform: scaleX(1);
}

/* Card Header */
.interactive-card-header {
  display: flex;
  align-items: center;
  margin-bottom: 0.75rem;
}

.overview-card .flex-shrink-0,
.interactive-card-icon {
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s ease;
}

.interactive-card-icon {
  flex-shrink: 0;
  padding: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.overview-card:hover .flex-shrink-0,
.interactive-card-static:hover .interactive-card-icon {
  transform: scale(1.1) rotate(5deg);
}

/* Card Titles */
.overview-card h3,
.interactive-card-header h4 {
  background: var(--color-gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 700;
}

.interactive-card-header h4 {
  font-size: 1.25rem;
}

/* Card Content & Lists */
.overview-card ul,
.interactive-card-description {
  color: var(--color-text-body);
}

.interactive-card-description {
  flex-grow: 1;
  /* Allow description to push elements down */
  margin-bottom: 1rem;
}

.overview-card li {
  position: relative;
  padding-left: 1.5rem;
  margin-bottom: 0.75rem;
  line-height: 1.6;
  transition: transform 0.2s ease, color 0.2s ease;
}

.overview-card li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: bold;
  transition: transform 0.2s ease;
}

.overview-card li:hover {
  transform: translateX(4px);
  color: var(--color-text-header);
}

/* Card Image Containers */
.slideshow-container,
.interactive-card-image-container {
  position: relative;
  width: 100%;
  height: var(--image-container-height);
  overflow: hidden;
  border-radius: var(--radius-sm);
  background: var(--color-background-light);
  margin: auto 0 1rem 0;
  border: 1px solid var(--color-border);
}

.slideshow-container img,
.interactive-card-image {
  width: 100%;
  height: 100%;
  object-fit: contain;
  /* Keep image aspect ratio */
  object-position: center;
  transition: all 0.3s ease;
  pointer-events: none;
  /* <-- 为轮播图图片添加这一行 */
}

.slideshow-container img.active {
  opacity: 1;
  pointer-events: auto;
  /* <-- 添加这一行 */
}

/* 确保交互式卡片的图片仍然可以点击 */
.interactive-card-image {
  cursor: pointer;
  pointer-events: auto;
  /* <-- 确保非轮播图的图片可以点击 */
}

.interactive-card-image:hover {
  transform: scale(1.05);
}

/* Card Buttons */
.overview-card a,
.interactive-card-button {
  display: block;
  width: 100%;
  text-align: center;
  font-weight: 600;
  padding: 0.75rem 0;
  border-radius: var(--radius-sm);
  transition: var(--index-transition-base);
  background: linear-gradient(135deg, #e0e7ff, #c7d2fe);
  color: var(--color-text-header);
  border: 1px solid transparent;
  position: relative;
  overflow: hidden;
  margin-top: auto;
}

.overview-card a:hover,
.interactive-card-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-interactive);
  background: linear-gradient(135deg, #c7d2fe, #a5b4fc);
}

/* Button Shimmer Effect */
.overview-card a::before,
.interactive-card-button::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.6),
    transparent
  );
  transition: left 0.6s ease;
}

.overview-card a:hover::before,
.interactive-card-button:hover::before {
  left: 100%;
}

/* Card Grid */
.interactive-card-grid {
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
}

/* ============================================= */
/* ==              COMPONENTS                 == */
/* ============================================= */

/* --- Slideshow --- */
.slideshow-container img {
  position: absolute;
  top: 0;
  left: 0;
  opacity: 0;
  transition: opacity 0.5s ease-in-out;
}

.slideshow-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background-color: rgba(0, 0, 0, 0.3);
  color: white;
  border: none;
  padding: 0.5rem;
  cursor: pointer;
  z-index: 10;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  transition: background-color 0.2s ease;
}

.slideshow-arrow:hover {
  background-color: rgba(0, 0, 0, 0.6);
}

.slideshow-arrow.prev {
  left: 0.5rem;
}

.slideshow-arrow.next {
  right: 0.5rem;
}

.slideshow-dots {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 20;
  /* FIX: pointer-events: none; REMOVED to make dots clickable */
}

.slideshow-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  background-color: #bbb;
  border-radius: 50%;
  margin: 0 4px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

.slideshow-dot.active {
  background-color: var(--color-primary);
}

/* --- Dark Mode --- */
html.dark .overview-card,
html.dark .interactive-card-static {
  background: var(--dark-color-card);
  border-color: var(--dark-color-border);
}

html.dark .interactive-card-header h4,
html.dark .overview-card h3 {
  color: var(--dark-color-text-header);
}

html.dark .interactive-card-description {
  color: var(--dark-color-text-body);
}

html.dark .slideshow-container,
html.dark .interactive-card-image-container {
  background-color: var(--dark-color-border);
}

html.dark .interactive-card-button,
html.dark .overview-card a {
  background-color: var(--color-primary-dark);
  color: #e0e7ff;
}

html.dark .interactive-card-button:hover,
html.dark .overview-card a:hover {
  background-color: var(--color-primary);
}

/* ============================================= */
/* ==           RESPONSIVE DESIGN             == */
/* ============================================= */

@media (max-width: 1023.98px) {
  .interactive-card-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.5rem;
  }
}

@media (max-width: 768px) {
  #overview-section-title {
    font-size: 2.25rem;
  }

  .interactive-chapter h2 {
    font-size: 2rem;
  }

  .overview-card {
    margin-bottom: 1.5rem;
  }

  .interactive-card-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
}

/* ============================================= */
/* ==          ANIMATIONS & UTILITIES         == */
/* ============================================= */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Staggered animation for chapters */
.interactive-chapter:nth-child(2) {
  animation-delay: 0.2s;
}

.interactive-chapter:nth-child(3) {
  animation-delay: 0.4s;
}

/* Custom Scrollbar for card content areas */
.overview-card ::-webkit-scrollbar {
  width: 6px;
}

.overview-card ::-webkit-scrollbar-track {
  background: #f1f5f9;
  border-radius: 3px;
}

.overview-card ::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, #c7d2fe, #a5b4fc);
  border-radius: 3px;
}

.overview-card ::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(135deg, #a5b4fc, #818cf8);
}

/* --- 1. General Body and Text Styles --- */
html.dark body {
  /* 设置全局深色背景和默认文字颜色 */
  background-color: #111827;
  /* gray-900 */
  color: #9ca3af;
  /* gray-400 */
}

/* 确保所有标题在深色模式下都有正确的颜色 */
html.dark h1,
html.dark h2,
html.dark h3,
html.dark h4,
html.dark h5,
html.dark h6 {
  /* 排除那些已经有渐变文字效果的标题 */
  &:not(#overview-section-title):not(.interactive-chapter h2) {
    color: #f9fafb;
    /* gray-50 */
  }
}

/* --- 2. Process Card Styles --- */
html.dark .process-card {
  background-color: #1f2937;
  /* gray-800 */
  border-color: #374151;
  /* gray-700 */
  border-left-color: transparent;
}

html.dark .process-card:hover {
  border-left-color: #6366f1;
  /* indigo-500 */
}

html.dark .process-card-text a {
  color: #818cf8;
  /* indigo-400 */
}

html.dark .process-card-text a:hover {
  color: #a5b4fc;
  /* indigo-300 */
}

/* --- 3. Component-Specific Styles --- */

/* Note Box (.dl-note) */
html.dark .dl-note {
  background-color: rgba(79, 70, 229, 0.15);
  /* Semi-transparent primary */
  border-left-color: #6366f1;
  /* indigo-500 */
  color: #d1d5db;
  /* gray-300 */
}

/* Toggle Switch */
html.dark .toggle-switch-container label {
  color: #d1d5db;
  /* gray-300 */
}

html.dark .slider {
  background-color: #374151;
  /* gray-700 */
}

/* Tab Buttons */
html.dark .tab-button {
  color: #9ca3af;
  /* gray-400 */
}

html.dark .tab-button:hover {
  color: #d1d5db;
  /* gray-300 */
}

html.dark .tab-button.active {
  border-bottom-color: #6366f1;
  /* indigo-500 */
  color: #818cf8;
  /* indigo-400 */
}

/* Mobile Menu Link Hover Fallback */
html.dark .mobile-nav-link:not(.nav-active):hover {
  background-color: #374151 !important;
  /* gray-700 */
  border-left-color: #4b5563 !important;
  /* gray-600 */
  color: #f9fafb !important;
  /* gray-50 */
}
html.dark .overview-card h3,
html.dark .interactive-card-header h4 {
  /* 1. 移除背景渐变 */
  background: none;

  /* 2. 恢复文字的默认填充行为 */
  -webkit-text-fill-color: initial;

  /* 3. 设置一个明亮的、可读的颜色 */
  color: #f9fafb; /* Tailwind's gray-50 */
}
/* 深色模式的卡片标题与按钮样式统一由 css/dark-mode.css 维护，移除本地重复规则 */

.overview-card .card-description > * {
  transition: transform 0.2s ease, color 0.2s ease;
}

/* 
 * 2. 为这些子元素定义一个统一的悬停效果 (浅色模式)。
 */
.overview-card .card-description > *:hover {
  transform: translateX(4px);
  color: var(--color-text-header);
  /* 悬停时文字变深 */
}

html.dark .overview-card a,
html.dark .interactive-card-button {
  /* 1. 使用 'background' 属性（而不是 background-color）来正确覆盖浅色模式的渐变 */
  background: #3730a3; /* 一个清晰可见的深靛蓝色 */

  /* 2. 设置一个明亮的、可读的文字颜色 */
  color: #e0e7ff; /* 浅靛蓝色/薰衣草色 */

  /* 3. 为按钮添加一个微妙的边框，使其在卡片上轮廓更清晰 */
  border: 1px solid #4338ca;
}

/* 4. 为暗色模式添加一个匹配的悬停效果，提升用户体验 */
html.dark .overview-card a:hover,
html.dark .interactive-card-button:hover {
  background: #4338ca; /* 悬停时颜色变亮 */
  border-color: #6366f1;
  color: #ffffff; /* 文字变为纯白，更突出 */
}

html.dark #nav-announcement-popup > div.px-4.py-3 {
  background-color: rgba(17, 24, 39, 0.88);
}

html.dark #nav-announcement-popup > div.px-4.py-3 > span {
  color: #e5e7eb;
}