/* =========================================
   1. Design Token & Themes
   ========================================= */
:root {
  /* 基础参数 */
  --font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --radius-md: 16px;
  --radius-full: 999px;
  --container-width: 1024px;
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  
  /* [Light Mode] 默认日间模式变量 */
  --bg-body: #f8fafc;
  --bg-card: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.8);
  --bg-hover: #f1f5f9;
  
  --text-main: #0f172a;
  --text-muted: #64748b;
  --text-invert: #ffffff;
  
  --primary: #2563eb;       /* 核心蓝 */
  --primary-glow: rgba(37, 99, 235, 0.2);
  
  --border-light: rgba(0, 0, 0, 0.06);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-card: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  --gradient-title: linear-gradient(135deg, #0f172a 0%, #3b82f6 100%);
  --decoration-blob: #e2e8f0;
}

/* [Dark Mode] 深色模式变量覆盖 */
[data-theme="dark"] {
  --bg-body: #0f172a;       /* 深岩灰背景 */
  --bg-card: #1e293b;       /* 稍亮的卡片背景 */
  --bg-glass: rgba(15, 23, 42, 0.8);
  --bg-hover: #334155;
  
  --text-main: #f1f5f9;     /* 亮灰白 */
  --text-muted: #94a3b8;    /* 柔和灰 */
  
  --primary: #60a5fa;       /* 亮蓝，暗色下更显眼 */
  --primary-glow: rgba(96, 165, 250, 0.25);
  
  --border-light: rgba(255, 255, 255, 0.08);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-card: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 0 20px rgba(96, 165, 250, 0.15); /* 加点蓝色光晕 */
  
  --gradient-title: linear-gradient(135deg, #f8fafc 0%, #60a5fa 100%);
  --decoration-blob: #1e293b;
}

/* =========================================
   2. Global Reset & Layout
   ========================================= */
* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: var(--font-main);
  background-color: var(--bg-body);
  color: var(--text-main);
  line-height: 1.6;
  /* 关键：平滑过渡背景色和文字颜色 */
  transition: background-color 0.4s ease, color 0.4s ease;
  overflow-x: hidden;
}

/* 新增：全局图片约束，防止图片撑破布局 */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

a { text-decoration: none; color: inherit; transition: var(--transition-base); }
ul { list-style: none; }

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section-padding { padding: 80px 0; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.column { flex-direction: column; }

/* 滚动条美化 */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-body); }
::-webkit-scrollbar-thumb { background: var(--text-muted); border-radius: 4px; opacity: 0.5; }

/* =========================================
   3. Navigation (Glassmorphism)
   ========================================= */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-light);
  transition: background-color 0.4s ease, border-color 0.4s ease;
}

.nav-container {
  height: 70px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-main);
}

.logo-dot {
  width: 8px;
  height: 8px;
  background: var(--primary);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--primary);
}

.nav-actions { display: flex; align-items: center; gap: 32px; }

.nav-links { display: flex; gap: 24px; }
.nav-links a {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
}
.nav-links a:hover, .nav-links a.active { color: var(--primary); }

.nav-controls { display: flex; align-items: center; gap: 12px; }

/* 按钮通用样式 */
.control-btn {
  background: transparent;
  border: 1px solid var(--border-light);
  color: var(--text-main);
  padding: 6px 14px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.control-btn:hover {
  background: var(--bg-hover);
  border-color: var(--primary);
  color: var(--primary);
}

/* 主题切换按钮特殊处理 */
.theme-toggle {
  width: 36px;
  height: 36px;
  padding: 0;
  border-radius: 50%;
  position: relative;
  overflow: hidden;
}

.theme-toggle i {
  position: absolute;
  transition: transform 0.5s cubic-bezier(0.68, -0.55, 0.27, 1.55), opacity 0.5s;
}

/* 图标切换动画逻辑 */
[data-theme="light"] .moon-icon { transform: translateY(20px) rotate(90deg); opacity: 0; }
[data-theme="light"] .sun-icon { transform: translateY(0) rotate(0); opacity: 1; }
[data-theme="dark"] .sun-icon { transform: translateY(-20px) rotate(-90deg); opacity: 0; }
[data-theme="dark"] .moon-icon { transform: translateY(0) rotate(0); opacity: 1; }

/* =========================================
   4. Hero Section / Intro
   ========================================= */
.intro {
  padding: 100px 0 60px;
  position: relative;
  text-align: center;
}

/* 背景装饰球 */
.bg-decoration {
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, var(--decoration-blob) 0%, transparent 70%);
  opacity: 0.5;
  z-index: -1;
  pointer-events: none;
}

.avatar-container {
  position: relative;
  margin-bottom: 24px;
}

.avatar {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid var(--bg-card);
  position: relative;
  z-index: 2;
  flex-shrink: 0; /* 防止头像被挤压 */
}

.avatar-glow {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background: var(--primary);
  filter: blur(25px);
  opacity: 0.4;
  z-index: 1;
  transform: scale(0.9);
  transition: opacity 0.3s;
}
.avatar-container:hover .avatar-glow { opacity: 0.7; }

.gradient-text {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 16px;
  background: var(--gradient-title);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent; /* 关键：文字透明显示背景渐变 */
  letter-spacing: -1px;
}

.subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 700px;
  margin: 0 auto;
}

/* =========================================
   5. Projects Grid & Detail Images
   ========================================= */
h2 {
  font-size: 2rem;
  text-align: center;
  margin-bottom: 48px;
  color: var(--text-main);
  position: relative;
  display: inline-block;
  width: 100%;
}
/* 标题下划线 */
h2::after {
  content: '';
  display: block;
  width: 40px;
  height: 4px;
  background: var(--primary);
  margin: 12px auto 0;
  border-radius: 2px;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  overflow: hidden;
  transition: var(--transition-base);
  /* 解决 Safari 下圆角溢出问题 */
  transform: translateZ(0); 
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
  border-color: var(--primary-glow);
}

/* 首页项目卡片缩略图 - 优化适配 */
.project-thumbnail {
  width: 100%;
  height: 220px;           /* 调整高度，显示更佳 */
  object-fit: cover;       /* 填满容器，防止拉伸 */
  object-position: center; /* 居中裁剪 */
  border-bottom: 1px solid var(--border-light);
  transition: transform 0.5s ease;
  background-color: var(--bg-hover);
}

.card:hover .project-thumbnail { transform: scale(1.05); }

.project-thumbnail-wrapper { overflow: hidden; }

.project-info { padding: 24px; }

.project-info h3 {
  font-size: 1.25rem;
  margin-bottom: 8px;
  color: var(--text-main);
}

.project-info p {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.project-link {
  font-weight: 600;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.project-link::after { content: '→'; transition: transform 0.2s; }
.project-link:hover::after { transform: translateX(4px); }

/* 子页面：详情大图样式 (新增) */
.project-detail-card { padding: 40px; }

.project-detail-desc {
  max-width: 800px;
  margin: 30px auto;
  line-height: 1.8;
  color: var(--text-muted);
}

.project-img {
  display: block;
  width: 100%;             /* 强制宽度撑满容器 */
  max-width: 100%;         /* 防止超出父容器 */
  height: auto;            /* 高度自动，保持比例 */
  object-fit: contain;     /* 保证图片内容完整显示 */
  border-radius: var(--radius-md);
  margin: 32px auto;       /* 上下增加间距 */
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-light);
}

/* =========================================
   6. Documents & Buttons
   ========================================= */
.publish-links-wrapper { text-align: center; margin-top: 40px; }

.publish-links {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
  background: var(--bg-card);
  padding: 12px;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-light);
}

.publish-link {
  padding: 10px 24px;
  border-radius: var(--radius-full);
  font-weight: 500;
  color: var(--text-muted);
  transition: all 0.3s ease;
  display: flex;
  align-items: center;
  gap: 8px;
}

.publish-link:hover {
  background: var(--bg-hover);
  color: var(--primary);
  transform: translateY(-2px);
}

/* =========================================
   7. Contact & Footer
   ========================================= */
.contact {
  background: var(--bg-card); /* 改为卡片色，不再是大色块 */
  border-top: 1px solid var(--border-light);
}

.contact-links {
  display: flex;
  justify-content: center;
  gap: 48px;
  margin-top: 40px;
}

.contact-item a {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  color: var(--text-muted);
}

.contact-item i {
  font-size: 2rem;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  color: var(--text-main);
}

.contact-item:hover i {
  transform: scale(1.2) rotate(8deg);
  color: var(--primary);
}
.contact-item:hover p { color: var(--primary); }

footer {
  text-align: center;
  padding: 30px;
  font-size: 0.9rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-light);
  background: var(--bg-body);
}

/* =========================================
   8. Mobile Responsive
   ========================================= */
@media (max-width: 768px) {
  .nav-links { display: none; } /* 暂时简化手机端 */
  
  .intro { padding-top: 60px; }
  .gradient-text { font-size: 2.2rem; }

  /* 手机端图片适配 */
  .avatar {
    width: 120px;
    height: 120px;
  }
  .project-thumbnail {
    height: 180px;
  }
  .project-img {
    margin: 20px auto;
    border-radius: 8px;
  }
  
  .publish-links {
    flex-direction: column;
    border-radius: var(--radius-md);
    width: 100%;
  }
  
  .contact-links {
    gap: 24px;
    flex-wrap: wrap;
  }
}


/* Paste this AFTER your existing CSS */

/* =========================================
   9. Open Source Section (New)
   ========================================= */
.opensource-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.os-card {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 24px;
  transition: var(--transition-base);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.os-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
  box-shadow: var(--shadow-card);
}

.os-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 12px;
}

.os-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
}

.os-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  flex-grow: 1;
}

.os-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.os-tag {
  font-size: 0.75rem;
  padding: 4px 10px;
  background: var(--bg-hover);
  color: var(--text-muted);
  border-radius: 20px;
}

.os-actions {
  display: flex;
  gap: 12px;
}

.os-btn {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
  display: flex;
  align-items: center;
  gap: 6px;
}
.os-btn:hover { text-decoration: underline; }

/* =========================================
   10. Timeline Section (New)
   ========================================= */
.timeline-container {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 30px;
}

/* Vertical Line */
.timeline-container::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--border-light);
}

.timeline-item {
  position: relative;
  margin-bottom: 40px;
}

.timeline-dot {
  position: absolute;
  left: -35px; /* Adjust based on padding */
  top: 5px;
  width: 12px;
  height: 12px;
  background: var(--bg-body);
  border: 2px solid var(--primary);
  border-radius: 50%;
  z-index: 1;
}

.timeline-date {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 6px;
  display: block;
}

.timeline-content h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--text-main);
}

.timeline-content p {
  font-size: 0.95rem;
  color: var(--text-muted);
}

/* =========================================
   11. Tech Stack Section (New)
   ========================================= */
.skills-wrapper {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
}

.skill-category h3 {
  font-size: 1.1rem;
  margin-bottom: 16px;
  color: var(--text-main);
  border-left: 3px solid var(--primary);
  padding-left: 12px;
}

.skill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.skill-badge {
  padding: 8px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all 0.2s;
}

.skill-badge:hover {
  border-color: var(--primary);
  color: var(--primary);
  transform: translateY(-2px);
}

/* 修复主题切换按钮的点击响应 */
.theme-toggle {
  cursor: pointer;
  z-index: 10; /* 提高层级 */
  /* 确保按钮有足够空间容纳图标 */
  width: 40px; 
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 防止图标拦截鼠标事件，确保点击穿透到 button */
.theme-toggle i {
  pointer-events: none; 
}

/* 确保导航栏层级够高 */
nav {
  z-index: 1000;
}

/* ... Previous CSS ... */

/* =========================================
   12. Project Tags (New)
   ========================================= */
.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px; /* Space between tags and 'View Details' link */
  margin-top: -12px;   /* Pull closer to description */
}

.project-tag {
  font-size: 0.75rem;
  padding: 3px 10px;
  background: var(--bg-hover);
  color: var(--primary);
  border-radius: 4px;
  font-weight: 500;
  border: 1px solid var(--border-light);
}

/* Adjust paragraph margin in project info to accommodate tags */
.project-info p {
  margin-bottom: 16px; 
}