/* ==========================================================================
   全局 CSS 变量与主题定义 (Modern Clean Theme)
   ========================================================================== */
:root {
  /* 浅色模式颜色 */
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-alt: #f1f5f9;
  --bg-card: rgba(255, 255, 255, 0.85);
  --border-color: #e2e8f0;
  --border-hover: #cbd5e1;

  --text-main: #0f172a;
  --text-muted: #475569;
  --text-light: #64748b;

  --accent-primary: #3b82f6;
  --accent-primary-hover: #2563eb;
  --accent-light: #eff6ff;
  --accent-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-glow: 0 0 25px -5px rgba(59, 130, 246, 0.3);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --nav-height: 70px;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 暗色模式变量 */
[data-theme="dark"] {
  --bg-primary: #090d16;
  --bg-secondary: #0f172a;
  --bg-alt: #0a0f1d;
  --bg-card: rgba(15, 23, 42, 0.75);
  --border-color: #1e293b;
  --border-hover: #334155;

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-light: #64748b;

  --accent-primary: #60a5fa;
  --accent-primary-hover: #3b82f6;
  --accent-light: rgba(59, 130, 246, 0.15);
  --accent-gradient: linear-gradient(135deg, #60a5fa 0%, #a78bfa 100%);

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 20px -3px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 30px -5px rgba(96, 165, 250, 0.25);
}

/* ==========================================================================
   全局重置与排版
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Plus Jakarta Sans', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-primary);
  background-image: 
    radial-gradient(at 10% 10%, rgba(59, 130, 246, 0.06) 0px, transparent 50%),
    radial-gradient(at 90% 25%, rgba(139, 92, 246, 0.05) 0px, transparent 50%),
    radial-gradient(at 50% 85%, rgba(59, 130, 246, 0.04) 0px, transparent 50%);
  background-attachment: fixed;
  color: var(--text-main);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

[data-theme="dark"] body {
  background-image: 
    radial-gradient(at 10% 10%, rgba(96, 165, 250, 0.09) 0px, transparent 50%),
    radial-gradient(at 90% 25%, rgba(167, 139, 250, 0.07) 0px, transparent 50%),
    radial-gradient(at 50% 85%, rgba(59, 130, 246, 0.06) 0px, transparent 50%);
}

.container {
  width: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

/* 渐变标题文字 */
.gradient-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

/* ==========================================================================
   导航栏 (Navbar)
   ========================================================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: var(--transition);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.25rem;
}

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

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

.nav-item {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
}

.nav-item:hover {
  color: var(--accent-primary);
}

.btn-nav {
  padding: 6px 16px;
  background: var(--accent-light);
  color: var(--accent-primary) !important;
  border-radius: var(--radius-full);
  font-weight: 600;
}

.btn-nav:hover {
  background: var(--accent-primary);
  color: #fff !important;
}

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

.theme-toggle {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
}

.theme-toggle:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
  background: var(--bg-alt);
}

.sun-icon { display: none; }
.moon-icon { display: block; }

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.mobile-menu-btn span {
  width: 22px;
  height: 2px;
  background-color: var(--text-main);
  transition: var(--transition);
}

/* ==========================================================================
   按钮组件 (Buttons)
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary {
  background: var(--accent-primary);
  color: #fff;
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--accent-primary-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-main);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
  transform: translateY(-2px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border-color: var(--border-color);
}

.btn-ghost:hover {
  background: var(--bg-alt);
  color: var(--text-main);
}

.btn-large {
  padding: 14px 28px;
  font-size: 1.05rem;
}

.btn-block {
  width: 100%;
}

/* ==========================================================================
   Hero 核心区域
   ========================================================================== */
.hero-section {
  padding-top: calc(var(--nav-height) + 60px);
  padding-bottom: 80px;
  position: relative;
}

.hero-container {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  align-items: center;
  gap: 48px;
}

.badge-status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--accent-light);
  color: var(--accent-primary);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.pulse-dot {
  width: 8px;
  height: 8px;
  background: #10b981;
  border-radius: 50%;
  box-shadow: 0 0 0 rgba(16, 185, 129, 0.4);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.6); }
  70% { box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
  100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-title {
  font-size: 2.85rem;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 1rem;
  color: var(--text-light);
  line-height: 1.8;
  margin-bottom: 32px;
  max-width: 580px;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 36px;
}

.social-links {
  display: flex;
  align-items: center;
  gap: 16px;
}

.social-item {
  color: var(--text-light);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background: var(--bg-secondary);
}

.social-item:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

/* Hero 右侧头像卡片 */
.hero-avatar-card {
  display: flex;
  justify-content: center;
}

.avatar-wrapper {
  position: relative;
  width: 260px;
  height: 260px;
}

.avatar-placeholder {
  width: 100%;
  height: 100%;
  border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 3.5rem;
  font-weight: 800;
  box-shadow: var(--shadow-glow);
  animation: morph 8s ease-in-out infinite;
}

@keyframes morph {
  0% { border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%; }
  50% { border-radius: 70% 30% 30% 70% / 70% 70% 30% 30%; }
  100% { border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%; }
}

.floating-badge {
  position: absolute;
  padding: 8px 14px;
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: 6px;
}

.badge-top {
  top: -10px;
  right: -20px;
  animation: float 4s ease-in-out infinite;
}

.badge-bottom {
  bottom: 10px;
  left: -20px;
  animation: float 4s ease-in-out infinite 2s;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* ==========================================================================
   Hero 核心数据量化展示栏 (Stats Strip)
   ========================================================================== */
.stats-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 48px;
  padding: 22px 28px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: var(--shadow-md);
  position: relative;
}

.stat-item {
  text-align: center;
  position: relative;
  padding: 4px 12px;
}

.stat-item:not(:last-child)::after {
  content: '';
  position: absolute;
  right: 0;
  top: 15%;
  height: 70%;
  width: 1px;
  background: var(--border-color);
}

.stat-number {
  display: block;
  font-size: 1.55rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.25;
  margin-bottom: 4px;
  font-family: 'JetBrains Mono', 'Plus Jakarta Sans', monospace, sans-serif;
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--text-light);
  font-weight: 500;
}

/* ==========================================================================
   通版 Section
   ========================================================================== */
.section {
  padding: 80px 0;
}

.section-alt {
  background-color: var(--bg-alt);
}

.section-header {
  text-align: center;
  margin-bottom: 50px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-light);
}

/* 卡片基础样式 */
.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-lg);
}

/* ==========================================================================
   关于我 (About Grid)
   ========================================================================== */
.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.about-card .card-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.about-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.about-card .card-text {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 16px;
  line-height: 1.7;
}

.about-card .card-meta {
  font-size: 0.85rem;
  color: var(--accent-primary);
  font-weight: 600;
}

/* ==========================================================================
   技术栈 (Skills)
   ========================================================================== */
.skills-wrapper {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 24px;
}

.skill-category {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.category-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--text-main);
  border-left: 3px solid var(--accent-primary);
  padding-left: 10px;
}

.tags-group {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag {
  padding: 6px 14px;
  background: var(--bg-alt);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 500;
  transition: var(--transition);
}

.tag:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
  background: var(--accent-light);
}

/* ==========================================================================
   竞赛与荣誉 (Honors & Awards)
   ========================================================================== */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.award-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 22px 24px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  transition: var(--transition);
  position: relative;
}

.award-card:hover {
  transform: translateY(-3px);
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-md);
}

.award-card.award-gold:hover {
  border-color: #f59e0b;
  box-shadow: 0 8px 24px -4px rgba(245, 158, 11, 0.25);
}

.award-card.award-blue:hover {
  border-color: #0284c7;
  box-shadow: 0 8px 24px -4px rgba(2, 132, 199, 0.25);
}

.award-card.award-purple:hover {
  border-color: #8b5cf6;
  box-shadow: 0 8px 24px -4px rgba(139, 92, 246, 0.25);
}

.award-card.award-green:hover {
  border-color: #10b981;
  box-shadow: 0 8px 24px -4px rgba(16, 185, 129, 0.25);
}

.award-card.award-orange:hover {
  border-color: #f97316;
  box-shadow: 0 8px 24px -4px rgba(249, 115, 22, 0.25);
}

.award-card.award-cyan:hover {
  border-color: #06b6d4;
  box-shadow: 0 8px 24px -4px rgba(6, 182, 212, 0.25);
}

.award-card.award-indigo:hover {
  border-color: #6366f1;
  box-shadow: 0 8px 24px -4px rgba(99, 102, 241, 0.25);
}

.award-badge {
  font-size: 1.85rem;
  line-height: 1;
  flex-shrink: 0;
}

.award-content h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 5px;
}

.award-content p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 8px;
}

.award-meta {
  font-size: 0.78rem;
  color: var(--accent-primary);
  font-weight: 600;
  background: var(--accent-light);
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  display: inline-block;
}

.meta-gold {
  background: rgba(245, 158, 11, 0.14);
  color: #d97706;
}

[data-theme="dark"] .meta-gold {
  color: #fbbf24;
}

/* ==========================================================================
   精选科研与开源项目 (Projects & Filters)
   ========================================================================== */
.project-filter-bar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
}

.filter-pill {
  padding: 8px 18px;
  font-size: 0.88rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  cursor: pointer;
  transition: var(--transition);
  outline: none;
}

.filter-pill:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
  background: var(--accent-light);
}

.filter-pill.active {
  background: var(--accent-gradient);
  color: #ffffff;
  border-color: transparent;
  box-shadow: 0 4px 14px rgba(59, 130, 246, 0.35);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}

.project-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease, opacity 0.25s ease;
  position: relative;
}

.project-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-lg);
}

.project-card.featured {
  border: 1px solid rgba(59, 130, 246, 0.35);
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-alt) 100%);
}

[data-theme="dark"] .project-card.featured {
  border: 1px solid rgba(96, 165, 250, 0.35);
  box-shadow: 0 8px 24px -6px rgba(0, 0, 0, 0.5), 0 0 20px -5px rgba(96, 165, 250, 0.15);
}

.project-card.featured::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
  border-top-left-radius: var(--radius-lg);
  border-top-right-radius: var(--radius-lg);
}

.project-card.hidden {
  display: none !important;
}

.project-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.project-type {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 4px 10px;
  background: var(--accent-light);
  color: var(--accent-primary);
  border-radius: var(--radius-full);
}

.project-type.paper-badge {
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15) 0%, rgba(168, 85, 247, 0.15) 100%);
  color: #7c3aed;
  border: 1px solid rgba(139, 92, 246, 0.3);
}

[data-theme="dark"] .project-type.paper-badge {
  color: #a78bfa;
}

.project-type.collab-badge {
  background: rgba(148, 163, 184, 0.15);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
}

.project-authors {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-top: -4px;
  margin-bottom: 12px;
}

.project-authors strong {
  color: var(--text-main);
  text-decoration: underline;
  text-decoration-color: var(--accent-primary);
  text-underline-offset: 3px;
}

.project-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.metric-chip {
  font-size: 0.76rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  background: rgba(59, 130, 246, 0.1);
  color: var(--accent-primary);
  border: 1px solid rgba(59, 130, 246, 0.2);
  font-family: 'JetBrains Mono', monospace, sans-serif;
}

[data-theme="dark"] .metric-chip {
  background: rgba(96, 165, 250, 0.12);
  border-color: rgba(96, 165, 250, 0.25);
  color: #93c5fd;
}

.metric-chip.accent {
  background: rgba(168, 85, 247, 0.12);
  border-color: rgba(168, 85, 247, 0.25);
  color: #c084fc;
}

.project-links {
  display: flex;
  gap: 8px;
}

.icon-link {
  color: var(--text-light);
  padding: 4px;
  border-radius: 4px;
  transition: var(--transition);
}

.icon-link:hover {
  color: var(--accent-primary);
  transform: translateY(-2px);
}

.project-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
  line-height: 1.4;
}

.project-desc {
  font-size: 0.93rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 24px;
  flex-grow: 1;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.project-tags span {
  font-size: 0.8rem;
  padding: 4px 10px;
  background: var(--bg-alt);
  color: var(--text-light);
  border-radius: var(--radius-sm);
  font-weight: 500;
}

/* ==========================================================================
   时间线 (Timeline)
   ========================================================================== */
.timeline {
  max-width: 720px;
  margin: 0 auto;
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 8px;
  width: 2px;
  background: var(--border-color);
}

.timeline-item {
  position: relative;
  margin-bottom: 36px;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -32px;
  top: 6px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--bg-secondary);
  border: 3px solid var(--accent-primary);
  box-shadow: 0 0 0 4px var(--bg-primary);
}

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

.timeline-content h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.timeline-content p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ==========================================================================
   近期文章 (Articles)
   ========================================================================== */
.articles-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.article-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  transition: var(--transition);
}

.article-item:hover {
  border-color: var(--accent-primary);
  transform: translateX(6px);
  box-shadow: var(--shadow-md);
}

.article-info {
  max-width: 75%;
}

.article-tag {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-primary);
  margin-bottom: 6px;
  display: inline-block;
}

.article-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.article-summary {
  font-size: 0.9rem;
  color: var(--text-light);
}

.article-meta {
  text-align: right;
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: 0.85rem;
}

.article-meta time {
  color: var(--text-light);
}

.read-more {
  color: var(--accent-primary);
  font-weight: 600;
}

/* ==========================================================================
   底部联系横幅 (Contact CTA)
   ========================================================================== */
.section-contact {
  padding-bottom: 100px;
}

.contact-card {
  background: var(--accent-gradient);
  border-radius: var(--radius-lg);
  padding: 50px;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-glow);
}

.contact-text h2 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.contact-text p {
  opacity: 0.9;
  font-size: 1.05rem;
}

.contact-actions {
  display: flex;
  gap: 16px;
}

.contact-actions .btn-primary {
  background: #fff;
  color: #1e3a8a;
}

.contact-actions .btn-primary:hover {
  background: #f1f5f9;
  color: #1d4ed8;
}

.contact-actions .btn-secondary {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(10px);
}

.contact-actions .btn-secondary:hover {
  background: rgba(255, 255, 255, 0.25);
  border-color: #fff;
}

/* ==========================================================================
   弹窗与提示条 (Modal & Toast)
   ========================================================================== */
.modal {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal.active {
  visibility: visible;
  opacity: 1;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(6px);
}

.modal-card {
  position: relative;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  width: 90%;
  max-width: 380px;
  text-align: center;
  box-shadow: var(--shadow-lg);
  z-index: 10;
  transform: translateY(20px);
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal.active .modal-card {
  transform: translateY(0);
}

.modal-close {
  position: absolute;
  top: 14px;
  right: 18px;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-light);
  cursor: pointer;
}

.modal-card h3 {
  font-size: 1.3rem;
  margin-bottom: 8px;
}

.modal-desc {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 20px;
}

.qr-placeholder {
  background: var(--bg-alt);
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-md);
  padding: 30px 20px;
  margin-bottom: 24px;
}

.qr-icon {
  font-size: 3rem;
  margin-bottom: 10px;
}

.wechat-id {
  font-size: 0.95rem;
  color: var(--text-muted);
}

/* Toast */
.toast {
  position: fixed;
  bottom: 30px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: #0f172a;
  color: #fff;
  padding: 12px 24px;
  border-radius: var(--radius-full);
  font-size: 0.95rem;
  font-weight: 500;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
  z-index: 3000;
  opacity: 0;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s ease;
  pointer-events: none;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* ==========================================================================
   页脚 (Footer)
   ========================================================================== */
.footer {
  border-top: 1px solid var(--border-color);
  padding: 32px 0;
  background: var(--bg-secondary);
}

.footer-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.9rem;
  color: var(--text-light);
}

.footer-badge {
  background: var(--bg-alt);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  font-size: 0.8rem;
  font-weight: 500;
}

/* ==========================================================================
   响应式断点适配 (Responsive Mobile)
   ========================================================================== */
@media (max-width: 900px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 36px;
  }

  .hero-desc {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-cta {
    justify-content: center;
  }

  .social-links {
    justify-content: center;
  }

  .about-grid,
  .skills-wrapper,
  .awards-grid {
    grid-template-columns: 1fr;
  }

  .contact-card {
    flex-direction: column;
    text-align: center;
    gap: 24px;
  }
}

@media (max-width: 768px) {
  .mobile-menu-btn {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    flex-direction: column;
    gap: 20px;
    padding: 24px;
    transform: translateY(-150%);
    transition: transform 0.3s ease;
    box-shadow: var(--shadow-lg);
  }

  .nav-links.active {
    transform: translateY(0);
  }

  .hero-title {
    font-size: 2.2rem;
  }

  .article-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .article-info {
    max-width: 100%;
  }

  .article-meta {
    text-align: left;
    flex-direction: row;
    justify-content: space-between;
    width: 100%;
  }

  .footer-container {
    flex-direction: column;
    text-align: center;
  }

  .stats-strip {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    padding: 16px;
  }

  .stat-item:not(:last-child)::after {
    display: none;
  }

  .stat-number {
    font-size: 1.35rem;
  }
}

@media (max-width: 520px) {
  .stats-strip {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .project-filter-bar {
    gap: 8px;
  }

  .filter-pill {
    font-size: 0.8rem;
    padding: 6px 14px;
    width: 100%;
    text-align: center;
  }
}