/* ===== CSS Variables ===== */
:root {
  /* Primary Colors */
  --primary: #00a1d6;
  --primary-light: #33b4de;
  --primary-dark: #0081b3;
  --secondary: #ff6b6b;
  --accent: #ffd166;
  
  /* Background Colors */
  --bg-primary: rgba(240, 245, 250, 0.92);
  --bg-secondary: rgba(255, 255, 255, 0.88);
  --bg-card: rgba(255, 255, 255, 0.75);
  
  /* Text Colors */
  --text-primary: #2d3748;
  --text-secondary: #4a5568;
  --text-light: #718096;
  
  /* Borders */
  --border-light: rgba(0, 0, 0, 0.08);
  --border-medium: rgba(0, 0, 0, 0.12);
  
  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);
  --shadow-glow: 0 0 20px rgba(0, 161, 214, 0.3);
  
  /* Glass Effect */
  --glass-blur: 20px;
  
  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  
  /* Transitions */
  --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-fast: all 0.2s ease;
}

/* Dark Mode */
.dark-mode {
  --bg-primary: rgba(15, 20, 30, 0.95);
  --bg-secondary: rgba(25, 30, 45, 0.9);
  --bg-card: rgba(35, 42, 60, 0.8);
  --text-primary: #f0f2f5;
  --text-secondary: #c0c6d4;
  --text-light: #8892a4;
  --border-light: rgba(255, 255, 255, 0.1);
  --border-medium: rgba(255, 255, 255, 0.15);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 30px rgba(0, 161, 214, 0.4);
}

/* ===== Reset & Base ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--text-primary);
  line-height: 1.7;
  min-height: 100vh;
  background-color: var(--bg-primary);
  transition: var(--transition);
  overflow-x: hidden;
}

/* ===== Custom Cursor ===== */
/* Default cursor - 蔚蓝档案风格箭头 */
* {
  cursor: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="28" height="28" viewBox="0 0 28 28"><polygon points="2,2 22,2 2,22" fill="rgba(100,200,255,0.7)" stroke="rgba(255,255,255,0.85)" stroke-width="1.5" stroke-linejoin="round"/><polygon points="5,5 18,5 5,18" fill="rgba(255,255,255,0.4)"/></svg>') 2 2, auto;
}

/* Interactive elements - 亮粉色箭头 */
a, button, [role="button"], .clickable,
input[type="submit"], input[type="button"],
.nav-item, .social-btn, .project-link {
  cursor: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="30" height="30" viewBox="0 0 30 30"><polygon points="3,3 25,3 3,25" fill="rgba(255,120,180,0.85)" stroke="rgba(255,255,255,0.95)" stroke-width="2" stroke-linejoin="round"/><polygon points="7,7 20,7 7,20" fill="rgba(255,255,255,0.6)"/><circle cx="9" cy="9" r="1.2" fill="rgba(255,255,255,0.9)"/></svg>') 3 3, pointer;
}

/* ===== Custom Background ===== */
.custom-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -2;
  background-image: url('https://images.unsplash.com/photo-1506905925346-21bda4d32df4?ixlib=rb-4.0.3&auto=format&fit=crop&w=1350&q=80');
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
  transition: background-image 1.2s ease;
  animation: bgZoom 30s ease-in-out infinite alternate;
}

@keyframes bgZoom {
  0% { transform: scale(1); }
  100% { transform: scale(1.05); }
}

/* ===== Glass Overlay ===== */
.glass-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  background: linear-gradient(135deg, 
    rgba(255, 255, 255, 0.05) 0%, 
    rgba(255, 255, 255, 0.02) 50%,
    rgba(0, 0, 0, 0.02) 100%);
  backdrop-filter: blur(1px);
  -webkit-backdrop-filter: blur(1px);
}

/* ===== Container Layout ===== */
.container {
  display: flex;
  min-height: 100vh;
  padding: 24px;
  gap: 24px;
  max-width: 1440px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

/* ===== Sidebar ===== */
.sidebar {
  width: 300px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 20px;
  position: sticky;
  top: 24px;
  height: calc(100vh - 48px);
  overflow-y: auto;
  transition: var(--transition);
}

/* Custom Scrollbar */
.sidebar::-webkit-scrollbar {
  width: 4px;
}
.sidebar::-webkit-scrollbar-track {
  background: transparent;
}
.sidebar::-webkit-scrollbar-thumb {
  background: var(--primary);
  border-radius: 4px;
  opacity: 0.5;
}

.glass-sidebar {
  background: var(--bg-card);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow-lg);
  animation: slideIn 0.6s ease-out;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* User Card */
.user-card {
  text-align: center;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-light);
  position: relative;
}

.user-card::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 2px;
}

.user-avatar {
  position: relative;
  width: 110px;
  height: 110px;
  margin: 0 auto 18px;
}

.avatar-img {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid var(--primary);
  box-shadow: var(--shadow-glow);
  transition: var(--transition);
  animation: avatarFloat 3s ease-in-out infinite;
}

@keyframes avatarFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-5px); }
}

.avatar-img:hover {
  transform: scale(1.08);
  border-color: var(--secondary);
  box-shadow: 0 0 30px rgba(255, 107, 107, 0.4);
}

.online-status {
  position: absolute;
  bottom: 8px;
  right: 8px;
  width: 18px;
  height: 18px;
  background: linear-gradient(135deg, #4CAF50, #8BC34A);
  border: 3px solid var(--bg-card);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(76, 175, 80, 0.4); }
  50% { box-shadow: 0 0 0 8px rgba(76, 175, 80, 0); }
}

.username {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--text-primary);
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.user-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 16px;
  font-style: italic;
}

.user-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-top: 12px;
}

.user-tag {
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.1), rgba(0, 161, 214, 0.05));
  color: var(--primary);
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  border: 1px solid rgba(0, 161, 214, 0.2);
  transition: var(--transition);
}

.user-tag:hover {
  background: var(--primary);
  color: white;
  transform: translateY(-2px);
}

/* Navigation */
.sidebar-nav {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding-top: 20px;
}

.nav-list {
  list-style: none;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--text-secondary);
  transition: var(--transition);
  margin-bottom: 6px;
  position: relative;
  overflow: hidden;
}

.nav-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 0;
  height: 0;
  background: linear-gradient(90deg, var(--primary), transparent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  transition: var(--transition);
  opacity: 0.15;
}

.nav-item:hover {
  background: rgba(0, 161, 214, 0.08);
  color: var(--primary);
  transform: translateX(5px);
}

.nav-item:hover::before {
  width: 100%;
}

.nav-item.active {
  background: linear-gradient(90deg, rgba(0, 161, 214, 0.15), rgba(0, 161, 214, 0.05));
  color: var(--primary);
  font-weight: 600;
}

.nav-item.active::before {
  width: 100%;
}

.nav-icon {
  font-size: 1.3rem;
  width: 28px;
  text-align: center;
  transition: var(--transition);
}

.nav-item:hover .nav-icon,
.nav-item.active .nav-icon {
  transform: scale(1.2);
}

.nav-text {
  font-size: 1rem;
}

/* Social Links */
.social-links {
  display: flex;
  justify-content: center;
  gap: 14px;
  padding: 20px 0 0;
  border-top: 1px solid var(--border-light);
  margin-top: 20px;
}

.social-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.1), rgba(0, 161, 214, 0.05));
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
  font-size: 1.2rem;
  border: 1px solid rgba(0, 161, 214, 0.15);
}

.social-btn:hover {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  transform: translateY(-4px) scale(1.1);
  box-shadow: var(--shadow-glow);
}

/* Sidebar Toggle */
.sidebar-toggle {
  display: none;
  position: fixed;
  top: 24px;
  left: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  border: none;
  font-size: 1.3rem;
  cursor: pointer;
  z-index: 1001;
  box-shadow: var(--shadow-lg);
  transition: var(--transition);
  align-items: center;
  justify-content: center;
}

.sidebar-toggle:hover {
  transform: rotate(90deg) scale(1.1);
  box-shadow: var(--shadow-glow);
}

/* ===== Main Content ===== */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 24px;
  min-width: 0;
}

.main-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 0;
  animation: fadeInDown 0.6s ease-out;
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.site-title {
  font-size: 2.2rem;
  font-weight: 800;
  background: linear-gradient(135deg, #fff, rgba(255, 255, 255, 0.8));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  letter-spacing: -0.5px;
}

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

.theme-toggle, .bg-toggle {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 1px solid var(--border-medium);
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
  font-size: 1.1rem;
}

.theme-toggle:hover, .bg-toggle:hover {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  transform: rotate(15deg) scale(1.1);
  box-shadow: var(--shadow-glow);
}

/* ===== Glass Cards ===== */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: blur(var(--glass-blur));
  -webkit-backdrop-filter: blur(var(--glass-blur));
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  overflow: hidden;
  position: relative;
}

.glass-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.5), transparent);
}

.glass-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: rgba(0, 161, 214, 0.3);
}

/* ===== Content Sections ===== */
.content-sections {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.content-section {
  display: none;
  flex-direction: column;
  gap: 24px;
  animation: fadeIn 0.4s ease-out;
}

.content-section.active {
  display: flex;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(15px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Section Card */
.section-card {
  padding: 28px;
  animation: slideUp 0.5s ease-out backwards;
}

.section-card:nth-child(1) { animation-delay: 0.1s; }
.section-card:nth-child(2) { animation-delay: 0.2s; }
.section-card:nth-child(3) { animation-delay: 0.3s; }

@keyframes slideUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 2px solid var(--border-light);
  position: relative;
}

.section-header::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 80px;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
}

.section-header h3 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-header h3 i {
  color: var(--primary);
  font-size: 1.2rem;
}

/* Welcome Content */
.welcome-content {
  line-height: 2;
}

.welcome-content p {
  margin-bottom: 14px;
  color: var(--text-secondary);
  font-size: 1.05rem;
  position: relative;
  padding-left: 20px;
}

.welcome-content p::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--primary);
  font-weight: bold;
}

/* Skills Grid */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
}

.skill-category h4 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.skill-category h4::before {
  content: '◆';
  color: var(--primary);
  font-size: 0.8rem;
}

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

.skill-tag {
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.1), rgba(0, 161, 214, 0.05));
  color: var(--primary);
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  border: 1px solid rgba(0, 161, 214, 0.15);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.skill-tag::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
  transition: var(--transition);
}

.skill-tag:hover {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  transform: translateY(-3px);
  box-shadow: 0 4px 15px rgba(0, 161, 214, 0.3);
}

.skill-tag:hover::before {
  left: 100%;
}

/* Updates List */
.updates-list {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.update-item {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  padding: 16px;
  background: rgba(0, 0, 0, 0.02);
  border-radius: var(--radius-md);
  border-left: 3px solid var(--primary);
  transition: var(--transition);
}

.dark-mode .update-item {
  background: rgba(255, 255, 255, 0.03);
}

.update-item:hover {
  background: rgba(0, 161, 214, 0.05);
  transform: translateX(5px);
}

.update-date {
  font-weight: 700;
  color: var(--primary);
  min-width: 110px;
  font-size: 0.95rem;
  font-family: 'Courier New', monospace;
}

.update-content {
  color: var(--text-secondary);
  flex: 1;
  line-height: 1.6;
}

/* Articles List */
.articles-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.article-item {
  padding: 20px;
  background: rgba(0, 0, 0, 0.02);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  transition: var(--transition);
  cursor: pointer;
}

.dark-mode .article-item {
  background: rgba(255, 255, 255, 0.02);
}

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

.article-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 12px;
  flex-wrap: wrap;
  gap: 10px;
}

.article-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-primary);
  flex: 1;
  min-width: 200px;
  transition: var(--transition);
}

.article-item:hover .article-title {
  color: var(--primary);
}

.article-date {
  font-size: 0.9rem;
  color: var(--text-light);
  white-space: nowrap;
}

.article-excerpt {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 14px;
}

.article-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
}

.article-category {
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.1), rgba(0, 161, 214, 0.05));
  color: var(--primary);
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  border: 1px solid rgba(0, 161, 214, 0.15);
}

/* Projects Grid */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.project-item {
  padding: 24px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.03), rgba(0, 161, 214, 0.01));
  border: 1px solid var(--border-light);
  transition: var(--transition);
}

.project-item:hover {
  border-color: var(--primary);
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
  flex-wrap: wrap;
  gap: 12px;
}

.project-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text-primary);
}

.project-links {
  display: flex;
  gap: 10px;
}

.project-link {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 161, 214, 0.1);
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
  font-size: 1rem;
}

.project-link:hover {
  background: var(--primary);
  color: white;
  transform: translateY(-3px) rotate(10deg);
}

.project-desc {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 16px;
}

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

.tech-tag {
  background: linear-gradient(135deg, rgba(255, 107, 107, 0.1), rgba(255, 107, 107, 0.05));
  color: var(--secondary);
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  border: 1px solid rgba(255, 107, 107, 0.15);
  transition: var(--transition);
}

.tech-tag:hover {
  background: var(--secondary);
  color: white;
}

/* About Content */
.about-content {
  line-height: 2;
}

.about-text p {
  margin-bottom: 18px;
  color: var(--text-secondary);
  font-size: 1.05rem;
}

.about-list {
  margin: 12px 0 18px 24px;
  color: var(--text-secondary);
}

.about-list li {
  margin-bottom: 10px;
  line-height: 1.7;
  position: relative;
}

.about-list li::marker {
  color: var(--primary);
}

/* Timeline */
.timeline {
  position: relative;
  padding-left: 24px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--primary), var(--accent));
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  margin-bottom: 28px;
  padding-left: 20px;
}

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

.timeline-item::before {
  content: '';
  position: absolute;
  left: -9px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--primary);
  border: 3px solid var(--bg-card);
  box-shadow: 0 0 0 4px rgba(0, 161, 214, 0.2);
}

.timeline-date {
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 6px;
  font-size: 1rem;
  font-family: 'Courier New', monospace;
}

.timeline-content h4 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.timeline-content p {
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Contact Content */
.contact-content p {
  color: var(--text-secondary);
  margin-bottom: 24px;
  line-height: 1.8;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin: 28px 0;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 16px;
  background: rgba(0, 0, 0, 0.02);
  border-radius: var(--radius-md);
  transition: var(--transition);
}

.dark-mode .contact-item {
  background: rgba(255, 255, 255, 0.02);
}

.contact-item:hover {
  background: rgba(0, 161, 214, 0.05);
  transform: translateX(5px);
}

.contact-item i {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.1), rgba(0, 161, 214, 0.05));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  font-size: 1.3rem;
  transition: var(--transition);
}

.contact-item:hover i {
  background: var(--primary);
  color: white;
}

.contact-label {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 4px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.contact-value {
  color: var(--text-primary);
  font-size: 1.1rem;
  text-decoration: none;
  transition: var(--transition);
}

.contact-value:hover {
  color: var(--primary);
}

.contact-social {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 28px;
}

@media (min-width: 640px) {
  .contact-social {
    grid-template-columns: repeat(4, 1fr);
  }
}

.social-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 22px 16px;
  border-radius: var(--radius-md);
  text-decoration: none;
  color: var(--text-primary);
  transition: var(--transition);
  background: rgba(0, 0, 0, 0.02);
  border: 1px solid transparent;
}

.dark-mode .social-link {
  background: rgba(255, 255, 255, 0.02);
}

.social-link:hover {
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.1), rgba(0, 161, 214, 0.05));
  border-color: rgba(0, 161, 214, 0.3);
  transform: translateY(-4px);
  color: var(--primary);
}

.social-link i {
  font-size: 2rem;
  transition: var(--transition);
}

.social-link:hover i {
  transform: scale(1.2);
}

.social-link span {
  font-size: 0.9rem;
  font-weight: 500;
}

/* ===== Footer ===== */
.glass-footer {
  margin-top: 32px;
  padding: 28px;
  border-top: 1px solid var(--border-light);
  animation: fadeIn 0.6s ease-out;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-left {
  display: flex;
  align-items: center;
  gap: 18px;
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, #fff, rgba(255, 255, 255, 0.8));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-tagline {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-style: italic;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-link {
  color: var(--text-secondary);
  text-decoration: none;
  transition: var(--transition);
  font-size: 0.95rem;
}

.footer-link:hover {
  color: var(--primary);
}

.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid var(--border-light);
  text-align: center;
}

.copyright {
  color: var(--text-light);
  font-size: 0.9rem;
  margin-bottom: 6px;
}

.footer-note {
  color: var(--text-light);
  font-size: 0.8rem;
  font-style: italic;
}

/* ===== Background Selector ===== */
.bg-selector {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.9);
  width: 92%;
  max-width: 620px;
  background: var(--bg-card);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow-lg);
  z-index: 1001;
  opacity: 0;
  visibility: hidden;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.bg-selector.active {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, -50%) scale(1);
}

.bg-selector-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(5px);
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
}

.bg-selector-overlay.active {
  opacity: 1;
  visibility: visible;
}

.bg-selector-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-light);
}

.bg-selector-header h3 {
  font-size: 1.4rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.close-selector {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: none;
  background: linear-gradient(135deg, var(--secondary), #ff4757);
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.close-selector:hover {
  transform: rotate(90deg) scale(1.1);
}

.bg-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-bottom: 20px;
}

@media (min-width: 640px) {
  .bg-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.bg-option {
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.bg-option:hover {
  transform: translateY(-6px);
}

.bg-option.active .bg-preview {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(0, 161, 214, 0.3);
}

.bg-option.active span {
  color: var(--primary);
  font-weight: 600;
}

.bg-preview {
  width: 100%;
  height: 100px;
  border-radius: var(--radius-md);
  background-size: cover;
  background-position: center;
  margin-bottom: 10px;
  border: 3px solid transparent;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.bg-preview::after {
  content: '✓';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0);
  width: 32px;
  height: 32px;
  background: var(--primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  opacity: 0;
  transition: var(--transition);
}

.bg-option.active .bg-preview::after {
  transform: translate(-50%, -50%) scale(1);
  opacity: 1;
}

.bg-option span {
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: var(--transition);
}

.custom-bg-upload {
  text-align: center;
  padding-top: 18px;
  border-top: 1px solid var(--border-light);
}

.upload-btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 24px;
  background: linear-gradient(135deg, rgba(0, 161, 214, 0.1), rgba(0, 161, 214, 0.05));
  color: var(--primary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
  font-weight: 500;
  border: 1px dashed rgba(0, 161, 214, 0.3);
}

.upload-btn:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
  .container {
    flex-direction: column;
    padding: 16px;
  }
  
  .sidebar {
    width: 100%;
    height: auto;
    position: relative;
    top: 0;
  }
  
  .sidebar-nav {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    z-index: 1000;
    padding: 80px 24px 24px;
    flex-direction: column;
  }
  
  .sidebar.active .sidebar-nav {
    display: flex;
  }
  
  .sidebar.active .glass-sidebar {
    background: transparent;
    backdrop-filter: none;
    border: none;
    box-shadow: none;
  }
  
  .sidebar-toggle {
    display: flex;
  }
  
  .main-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    padding-left: 60px;
  }
  
  .header-actions {
    align-self: flex-end;
  }
}

@media (max-width: 768px) {
  .container {
    padding: 12px;
  }
  
  .section-card {
    padding: 20px;
  }
  
  .site-title {
    font-size: 1.6rem;
  }
  
  .article-header,
  .project-header {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .contact-social {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-content {
    flex-direction: column;
    text-align: center;
  }
  
  .footer-left {
    flex-direction: column;
  }
  
  .footer-links {
    justify-content: center;
  }
  
  .bg-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .user-tags {
    flex-direction: column;
    align-items: center;
  }
  
  .skill-tags {
    justify-content: center;
  }
  
  .project-tech {
    justify-content: center;
  }
  
  .contact-social {
    grid-template-columns: 1fr;
  }
  
  .skills-grid {
    grid-template-columns: 1fr;
  }
}

/* ===== Utility Classes ===== */
.hidden {
  display: none !important;
}

.fade-in {
  animation: fadeIn 0.4s ease-out;
}

/* ===== Loading Animation ===== */
.loading {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 200px;
}

.loading::after {
  content: '';
  width: 40px;
  height: 40px;
  border: 3px solid var(--border-light);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===== Particle Effect (optional enhancement) ===== */
.particles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.particle {
  position: absolute;
  width: 4px;
  height: 4px;
  background: var(--primary);
  border-radius: 50%;
  opacity: 0.3;
  animation: float 15s infinite;
}

@keyframes float {
  0%, 100% {
    transform: translateY(100vh) rotate(0deg);
    opacity: 0;
  }
  10% {
    opacity: 0.3;
  }
  90% {
    opacity: 0.3;
  }
  100% {
    transform: translateY(-100vh) rotate(720deg);
    opacity: 0;
  }
}