/* CSS Variables for Theme Support */
:root {
  /* Light Theme Colors */
  --bg-primary: #F7FAFC;
  --bg-secondary: #f7f9ff;
  --bg-card: rgba(255, 255, 255, 0.6);
  --bg-card-hover: rgba(255, 255, 255, 0.95);
  --text-primary: #11142D;
  --text-secondary: #616B7E;
  --text-muted: #9B9CAE;
  --border-color: rgba(17, 20, 45, 0.1);
  --accent-blue: #193FB9;
  --accent-blue-light: rgba(25, 63, 185, 0.1);
  --shadow-sm: 0 2px 4px rgba(25, 63, 185, 0.06);
  --shadow-md: 0 4px 12px rgba(25, 63, 185, 0.1);
  --shadow-lg: 0 8px 24px rgba(25, 63, 185, 0.15);
  --icon-filter: none;
  
  /* Typography */
  --font-chinese: "Noto Sans SC", sans-serif;
  --font-english: "Bitter", serif;
  
  /* Spacing */
  --spacing-xs: 0.1rem;
  --spacing-sm: 0.25rem;
  --spacing-md: 0.5rem;
  --spacing-lg: 0.75rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 5rem;
  
  /* Font Sizes */
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* Dark Theme */
.theme-dark {
  --bg-primary: #0F1419;
  --bg-secondary: #131416;
  --bg-card: rgba(32, 33, 37, 0.8);
  --bg-card-hover: rgba(26, 31, 46, 0.95);
  --text-primary: #E2E8F0;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;
  --border-color: rgba(226, 232, 240, 0.1);
  --accent-blue: #60A5FA;
  --accent-blue-light: rgba(96, 165, 250, 0.1);
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  --icon-filter: invert(1);
}

/* Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-chinese);
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--transition-normal), color var(--transition-normal);
}

/* 全局字体规则 - 中文使用 Noto Sans SC */
[data-lang="zh"] *:not(.material-icons),
[lang="zh"] *:not(.material-icons),
.chinese-text:not(.material-icons) {
  font-family: var(--font-chinese) !important;
}

/* 全局字体规则 - 英文使用 Bitter */
[data-lang="en"] *:not(.material-icons),
[lang="en"] *:not(.material-icons),
.english-text:not(.material-icons) {
  font-family: var(--font-english) !important;
}

/* 默认字体设置 */
body {
  font-family: var(--font-chinese);
}

/* Material Icons 样式 */
.material-icons {
  font-family: 'Material Icons' !important;
  font-weight: normal;
  font-style: normal;
  font-size: 18px;
  line-height: 1;
  letter-spacing: normal;
  text-transform: none;
  display: inline-block;
  white-space: nowrap;
  word-wrap: normal;
  direction: ltr;
  -webkit-font-feature-settings: 'liga';
  -webkit-font-smoothing: antialiased;
  vertical-align: middle;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-english);
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
  margin-bottom: var(--spacing-md);
  color: var(--text-secondary);
}

/* Header */
.header {
  padding: var(--spacing-2xl) var(--spacing-xl) var(--spacing-sm) var(--spacing-xl);
  background: transparent;
  position: relative;
  overflow: hidden;
}

/* Vanta.js Birds Effect Container - Full Screen */
.vanta-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
}


.profile-section {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
  position: relative;
  z-index: 2;
}

.profile-image {
  flex-shrink: 0;
}

.profile-image img {
  width: 150px;
  height: 150px;
  border-radius: var(--radius-md);
  object-fit: cover;
  transition: transform var(--transition-normal);
  /* Fade out bottom 20%: opaque until 80%, then transparent to 100% */
  -webkit-mask-image: linear-gradient(to bottom, #000 70%, transparent 100%);
  mask-image: linear-gradient(to bottom, #000 70%, transparent 100%);
}

.profile-image img:hover {
  transform: scale(1.05);
}

.profile-info {
  flex: 1;
}

.profile-name {
  font-size: var(--font-size-2xl);
  font-weight: 300;
  color: var(--text-primary);
  margin-bottom: var(--spacing-sm);
}

.profile-title {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: var(--spacing-xs);
}

.profile-location {
  font-size: 1rem;
  color: var(--text-muted);
  margin-bottom: var(--spacing-lg);
}

/* Profile actions removed - download button moved to nav */

/* Navigation */
.nav-menu {
  background: transparent;
  backdrop-filter: none;
  position: sticky;
  top: 0;
  z-index: 100;
  height: 40px;
}

.nav-menu .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: nowrap;
  gap: var(--spacing-lg);
}

.nav-items {
  display: flex;
  gap: var(--spacing-lg);
  flex: 1;
  justify-content: stretch;
  flex-wrap: nowrap;
  height: 40px;
  margin-top: 10px;
}

.nav-item {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  background: rgba(255,255,255,0.18);
  border: none;
  color: var(--text-primary);
  font-size: var(--font-size-sm);
  font-weight: 400;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  white-space: nowrap;
  border-radius: var(--radius-xl);
  backdrop-filter: blur(12px);
  transition: background 0.2s, color 0.2s, flex 0.3s;
  min-width: 20px;
  line-height: normal;
  height: 30px;
  padding: 0 var(--spacing-sm);
  border: 1px solid var(--border-color);
  padding: 0 var(--spacing-lg);
}


.nav-item:hover, .nav-item.active {
  color: var(--text-primary);
  color: var(--text-primary);
  background: rgba(255,255,255,0.65);
  box-shadow: 0 2px 8px rgba(25,63,185,0.08);
}

/* .nav-item.active visual now handled by .nav-item:hover, .nav-item.active above */

.nav-controls {
  display: flex;
  gap: var(--spacing-sm);
  flex-shrink: 0;
  align-items: center;
}

.nav-download-btn {
  font-size: var(--font-size-sm);
  padding: var(--spacing-xs) var(--spacing-sm);
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

/* Main Content */
.main-content {
  flex-shrink: 0;
  margin: var(--spacing-xl) var(--spacing-lg);
  border-radius: var(--radius-md);
  min-height: 50vh;
  background: transparent;
  position: relative;
  display: flex;
  flex-direction: column;
  padding: var(--spacing-sm);
}

/* Waterfall Layout */
.waterfall-container {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}


/* Full Width Sections */
.full-width-section {
  border-radius: 0;
  padding: var(--spacing-xl) 0;
}

.full-width-section .experiences-timeline,
.full-width-section .projects-grid,
.full-width-section .contact-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}


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

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-sm);
  border: none;
  border-radius: var(--radius-lg);
  font-family: var(--font-chinese);
  font-size: var(--font-size-sm);
  font-weight: 400;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left var(--transition-normal);
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
  color: white;
  box-shadow: var(--shadow-sm);
  font-size: small;
  padding: var(--spacing-sm) var(--spacing-md);
}

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

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-size: small;
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: var(--accent-blue-light);
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* Footer */
.footer {
  background: transparent;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
  padding: var(--spacing-md) 0;
  position: relative;
  z-index: 1;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.footer-text {
  color: var(--text-muted);
  font-size: var(--font-size-xs);
}

/* Loading Overlay */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

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

.loading-spinner {
  background: var(--bg-card);
  padding: var(--spacing-xl);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border-color);
  border-top: 3px solid var(--accent-blue);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-md);
  }
  
  .profile-section {
    flex-direction: column;
    text-align: center;
    gap: var(--spacing-lg);
  }
  
  .profile-name {
    font-size: 2rem;
  }
  
  .nav-menu .container {
    flex-direction: row;
    gap: var(--spacing-sm);
    flex-wrap: nowrap;
    min-height: 40px;
  }
  
  .nav-items {
    flex-wrap: nowrap;
    justify-content: stretch;
    flex: 1;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
  
  .nav-item {
    padding: 0 var(--spacing-sm);
    font-size: var(--font-size-sm);
    flex: 1;
  }
  
  .nav-item.active {
    flex: 2;
  }
  
  .nav-controls {
    flex-shrink: 0;
  }
  
  .nav-download-btn {
    font-size: 0.8rem;
    padding: var(--spacing-xs);
    height: 36px;
  }
  
  .nav-download-btn span:last-child {
    display: none;
  }
  
  .footer-content {
    flex-direction: column;
    text-align: center;
  }
  
  /* Waterfall responsive */
  .waterfall-container {
    gap: var(--spacing-md);
  }
  
  .full-width-section {
    padding: var(--spacing-2xl) 0;
  }
  
  .full-width-section .experiences-timeline,
  .full-width-section .projects-grid,
  .full-width-section .contact-content {
    padding: 0 var(--spacing-md);
  }
}

@media (max-width: 480px) {
  .profile-name {
    font-size: 1.75rem;
  }
  
  
  /* 保证小屏下 nav-item 文字不隐藏 */
  .nav-item .icon {
    width: 16px;
    height: 16px;
  }
  .nav-item span:last-child {
    display: inline;
  }
  
  .nav-item.active {
    flex: 2;
  }
  
  .btn {
    padding: var(--spacing-xs) var(--spacing-md);
  
  .nav-download-btn {
    font-size: 0.75rem;
    padding: var(--spacing-xs);
    height: 32px;
  }
  
  /* Waterfall mobile */
  .waterfall-container {
    gap: var(--spacing-xl);
  }
  
  .full-width-section {
    padding: var(--spacing-xl) 0;
  }
  
  .full-width-section .experiences-timeline,
  .full-width-section .projects-grid,
  .full-width-section .contact-content {
    padding: 0 var(--spacing-sm);
  }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

.hidden { display: none; }
.visible { display: block; }

.fade-in {
  animation: fadeIn var(--transition-normal);
}

/* Smooth scrolling for anchor links */
html {
  scroll-behavior: smooth;
}

/* Focus styles for accessibility */
button:focus,
input:focus,
textarea:focus,
select:focus {
  outline: none !important;
  box-shadow: none !important;
  border-color: transparent !important;
}

/* Selection styles */
::selection {
  background: var(--accent-blue-light);
  color: var(--text-primary);
}
}