:root {
  --font-body: "Inter", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-display: "Inter", "Noto Sans SC", system-ui, sans-serif;
  
  /* 高级配色方案 - Light Mode */
  --color-bg: #fafbfc;
  --color-surface: #ffffff;
  --color-surface-muted: #f5f7fa;
  --color-surface-elevated: #ffffff;
  --color-text: #0f172a;
  --color-text-muted: #64748b;
  --color-text-subtle: #94a3b8;
  --color-border: #e2e8f0;
  --color-border-strong: #cbd5e1;
  
  /* 渐变和强调色 */
  --color-accent: #3b82f6;
  --color-accent-hover: #2563eb;
  --color-accent-soft: rgba(59, 130, 246, 0.1);
  --color-accent-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  
  /* 阴影系统 */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
  --shadow-colored: 0 20px 25px -5px rgba(59, 130, 246, 0.1), 0 10px 10px -5px rgba(59, 130, 246, 0.04);
  
  --color-nav-bg: rgba(255, 255, 255, 0.8);
  --color-hero-bg: #0f172a;
  --color-hero-overlay: rgba(15, 23, 42, 0.4);
  --color-code-bg: #f8fafc;
  --color-code-border: #e2e8f0;
  --projects-drawer-offset: clamp(64px, 8vh, 96px);
  
  /* Z-index 层级系统 */
  --z-base: 0;
  --z-content: 1;
  --z-overlay: 2;
  --z-sticky: 3;
  --z-dropdown: 10;
  --z-modal: 100;
  --z-drawer: 200;
  --z-lightbox: 300;
  --z-tooltip: 400;
  --z-max: 999;
  
  color-scheme: light;
}

/* DoIt 主题使用 body[theme="dark"] 和 html.dark */
html[data-theme="dark"],
body[theme="dark"],
html.dark,
.dark {
  /* 高级配色方案 - Dark Mode */
  --color-bg: #0a0e1a;
  --color-surface: #131827;
  --color-surface-muted: #1a1f2e;
  --color-surface-elevated: #1e2332;
  --color-text: #f1f5f9;
  --color-text-muted: #94a3b8;
  --color-text-subtle: #64748b;
  --color-border: rgba(148, 163, 184, 0.16);
  --color-border-strong: rgba(148, 163, 184, 0.24);
  
  /* 渐变和强调色 */
  --color-accent: #60a5fa;
  --color-accent-hover: #3b82f6;
  --color-accent-soft: rgba(96, 165, 250, 0.15);
  --color-accent-gradient: linear-gradient(135deg, #60a5fa 0%, #a78bfa 100%);
  
  /* 阴影系统 */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.4);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.6), 0 10px 10px -5px rgba(0, 0, 0, 0.4);
  --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.8);
  --shadow-colored: 0 20px 25px -5px rgba(96, 165, 250, 0.2), 0 10px 10px -5px rgba(96, 165, 250, 0.1);
  
  --color-nav-bg: rgba(19, 24, 39, 0.8);
  --color-hero-bg: #0a0e1a;
  --color-hero-overlay: rgba(10, 14, 26, 0.6);
  --color-code-bg: #1a1f2e;
  --color-code-border: rgba(148, 163, 184, 0.2);
  
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-body);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-accent-hover);
  text-decoration: none;
}

/* 高级按钮系统 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border-radius: 12px;
  border: 1px solid transparent;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.875rem 1.875rem;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

.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 0.5s;
}

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

.btn:hover {
  transform: translateY(-2px);
}

.btn:active {
  transform: translateY(0);
}

.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
  border-radius: 12px;
}

.btn.primary {
  background: var(--color-accent-gradient);
  color: #ffffff;
  box-shadow: var(--shadow-colored);
  border: none;
}

.btn.primary:hover {
  box-shadow: var(--shadow-xl), var(--shadow-colored);
  filter: brightness(1.05);
}

.btn.ghost {
  border-color: var(--color-border);
  color: var(--color-text);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(10px);
}

.btn.ghost:hover {
  background: var(--color-surface-elevated);
  border-color: var(--color-accent);
  box-shadow: var(--shadow-md);
  color: var(--color-accent);
}

html[data-theme="dark"] .btn.ghost {
  background: var(--color-surface-elevated);
  border-color: var(--color-border);
  color: var(--color-text);
}

html[data-theme="dark"] .btn.ghost:hover {
  background: var(--color-surface);
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.btn--small {
  padding: 0.625rem 1.375rem;
  font-size: 0.875rem;
  border-radius: 10px;
}

.btn--pill {
  padding-inline: 1.25rem;
  border-radius: 999px;
}

/* 高级标签系统 */
.chip {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  padding: 0.5rem 1.125rem;
  border-radius: 999px;
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-sm);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.chip:hover {
  background: var(--color-accent-soft);
  border-color: var(--color-accent);
  color: var(--color-accent);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

/* 高级排版系统 */
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.4em;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-text-muted);
  margin-bottom: 0.75rem;
  display: block;
}

.eyebrow.small {
  letter-spacing: 0.3em;
  font-size: 0.7rem;
  font-weight: 600;
}

.subtitle {
  color: var(--color-text-muted);
  font-size: 1.125rem;
  line-height: 1.7;
  margin: 0 auto;
  max-width: 640px;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.tc {
  text-align: center;
}