:root {
  --color-primary: #2563EB;
  --color-primary-dark: #1B4FD9;
  --color-primary-light: #3B82F6;
  --color-primary-rgb: 37, 99, 235;

  --color-accent: #06B6D4;
  --color-accent-glow: rgba(6, 182, 212, 0.35);

  --color-bg-dark: #0B1120;
  --color-bg-dark-2: #111827;
  --color-bg-dark-card: rgba(17, 24, 39, 0.72);

  --color-bg-light: #FFFFFF;
  --color-bg-subtle: #F0F5FF;
  --color-bg-muted: #E8EEF8;

  --color-text-primary: #0F172A;
  --color-text-secondary: #475569;
  --color-text-muted: #94A3B8;
  --color-text-on-dark: #F1F5F9;

  --color-border: rgba(148, 163, 184, 0.2);
  --color-border-glow: rgba(37, 99, 235, 0.3);

  --color-hot: #EF4444;
  --color-new: #06B6D4;

  --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Inter', system-ui, sans-serif;
  /* 旧站 header：PingFangSC-Medium + font-weight 500（勿叠加 600，否则会假粗） */
  --header-font: PingFangSC-Medium, 'PingFang SC', 'Microsoft YaHei', 'Microsoft YaHei UI', 'WenQuanYi Micro Hei', sans-serif;
  --container-max: 1440px;
  --header-height: 72px;
  --header-nav-size: 16px;
  --header-nav-size-lg: 16px;
  --header-nav-weight: 500;
  --header-nav-padding-x: 12px;
  --section-gap: 96px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-glow: 0 8px 32px rgba(37, 99, 235, 0.12);
  --transition: 0.3s ease;

  /* Header — light formal tech (neutral, no blue bar) */
  --header-bg: rgba(255, 255, 255, 0.98);
  --header-bg-scrolled: rgba(255, 255, 255, 1);
  --header-border: rgba(15, 23, 42, 0.08);
  --header-text: #181818;
  --header-text-hover: #0f172a;
  --header-nav-hover-bg: rgba(15, 23, 42, 0.05);
  --header-nav-indicator: #2563eb;
  --header-panel-bg: #ffffff;
  --header-panel-side: #f4f7fc;
  --header-panel-border: rgba(15, 23, 42, 0.08);
  --header-panel-text: #555555;
  --header-panel-title: #181818;
  --header-panel-accent: #2563eb;
  --header-panel-hover: #eef2f8;
}

@media (max-width: 768px) {
  :root {
    --section-gap: 64px;
    --header-height: 60px;
  }
}