:root {
  color-scheme: dark;
  --font-geist-sans: 'Segoe UI', 'Microsoft YaHei', sans-serif;
  --font-geist-mono: 'Cascadia Code', Consolas, monospace;
  --background: #0b141e;
  --foreground: #dce7f0;
  --card: #101e2a;
  --card-foreground: #dce7f0;
  --popover: #162936;
  --popover-foreground: #e6f0f7;
  --primary: #24735f;
  --primary-foreground: #f1faf6;
  --secondary: #1b3040;
  --secondary-foreground: #d4e4ee;
  --muted: #142532;
  --muted-foreground: #9eb2c3;
  --accent: #1b4037;
  --accent-foreground: #a4e6cb;
  --destructive: #ff9baa;
  --border: #2a3d4d;
  --input: #3b5365;
  --ring: #79d4b4;
  --sidebar: #0b1b23;
  --sidebar-foreground: #d4e5ed;
  --sidebar-primary: #a6edcf;
  --sidebar-primary-foreground: #112d35;
  --sidebar-accent: #1b3a3f;
  --sidebar-accent-foreground: #e5fff4;
  --sidebar-border: #29464e;
  --sidebar-ring: #8fddc0;
  --chart-1: #72c0e7;
  --chart-2: #dfb660;
  --chart-3: #caa2dc;
  --chart-4: #7bc59b;
  --chart-5: #f0a78a;
  --radius: 0.7rem;
}
/* Shared visual language for experiments and self-contained study notes. */
.learning-mode { display:flex; gap:8px; flex-wrap:wrap; }
.learning-mode a { padding:8px 14px; border:1px solid var(--border); border-radius:8px; font-size:14px; text-decoration:none; background:var(--card); color:var(--foreground); }
.learning-mode a[aria-current] { background:#17675b; border-color:#17675b; color:#eef6fb; }
.learning-mode a:hover { border-color:var(--ring); }