:root {
    /* Brand */

    --color-primary: #0f62fe;
    --color-primary-hover: #0353e9;

    /* Background */

    --color-body: #f5f7fa;
    --color-surface: #ffffff;

    /* Text */

    --color-text: #1f2937;
    --color-text-light: #6b7280;
    --color-text-subtle: #9ca3af;

    /* Borders */

    --color-border: #d8dee9;
    --color-border-light: #e5e7eb;

    /* Interactive surfaces */

    --color-muted-surface: #f3f4f6;
    --color-hover-surface: #f8fafc;
    --color-focus-ring: rgba(37, 99, 235, 0.15);

    /* Status */

    --color-success: #16a34a;
    --color-warning: #f59e0b;
    --color-danger: #dc2626;

    /* Radius */

    --radius-sm: 6px;
    --radius: 8px;
    --radius-lg: 12px;

    /* Shadow */

    --shadow: 0 8px 25px rgba(15, 23, 42, 0.08);
    --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.05);
    --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.18);

    /* Typography */

    --font: 'Segoe UI', Roboto, Arial, sans-serif;

    --font-size-sm: 13px;
    --font-size: 14px;
    --font-size-lg: 16px;

    /* Layout */

    --sidebar-width: 250px;

    --header-height: 52px;

    /* Spacing and controls */

    --space-1: 4px;
    --space-2: 8px;
    --space-3: 10px;
    --space-4: 12px;
    --space-5: 16px;
    --space-6: 20px;
    --space-8: 24px;
    --control-height: 36px;
    --tree-indent-step: 20px;
}