:root {
  /* XTree Gold DOS File Manager Theme - Authentic 1980s Interface */
  
  /* Core XTree Gold Palette - Exact Match */
  --background: 240 100% 16%;           /* Classic XTree blue background */
  --foreground: 60 100% 88%;            /* Bright yellow text */
  
  /* Card Elements - File Panels */
  --card: 240 100% 16%;                 /* Same blue as main background */
  --card-foreground: 60 100% 88%;       /* Bright yellow panel text */
  
  /* Popover Elements - Context Menus */
  --popover: 240 100% 12%;              /* Slightly darker blue for menus */
  --popover-foreground: 60 100% 90%;    /* Bright yellow menu text */
  
  /* Primary - XTree Gold Highlight (Cyan Selection) */
  --primary: 180 100% 70%;              /* Bright cyan for selections */
  --primary-foreground: 240 100% 10%;   /* Dark blue text on cyan */
  
  /* Secondary - Directory Highlights */
  --secondary: 180 100% 50%;            /* Pure cyan for directories */
  --secondary-foreground: 240 100% 10%; /* Dark blue on cyan */
  
  /* Muted - Status Areas */
  --muted: 240 100% 14%;                /* Slightly darker blue */
  --muted-foreground: 60 80% 75%;       /* Dimmed yellow */
  
  /* Accent - Function Keys & Highlights */
  --accent: 60 100% 50%;                /* Pure yellow for F-keys */
  --accent-foreground: 240 100% 10%;    /* Dark blue on yellow */
  
  /* Destructive - Delete/Error */
  --destructive: 0 100% 60%;            /* Bright red for warnings */
  --destructive-foreground: 60 90% 95%; /* Light yellow on red */
  
  /* Interactive Elements */
  --border: 60 100% 70%;                /* Yellow border lines */
  --input: 240 100% 14%;                /* Dark blue input fields */
  --ring: 180 100% 70%;                 /* Cyan focus ring */
  
  /* Border Radius - Sharp DOS aesthetic */
  --radius: 0rem;                       /* No rounding - pure DOS */
  
  /* Chart Colors - Authentic DOS 16-color palette */
  --chart-1: 180 100% 70%;              /* Bright cyan */
  --chart-2: 60 100% 50%;               /* Yellow */
  --chart-3: 120 100% 50%;              /* Green */
  --chart-4: 300 100% 50%;              /* Magenta */
  --chart-5: 0 100% 60%;                /* Red */
  
  /* Authentic XTree Gold Colors */
  --xtree-blue: 240 100% 16%;           /* Main background blue */
  --xtree-yellow: 60 100% 88%;          /* Text yellow */
  --xtree-cyan: 180 100% 70%;           /* Selection cyan */
  --xtree-white: 0 0% 100%;             /* Pure white */
  --xtree-green: 120 100% 50%;          /* DOS green */
  --xtree-magenta: 300 100% 50%;        /* DOS magenta */
  --xtree-red: 0 100% 60%;              /* DOS red */
  
  /* File Type Colors - Authentic XTree */
  --executable-color: 0 0% 100%;        /* White for executables */
  --directory-color: 180 100% 70%;      /* Cyan for directories */
  --archive-color: 300 100% 50%;        /* Magenta for archives */
  --text-color: 60 100% 88%;            /* Yellow for text */
  --system-color: 0 100% 60%;           /* Red for system files */
  
  /* Menu Bar Colors */
  --menu-bar: 240 100% 8%;              /* Dark blue menu bar */
  --menu-text: 60 100% 88%;             /* Yellow menu text */
  --menu-highlight: 180 100% 50%;       /* Cyan menu highlight */

    /* ============================================ */
    /* SENTIENT BRIDGE VARIABLES                   */
    /* For Sheet, Docs, Slides theme support       */
    /* ============================================ */

    /* Backgrounds */
    --sentient-bg-primary: hsl(var(--background));
    --sentient-bg-secondary: hsl(var(--card));
    --sentient-bg-tertiary: hsl(var(--muted));
    --sentient-bg-hover: hsla(var(--primary) / 0.08);
    --sentient-bg-active: hsla(var(--primary) / 0.15);

    /* Text */
    --sentient-text-primary: hsl(var(--foreground));
    --sentient-text-secondary: hsl(var(--muted-foreground));
    --sentient-text-tertiary: hsla(var(--muted-foreground) / 0.7);
    --sentient-text-muted: hsla(var(--muted-foreground) / 0.5);

    /* Accent Colors */
    --sentient-accent: hsl(var(--primary));
    --sentient-accent-hover: hsl(var(--primary) / 0.85);
    --sentient-accent-light: hsla(var(--primary) / 0.1);
    --sentient-accent-dark: hsl(var(--primary) / 0.7);

    /* Borders */
    --sentient-border: hsl(var(--border));
    --sentient-border-light: hsla(var(--border) / 0.5);
    --sentient-border-accent: hsla(var(--primary) / 0.3);

    /* Surfaces */
    --sentient-surface: hsl(var(--card));
    --sentient-surface-hover: hsla(var(--primary) / 0.08);
    --sentient-surface-active: hsla(var(--primary) / 0.15);
    --sentient-surface-elevated: hsl(var(--popover));

    /* Inputs */
    --sentient-input-bg: hsl(var(--input));
    --sentient-input-border: hsl(var(--border));
    --sentient-input-focus: hsl(var(--ring));

    /* Status Colors */
    --sentient-success: hsl(142 76% 36%);
    --sentient-success-bg: hsla(142 76% 36% / 0.15);
    --sentient-warning: hsl(38 92% 50%);
    --sentient-warning-bg: hsla(38 92% 50% / 0.15);
    --sentient-error: hsl(var(--destructive));
    --sentient-error-bg: hsla(var(--destructive) / 0.15);

    /* Typography */
    --sentient-font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

    /* Shadows */
    --sentient-shadow-sm: 0 1px 2px 0 hsla(var(--foreground) / 0.05);
    --sentient-shadow-md: 0 4px 6px -1px hsla(var(--foreground) / 0.1), 0 2px 4px -1px hsla(var(--foreground) / 0.06);
    --sentient-shadow-lg: 0 10px 15px -3px hsla(var(--foreground) / 0.1), 0 4px 6px -2px hsla(var(--foreground) / 0.05);

    /* Border Radius */
    --sentient-radius: var(--radius);
    --sentient-radius-sm: calc(var(--radius) * 0.5);
    --sentient-radius-md: var(--radius);
    --sentient-radius-lg: calc(var(--radius) * 1.5);
    --sentient-radius-xl: calc(var(--radius) * 2);
}

/* Authentic XTree Gold Enhancement Classes */
.xtree-main-panel {
  background: hsl(var(--xtree-blue));
  color: hsl(var(--xtree-yellow));
  font-family: 'Perfect DOS VGA 437', 'Courier New', monospace;
  font-size: 16px;
  line-height: 1;
  border: none;
}

.xtree-menu-bar {
  background: hsl(var(--menu-bar));
  color: hsl(var(--menu-text));
  padding: 0;
  height: 20px;
  display: flex;
  align-items: center;
  font-weight: normal;
}

.xtree-menu-item {
  padding: 0 8px;
  color: hsl(var(--xtree-yellow));
  background: transparent;
}

.xtree-menu-item:hover,
.xtree-menu-item.active {
  background: hsl(var(--xtree-cyan));
  color: hsl(240 100% 10%);
}

.xtree-dual-pane {
  display: flex;
  height: calc(100vh - 60px);
}

.xtree-left-pane,
.xtree-right-pane {
  flex: 1;
  background: hsl(var(--xtree-blue));
  color: hsl(var(--xtree-yellow));
  padding: 0;
  margin: 0;
}

.xtree-directory-tree {
  color: hsl(var(--directory-color));
  background: hsl(var(--xtree-blue));
  padding: 4px;
}

.xtree-file-list {
  background: hsl(var(--xtree-blue));
  color: hsl(var(--xtree-yellow));
  font-family: 'Perfect DOS VGA 437', 'Courier New', monospace;
  font-size: 16px;
  line-height: 20px;
  padding: 4px;
}

.xtree-file-selected {
  background: hsl(var(--xtree-cyan));
  color: hsl(240 100% 10%);
}

.xtree-directory {
  color: hsl(var(--directory-color));
}

.xtree-executable {
  color: hsl(var(--executable-color));
}

.xtree-archive {
  color: hsl(var(--archive-color));
}

.xtree-text-file {
  color: hsl(var(--text-color));
}

.xtree-system-file {
  color: hsl(var(--system-color));
}

.xtree-status-line {
  background: hsl(var(--xtree-blue));
  color: hsl(var(--xtree-yellow));
  height: 20px;
  padding: 0 8px;
  display: flex;
  align-items: center;
  font-size: 16px;
}

.xtree-function-bar {
  background: hsl(var(--menu-bar));
  color: hsl(var(--xtree-yellow));
  height: 20px;
  display: flex;
  padding: 0;
  font-size: 14px;
}

.xtree-function-key {
  padding: 0 4px;
  color: hsl(var(--xtree-yellow));
  border-right: 1px solid hsl(var(--xtree-yellow));
}

.xtree-function-key:last-child {
  border-right: none;
}

.xtree-path-bar {
  background: hsl(var(--xtree-blue));
  color: hsl(var(--xtree-yellow));
  padding: 2px 8px;
  border-bottom: 1px solid hsl(var(--xtree-yellow));
}

.xtree-disk-info {
  background: hsl(var(--xtree-blue));
  color: hsl(var(--xtree-yellow));
  padding: 4px 8px;
  text-align: right;
  font-size: 14px;
}

/* Authentic DOS Box Drawing Characters */
.xtree-box-char {
  font-family: 'Perfect DOS VGA 437', 'Courier New', monospace;
  line-height: 1;
  letter-spacing: 0;
}

/* Classic Text Mode Cursor */
.xtree-cursor {
  background: hsl(var(--xtree-yellow));
  color: hsl(var(--xtree-blue));
  animation: blink 1s infinite;
}

@keyframes blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}

/* Authentic DOS Window Styling */
.xtree-window {
  border: 2px outset hsl(var(--xtree-blue));
  background: hsl(var(--xtree-blue));
  box-shadow: none;
  border-radius: 0;
}