:root {
    /* St. Bonaventure Hospital Medical Palette */
    --fusion-bg: #eef4f8;
    
    /* Clinical Glass Panels & Medical Monitors */
    --glass-panel: #ffffff;
    --glass-panel-hover: #e3edf5;
    --glass-border: 1px solid #b0c4de;
    --glass-border-subtle: 1px solid #dce6f0;
    --glass-shadow: 0 2px 8px rgba(10, 37, 64, 0.08), 0 1px 3px rgba(0, 0, 0, 0.05);
    --blur-filter: blur(8px);

    /* Medical & Diagnostic Accent Colors */
    --scrub-blue: #0077b6;
    --surgical-teal: #00a896;
    --vital-green: #06d6a0;
    --alert-crimson: #d90429;
    --sanitized-white: #ffffff;
    
    /* Button States */
    --btn-bg: #f4f8fb;
    --btn-border: #b0c4de;
    --btn-hover-bg: #0077b6;
    --btn-hover-text: #ffffff;
    
    /* Typography & Accents */
    --text-main: #1c2d42;
    --text-muted: #5a738e;
    --text-dim: #0077b6;
    --text-dark: #0f172a;

    /* Diagnostic Highlight Overlay */
    --overlay-border: #00a896;
    --overlay-bg: rgba(0, 168, 150, 0.15);

    /* Medical Terminal Palette */
    --term-bg: #0f172a;
    --term-cmd: #38bdf8;
    --term-out: #cbd5e1;
    --term-err: #f87171;

    /* Technical/Clinical Typography */
    --font-sans: "Inter", "Segoe UI", -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: "JetBrains Mono", "Fira Code", "Consolas", monospace;
    --font-size-sm: 11px;
    --font-size-md: 12px;

    /* Layout & Sharp Geometries */
    --sidebar-width: 200px;
    --terminal-height-collapsed: 80px;
    --terminal-height-expanded: 180px;
    
    --border-radius-sm: 4px;
    --border-radius-btn: 6px;
  }

  * {
    box-sizing: border-box;
  }

  body {
    margin: 0;
    font-family: var(--font-sans);
    background: var(--fusion-bg);
    background-attachment: fixed;
    color: var(--text-main);
    display: flex;
    height: 100vh;
    overflow: hidden;
  }

  /* LEFT SIDEBAR */
  #left-sidebar {
    width: var(--sidebar-width);
    background: var(--glass-panel);
    border-right: var(--glass-border);
    padding: 12px 10px;
    overflow-y: auto;
    box-shadow: var(--glass-shadow);
  }

  .sidebar-section {
    margin-bottom: 20px;
  }

  .sidebar-section:nth-child(1) {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-gap: 8px;
  }

  .sidebar-section h3 {
    margin: 0 0 10px 0;
    font-size: var(--font-size-md);
    color: var(--scrub-blue);
    background: #e3edf5;
    border: 1px solid #b0c4de;
    padding: 6px 10px;
    border-radius: var(--border-radius-sm);
    grid-column: span 2;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    text-align: center;
  }
  
  /* Layout Utilities */
.element-tools-grid {
display: grid;
grid-template-columns: 1fr 1fr;
gap: 6px;
}

.grid-span-2 {
grid-column: span 2;
}

  /* Base Button Style */
  #left-sidebar button, #right-sidebar button {
    display: block;
    width: 100%;
    margin-bottom: 8px;
    padding: 7px 12px;
    background: var(--btn-bg);
    border: 1px solid var(--btn-border);
    border-radius: var(--border-radius-btn);
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 500;
    letter-spacing: 0.3px;
    color: var(--text-main);
    cursor: pointer;
    transition: all 0.2s ease-in-out;
  }

  /* Alternating Clinical Accents */
  button:nth-child(4n+1) {
    border-left: 3px solid var(--scrub-blue) !important;
    color: var(--scrub-blue) !important;
  }
  button:nth-child(4n+1):hover {
    background: var(--scrub-blue) !important;
    color: #ffffff !important;
    box-shadow: 0 2px 6px rgba(0, 119, 182, 0.3);
  }

  button:nth-child(4n+2) {
    border-left: 3px solid var(--surgical-teal) !important;
    color: var(--surgical-teal) !important;
  }
  button:nth-child(4n+2):hover {
    background: var(--surgical-teal) !important;
    color: #ffffff !important;
    box-shadow: 0 2px 6px rgba(0, 168, 150, 0.3);
  }

  button:nth-child(4n+3) {
    border-left: 3px solid var(--vital-green) !important;
    color: #048a67 !important;
  }
  button:nth-child(4n+3):hover {
    background: var(--vital-green) !important;
    color: #0f172a !important;
    box-shadow: 0 2px 6px rgba(6, 214, 160, 0.3);
  }

  button:nth-child(4n+0) {
    border-left: 3px solid #5a738e !important;
    color: #5a738e !important;
  }
  button:nth-child(4n+0):hover {
    background: #5a738e !important;
    color: #ffffff !important;
    box-shadow: 0 2px 6px rgba(90, 115, 142, 0.3);
  }

  pre {
    background: #f0f5fa;
    padding: 8px;
    border-radius: var(--border-radius-sm);
    border: var(--glass-border-subtle);
    font-family: var(--font-mono);
    font-size: var(--font-size-sm);
    color: var(--text-main);
    white-space: pre-wrap;
  }

  /* MAIN AREA */
  #main-area {
    flex: 1;
    display: flex;
    position: relative;
  }

  /* PREVIEW */
  #preview-wrap {
    flex: 1;
    background: #ffffff;
    position: relative;
    margin: 10px;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    border: var(--glass-border);
    box-shadow: var(--glass-shadow);
  }

  #preview {
    width: 100%;
    height: 100%;
    border: none;
  }

  #highlight-overlay {
    position: absolute;
    pointer-events: none;
    border: 2px solid var(--overlay-border);
    background: var(--overlay-bg);
    border-radius: 2px;
    display: none;
  }

  /* RIGHT SIDEBAR */
  #right-sidebar {
    width: var(--sidebar-width);
    background: var(--glass-panel);
    border-left: var(--glass-border);
    padding: 12px 10px;
    overflow-y: auto;
    box-shadow: var(--glass-shadow);
  }



  /* Medical Alert Red State */
  button.danger {
    border-left: 3px solid var(--alert-crimson) !important;
    color: var(--alert-crimson) !important;
  }

  button.danger:hover {
    background: var(--alert-crimson) !important;
    color: #ffffff !important;
    box-shadow: 0 2px 6px rgba(217, 4, 41, 0.4) !important;
  }

  /* DOM TREE */
  #tree-container {
    max-height: 200px;
    overflow: scroll;
  }

  #tree-container .node-row {
    font-family: var(--font-mono);
    font-size: var(--font-size-sm);
    padding: 4px 6px;
    margin-bottom: 12px;
    border-radius: 2px;
    cursor: pointer;
    display: flex;
    align-items: center;
    color: var(--text-main);
    transition: background 0.15s ease;
  }

  #tree-container .node-row:hover {
    background: var(--glass-panel-hover);
    color: var(--scrub-blue);
  }

  .node-toggle {
    width: 14px;
    text-align: center;
    margin-right: 4px;
    cursor: pointer;
    color: var(--surgical-teal);
  }

  /* TERMINAL (Designed like a Patient Monitor / EEG Screen) */
  #terminal-bar {
    position: absolute;
    bottom: 0;
    left: 210px;
    right: 210px;
    background: var(--term-bg);
    border: 1px solid #1e293b;
    border-bottom: none;
    border-radius: 6px 6px 0 0;
    display: flex;
    flex-direction: column;
    height: var(--terminal-height-collapsed);
    transition: height 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.2);
  }

  #terminal-bar:hover {
    height: var(--terminal-height-expanded);
  }

  #terminal-header {
    padding: 6px 12px;
    background: #1e293b;
    font-size: var(--font-size-sm);
    color: #94a3b8;
    display: flex;
    justify-content: space-between;
    border-bottom: 1px solid #334155;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-transform: uppercase;
  }

  #terminal-log {
    flex: 1;
    overflow-y: auto;
    padding: 8px 12px;
    font-family: var(--font-mono);
    font-size: var(--font-size-sm);
  }

  .line.cmd { color: var(--term-cmd); font-weight: 500; }
  .line.out { color: var(--term-out); }
  .line.err { color: var(--term-err); font-weight: 500; }

  #terminal-input-row {
    padding: 8px 10px;
    background: #0f172a;
    display: flex;
    gap: 8px;
    border-top: 1px solid #334155;
  }

  #prompt-label {
    color: var(--surgical-teal);
    font-family: var(--font-mono);
    font-weight: bold;
  }

  #input {
    flex: 1;
    background: #1e293b;
    border: 1px solid #334155;
    color: #f8fafc;
    padding: 5px 12px;
    font-family: var(--font-mono);
    border-radius: var(--border-radius-btn);
    font-weight: 400;
    transition: all 0.2s ease;
  }

  #input:focus {
    outline: none;
    background: #0f172a;
    border-color: var(--scrub-blue);
    box-shadow: 0 0 8px rgba(56, 189, 248, 0.3);
  }

  /* Solid Surgical Blue Run Button */
  #btn-run {
    background: var(--scrub-blue) !important;
    border: 1px solid var(--scrub-blue) !important;
    border-radius: var(--border-radius-btn) !important;
    color: #ffffff !important;
    font-weight: 600;
    padding: 5px 18px;
    cursor: pointer;
    font-family: var(--font-sans);
    transition: all 0.2s ease;
  }

  #btn-run:hover {
    background: #005f92 !important;
    border-color: #005f92 !important;
    box-shadow: 0 2px 6px rgba(0, 119, 182, 0.4) !important;
  }