:root {
    /* Greys & surfaces */
    --bg-main: #F5F5F7;          /* macOS window background */
    --bg-panel: #FFFFFF;         /* white cards */
    --bg-card: #FFFFFF;
    --bg-input: #F7F3EF;
    --border-soft: #EAE0D5; /* Soft beige/brown */
    --border-focus: #B88B7A; /* Muted terracotta */

    /* Text */
    --text-primary: #1D1D1F;
    --text-secondary: #5F5F62;
    --text-heading: #4A3C35;

    /* Accent */
    --accent: #0A84FF;           /* macOS blue */
    --accent-hover: #0060DF;
    --accent-light: #E5F1FF;
    --accent-rgb: 10, 132, 255;

    /* Feedback */
    --success: #32D74B;
    --error: #FF375F;
    --warning-background: #F9EFC9; /* Soft yellow */
    --warning-text: #8C6D31;
    --warning-border: #F0D9A5;

    /* Mapped Variables */
    --grey-darkest: var(--bg-main);
    --grey-darker: var(--bg-panel);
    --grey-dark: var(--border-soft);
    --grey-medium: var(--text-secondary);
    --grey-light: var(--text-secondary);
    --grey-lightest: var(--text-primary);

    --border-color: #D1D1D6;     /* light divider */
    --theme-page-bg: var(--bg-main);
    --background-card: var(--bg-panel);
    --input-background: var(--bg-input);
    --diagram-bg-empty: var(--bg-input);
    --diagram-bg-content: #ffffff;

    --success-color: #7CB581; /* Muted green */
    --success-hover: #6A9C6F;
    --success-text: #FFFFFF;
    --error-color: #D98585; /* Muted red */
    --error-text: #FFFFFF;
}

:root.dark {
    --bg-main: #1e1f24;
    --bg-panel: #2b2d31;
    --bg-card: #2b2d31;
    --bg-input: #3a3d44;
    --border-soft: #3f434a;
    --border-focus: #4f8cff;

    --text-primary: #f1f1f1;
    --text-secondary: #c0c2c5;
    --text-heading: #ffffff;

    --accent: #3d8bff;
    --accent-hover: #5ea0ff;
    --accent-light: #334b6e;
    --accent-rgb: 61,139,255;

    --success: #4caf50;
    --error: #e53935;

    --border-color: #4a4d52;
    --background-card: var(--bg-panel);
    --input-background: #33363b;
    --diagram-bg-empty: #2b2d31;
    --diagram-bg-content: #1e1f24;
}

html,
body {
    height: 100%;
    margin: 0;
    padding: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
}

html.dark body {
    background-color: var(--bg-main);
    color: var(--text-primary);
}

body {
    font-weight: 400;
    padding: 24px; /* Added padding */
}

h1, h2, button, .section-header {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    font-weight: 600;
    color: var(--text-heading);
}

/* Input Range Slider */
input[type="range"] { -webkit-appearance: none; appearance: none; height: 8px; background: var(--bg-input); border-radius: 4px; outline: none; opacity: 0.9; transition: opacity .15s ease-in-out; flex-grow: 1; border: 1px solid var(--border-soft); }
input[type="range"]:hover { opacity: 1; }
input[type="range"]::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 18px; height: 18px; background: var(--accent); border-radius: 50%; cursor: pointer; border: 3px solid var(--bg-panel); box-shadow: 0 0 5px rgba(var(--accent-rgb), 0.5); }
input[type="range"]::-moz-range-thumb { width: 16px; height: 16px; background: var(--accent); border-radius: 50%; cursor: pointer; border: 2px solid var(--bg-panel); box-shadow: 0 0 5px rgba(var(--accent-rgb), 0.5); }

/* Other Inputs */
input:not(#userPrompt):not([type="range"]):not([type="checkbox"]), textarea:not(#userPrompt) {
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 8px; /* Softer corners */
    padding: 10px 14px;
    color: var(--text-primary);
    transition: border-color 0.2s, box-shadow 0.2s;
}

input:not(#userPrompt):not([type="range"]):not([type="checkbox"]):focus, textarea:not(#userPrompt):focus {
     outline: none; border-color: var(--accent) !important;
     box-shadow: 0 0 0 3px rgba(var(--accent-rgb), 0.3);
}

/* Checkbox */
input[type="checkbox"] {
    accent-color: var(--accent);
}

/* Ghost Button */
.ghost-button { padding: 8px 14px; border-radius: 10px; border: 1px solid var(--border-color); background: transparent; font-size: 14px; color: var(--text-secondary); cursor: pointer; transition: background .15s, border-color .15s; }
.ghost-button:hover { background: var(--accent-light); border-color: var(--accent); color: var(--accent-hover); }

/* History Item */
.history-item { width: 100%; text-align: left; padding: 8px 10px; border: 1px solid transparent; border-radius: 10px; background: var(--bg-main); font-size: 14px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; cursor: pointer; transition: background .15s; }
.history-item:hover { background: var(--accent-light); }
        
/* Number Input Fix */
input[type="number"]::-webkit-outer-spin-button, input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
input[type="number"] { -moz-appearance: textfield; padding: 8px 10px !important; }

/* Diagram Area */
#diagramWrapper {
    display: flex; /* Ensure inner div can take full height */
    flex-direction: column; /* Stack children vertically */
    overflow: hidden; /* Prevent double scrollbars */
    padding: 0; /* Remove padding if Excalidraw handles its own */
    border-style: solid; /* Keep border visible */
    border-color: var(--border-color);
}

#excalidraw-container {
    flex: 1; /* Take up all available space in the diagramWrapper */
    min-height: 0; /* Important for flex item to shrink properly */
    border-radius: 14px; /* Match parent border radius */
    overflow: hidden; /* Clip Excalidraw if it overflows */
}

/* Ensure Excalidraw UI looks good with the theme */
.excalidraw.excalidraw-container {
    /* Excalidraw usually has its own theme, but we can override some aspects if needed */
    --color-primary: var(--accent); /* Example: Use site accent for Excalidraw primary */
}

.excalidraw .Stack_horizontal {
    background-color: var(--bg-panel) !important; /* Match panel background */
    border-radius: 8px;
}

.excalidraw .ToolIcon_type_button {
    color: var(--text-primary) !important;
}

.excalidraw .ToolIcon_type_button--selected {
    color: var(--accent) !important;
    background-color: var(--accent-light) !important;
}

.excalidraw .Island {
    background-color: var(--bg-panel) !important;
    border: 1px solid var(--border-color) !important;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08) !important;
}

/* Collapsible Section */
.section-header { display: flex; justify-content: space-between; align-items: center; cursor: pointer; padding-bottom: 8px; border-bottom: none; }
.section-header h2 { color: var(--text-heading); font-size: 1.1em; margin: 0; padding: 0; border: none; font-weight: 600; }
.section-content {
  display: none;
  margin-top: 12px;
  padding: 4px 0;
}
.section-content.show { display: block; }
.chevron { width: 14px; height: 14px; transition: transform .2s ease; color: var(--text-secondary); }
.chevron.rotated { transform: rotate(90deg); }

/* Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg-input); border-radius: 4px; }
::-webkit-scrollbar-thumb { background: var(--border-soft); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-focus); }

/* Spinner */
@keyframes spin { to { transform: rotate(360deg); } }
.spinner { width: 18px; height: 18px; border-radius: 50%; border: 3px solid var(--border-color); border-top: 3px solid var(--accent); animation: spin 1s linear infinite; }

/* Main Card */
.main-card {
    background-color: var(--bg-panel);
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: 0 8px 24px rgba(0,0,0,0.15);
    overflow: visible;
}

/* Prompt wrapper now taller to support multiline */
.prompt-wrapper {
  position: relative;
  width: 100%;
  min-height: 120px; /* at least ~4 lines */
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 28px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
  transition: all 0.2s ease;
  flex-shrink: 0; /* Don't shrink */
}

.prompt-wrapper:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

.prompt-wrapper:focus-within {
  border-color: #1d1d1f;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

/* Adjust textarea for multiline */
.prompt-wrapper textarea,
#userPrompt {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  padding: 16px 80px 16px 24px !important;
  border: none !important;
  background: transparent !important;
  resize: none !important;
  outline: none !important;
  font-size: 16px !important;
  line-height: 24px !important;
  color: var(--text-primary) !important;
  min-height: 120px !important;
  max-height: 160px !important;
  overflow: hidden !important;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif !important;
}

.prompt-wrapper textarea::placeholder,
#userPrompt::placeholder {
  color: var(--text-secondary);
}

/* Send Button */
#generateDiagram {
  position: absolute;
  top: 50%;
  right: 8px;
  transform: translateY(-50%);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--accent);
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
  cursor: pointer;
}

#generateDiagram:hover {
  background: var(--accent-hover);
  transform: translateY(-50%) scale(1.05);
}

#generateDiagram:disabled {
  background: var(--border-color);
  cursor: not-allowed;
  transform: translateY(-50%);
}

#generateDiagram svg {
  color: #fff;
  width: 18px;
  height: 18px;
}
         
/* Loading state for generate button */
#generateDiagram.loading svg {
  display: none;
}
#generateDiagram.loading::after {
  content: "";
  width: 18px;
  height: 18px;
  border: 3px solid var(--border-color);
  border-top: 3px solid var(--accent);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

/* Status message simple colors */
#statusMessage {
  background: transparent !important;
  padding: 4px 0;
}
.text-success {
  color: var(--success);
}
.text-error {
  color: var(--error);
}
.hidden {
  display: none !important;
}

/* Utility status colour classes */
.status-success { background: var(--success); color: #fff; }
.status-error { background: var(--error); color: #fff; }
.status-info { background: var(--accent-light); color: var(--text-primary); }
         
/* Warning Box */
.warning-box {
    background-color: var(--warning-background);
    color: var(--warning-text);
    border-color: var(--warning-border);
}
.warning-box strong { color: var(--warning-text) !important; }

/* Layout helpers */
.container{max-width:1600px;margin:0 auto;padding:24px;display:flex;gap:24px;height:100%;}
.card{background:var(--bg-panel);border:1px solid var(--border-color);border-radius:14px;box-shadow:0 1px 3px rgba(0,0,0,.08);} 

/* Sidebar */
#sidebar{width:380px;min-width:300px;display:flex;flex-direction:column;gap:24px;padding:24px;}

/* Update sidebar container in index to handle overflow better */
.sidebar-container {
  display: flex;
  flex-direction: column;
  gap: 16px;
  height: 100%;
  overflow: hidden; /* Changed from auto to hidden */
  padding-right: 0;
}

/* Prompt section stays at top */
.prompt-section {
  flex-shrink: 0;
  margin-bottom: 16px; /* Add spacing between prompt and sections */
}

/* Controls */
label{font-size:14px;font-weight:500;color:var(--text-secondary);} 
input,textarea,select{width:100%;background:var(--bg-main);border:1px solid var(--border-color);border-radius:10px;padding:10px 12px;font-size:15px;color:var(--text-primary);} 
input:focus,textarea:focus,select:focus{outline:none;border-color:var(--accent);} 

/* Small utility classes */
.hidden{display:none;} 

/* Drop card - make sections more compact */
.drop-card {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 12px;
  box-shadow: 0 1px 4px rgba(0,0,0,.08);
  flex-shrink: 0;
}

/* Collapsible sections container */
.collapsible-sections {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-bottom: 16px;
  padding-right: 8px; /* Scrollbar spacing */
  min-height: 0; /* Important for flex overflow */
}

/* History content specific styling */
#historyContent {
  max-height: 250px;
  overflow-y: auto;
}

/* Loading indicator styling */
#loadingIndicator {
  display: inline-flex;
  align-items: center;
  height: 24px;
}

/* Neutralize main card styling so layout spans full width */
.main-card {
    background-color: transparent !important;
    border: none !important;
    box-shadow: none !important;
}

/* --- Collapsible Left Menu --- */
.left-menu { transform: translateX(-100%); }
.left-menu.open { transform: translateX(0); }
.menu-toggle { cursor: pointer; }

/* Chat messages styling */
.chat-messages { padding-right: 4px; }
.message-bubble { max-width: 90%; border-radius: 12px; padding: 10px 14px; font-size: 14px; line-height: 1.4; word-wrap: break-word; white-space: pre-line; }
.message-user { background: var(--accent); color: #fff; align-self: flex-end; }
.message-assistant { background: var(--bg-input); color: var(--text-primary); align-self: flex-start; }

/* Dark mode adjustments */
html.dark .message-user { background: var(--accent-hover); }
html.dark .message-assistant { background: var(--bg-panel); color: var(--text-primary); }

/* Menu toggle visibility */
.menu-toggle { width:44px; height:44px; border-radius:10px; background: var(--accent); color:#fff; display:flex; align-items:center; justify-content:center; font-size:24px; }
html.dark .menu-toggle { background: var(--accent-hover); }

/* Resizable left menu */
.left-menu { resize: horizontal; min-width: 260px; max-width: 600px; }

/* Diagram outline */
#diagramWrapper:not(.has-content) { border: 2px dashed var(--border-color); }
#diagramWrapper.has-content { border: 2px solid var(--border-color); }