/**
 * GuideAI - Improved Chat Interface Styles
 * Architecture: BEM methodology with CSS Custom Properties
 * Author: Senior Developer Team
 * Version: 2.0.0
 */

/* ===================================
   CSS Custom Properties (Design Tokens)
   =================================== */
:root {
  /* Color Palette */
  --color-primary: #6f42c1;
  --color-primary-light: #8c5fdc;
  --color-primary-dark: #5a34a3;
  --color-secondary: #4f8cff;
  --color-success: #28a745;
  --color-danger: #dc3545;
  --color-warning: #ffc107;
  --color-info: #17a2b8;
  
  /* Neutral Colors */
  --color-white: #ffffff;
  --color-gray-50: #f8f9fa;
  --color-gray-100: #e9ecef;
  --color-gray-200: #dee2e6;
  --color-gray-300: #ced4da;
  --color-gray-400: #adb5bd;
  --color-gray-500: #6c757d;
  --color-gray-600: #495057;
  --color-gray-700: #343a40;
  --color-gray-800: #212529;
  --color-gray-900: #111111;
  
  /* Semantic Colors */
  --color-text-primary: var(--color-gray-800);
  --color-text-secondary: var(--color-gray-600);
  --color-text-muted: var(--color-gray-500);
  --color-border: var(--color-gray-300);
  --color-background: var(--color-white);
  --color-background-alt: var(--color-gray-50);
  
  /* Spacing Scale */
  --space-xs: 0.25rem;    /* 4px */
  --space-sm: 0.5rem;     /* 8px */
  --space-md: 1rem;       /* 16px */
  --space-lg: 1.5rem;     /* 24px */
  --space-xl: 2rem;       /* 32px */
  --space-2xl: 3rem;      /* 48px */
  --space-3xl: 4rem;      /* 64px */
  
  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Typography */
  --font-family-base: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-family-mono: 'Courier New', Courier, monospace;
  
  --font-size-xs: 0.75rem;    /* 12px */
  --font-size-sm: 0.875rem;   /* 14px */
  --font-size-base: 1rem;     /* 16px */
  --font-size-lg: 1.125rem;   /* 18px */
  --font-size-xl: 1.25rem;    /* 20px */
  --font-size-2xl: 1.5rem;    /* 24px */
  --font-size-3xl: 1.875rem;  /* 30px */
  
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Z-Index Scale */
  --z-base: 1;
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
  
  /* Chat-Specific Variables */
  --chat-max-width: 1200px;
  --chat-min-height: 600px;
  --message-max-width: 75%;
  --input-min-height: 120px;
}

/* ===================================
   Chat Interface Wrapper
   =================================== */
.chat-interface-wrapper {
  width: 100%;
  max-width: var(--chat-max-width);
  margin: 0 auto;
}

.chat-interface {
  display: flex;
  flex-direction: column;
  min-height: var(--chat-min-height);
  background: var(--color-background);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

/* ===================================
   Chat Container
   =================================== */
.chat-container {
  display: flex;
  flex-direction: column;
  flex: 1;
  height: 100%;
}

/* ===================================
   Messages Area
   =================================== */
.messages-area {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-lg);
  background: var(--color-background-alt);
  scroll-behavior: smooth;
  
  /* Custom scrollbar */
  scrollbar-width: thin;
  scrollbar-color: var(--color-gray-400) var(--color-gray-100);
}

.messages-area::-webkit-scrollbar {
  width: 8px;
}

.messages-area::-webkit-scrollbar-track {
  background: var(--color-gray-100);
  border-radius: var(--radius-full);
}

.messages-area::-webkit-scrollbar-thumb {
  background: var(--color-gray-400);
  border-radius: var(--radius-full);
  transition: background var(--transition-base);
}

.messages-area::-webkit-scrollbar-thumb:hover {
  background: var(--color-gray-500);
}

/* Focus styles for accessibility */
.messages-area:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: -2px;
}

/* ===================================
   Chat Messages
   =================================== */
.chat-message {
  margin-bottom: var(--space-lg);
  animation: fadeInUp var(--transition-base);
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Message Wrapper */
.message-wrapper {
  max-width: var(--message-max-width);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

/* Bot messages (left-aligned) */
.chat-message.bot .message-wrapper {
  margin-right: auto;
}

/* User messages (right-aligned) */
.chat-message.user .message-wrapper {
  margin-left: auto;
  align-items: flex-end;
}

/* ===================================
   Message Header
   =================================== */
.message-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-sm);
  padding: 0 var(--space-xs);
}

.assistant-badge {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
}

.badge-icon {
  font-size: var(--font-size-lg);
}

.message-timestamp {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
}

/* ===================================
   Message Body
   =================================== */
.message-body {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-md) var(--space-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
}

.chat-message.user .message-body {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary-dark);
}

/* ===================================
   Welcome Message
   =================================== */
.welcome-message .message-body {
  background: linear-gradient(135deg, #e3f2fd 0%, #f3e5f5 100%);
  border: none;
  box-shadow: var(--shadow-md);
}

.welcome-message .alert-heading {
  color: var(--color-primary);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--space-md);
}

/* Features Grid */
.features-grid {
  margin-top: var(--space-lg);
}

.feature-card {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-md);
  background: var(--color-white);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
}

.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  font-size: var(--font-size-2xl);
  flex-shrink: 0;
}

.feature-content {
  flex: 1;
}

.feature-title {
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
}

.feature-description {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin: 0;
}

/* Getting Started CTA */
.getting-started-cta {
  background: rgba(111, 66, 193, 0.05);
  border-left: 3px solid var(--color-primary);
}

/* ===================================
   Input Area
   =================================== */
.input-area {
  background: var(--color-white);
  border-top: 1px solid var(--color-border);
  padding: var(--space-lg);
}

/* ===================================
   Input Group
   =================================== */
.input-group-wrapper {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* ===================================
   Textarea Container
   =================================== */
.textarea-container {
  position: relative;
  flex: 1;
}

.chat-input {
  width: 100%;
  min-height: var(--input-min-height);
  padding: var(--space-md);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  font-size: var(--font-size-base);
  font-family: var(--font-family-base);
  line-height: var(--line-height-normal);
  resize: vertical;
  transition: all var(--transition-base);
}

.chat-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(111, 66, 193, 0.1);
}

.chat-input::placeholder {
  color: var(--color-text-muted);
}

/* ===================================
   Character Counter
   =================================== */
.char-counter {
  position: absolute;
  bottom: var(--space-sm);
  right: var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  pointer-events: none;
}

.counter-text {
  display: flex;
  align-items: center;
  gap: 2px;
}

.char-counter.warning {
  color: var(--color-warning);
}

.char-counter.danger {
  color: var(--color-danger);
  font-weight: var(--font-weight-semibold);
}

/* ===================================
   Actions Grid
   =================================== */
.actions-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.actions-row {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.primary-actions {
  justify-content: flex-end;
}

.secondary-actions {
  justify-content: flex-start;
}

/* ===================================
   Action Buttons
   =================================== */
.btn-action {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-white);
  color: var(--color-text-primary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn-action:hover:not(:disabled) {
  background: var(--color-gray-50);
  border-color: var(--color-primary);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.btn-action:active:not(:disabled) {
  transform: translateY(0);
}

.btn-action:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-action:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Send Button (Primary) */
.btn-send {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
  font-weight: var(--font-weight-semibold);
}

.btn-send:hover:not(:disabled) {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
}

/* Voice Button */
.btn-voice {
  border-color: var(--color-secondary);
  color: var(--color-secondary);
}

.btn-voice:hover:not(:disabled) {
  background: rgba(79, 140, 255, 0.1);
}

.btn-voice.active {
  background: var(--color-secondary);
  color: var(--color-white);
}

/* Prompts Button */
.btn-prompts {
  border-color: var(--color-warning);
  color: var(--color-warning);
}

.btn-prompts:hover:not(:disabled) {
  background: rgba(255, 193, 7, 0.1);
}

.btn-prompts.active {
  background: var(--color-warning);
  color: var(--color-gray-900);
}

/* Clear Button */
.btn-clear {
  border-color: var(--color-danger);
  color: var(--color-danger);
}

.btn-clear:hover:not(:disabled) {
  background: rgba(220, 53, 69, 0.1);
}

/* ===================================
   Prompt Drawer
   =================================== */
.prompt-drawer {
  max-height: 0;
  overflow: hidden;
  background: var(--color-white);
  border-top: 1px solid var(--color-border);
  transition: max-height var(--transition-slow);
}

.prompt-drawer[aria-hidden="false"] {
  max-height: 600px;
}

.drawer-header {
  position: relative;
  padding: var(--space-lg);
  border-bottom: 1px solid var(--color-border);
}

.drawer-title {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-primary);
  margin: 0;
}

.drawer-subtitle {
  margin-top: var(--space-xs);
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.drawer-close {
  position: absolute;
  top: var(--space-lg);
  right: var(--space-lg);
  padding: var(--space-xs);
  border: none;
  background: transparent;
  font-size: var(--font-size-2xl);
  line-height: 1;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: color var(--transition-fast);
}

.drawer-close:hover {
  color: var(--color-text-primary);
}

/* ===================================
   Prompts List
   =================================== */
.drawer-content {
  padding: var(--space-lg);
  max-height: 450px;
  overflow-y: auto;
}

.prompts-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.prompt-button {
  width: 100%;
  display: flex;
  align-items: flex-start;
  gap: var(--space-md);
  padding: var(--space-md);
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-align: left;
  cursor: pointer;
  transition: all var(--transition-base);
}

.prompt-button:hover {
  background: var(--color-background-alt);
  border-color: var(--color-primary);
  transform: translateX(4px);
}

.prompt-button:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.prompt-icon {
  flex-shrink: 0;
  font-size: var(--font-size-lg);
}

.prompt-text {
  flex: 1;
  font-size: var(--font-size-sm);
  color: var(--color-text-primary);
  line-height: var(--line-height-normal);
}

/* Emergency Prompt */
.prompt-emergency .prompt-button {
  border-color: var(--color-warning);
  background: rgba(255, 193, 7, 0.05);
}

.prompt-emergency .prompt-button:hover {
  background: rgba(255, 193, 7, 0.1);
}

/* ===================================
   Emergency Section
   =================================== */
.drawer-emergency {
  margin-top: var(--space-xl);
  padding: var(--space-lg);
  background: rgba(220, 53, 69, 0.05);
  border: 1px solid rgba(220, 53, 69, 0.2);
  border-radius: var(--radius-lg);
}

.emergency-title {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-danger);
  margin-bottom: var(--space-md);
}

.btn-emergency {
  width: 100%;
  padding: var(--space-md);
  margin-bottom: var(--space-sm);
}

.emergency-description {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin: 0;
}

/* ===================================
   Responsive Design
   =================================== */

/* Tablet */
@media (max-width: 992px) {
  .messages-area {
    padding: var(--space-md);
  }
  
  .message-wrapper {
    max-width: 85%;
  }
  
  .input-area {
    padding: var(--space-md);
  }
  
  .actions-row {
    flex-wrap: wrap;
  }
}

/* Mobile */
@media (max-width: 768px) {
  .chat-interface {
    border-radius: 0;
    min-height: 100vh;
  }
  
  .messages-area {
    padding: var(--space-sm);
  }
  
  .message-wrapper {
    max-width: 95%;
  }
  
  .message-body {
    padding: var(--space-sm) var(--space-md);
  }
  
  .input-area {
    padding: var(--space-sm);
  }
  
  .chat-input {
    min-height: 100px;
    font-size: var(--font-size-sm);
  }
  
  .actions-row {
    flex-direction: column;
  }
  
  .btn-action {
    width: 100%;
    justify-content: center;
  }
  
  .btn-text {
    flex: 1;
    text-align: center;
  }
  
  .features-grid .row {
    flex-direction: column;
  }
  
  .drawer-content {
    max-height: 350px;
  }
}

/* Small Mobile */
@media (max-width: 480px) {
  .feature-card {
    flex-direction: column;
    text-align: center;
  }
  
  .drawer-title {
    font-size: var(--font-size-lg);
  }
  
  .prompt-button {
    padding: var(--space-sm);
  }
}

/* ===================================
   Accessibility Enhancements
   =================================== */

/* Focus visible for keyboard navigation */
*:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* High contrast mode */
@media (prefers-contrast: high) {
  .chat-input,
  .btn-action,
  .message-body {
    border-width: 2px;
  }
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
  :root {
    --color-background: var(--color-gray-900);
    --color-background-alt: var(--color-gray-800);
    --color-text-primary: var(--color-gray-100);
    --color-text-secondary: var(--color-gray-300);
    --color-border: var(--color-gray-700);
  }
  
  .chat-input,
  .message-body {
    background: var(--color-gray-800);
    color: var(--color-gray-100);
  }
  
  .welcome-message .message-body {
    background: linear-gradient(135deg, rgba(111, 66, 193, 0.2) 0%, rgba(79, 140, 255, 0.2) 100%);
  }
}

/* ===================================
   Print Styles
   =================================== */
@media print {
  .input-area,
  .drawer-header,
  .actions-grid {
    display: none !important;
  }
  
  .chat-interface {
    box-shadow: none;
    border: 1px solid var(--color-gray-300);
  }
  
  .messages-area {
    overflow: visible;
    max-height: none;
  }
  
  .chat-message {
    page-break-inside: avoid;
  }
}