/* ==========================================================================
   STUDY BUDDY - Modern Educational Chatbot UI Stylesheet
   ========================================================================== */

/* --- CSS Custom Variables & Theme Tokens --- */
:root {
  /* Color Palette - Light Theme */
  --primary-hue: 245;
  --primary-50: #EEF2FF;
  --primary-100: #E0E7FF;
  --primary-500: #6366F1;
  --primary-600: #4F46E5;
  --primary-700: #4338CA;
  
  --accent-teal: #10B981;
  --accent-amber: #F59E0B;
  --accent-rose: #F43F5E;
  --accent-sky: #0EA5E9;

  --bg-app: #F8FAFC;
  --bg-sidebar: #FFFFFF;
  --bg-header: rgba(255, 255, 255, 0.85);
  --bg-card: #FFFFFF;
  --bg-chat-user: linear-gradient(135deg, #4F46E5 0%, #6366F1 100%);
  --bg-chat-bot: #FFFFFF;
  --bg-input: #FFFFFF;
  --bg-code: #1E293B;

  --text-main: #0F172A;
  --text-muted: #64748B;
  --text-light: #94A3B8;
  --text-on-primary: #FFFFFF;

  --border-color: #E2E8F0;
  --border-focus: #818CF8;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px -2px rgba(0, 0, 0, 0.08), 0 2px 6px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 12px 32px -4px rgba(79, 70, 229, 0.12), 0 4px 16px -2px rgba(0, 0, 0, 0.04);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'Fira Code', monospace;
}

/* Dark Mode Theme Tokens */
body.theme-dark {
  --bg-app: #090D16;
  --bg-sidebar: #0F172A;
  --bg-header: rgba(15, 23, 42, 0.85);
  --bg-card: #1E293B;
  --bg-chat-bot: #1E293B;
  --bg-input: #1E293B;
  --bg-code: #0F172A;

  --text-main: #F8FAFC;
  --text-muted: #94A3B8;
  --text-light: #64748B;

  --border-color: #334155;
  --border-focus: #6366F1;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.5);
}

/* --- Base Resets --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  width: 100%;
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-main);
  line-height: 1.6;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

/* --- Layout Container --- */
.app-container {
  display: flex;
  width: 100vw;
  height: 100vh;
  overflow: hidden;
}

/* --- Sidebar Styling --- */
.sidebar {
  width: 280px;
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-normal);
  z-index: 100;
}

.sidebar-header {
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary-600), var(--primary-500));
  color: white;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: 0 4px 10px rgba(79, 70, 229, 0.3);
}

.brand-text h2 {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.brand-tag {
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--primary-600);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.sidebar-body {
  flex: 1;
  padding: 1.25rem 1.25rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.new-chat-sidebar-btn {
  width: 100%;
  padding: 0.8rem 1rem;
  border-radius: var(--radius-md);
  justify-content: center;
  font-weight: 600;
}

.sidebar-section {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.section-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  letter-spacing: 0.08em;
}

.subject-tags {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.subject-chip {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 0.85rem;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  text-align: left;
  transition: all var(--transition-fast);
}

.subject-chip:hover {
  background-color: var(--primary-50);
  color: var(--primary-600);
}

body.theme-dark .subject-chip:hover {
  background-color: rgba(99, 102, 241, 0.15);
  color: #A5B4FC;
}

.subject-chip.active {
  background-color: var(--primary-50);
  border-color: var(--primary-100);
  color: var(--primary-600);
  font-weight: 700;
}

body.theme-dark .subject-chip.active {
  background-color: rgba(99, 102, 241, 0.2);
  border-color: rgba(99, 102, 241, 0.3);
  color: #A5B4FC;
}

.subject-chip i {
  font-size: 1rem;
  width: 20px;
  text-align: center;
}

.tips-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.tips-list li {
  font-size: 0.8rem;
  color: var(--text-muted);
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  line-height: 1.4;
}

.tips-list li i {
  color: var(--accent-teal);
  margin-top: 0.15rem;
}

.sidebar-footer {
  padding: 1rem 1.25rem;
  border-top: 1px solid var(--border-color);
}

.api-status-card {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem;
  background-color: var(--primary-50);
  border: 1px solid var(--primary-100);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

body.theme-dark .api-status-card {
  background-color: rgba(30, 41, 59, 0.8);
  border-color: var(--border-color);
}

.api-status-card:hover {
  filter: brightness(0.97);
}

.status-indicator-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--accent-amber);
  box-shadow: 0 0 8px var(--accent-amber);
}

.status-indicator-dot.connected {
  background-color: var(--accent-teal);
  box-shadow: 0 0 8px var(--accent-teal);
}

.status-info {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.status-title {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.status-sub {
  font-size: 0.7rem;
  color: var(--text-muted);
}

/* --- Main Content Area --- */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  background-color: var(--bg-app);
  position: relative;
  overflow: hidden;
}

/* --- Header Navbar --- */
.chat-header {
  height: 70px;
  padding: 0 1.5rem;
  background-color: var(--bg-header);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  z-index: 10;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.tutor-avatar-header {
  position: relative;
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, #6366F1, #8B5CF6);
  color: white;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.25);
}

.online-badge {
  position: absolute;
  bottom: -2px;
  right: -2px;
  width: 12px;
  height: 12px;
  background-color: var(--accent-teal);
  border: 2px solid var(--bg-header);
  border-radius: 50%;
}

.tutor-info .tutor-name {
  font-size: 1.05rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.badge-ai {
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.15rem 0.45rem;
  background-color: var(--primary-50);
  color: var(--primary-600);
  border-radius: var(--radius-full);
  border: 1px solid var(--primary-100);
}

body.theme-dark .badge-ai {
  background-color: rgba(99, 102, 241, 0.2);
  color: #A5B4FC;
  border-color: rgba(99, 102, 241, 0.3);
}

.tutor-status {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* --- Buttons System --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.55rem 1rem;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition-fast);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-600), var(--primary-500));
  color: var(--text-on-primary);
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.25);
}

.btn-primary:hover {
  filter: brightness(1.08);
  transform: translateY(-1px);
}

.btn-outline {
  background-color: transparent;
  border-color: var(--border-color);
  color: var(--text-main);
}

.btn-outline:hover {
  background-color: var(--primary-50);
  border-color: var(--primary-100);
  color: var(--primary-600);
}

body.theme-dark .btn-outline:hover {
  background-color: var(--bg-card);
  color: #A5B4FC;
}

.icon-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  background-color: var(--primary-50);
  color: var(--primary-600);
  border-color: var(--primary-100);
}

body.theme-dark .icon-btn:hover {
  background-color: var(--bg-card);
  color: #A5B4FC;
}

.icon-btn-sm {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  border: none;
  background: transparent;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: color var(--transition-fast);
}

.icon-btn-sm:hover {
  color: var(--primary-600);
}

/* --- Chat Scroll Body --- */
.chat-body {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  scroll-behavior: smooth;
}

/* --- Welcome Hero State --- */
.welcome-container {
  max-width: 760px;
  margin: 2rem auto;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  animation: fadeIn 0.4s ease-out;
}

.welcome-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.9rem;
  background-color: var(--primary-50);
  color: var(--primary-600);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  border: 1px solid var(--primary-100);
}

body.theme-dark .welcome-badge {
  background-color: rgba(99, 102, 241, 0.15);
  color: #A5B4FC;
  border-color: rgba(99, 102, 241, 0.3);
}

.welcome-title {
  font-size: 1.8rem;
  font-weight: 800;
  line-height: 1.3;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.welcome-subtitle {
  font-size: 0.98rem;
  color: var(--text-muted);
  max-width: 620px;
  line-height: 1.6;
}

.quick-cards-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
  width: 100%;
  margin-top: 1rem;
}

.quick-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.1rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  text-align: left;
  cursor: pointer;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
  position: relative;
}

.quick-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary-500);
  box-shadow: var(--shadow-md);
}

.card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.math-bg { background-color: rgba(245, 158, 11, 0.15); color: var(--accent-amber); }
.science-bg { background-color: rgba(16, 185, 129, 0.15); color: var(--accent-teal); }
.english-bg { background-color: rgba(14, 165, 233, 0.15); color: var(--accent-sky); }
.coding-bg { background-color: rgba(79, 70, 229, 0.15); color: var(--primary-600); }

.card-content {
  flex: 1;
  overflow: hidden;
}

.card-content h4 {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.2rem;
}

.card-content p {
  font-size: 0.78rem;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.card-arrow {
  color: var(--text-light);
  font-size: 0.85rem;
  transition: transform var(--transition-fast);
}

.quick-card:hover .card-arrow {
  transform: translateX(3px);
  color: var(--primary-600);
}

/* --- Messages List --- */
.messages-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: 860px;
  width: 100%;
  margin: 0 auto;
}

/* --- Chat Message Row --- */
.message-row {
  display: flex;
  gap: 0.85rem;
  width: 100%;
  animation: slideUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.message-row.user-row {
  flex-direction: row-reverse;
}

.avatar-wrapper {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1.1rem;
}

.bot-avatar {
  background: linear-gradient(135deg, #6366F1, #8B5CF6);
  color: white;
  box-shadow: 0 4px 10px rgba(99, 102, 241, 0.25);
}

.user-avatar {
  background: linear-gradient(135deg, #0EA5E9, #2563EB);
  color: white;
  box-shadow: 0 4px 10px rgba(14, 165, 233, 0.25);
}

/* --- Chat Bubble Styling --- */
.bubble-wrapper {
  display: flex;
  flex-direction: column;
  max-width: 78%;
}

.message-row.user-row .bubble-wrapper {
  align-items: flex-end;
}

.message-sender-name {
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
  padding: 0 0.25rem;
}

.chat-bubble {
  padding: 1rem 1.25rem;
  border-radius: var(--radius-lg);
  font-size: 0.95rem;
  line-height: 1.6;
  position: relative;
  word-break: break-word;
}

/* Bot Bubble (Left Side) */
.bot-row .chat-bubble {
  background-color: var(--bg-chat-bot);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  border-top-left-radius: 4px;
  box-shadow: var(--shadow-sm);
}

/* User Bubble (Right Side) */
.user-row .chat-bubble {
  background: var(--bg-chat-user);
  color: var(--text-on-primary);
  border-top-right-radius: 4px;
  box-shadow: 0 4px 14px rgba(79, 70, 229, 0.25);
}

/* Bubble Copy Button */
.bubble-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.4rem;
  opacity: 0.8;
}

.copy-btn {
  font-size: 0.72rem;
  color: var(--text-muted);
  background: transparent;
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast);
}

.copy-btn:hover {
  background-color: var(--primary-50);
  color: var(--primary-600);
}

body.theme-dark .copy-btn:hover {
  background-color: var(--bg-card);
  color: #A5B4FC;
}

/* --- Markdown Formatted Response Content --- */
.chat-bubble p {
  margin-bottom: 0.75rem;
}

.chat-bubble p:last-child {
  margin-bottom: 0;
}

.chat-bubble strong {
  font-weight: 700;
}

.chat-bubble ul, .chat-bubble ol {
  margin-left: 1.4rem;
  margin-bottom: 0.75rem;
}

.chat-bubble li {
  margin-bottom: 0.25rem;
}

.chat-bubble blockquote {
  border-left: 4px solid var(--primary-500);
  padding-left: 0.8rem;
  margin: 0.75rem 0;
  color: var(--text-muted);
  font-style: italic;
}

.chat-bubble code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background-color: rgba(99, 102, 241, 0.12);
  color: var(--primary-600);
  padding: 0.15rem 0.35rem;
  border-radius: 4px;
}

body.theme-dark .chat-bubble code {
  color: #A5B4FC;
  background-color: rgba(99, 102, 241, 0.2);
}

.user-row .chat-bubble code {
  background-color: rgba(255, 255, 255, 0.2);
  color: #FFFFFF;
}

/* Code Blocks */
.code-block-container {
  margin: 0.85rem 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  background-color: var(--bg-code);
  box-shadow: var(--shadow-sm);
}

.code-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.4rem 0.85rem;
  background-color: rgba(0, 0, 0, 0.3);
  color: #94A3B8;
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

.code-block-container pre {
  padding: 0.85rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: #F8FAFC;
  line-height: 1.5;
}

.code-block-container pre code {
  background-color: transparent !important;
  color: inherit !important;
  padding: 0 !important;
}

/* --- Typing Indicator (Loading State) --- */
.typing-bubble {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.85rem 1.1rem !important;
}

.typing-text {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.dots-wave {
  display: flex;
  align-items: center;
  gap: 4px;
}

.dots-wave span {
  width: 6px;
  height: 6px;
  background-color: var(--primary-500);
  border-radius: 50%;
  animation: bounceDot 1.4s infinite ease-in-out both;
}

.dots-wave span:nth-child(1) { animation-delay: -0.32s; }
.dots-wave span:nth-child(2) { animation-delay: -0.16s; }

/* --- Quick Suggestions Horizontal Bar --- */
.quick-suggestions-wrapper {
  max-width: 860px;
  width: 100%;
  margin: 0 auto;
  padding: 0.5rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  animation: fadeIn 0.3s ease;
}

.chips-label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.chips-label i {
  color: var(--accent-amber);
}

.chips-scroll {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding-bottom: 0.2rem;
  scrollbar-width: none;
}

.chips-scroll::-webkit-scrollbar {
  display: none;
}

.suggestion-chip {
  padding: 0.4rem 0.85rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-family: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-main);
  white-space: nowrap;
  cursor: pointer;
  transition: all var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.suggestion-chip:hover {
  background-color: var(--primary-50);
  border-color: var(--primary-500);
  color: var(--primary-600);
  transform: translateY(-1px);
}

body.theme-dark .suggestion-chip:hover {
  background-color: rgba(99, 102, 241, 0.2);
  color: #A5B4FC;
}

/* --- Chat Input Footer --- */
.chat-footer {
  padding: 0.75rem 1.5rem 1.25rem 1.5rem;
  max-width: 860px;
  width: 100%;
  margin: 0 auto;
}

.input-container {
  display: flex;
  flex-direction: column;
  background-color: var(--bg-input);
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 0.75rem 0.85rem 0.6rem 1rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  box-shadow: var(--shadow-md);
}

.input-container:focus-within {
  border-color: var(--primary-500);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
}

.input-container textarea {
  width: 100%;
  border: none;
  background: transparent;
  outline: none;
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--text-main);
  resize: none;
  max-height: 150px;
  min-height: 24px;
  line-height: 1.5;
}

.input-container textarea::placeholder {
  color: var(--text-light);
}

.input-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 0.5rem;
  padding-top: 0.3rem;
  border-top: 1px solid rgba(0, 0, 0, 0.04);
}

body.theme-dark .input-actions {
  border-top-color: rgba(255, 255, 255, 0.05);
}

.input-hint {
  font-size: 0.72rem;
  color: var(--text-light);
}

.send-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  border: none;
  background: linear-gradient(135deg, var(--primary-600), var(--primary-500));
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  box-shadow: 0 4px 10px rgba(79, 70, 229, 0.3);
}

.send-btn:hover {
  transform: scale(1.05);
  filter: brightness(1.1);
}

.send-btn:disabled {
  background: var(--border-color);
  color: var(--text-light);
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
}

.footer-disclaimer {
  text-align: center;
  font-size: 0.7rem;
  color: var(--text-light);
  margin-top: 0.6rem;
}

/* --- API Key Setup Modal --- */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-normal);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-card {
  width: 100%;
  max-width: 480px;
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transform: scale(0.95);
  transition: transform var(--transition-normal);
}

.modal-overlay.active .modal-card {
  transform: scale(1);
}

.modal-header {
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
}

.modal-title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--primary-600);
}

.modal-title h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
}

.modal-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-group label {
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--text-main);
}

.input-password-wrapper {
  display: flex;
  align-items: center;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0 0.5rem;
  background-color: var(--bg-app);
}

.input-password-wrapper input {
  flex: 1;
  padding: 0.65rem;
  border: none;
  background: transparent;
  outline: none;
  font-family: inherit;
  font-size: 0.9rem;
  color: var(--text-main);
}

.help-text {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.help-text a {
  color: var(--primary-600);
  text-decoration: none;
  font-weight: 600;
}

.help-text a:hover {
  text-decoration: underline;
}

.api-info-box {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  padding: 0.75rem 0.9rem;
  background-color: var(--primary-50);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  color: var(--primary-600);
}

body.theme-dark .api-info-box {
  background-color: rgba(99, 102, 241, 0.15);
  color: #A5B4FC;
}

.modal-footer {
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
  gap: 0.75rem;
  background-color: var(--bg-app);
}

/* --- Toast Notification System --- */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  z-index: 1100;
}

.toast {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1.2rem;
  background-color: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-main);
  animation: slideInRight 0.3s ease;
}

.toast-error {
  border-left: 4px solid var(--accent-rose);
}

.toast-error i { color: var(--accent-rose); }

.toast-success {
  border-left: 4px solid var(--accent-teal);
}

.toast-success i { color: var(--accent-teal); }

/* --- Keyframe Animations --- */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(30px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes bounceDot {
  0%, 80%, 100% { transform: scale(0); }
  40% { transform: scale(1); }
}

/* --- Responsive Media Queries --- */
.mobile-only {
  display: none;
}

@media (max-width: 900px) {
  .sidebar {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    transform: translateX(-100%);
    box-shadow: var(--shadow-lg);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .mobile-only {
    display: flex;
  }

  .quick-cards-grid {
    grid-template-columns: 1fr;
  }

  .bubble-wrapper {
    max-width: 88%;
  }

  .btn-text {
    display: none;
  }
}