/* ===== RESET & BASE ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #0d0d0d;
  --bg-secondary: #1a1a1a;
  --bg-sidebar: #121212;
  --bg-input: #1e1e1e;
  --bg-message-user: #2a2a2a;
  --bg-message-ai: #1a1a1a;
  --text-primary: #e0e0e0;
  --text-secondary: #a0a0a0;
  --text-muted: #666;
  --accent: #8b5cf6;
  --accent-hover: #7c3aed;
  --border-color: #2a2a2a;
  --shadow: 0 4px 24px rgba(0,0,0,0.6);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.2s ease;
}

/* Thème clair */
[data-theme="light"] {
  --bg-primary: #f5f5f5;
  --bg-secondary: #ffffff;
  --bg-sidebar: #e8e8e8;
  --bg-input: #ffffff;
  --bg-message-user: #d1d5db;
  --bg-message-ai: #ffffff;
  --text-primary: #1f2937;
  --text-secondary: #4b5563;
  --text-muted: #9ca3af;
  --border-color: #d1d5db;
  --shadow: 0 4px 20px rgba(0,0,0,0.08);
}

html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  transition: background var(--transition), color var(--transition);
}

body {
  display: flex;
  min-height: 100vh;
  overflow: hidden;
}

/* ===== SIDEBAR ===== */
.sidebar {
  width: 260px;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease, background var(--transition);
  flex-shrink: 0;
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 100;
  overflow-y: auto;
}

.sidebar-inner {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 16px 12px;
}

.logo-area {
  padding: 12px 8px 20px 8px;
}

.logo-text {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, #8b5cf6, #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-text i {
  -webkit-text-fill-color: #8b5cf6;
  background: none;
  font-size: 20px;
}

.new-chat-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition), transform 0.1s;
  width: 100%;
  margin-bottom: 20px;
}

.new-chat-btn:hover {
  background: var(--accent-hover);
}
.new-chat-btn:active {
  transform: scale(0.97);
}

.history-container {
  flex: 1;
  overflow-y: auto;
  margin-bottom: 12px;
}

.history-title {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
  padding: 8px 8px 12px 8px;
}

.history-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.history-item {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition);
  font-size: 14px;
  color: var(--text-secondary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.history-item:hover {
  background: var(--bg-secondary);
}

.history-item.active {
  background: var(--bg-secondary);
  border-left: 3px solid var(--accent);
  color: var(--text-primary);
}

.history-item .delete-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 16px;
  padding: 0 4px;
  opacity: 0.5;
  transition: opacity var(--transition);
}

.history-item .delete-btn:hover {
  opacity: 1;
  color: #ef4444;
}

.sidebar-footer {
  border-top: 1px solid var(--border-color);
  padding-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.sidebar-btn {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 14px;
  cursor: pointer;
  transition: background var(--transition);
  width: 100%;
}

.sidebar-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.user-profile {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 8px;
  border-radius: var(--radius-sm);
}

.avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 14px;
  flex-shrink: 0;
}

.user-profile .avatar {
  background: var(--accent);
  color: #fff;
}

.user-profile .username {
  font-size: 14px;
  font-weight: 500;
}

/* ===== MAIN CONTENT ===== */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  margin-left: 260px;
  background: var(--bg-primary);
  transition: margin-left 0.3s ease, background var(--transition);
}

.mobile-header {
  display: none;
  padding: 12px 16px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.menu-toggle {
  background: none;
  border: none;
  font-size: 24px;
  color: var(--text-primary);
  cursor: pointer;
  padding: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.mobile-logo {
  font-size: 18px;
  font-weight: 600;
  background: linear-gradient(135deg, #8b5cf6, #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: flex;
  align-items: center;
  gap: 8px;
}

.mobile-logo i {
  -webkit-text-fill-color: #8b5cf6;
  background: none;
  font-size: 16px;
}

/* ===== CHAT AREA ===== */
.chat-area {
  flex: 1;
  overflow-y: auto;
  padding: 20px 24px 8px 24px;
  display: flex;
  flex-direction: column;
}

.messages-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-bottom: 12px;
}

.message {
  display: flex;
  gap: 12px;
  max-width: 85%;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

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

.message.ai-message {
  align-self: flex-start;
}

.avatar.ai-avatar {
  background: linear-gradient(135deg, #8b5cf6, #6d28d9);
  color: #fff;
}

.message-wrapper {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 6px;
}

.message-content {
  background: var(--bg-message-ai);
  padding: 12px 16px;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  color: var(--text-primary);
  line-height: 1.6;
  font-size: 15px;
  position: relative;
}

.user-message .message-content {
  background: var(--bg-message-user);
  border-radius: var(--radius) var(--radius-sm) var(--radius-sm) var(--radius);
}

.ai-message .message-content {
  border-radius: var(--radius-sm) var(--radius) var(--radius) var(--radius-sm);
}

.message-content p {
  margin-bottom: 6px;
}
.message-content p:last-child {
  margin-bottom: 0;
}

/* ===== MESSAGE ACTIONS ===== */
.message-actions {
  display: flex;
  gap: 8px;
  opacity: 0;
  transition: opacity var(--transition);
  margin-top: 4px;
}

.message.ai-message:hover .message-actions {
  opacity: 1;
}

.action-btn {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 4px 8px;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 14px;
  transition: all var(--transition);
  display: flex;
  align-items: center;
  gap: 4px;
}

.action-btn:hover {
  background: var(--bg-input);
  color: var(--text-primary);
  border-color: var(--accent);
}

/* ===== EDITING ===== */
.edit-input {
  width: 100%;
  padding: 8px 12px;
  background: var(--bg-input);
  color: var(--text-primary);
  border: 2px solid var(--accent);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-family: inherit;
  line-height: 1.6;
  resize: vertical;
  min-height: 60px;
  outline: none;
}

.edit-actions {
  display: flex;
  gap: 8px;
  margin-top: 8px;
}

.edit-save-btn,
.edit-cancel-btn {
  padding: 6px 12px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: all var(--transition);
}

.edit-save-btn {
  background: var(--accent);
  color: #fff;
}

.edit-save-btn:hover {
  background: var(--accent-hover);
}

.edit-cancel-btn {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.edit-cancel-btn:hover {
  background: var(--bg-input);
  color: var(--text-primary);
}

/* ===== USAGE INDICATOR ===== */
.usage-indicator {
  font-size: 11px;
  color: var(--text-muted);
  opacity: 0.7;
  margin-top: 4px;
  padding: 0 4px;
}

/* ===== TYPING INDICATOR ===== */
.typing-indicator {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 0 16px 0;
  animation: fadeIn 0.3s ease;
}

.typing-dots {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-message-ai);
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow);
}

.typing-dots span {
  display: inline-block;
  width: 8px;
  height: 8px;
  background: var(--text-muted);
  border-radius: 50%;
  animation: dotBounce 1.4s infinite ease-in-out both;
}

.typing-dots span:nth-child(1) { animation-delay: 0s; }
.typing-dots span:nth-child(2) { animation-delay: 0.2s; }
.typing-dots span:nth-child(3) { animation-delay: 0.4s; }

@keyframes dotBounce {
  0%, 80%, 100% { transform: scale(0.6); opacity: 0.4; }
  40% { transform: scale(1); opacity: 1; }
}

.typing-text {
  margin-left: 6px;
  font-size: 14px;
  color: var(--text-secondary);
}

/* ===== INPUT AREA ===== */
.input-area {
  padding: 12px 24px 20px 24px;
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  flex-shrink: 0;
  transition: background var(--transition);
}

.input-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-input);
  padding: 6px 12px 6px 6px;
  border-radius: 50px;
  border: 1px solid var(--border-color);
  transition: border var(--transition), background var(--transition);
}

.input-wrapper:focus-within {
  border-color: var(--accent);
}

.input-btn {
  background: none;
  border: none;
  font-size: 18px;
  padding: 8px;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: 50%;
  transition: background var(--transition), color var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
}

.input-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

#messageInput {
  flex: 1;
  border: none;
  background: transparent;
  padding: 10px 6px;
  font-size: 16px;
  color: var(--text-primary);
  outline: none;
  min-width: 0;
}

#messageInput::placeholder {
  color: var(--text-muted);
}

.send-btn {
  background: var(--accent);
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  color: #fff;
  font-size: 16px;
  cursor: pointer;
  transition: background var(--transition), transform 0.1s;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.send-btn:hover {
  background: var(--accent-hover);
}
.send-btn:active {
  transform: scale(0.92);
}

.input-footer {
  text-align: center;
  font-size: 11px;
  color: var(--text-muted);
  padding-top: 8px;
  opacity: 0.7;
}

/* ===== MODAL ===== */
.modal {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(4px);
  align-items: center;
  justify-content: center;
  z-index: 200;
}

.modal.open {
  display: flex;
}

.modal-content {
  background: var(--bg-secondary);
  padding: 28px 32px;
  border-radius: var(--radius);
  max-width: 420px;
  width: 90%;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
}

.modal-content h2 {
  margin-bottom: 20px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 10px;
}

.modal-content h2 i {
  color: var(--accent);
}

.setting-group {
  margin-bottom: 20px;
}

.setting-group label {
  display: block;
  font-weight: 500;
  margin-bottom: 6px;
}

.setting-group select {
  width: 100%;
  padding: 10px 12px;
  background: var(--bg-input);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 15px;
  outline: none;
}

.modal-close-btn {
  width: 100%;
  padding: 12px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: background var(--transition);
  margin-top: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.modal-close-btn:hover {
  background: var(--accent-hover);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
    width: 280px;
  }
  .sidebar.open {
    transform: translateX(0);
  }
  .main-content {
    margin-left: 0;
  }
  .mobile-header {
    display: flex;
  }
  .chat-area {
    padding: 12px 16px 8px 16px;
  }
  .message {
    max-width: 95%;
  }
  .input-area {
    padding: 10px 12px 16px 12px;
  }
  .input-wrapper {
    padding: 4px 8px 4px 4px;
  }
  .logo-text {
    font-size: 20px;
  }
}

@media (max-width: 480px) {
  .chat-area {
    padding: 8px 10px 4px 10px;
  }
  .message-content {
    font-size: 14px;
    padding: 10px 14px;
  }
  .input-wrapper {
    gap: 4px;
  }
  .input-btn {
    width: 34px;
    height: 34px;
    font-size: 16px;
  }
  .send-btn {
    width: 34px;
    height: 34px;
    font-size: 14px;
  }
  #messageInput {
    font-size: 15px;
    padding: 8px 4px;
  }
}