/* ============================================
   Chat Interface Styles
   ============================================ */

/* --- Chat layout --- */
.chat-container {
  display: flex;
  flex-direction: column;
  height: calc(100vh - 130px);
  max-width: 860px;
  margin: 0 auto;
}

.chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: var(--space-4);
  flex-shrink: 0;
}

.chat-header-info {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.chat-header-title {
  font-size: var(--text-lg);
  font-weight: 600;
  font-family: var(--font-jp);
}

.chat-header-subtitle {
  font-size: var(--text-xs);
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.chat-lesson-indicator {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  background: var(--accent-amber-glow);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--text-accent);
}

/* --- Message list --- */
.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-4) 0;
  scroll-behavior: smooth;
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

/* --- Message bubbles --- */
.message {
  display: flex;
  gap: var(--space-3);
  max-width: 85%;
  animation: messageIn 0.35s ease-out;
}

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

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

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

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-lg);
  flex-shrink: 0;
  margin-top: 2px;
}

.message-tutor .message-avatar {
  background: var(--accent-amber-glow);
  border: 1px solid rgba(245, 158, 11, 0.2);
}

.message-user .message-avatar {
  background: var(--accent-blue-glow);
  border: 1px solid rgba(59, 130, 246, 0.2);
}

.message-content {
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-lg);
  font-size: var(--text-base);
  line-height: 1.7;
  position: relative;
}

.message-tutor .message-content {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  border-top-left-radius: var(--radius-sm);
}

.message-user .message-content {
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.15);
  border-top-right-radius: var(--radius-sm);
  color: var(--text-primary);
}

/* Japanese text in messages */
.message-content .jp {
  font-family: var(--font-jp);
  font-size: 1.15em;
  line-height: 1.9;
  color: var(--text-primary);
  display: inline;
}

/* Furigana rendering */
.message-content ruby {
  font-family: var(--font-jp);
}

.message-content ruby rt {
  font-size: 0.55em;
  color: var(--text-tertiary);
}

/* Bold / emphasis in messages */
.message-content strong {
  color: var(--text-accent);
  font-weight: 600;
}

.message-content em {
  color: var(--accent-purple);
  font-style: italic;
}

/* Lists in messages */
.message-content ul,
.message-content ol {
  margin: var(--space-3) 0;
  padding-left: var(--space-6);
}

.message-content li {
  margin-bottom: var(--space-2);
  color: var(--text-secondary);
}

.message-content li::marker {
  color: var(--text-accent);
}

/* Code blocks in messages (lesson summaries) */
.message-content pre {
  margin: var(--space-4) 0;
  padding: var(--space-4);
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  overflow-x: auto;
  white-space: pre-wrap;
  word-wrap: break-word;
  line-height: 1.6;
}

.message-content code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  padding: 1px 4px;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 3px;
  color: var(--accent-purple);
}

.message-content pre code {
  padding: 0;
  background: none;
  color: var(--text-secondary);
}

/* Paragraphs in messages */
.message-content p {
  color: inherit;
}

.message-content p + p {
  margin-top: var(--space-3);
}

/* --- Typing indicator --- */
.typing-indicator {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) 0;
  font-size: var(--text-sm);
  color: var(--text-tertiary);
}

.typing-dots {
  display: flex;
  gap: 4px;
}

.typing-dot {
  width: 6px;
  height: 6px;
  background: var(--text-tertiary);
  border-radius: 50%;
  animation: typingBounce 1.2s infinite;
}

.typing-dot:nth-child(2) { animation-delay: 0.15s; }
.typing-dot:nth-child(3) { animation-delay: 0.3s; }

@keyframes typingBounce {
  0%, 60%, 100% {
    transform: translateY(0);
    opacity: 0.4;
  }
  30% {
    transform: translateY(-6px);
    opacity: 1;
  }
}

/* --- Streaming text animation --- */
.streaming-cursor::after {
  content: '\u258C';
  color: var(--accent-amber);
  animation: cursorBlink 0.8s step-end infinite;
  margin-left: 1px;
}

@keyframes cursorBlink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

/* --- Chat input area --- */
.chat-input-area {
  flex-shrink: 0;
  padding: var(--space-4) 0;
  border-top: 1px solid var(--border-subtle);
}

.chat-input-wrapper {
  display: flex;
  gap: var(--space-3);
  align-items: flex-end;
}

.chat-input {
  flex: 1;
  padding: var(--space-3) var(--space-4);
  background: var(--bg-input);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-lg);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: var(--text-base);
  line-height: 1.5;
  resize: none;
  outline: none;
  min-height: 44px;
  max-height: 140px;
  transition: border-color var(--transition-fast);
}

.chat-input:focus {
  border-color: var(--accent-amber);
}

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

.chat-send-btn {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--gradient-amber);
  border: none;
  border-radius: var(--radius-md);
  color: #0a0e1a;
  font-size: var(--text-lg);
  cursor: pointer;
  transition: all var(--transition-base);
  flex-shrink: 0;
}

.chat-send-btn:hover {
  box-shadow: var(--shadow-glow-amber);
  transform: scale(1.05);
}

.chat-send-btn:active {
  transform: scale(0.95);
}

.chat-send-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

/* --- Lesson summary card (special rendering) --- */
.lesson-summary {
  margin: var(--space-4) 0;
  padding: var(--space-5);
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.08), rgba(167, 139, 250, 0.05));
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-lg);
}

.lesson-summary-title {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--text-accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-3);
}

.lesson-summary-content {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.7;
  white-space: pre-wrap;
  color: var(--text-secondary);
}

.lesson-summary-copy {
  margin-top: var(--space-4);
  display: flex;
  justify-content: flex-end;
}

/* --- Welcome message --- */
.chat-welcome {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-12) var(--space-4);
  gap: var(--space-4);
  flex: 1;
}

.chat-welcome-icon {
  font-size: 4rem;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.chat-welcome-title {
  font-size: var(--text-2xl);
  font-weight: 700;
}

.chat-welcome-text {
  font-size: var(--text-sm);
  color: var(--text-tertiary);
  max-width: 500px;
  line-height: 1.7;
}

/* --- Responsive chat --- */
@media (max-width: 768px) {
  .chat-container {
    height: calc(100vh - 110px);
  }

  .message {
    max-width: 92%;
  }

  .message-content {
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-sm);
  }

  .message-avatar {
    width: 30px;
    height: 30px;
    font-size: var(--text-base);
  }
}