/* ============================================================
   AI Chat Panel — Groq-powered study assistant
   ============================================================ */

.ai-chat__backdrop {
  position: fixed;
  inset: 0;
  z-index: 800;
  background: rgba(0, 0, 0, 0.35);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-normal) var(--ease-out);
}

.ai-chat__backdrop.is-visible {
  opacity: 1;
  pointer-events: auto;
}

.ai-chat {
  position: fixed;
  top: 0;
  right: 0;
  z-index: 810;
  display: flex;
  flex-direction: column;
  width: min(420px, 100vw);
  height: 100vh;
  height: 100dvh;
  background: var(--color-bg-elevated);
  border-left: 1px solid var(--color-border);
  box-shadow: var(--shadow-lg);
  transform: translateX(100%);
  transition: transform var(--duration-normal) var(--ease-out);
}

.ai-chat.is-open {
  transform: translateX(0);
}

.ai-chat__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 16px 16px 12px;
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.ai-chat__title {
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin: 0;
}

.ai-chat__subtitle {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  margin: 2px 0 0;
}

.ai-chat__header-actions {
  display: flex;
  align-items: center;
  gap: 6px;
}

.ai-chat__provider {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
}

.ai-chat__provider-label {
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 0.65rem;
}

.ai-chat__provider-select {
  font-size: var(--font-size-xs);
  padding: 0.2rem 0.35rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: var(--color-bg-secondary, rgba(255,255,255,0.04));
  color: var(--color-text-primary);
  max-width: 88px;
}

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

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

.ai-chat__context-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  font-size: var(--font-size-xs);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
  overflow: hidden;
}

.ai-chat__context-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--color-text-secondary);
  cursor: pointer;
  white-space: nowrap;
}

.ai-chat__context-pill {
  padding: 2px 8px;
  background: var(--color-accent-soft);
  color: var(--color-accent);
  border-radius: 999px;
  font-size: var(--font-size-xs);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 160px;
}

.ai-chat__messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.ai-chat__empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 32px 16px;
  animation: fadeInUp var(--duration-slow) var(--ease-out) both;
}

.ai-chat__empty-icon {
  color: var(--color-text-tertiary);
  margin-bottom: 12px;
}

.ai-chat__empty-title {
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-semibold);
  margin-bottom: 8px;
}

.ai-chat__empty-text {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: 16px;
  line-height: var(--line-height-relaxed);
}

.ai-chat__suggestions {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
}

.ai-chat__suggestion {
  padding: 10px 14px;
  font-size: var(--font-size-sm);
  text-align: left;
  color: var(--color-text-primary);
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out);
}

.ai-chat__suggestion:hover {
  background: var(--color-bg-hover);
  border-color: var(--color-accent);
}

/* Messages */
.ai-chat__msg {
  animation: fadeInUp var(--duration-fast) var(--ease-out) both;
}

.ai-chat__msg--user .ai-chat__msg-body {
  background: var(--color-accent-soft);
  border-radius: var(--radius-md) var(--radius-md) 4px var(--radius-md);
}

.ai-chat__msg--assistant .ai-chat__msg-body {
  background: var(--color-bg-subtle);
  border-radius: var(--radius-md) var(--radius-md) var(--radius-md) 4px;
}

.ai-chat__msg--error .ai-chat__msg-body {
  border: 1px solid #c4705a;
}

.ai-chat__msg-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
}

.ai-chat__msg-role {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-secondary);
}

.ai-chat__msg-time {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
}

.ai-chat__msg-body {
  padding: 10px 12px;
}

.ai-chat__msg-text {
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
}

.ai-chat__msg-md {
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  word-break: break-word;
}

.ai-chat__msg-md .ai-md__h2,
.ai-chat__msg-md .ai-md__h3,
.ai-chat__msg-md .ai-md__h4 {
  font-weight: var(--font-weight-semibold);
  margin: 8px 0 4px;
}

.ai-chat__msg-md .ai-md__p {
  margin: 0 0 8px;
}

.ai-chat__msg-md .ai-md__ul,
.ai-chat__msg-md .ai-md__ol {
  margin: 4px 0 8px;
  padding-left: 20px;
}

.ai-chat__msg-md .ai-md__code {
  padding: 1px 5px;
  background: var(--color-bg-hover);
  border-radius: 4px;
  font-size: 0.9em;
}

.ai-chat__msg-md .ai-md__pre {
  padding: 10px;
  background: var(--color-bg);
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin: 8px 0;
  font-size: var(--font-size-xs);
}

.ai-chat__msg-actions {
  display: flex;
  gap: 8px;
  margin-top: 4px;
}

.ai-chat__msg-btn {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  background: none;
  border: none;
  cursor: pointer;
  padding: 2px 0;
}

.ai-chat__msg-btn:hover {
  color: var(--color-accent);
}

.ai-chat__msg--streaming .ai-chat__msg-md::after {
  content: '▋';
  animation: aiBlink 0.8s step-end infinite;
  color: var(--color-accent);
  margin-left: 2px;
}

@keyframes aiBlink {
  50% { opacity: 0; }
}

/* Thinking loader */
.ai-chat__thinking {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

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

.ai-chat__thinking-dots span {
  width: 6px;
  height: 6px;
  background: var(--color-accent);
  border-radius: 50%;
  animation: aiDotPulse 1.2s ease-in-out infinite;
}

.ai-chat__thinking-dots span:nth-child(2) { animation-delay: 0.15s; }
.ai-chat__thinking-dots span:nth-child(3) { animation-delay: 0.3s; }

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

/* Composer */
.ai-chat__composer {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 12px 16px 16px;
  border-top: 1px solid var(--color-border);
  flex-shrink: 0;
}

.ai-chat__input {
  width: 100%;
  min-height: 44px;
  max-height: 120px;
  padding: 10px 12px;
  font-family: inherit;
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-primary);
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  resize: none;
  transition: border-color var(--duration-fast) var(--ease-out);
}

.ai-chat__input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.ai-chat__input:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.ai-chat__composer-actions {
  display: flex;
  justify-content: flex-end;
}

.ai-chat__send-btn,
.ai-chat__stop-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  padding: 0 14px;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-out),
              transform var(--duration-fast) var(--ease-out);
}

.ai-chat__send-btn {
  background: var(--color-accent);
  color: var(--color-text-inverse);
}

.ai-chat__send-btn:hover:not(:disabled) {
  filter: brightness(1.08);
}

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

.ai-chat__stop-btn {
  background: #8b4513;
  color: #fff;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
}

.ai-chat__send-btn:active,
.ai-chat__stop-btn:active {
  transform: scale(0.96);
}

/* Navbar AI button accent */
.navbar__btn--ai {
  color: var(--color-accent);
}

.navbar__btn--ai:hover {
  background: var(--color-accent-soft);
}

@media (max-width: 480px) {
  .ai-chat {
    width: 100vw;
  }
}