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

:root {
  --bg: #0d0f14;
  --bg-2: #131620;
  --bg-3: #1a1d2e;
  --bg-4: #1f2235;
  --border: rgba(255,255,255,0.07);
  --border-2: rgba(255,255,255,0.12);
  --text: #e2e4f0;
  --text-2: #8b8fa8;
  --text-3: #555876;
  --accent: #818cf8;
  --accent-2: #c084fc;
  --accent-glow: rgba(129,140,248,0.15);
  --green: #34d399;
  --red: #f87171;
  --sidebar-w: 260px;
  --radius: 12px;
  --radius-sm: 8px;
  --font: 'Inter', sans-serif;
  --mono: 'JetBrains Mono', monospace;
  --trans: 0.2s cubic-bezier(0.4,0,0.2,1);
}

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  display: flex;
  font-size: 14px;
  line-height: 1.6;
}

/* ─── Sidebar ───────────────────────────────────────────────────────────── */
.sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  background: var(--bg-2);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  transition: width var(--trans), min-width var(--trans), transform var(--trans);
  position: relative;
  z-index: 10;
}

.sidebar:not(.open) {
  width: 0;
  min-width: 0;
  overflow: hidden;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex-shrink: 0;
}

.logo-text {
  font-weight: 700;
  font-size: 15px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  white-space: nowrap;
}

.icon-btn {
  background: none;
  border: none;
  color: var(--text-2);
  cursor: pointer;
  padding: 6px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--trans), color var(--trans);
  flex-shrink: 0;
}

.icon-btn:hover {
  background: var(--bg-3);
  color: var(--text);
}

.new-chat-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 12px 12px 8px;
  padding: 9px 14px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border: none;
  border-radius: var(--radius-sm);
  color: white;
  font-family: var(--font);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: opacity var(--trans), transform var(--trans);
  white-space: nowrap;
  flex-shrink: 0;
}

.new-chat-btn:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.new-chat-btn:active { transform: translateY(0); }

.conv-list-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 8px 16px 4px;
  flex-shrink: 0;
}

.conv-list {
  flex: 1;
  overflow-y: auto;
  padding: 4px 8px;
}

.conv-list::-webkit-scrollbar { width: 4px; }
.conv-list::-webkit-scrollbar-track { background: transparent; }
.conv-list::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 2px; }

.conv-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--trans);
  position: relative;
  group: true;
}

.conv-item:hover { background: var(--bg-3); }
.conv-item.active { background: var(--accent-glow); }
.conv-item.active .conv-item-title { color: var(--accent); }

.conv-item-icon {
  color: var(--text-3);
  flex-shrink: 0;
  font-size: 14px;
}

.conv-item-info { flex: 1; min-width: 0; }

.conv-item-title {
  font-size: 13px;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  font-weight: 500;
}

.conv-item-meta {
  font-size: 11px;
  color: var(--text-3);
  margin-top: 1px;
}

.conv-delete-btn {
  opacity: 0;
  background: none;
  border: none;
  color: var(--text-3);
  cursor: pointer;
  padding: 2px 4px;
  border-radius: 4px;
  transition: opacity var(--trans), color var(--trans), background var(--trans);
  flex-shrink: 0;
  font-size: 14px;
  line-height: 1;
}

.conv-item:hover .conv-delete-btn { opacity: 1; }
.conv-delete-btn:hover { color: var(--red); background: rgba(248,113,113,0.1); }

.sidebar-footer {
  padding: 12px 16px;
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 6px var(--green);
  animation: pulse 2s infinite;
  flex-shrink: 0;
}

.status-dot.error { background: var(--red); box-shadow: 0 0 6px var(--red); }
.status-dot.loading { background: var(--accent); box-shadow: 0 0 6px var(--accent); animation: pulse 0.8s infinite; }

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

#status-text {
  font-size: 12px;
  color: var(--text-3);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ─── Main ──────────────────────────────────────────────────────────────── */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  min-width: 0;
}

/* ─── Topbar ────────────────────────────────────────────────────────────── */
.topbar {
  display: flex;
  align-items: center;
  padding: 0 20px;
  height: 56px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-2);
  gap: 12px;
  flex-shrink: 0;
}

.topbar-center {
  flex: 1;
  text-align: center;
  min-width: 0;
}

.conv-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-2);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.topbar-right {
  display: flex;
  align-items: center;
  gap: 6px;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  color: var(--text-2);
  padding: 4px 10px;
  background: var(--bg-3);
  border: 1px solid var(--border);
  border-radius: 999px;
  white-space: nowrap;
}

.mobile-only { display: none; }

/* ─── Chat Container ────────────────────────────────────────────────────── */
.chat-container {
  flex: 1;
  overflow-y: auto;
  padding: 0;
  position: relative;
  scroll-behavior: smooth;
}

.chat-container::-webkit-scrollbar { width: 6px; }
.chat-container::-webkit-scrollbar-track { background: transparent; }
.chat-container::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 3px; }

/* ─── Welcome Screen ────────────────────────────────────────────────────── */
.welcome-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: calc(100vh - 160px);
  padding: 40px 20px;
  text-align: center;
  animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.welcome-logo {
  margin-bottom: 20px;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.welcome-title {
  font-size: 36px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
}

.welcome-sub {
  color: var(--text-2);
  font-size: 15px;
  margin-bottom: 40px;
}

.welcome-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  max-width: 600px;
}

.chip {
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  color: var(--text);
  font-family: var(--font);
  font-size: 13px;
  padding: 10px 16px;
  border-radius: 999px;
  cursor: pointer;
  transition: all var(--trans);
  white-space: nowrap;
}

.chip:hover {
  background: var(--accent-glow);
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px var(--accent-glow);
}

/* ─── Messages ──────────────────────────────────────────────────────────── */
.messages {
  padding: 24px 0 16px;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.msg {
  display: flex;
  gap: 14px;
  padding: 16px 24px;
  animation: msgIn 0.25s ease;
  transition: background var(--trans);
}

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

.msg.user { background: transparent; }
.msg.assistant { background: var(--bg-2); }
.msg.assistant:hover { background: var(--bg-3); }

.msg-avatar {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  flex-shrink: 0;
  margin-top: 2px;
}

.msg.user .msg-avatar {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: white;
  font-weight: 700;
  font-size: 13px;
}

.msg.assistant .msg-avatar {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: white;
}

.msg-avatar svg { width: 16px; height: 16px; }

.msg-body { flex: 1; min-width: 0; }

.msg-role {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 6px;
}

.msg.assistant .msg-role { color: var(--accent); }

.msg-content {
  color: var(--text);
  line-height: 1.7;
  word-break: break-word;
}

/* Markdown styles */
.msg-content h1, .msg-content h2, .msg-content h3 {
  font-weight: 700;
  margin: 16px 0 8px;
  color: var(--text);
}
.msg-content h1 { font-size: 20px; }
.msg-content h2 { font-size: 17px; }
.msg-content h3 { font-size: 15px; }

.msg-content p { margin-bottom: 10px; }
.msg-content p:last-child { margin-bottom: 0; }

.msg-content ul, .msg-content ol {
  padding-left: 20px;
  margin-bottom: 10px;
}
.msg-content li { margin-bottom: 4px; }

.msg-content code {
  font-family: var(--mono);
  font-size: 12.5px;
  background: var(--bg-4);
  border: 1px solid var(--border-2);
  padding: 1px 5px;
  border-radius: 4px;
  color: #c084fc;
}

.msg-content pre {
  background: var(--bg-4);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  overflow-x: auto;
  margin: 10px 0;
  position: relative;
}

.msg-content pre code {
  background: none;
  border: none;
  padding: 0;
  color: var(--text);
  font-size: 13px;
}

.msg-content pre::-webkit-scrollbar { height: 4px; }
.msg-content pre::-webkit-scrollbar-thumb { background: var(--border-2); border-radius: 2px; }

.msg-content a { color: var(--accent); text-decoration: underline; }
.msg-content a:hover { color: var(--accent-2); }

.msg-content blockquote {
  border-left: 3px solid var(--accent);
  padding-left: 12px;
  color: var(--text-2);
  margin: 8px 0;
}

.msg-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 10px 0;
  font-size: 13px;
}
.msg-content th, .msg-content td {
  border: 1px solid var(--border-2);
  padding: 7px 12px;
  text-align: left;
}
.msg-content th { background: var(--bg-4); font-weight: 600; }
.msg-content tr:nth-child(even) { background: rgba(255,255,255,0.02); }

.msg-content strong { font-weight: 700; color: #e2e4f0; }
.msg-content em { color: var(--text-2); }
.msg-content hr { border: none; border-top: 1px solid var(--border); margin: 16px 0; }

/* Typing cursor */
.typing-cursor {
  display: inline-block;
  width: 2px;
  height: 15px;
  background: var(--accent);
  border-radius: 1px;
  margin-left: 2px;
  vertical-align: middle;
  animation: blink 0.9s step-end infinite;
}

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

/* Thinking indicator */
.thinking {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text-3);
  font-size: 13px;
  padding: 4px 0;
}

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

.thinking-dots span {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
  animation: bounce 1.2s infinite;
}
.thinking-dots span:nth-child(2) { animation-delay: 0.2s; }
.thinking-dots span:nth-child(3) { animation-delay: 0.4s; }

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

/* Error message */
.msg-error {
  color: var(--red);
  background: rgba(248,113,113,0.08);
  border: 1px solid rgba(248,113,113,0.2);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 13px;
  margin-top: 6px;
}

/* ─── Input Area ────────────────────────────────────────────────────────── */
.input-area {
  padding: 12px 24px 16px;
  background: var(--bg);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.input-wrapper {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  padding: 10px 12px;
  transition: border-color var(--trans), box-shadow var(--trans);
}

.input-wrapper:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.user-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.6;
  resize: none;
  max-height: 200px;
  overflow-y: auto;
  padding: 0;
}

.user-input::placeholder { color: var(--text-3); }
.user-input::-webkit-scrollbar { width: 3px; }
.user-input::-webkit-scrollbar-thumb { background: var(--border-2); }

.send-btn {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  border: none;
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity var(--trans), transform var(--trans);
  flex-shrink: 0;
}

.send-btn:hover:not(:disabled) { opacity: 0.85; transform: scale(1.05); }
.send-btn:active:not(:disabled) { transform: scale(0.95); }
.send-btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }

.input-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 8px;
  padding: 0 2px;
}

.model-badge {
  font-size: 11px;
  color: var(--text-3);
  background: var(--bg-3);
  border: 1px solid var(--border);
  padding: 2px 8px;
  border-radius: 999px;
}

.input-hint {
  font-size: 11px;
  color: var(--text-3);
}

/* ─── Model Selector ───────────────────────────────────────────────────── */
.model-selector {
  position: relative;
}

.model-badge {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  color: var(--text-2);
  background: var(--bg-3);
  border: 1px solid var(--border);
  padding: 3px 10px;
  border-radius: 999px;
  cursor: pointer;
  font-family: var(--font);
  transition: all var(--trans);
  white-space: nowrap;
}

.model-badge:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
}

.model-badge.open {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
}

.model-dropdown {
  position: absolute;
  bottom: calc(100% + 8px);
  left: 0;
  width: 260px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  padding: 6px;
  box-shadow: 0 -8px 32px rgba(0,0,0,0.4), 0 0 0 1px rgba(255,255,255,0.04);
  z-index: 100;
  opacity: 0;
  transform: translateY(8px) scale(0.97);
  pointer-events: none;
  transition: opacity 0.15s ease, transform 0.15s ease;
}

.model-dropdown.open {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: all;
}

.model-dropdown-title {
  font-size: 10px;
  font-weight: 700;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 6px 10px 4px;
}

.model-option {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--trans);
}

.model-option:hover { background: var(--bg-4); }

.model-option.active {
  background: var(--accent-glow);
}

.model-option.active .model-opt-name { color: var(--accent); }

.model-opt-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

.model-opt-name em {
  font-style: normal;
  color: var(--accent);
  font-weight: 500;
  font-size: 12px;
}

.model-opt-desc {
  font-size: 11px;
  color: var(--text-3);
}

.model-divider {
  height: 1px;
  background: var(--border);
  margin: 4px 6px;
}

/* ─── Responsive ────────────────────────────────────────────────────────── */
@media (max-width: 640px) {
  .mobile-only { display: flex; }
  .sidebar {
    position: fixed;
    top: 0; left: 0;
    height: 100vh;
    z-index: 100;
    transform: translateX(-100%);
    width: var(--sidebar-w) !important;
    min-width: var(--sidebar-w) !important;
  }
  .sidebar.open { transform: translateX(0); }
  .sidebar-overlay {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 99;
  }
  .input-area { padding: 10px 14px 12px; }
  .msg { padding: 12px 14px; }
  .welcome-title { font-size: 26px; }
  .input-hint { display: none; }
  #toggle-sidebar { display: none; }
}

/* ─── Message action buttons ─────────────────────────────────────────────── */
.msg-actions {
  display: flex;
  gap: 6px;
  margin-top: 10px;
  opacity: 0;
  transition: opacity 0.2s;
}

.msg:hover .msg-actions,
.msg-actions:focus-within {
  opacity: 1;
}

.msg-action-btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  background: var(--bg-3);
  border: 1px solid var(--border-2);
  border-radius: 6px;
  color: var(--text-2);
  font-family: var(--font);
  font-size: 12px;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.msg-action-btn:hover {
  background: var(--bg-2);
  color: var(--accent);
  border-color: var(--accent);
}