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

:root {
  --bg: #0f0f11;
  --surface: #1a1a1f;
  --surface2: #222228;
  --border: #2e2e38;
  --accent: #7c6af7;
  --accent-hover: #6a58e5;
  --accent-soft: rgba(124,106,247,0.15);
  --text: #f0f0f5;
  --text-muted: #8888a0;
  --text-dim: #5a5a70;
  --user-bubble: #7c6af7;
  --ai-bubble: #1e1e26;
  --radius: 14px;
  --radius-sm: 8px;
  --sidebar-w: 260px;
  --font: 'Inter', system-ui, sans-serif;
  --transition: 0.2s ease;
}

html, body {
  height: 100%;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
}

/* ── Layout ── */
body { display: flex; }

.sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  height: 100vh;
  transition: transform var(--transition), width var(--transition), min-width var(--transition);
  z-index: 100;
  overflow: hidden;
}

.sidebar.collapsed {
  transform: translateX(-100%);
  width: 0;
  min-width: 0;
}

.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* ── Sidebar ── */
.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 16px 14px;
  border-bottom: 1px solid var(--border);
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.3px;
}

.logo-icon {
  font-size: 1.3rem;
  color: var(--accent);
}

.sidebar-toggle {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.sidebar-toggle:hover { color: var(--text); background: var(--surface2); }

.new-chat-btn {
  margin: 14px 12px 8px;
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition);
}
.new-chat-btn:hover { background: var(--accent-hover); }

.chat-history {
  flex: 1;
  overflow-y: auto;
  padding: 8px 8px 0;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.history-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  padding: 4px 8px 8px;
}

.history-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 10px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-muted);
  transition: background var(--transition), color var(--transition);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.history-item:hover, .history-item.active { background: var(--surface2); color: var(--text); }

.history-item svg { flex-shrink: 0; }

.sidebar-footer {
  padding: 12px;
  border-top: 1px solid var(--border);
}

.settings-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 9px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  width: 100%;
  transition: background var(--transition), color var(--transition);
}
.settings-btn:hover { background: var(--surface2); color: var(--text); }

/* ── Topbar ── */
.topbar {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  flex-shrink: 0;
}

.menu-btn, .clear-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 6px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  transition: color var(--transition), background var(--transition);
}
.menu-btn:hover, .clear-btn:hover { color: var(--text); background: var(--surface2); }

.model-selector {
  flex: 1;
  display: flex;
  justify-content: center;
}

.model-selector select {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 7px 14px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-family: var(--font);
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition);
}
.model-selector select:hover, .model-selector select:focus { border-color: var(--accent); }

/* ── Chat Area ── */
.chat-area {
  flex: 1;
  overflow-y: auto;
  padding: 20px 16px;
  scroll-behavior: smooth;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

/* ── Welcome ── */
.welcome {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: calc(100vh - 200px);
  text-align: center;
  padding: 20px;
  animation: fadeIn 0.5s ease;
}

.welcome-icon {
  font-size: 3rem;
  color: var(--accent);
  margin-bottom: 20px;
  animation: pulse 3s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.7; transform: scale(1.05); }
}

.welcome h1 {
  font-size: 1.9rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  margin-bottom: 10px;
  background: linear-gradient(135deg, #f0f0f5 0%, #8888a0 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.welcome p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 28px;
}

.suggestions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  max-width: 560px;
  margin-bottom: 28px;
}

.suggestion-pill {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 10px 16px;
  border-radius: 20px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font);
}
.suggestion-pill:hover { border-color: var(--accent); color: var(--text); background: var(--accent-soft); }

.api-notice {
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 180, 0, 0.1);
  border: 1px solid rgba(255, 180, 0, 0.3);
  color: #ffca5a;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.83rem;
  max-width: 400px;
}
.api-notice.hidden { display: none; }

/* ── Messages ── */
.messages { display: flex; flex-direction: column; gap: 20px; max-width: 760px; margin: 0 auto; }

.msg { display: flex; gap: 12px; animation: fadeUp 0.3s ease; }
.msg.user { flex-direction: row-reverse; }

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

.msg-avatar {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
  flex-shrink: 0;
  margin-top: 2px;
}

.msg.user .msg-avatar { background: var(--user-bubble); color: #fff; }
.msg.ai .msg-avatar { background: var(--surface2); color: var(--accent); font-size: 1rem; }

.msg-content { max-width: calc(100% - 80px); }

.msg-bubble {
  padding: 12px 16px;
  border-radius: var(--radius);
  font-size: 0.92rem;
  line-height: 1.65;
  word-break: break-word;
}

.msg.user .msg-bubble {
  background: var(--user-bubble);
  color: #fff;
  border-bottom-right-radius: 4px;
}

.msg.ai .msg-bubble {
  background: var(--ai-bubble);
  color: var(--text);
  border-bottom-left-radius: 4px;
  border: 1px solid var(--border);
}

.msg-time {
  font-size: 0.72rem;
  color: var(--text-dim);
  margin-top: 5px;
  padding: 0 4px;
}

.msg.user .msg-time { text-align: right; }

/* Code blocks inside AI messages */
.msg-bubble pre {
  background: #12121a;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px;
  margin: 10px 0;
  overflow-x: auto;
  font-size: 0.82rem;
  line-height: 1.5;
}
.msg-bubble code {
  font-family: 'Courier New', monospace;
  font-size: 0.85em;
  background: rgba(255,255,255,0.06);
  padding: 2px 5px;
  border-radius: 4px;
}
.msg-bubble pre code { background: none; padding: 0; }

/* Typing indicator */
.typing-indicator .msg-bubble {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 14px 18px;
}
.dot {
  width: 7px;
  height: 7px;
  background: var(--text-dim);
  border-radius: 50%;
  animation: bounce 1.2s ease-in-out infinite;
}
.dot:nth-child(2) { animation-delay: 0.2s; }
.dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes bounce {
  0%, 80%, 100% { transform: translateY(0); opacity: 0.4; }
  40% { transform: translateY(-6px); opacity: 1; }
}

/* ── Input Area ── */
.input-wrap {
  padding: 12px 16px 18px;
  background: var(--bg);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.input-box {
  display: flex;
  align-items: flex-end;
  gap: 10px;
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 12px;
  max-width: 760px;
  margin: 0 auto;
  transition: border-color var(--transition);
}

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

.input-box textarea {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  resize: none;
  color: var(--text);
  font-size: 0.92rem;
  font-family: var(--font);
  line-height: 1.55;
  max-height: 160px;
  overflow-y: auto;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.input-box textarea::placeholder { color: var(--text-dim); }

.send-btn {
  background: var(--accent);
  border: none;
  border-radius: var(--radius-sm);
  color: #fff;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  flex-shrink: 0;
  transition: background var(--transition), opacity var(--transition);
}
.send-btn:hover:not(:disabled) { background: var(--accent-hover); }
.send-btn:disabled { opacity: 0.35; cursor: not-allowed; }

.input-hint {
  text-align: center;
  font-size: 0.72rem;
  color: var(--text-dim);
  margin-top: 8px;
}

/* ── Modal ── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.65);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}
.modal-overlay.open { opacity: 1; pointer-events: auto; }

.modal {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 100%;
  max-width: 480px;
  margin: 16px;
  transform: scale(0.96);
  transition: transform var(--transition);
  box-shadow: 0 24px 64px rgba(0,0,0,0.5);
}
.modal-overlay.open .modal { transform: scale(1); }

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 22px 16px;
  border-bottom: 1px solid var(--border);
}
.modal-header h2 { font-size: 1.05rem; font-weight: 600; }
.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: var(--radius-sm);
  transition: color var(--transition);
}
.modal-close:hover { color: var(--text); }

.modal-body { padding: 20px 22px; display: flex; flex-direction: column; gap: 20px; }

.setting-group { display: flex; flex-direction: column; gap: 7px; }
.setting-group label { font-size: 0.88rem; font-weight: 600; color: var(--text); }
.optional { font-weight: 400; color: var(--text-dim); font-size: 0.8rem; }

.api-key-row { display: flex; gap: 8px; }

.setting-group input[type="password"],
.setting-group input[type="text"],
.setting-group textarea {
  background: var(--surface2);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.88rem;
  font-family: var(--font);
  padding: 10px 12px;
  outline: none;
  transition: border-color var(--transition);
  flex: 1;
  resize: vertical;
}
.setting-group input:focus, .setting-group textarea:focus { border-color: var(--accent); }
.setting-group textarea { resize: vertical; }

.toggle-vis {
  background: var(--surface2);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  cursor: pointer;
  padding: 0 10px;
  display: flex;
  align-items: center;
  transition: color var(--transition), border-color var(--transition);
}
.toggle-vis:hover { color: var(--text); border-color: var(--accent); }

.setting-group input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  height: 5px;
  background: var(--border);
  border-radius: 3px;
  border: none;
  padding: 0;
  cursor: pointer;
}
.setting-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
}

.setting-hint { font-size: 0.78rem; color: var(--text-dim); line-height: 1.5; }

.modal-footer {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  padding: 16px 22px 20px;
  border-top: 1px solid var(--border);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: background var(--transition);
}
.btn-primary:hover { background: var(--accent-hover); }

.btn-secondary {
  background: none;
  color: var(--text-muted);
  border: 1.5px solid var(--border);
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  cursor: pointer;
  font-family: var(--font);
  transition: all var(--transition);
}
.btn-secondary:hover { border-color: #e55; color: #e55; }

/* Error message */
.error-msg {
  background: rgba(230, 60, 60, 0.1);
  border: 1px solid rgba(230,60,60,0.3);
  color: #f07070;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  line-height: 1.5;
  border-bottom-left-radius: 4px;
}

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

/* ── Scrollbar styling ── */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* ── Responsive ── */
@media (max-width: 640px) {
  .sidebar {
    position: fixed;
    top: 0; left: 0;
    height: 100%;
    box-shadow: 4px 0 20px rgba(0,0,0,0.5);
  }
  .sidebar.collapsed {
    transform: translateX(-100%);
    width: var(--sidebar-w);
    min-width: var(--sidebar-w);
    box-shadow: none;
  }
  .welcome h1 { font-size: 1.4rem; }
  .suggestions { flex-direction: column; align-items: center; }
  .suggestion-pill { width: 100%; max-width: 320px; text-align: center; }
  .msg-content { max-width: calc(100% - 55px); }
}