:root {
  --bg-main: #212121;
  --bg-sidebar: #171717;
  --bg-surface: #2f2f2f;
  --bg-surface-hover: #383838;
  --bg-surface-active: #424242;
  --bg-code: #18181b;
  --text-primary: #ececec;
  --text-secondary: #b4b4b4;
  --text-muted: #8e8e8e;
  --border-color: #333333;
  --border-subtle: #2a2a2a;
  --accent-color: #10a37f;
  --accent-hover: #1a7f64;
  --accent-glow: rgba(16, 163, 127, 0.2);
  --danger-color: #ef4444;
  --user-bubble: #2f2f2f;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.4);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-main);
  color: var(--text-primary);
  height: 100vh;
  display: flex;
  overflow: hidden;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ==================== LOGIN MODAL / GATE ==================== */
#auth-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 15, 15, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

#auth-overlay.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.auth-card {
  background: #1e1e1e;
  border: 1px solid var(--border-color);
  border-radius: 20px;
  width: 100%;
  max-width: 420px;
  padding: 36px 32px;
  box-shadow: var(--shadow-lg);
  text-align: center;
  animation: modalPop 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalPop {
  0% { transform: scale(0.92); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

.auth-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  background: linear-gradient(135deg, #10a37f 0%, #0d8265 100%);
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  box-shadow: 0 4px 15px var(--accent-glow);
}

.auth-card h2 {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.auth-card p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.password-field-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.password-input {
  width: 100%;
  padding: 13px 44px 13px 16px;
  background: #2b2b2b;
  border: 1px solid #404040;
  border-radius: 12px;
  color: #fff;
  font-size: 15px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

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

.toggle-password-btn {
  position: absolute;
  right: 12px;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 4px;
}

.toggle-password-btn:hover {
  color: var(--text-primary);
}

.auth-submit-btn {
  background: var(--accent-color);
  color: #fff;
  border: none;
  padding: 13px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s, transform 0.1s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.auth-submit-btn:hover {
  background: var(--accent-hover);
}

.auth-submit-btn:active {
  transform: scale(0.98);
}

.auth-error {
  color: var(--danger-color);
  font-size: 13px;
  min-height: 18px;
  margin-top: 4px;
  display: none;
}

.auth-error.visible {
  display: block;
}

.shake {
  animation: shake 0.4s cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
}

@keyframes shake {
  10%, 90% { transform: translate3d(-2px, 0, 0); }
  20%, 80% { transform: translate3d(3px, 0, 0); }
  30%, 50%, 70% { transform: translate3d(-5px, 0, 0); }
  40%, 60% { transform: translate3d(5px, 0, 0); }
}

/* ==================== APP LAYOUT ==================== */
#app-container {
  display: flex;
  width: 100vw;
  height: 100vh;
  position: relative;
}

/* SIDEBAR */
.sidebar {
  width: 260px;
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  transition: width 0.25s ease, transform 0.25s ease;
  z-index: 20;
  flex-shrink: 0;
}

.sidebar.collapsed {
  width: 0;
  transform: translateX(-100%);
  overflow: hidden;
  border: none;
}

.sidebar-header {
  padding: 14px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.new-chat-btn {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border-radius: 10px;
  background-color: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.15s;
}

.new-chat-btn:hover {
  background-color: var(--bg-surface-hover);
}

.sidebar-toggle-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  padding: 8px;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-left: 6px;
}

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

.conversations-container {
  flex: 1;
  overflow-y: auto;
  padding: 8px 10px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.chat-history-group-title {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 10px 8px 4px;
}

.conversation-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 9px 10px;
  border-radius: 8px;
  color: var(--text-secondary);
  font-size: 13.5px;
  cursor: pointer;
  transition: background-color 0.15s, color 0.15s;
  position: relative;
  text-decoration: none;
  user-select: none;
}

.conversation-item:hover {
  background-color: var(--bg-surface);
  color: var(--text-primary);
}

.conversation-item.active {
  background-color: var(--bg-surface-active);
  color: #fff;
  font-weight: 500;
}

.conversation-title {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  flex: 1;
  margin-right: 8px;
}

.delete-conv-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  opacity: 0;
  cursor: pointer;
  padding: 2px 4px;
  border-radius: 4px;
  transition: opacity 0.15s, color 0.15s;
}

.conversation-item:hover .delete-conv-btn {
  opacity: 1;
}

.delete-conv-btn:hover {
  color: var(--danger-color);
}

.sidebar-footer {
  padding: 12px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.user-profile-widget {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  overflow: hidden;
}

.user-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, #3b82f6, #8b5cf6);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 600;
  flex-shrink: 0;
}

.user-info {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.user-name {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.user-status {
  font-size: 11px;
  color: var(--accent-color);
  display: flex;
  align-items: center;
  gap: 4px;
}

.user-status::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--accent-color);
}

.logout-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  padding: 6px;
  border-radius: 6px;
  cursor: pointer;
  transition: color 0.15s, background-color 0.15s;
}

.logout-btn:hover {
  color: var(--danger-color);
  background-color: var(--bg-surface-hover);
}

/* MAIN CHAT AREA */
.main-chat {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  position: relative;
  overflow: hidden;
  background-color: var(--bg-main);
}

/* TOP NAVBAR */
.chat-topbar {
  height: 54px;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  flex-shrink: 0;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 12px;
}

.menu-toggle-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  padding: 7px;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.menu-toggle-btn:hover {
  background-color: var(--bg-surface-hover);
  color: var(--text-primary);
}

.model-selector {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  border-radius: 10px;
  padding: 6px 12px;
  font-size: 14px;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  outline: none;
}

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

.badge-backend-secured {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  color: #10a37f;
  background: rgba(16, 163, 127, 0.1);
  border: 1px solid rgba(16, 163, 127, 0.25);
  padding: 4px 10px;
  border-radius: 20px;
}

/* MESSAGES SCROLL CONTAINER */
.messages-container {
  flex: 1;
  overflow-y: auto;
  padding: 24px 20px 100px;
  scroll-behavior: smooth;
  display: flex;
  flex-direction: column;
}

.messages-inner {
  max-width: 780px;
  width: 100%;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* EMPTY / WELCOME STATE */
.welcome-hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: auto 0;
  text-align: center;
  padding: 40px 20px;
}

.welcome-logo {
  width: 52px;
  height: 52px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--accent-color);
  box-shadow: 0 4px 20px rgba(0,0,0,0.25);
}

.welcome-hero h1 {
  font-size: 26px;
  font-weight: 600;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.prompt-suggestions {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  max-width: 680px;
  width: 100%;
}

@media (max-width: 640px) {
  .prompt-suggestions {
    grid-template-columns: 1fr;
  }
}

.suggestion-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 14px 16px;
  text-align: left;
  cursor: pointer;
  transition: border-color 0.2s, background-color 0.2s, transform 0.1s;
}

.suggestion-card:hover {
  background: var(--bg-surface-hover);
  border-color: #555;
  transform: translateY(-1px);
}

.suggestion-title {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.suggestion-desc {
  font-size: 12px;
  color: var(--text-muted);
}

/* MESSAGE ROWS */
.message-row {
  display: flex;
  width: 100%;
}

.message-row.user {
  justify-content: flex-end;
}

.message-row.assistant {
  justify-content: flex-start;
}

.user-bubble {
  background-color: var(--user-bubble);
  padding: 12px 18px;
  border-radius: 20px 20px 4px 20px;
  color: #fff;
  max-width: 82%;
  font-size: 15px;
  line-height: 1.55;
  word-break: break-word;
}

.assistant-body {
  width: 100%;
  max-width: 100%;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.assistant-header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
}

.assistant-avatar {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--accent-color);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* REASONING / THINKING ACCORDION */
.thought-box {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  overflow: hidden;
  font-size: 13px;
}

.thought-header {
  padding: 9px 12px;
  background: rgba(255, 255, 255, 0.02);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  color: var(--text-secondary);
  font-weight: 500;
  user-select: none;
}

.thought-header:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
}

.thought-title-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.thought-icon-pulse {
  animation: subtleGlow 2s infinite ease-in-out;
  color: #60a5fa;
}

@keyframes subtleGlow {
  0%, 100% { opacity: 0.6; }
  50% { opacity: 1; }
}

.thought-content {
  padding: 12px 14px;
  border-top: 1px solid var(--border-color);
  color: #a1a1aa;
  font-family: var(--font-mono);
  font-size: 12.5px;
  white-space: pre-wrap;
  line-height: 1.6;
}

/* AGENT TOOL CALLS */
.agent-step-box {
  background: #1c1c1f;
  border: 1px solid #333338;
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 13px;
}

.agent-step-title {
  display: flex;
  align-items: center;
  gap: 8px;
  color: #38bdf8;
  font-weight: 600;
  margin-bottom: 6px;
}

.agent-step-detail {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-secondary);
  background: #121214;
  padding: 8px 10px;
  border-radius: 6px;
  overflow-x: auto;
}

/* MARKDOWN STYLING */
.markdown-content {
  font-size: 15px;
  line-height: 1.65;
  color: var(--text-primary);
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3 {
  margin: 16px 0 8px;
  color: #fff;
  font-weight: 600;
}

.markdown-content p {
  margin-bottom: 12px;
}

.markdown-content ul,
.markdown-content ol {
  margin-left: 22px;
  margin-bottom: 12px;
}

.markdown-content li {
  margin-bottom: 4px;
}

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

.code-block-wrapper {
  background: var(--bg-code);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  margin: 14px 0;
  overflow: hidden;
}

.code-header {
  background: #27272a;
  padding: 6px 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-muted);
}

.copy-code-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 12px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.copy-code-btn:hover {
  color: #fff;
}

pre code {
  display: block;
  padding: 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: #e4e4e7;
  overflow-x: auto;
  line-height: 1.5;
}

/* BOTTOM COMPOSER / INPUT */
.composer-area {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(180deg, rgba(33,33,33,0) 0%, rgba(33,33,33,0.95) 30%, rgba(33,33,33,1) 100%);
  padding: 10px 20px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  z-index: 10;
}

.composer-container {
  max-width: 780px;
  width: 100%;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 10px 14px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color 0.2s;
}

.composer-container:focus-within {
  border-color: #555;
}

.composer-input-row {
  display: flex;
  align-items: flex-end;
  gap: 10px;
}

.chat-textarea {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  color: #fff;
  font-family: var(--font-family);
  font-size: 15px;
  line-height: 1.45;
  resize: none;
  max-height: 200px;
  min-height: 24px;
  padding: 4px 2px;
}

.chat-textarea::placeholder {
  color: var(--text-muted);
}

.send-btn {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: #404040;
  color: #888;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: not-allowed;
  transition: background-color 0.15s, color 0.15s, transform 0.1s;
  flex-shrink: 0;
}

.send-btn.active {
  background: #ffffff;
  color: #000000;
  cursor: pointer;
}

.send-btn.active:hover {
  background: #e6e6e6;
  transform: scale(1.05);
}

/* AGENT TOOL TOGGLES (TOOLBAR) */
.composer-toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 4px;
  border-top: 1px solid rgba(255,255,255,0.06);
  flex-wrap: wrap;
}

.tool-toggle-chip {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.08);
  color: var(--text-secondary);
  border-radius: 16px;
  padding: 4px 10px;
  font-size: 12px;
  display: flex;
  align-items: center;
  gap: 5px;
  cursor: pointer;
  transition: all 0.15s;
  user-select: none;
}

.tool-toggle-chip:hover {
  background: rgba(255,255,255,0.1);
  color: var(--text-primary);
}

.tool-toggle-chip.active {
  background: rgba(16, 163, 127, 0.2);
  border-color: var(--accent-color);
  color: #34d399;
}

.composer-disclaimer {
  font-size: 11.5px;
  color: var(--text-muted);
  margin-top: 8px;
  text-align: center;
}

/* SPINNER & LOADING */
.dot-flashing {
  position: relative;
  width: 6px;
  height: 6px;
  border-radius: 5px;
  background-color: var(--text-secondary);
  color: var(--text-secondary);
  animation: dotFlashing 1s infinite linear alternate;
  animation-delay: 0.5s;
}

.dot-flashing::before, .dot-flashing::after {
  content: "";
  display: inline-block;
  position: absolute;
  top: 0;
}

.dot-flashing::before {
  left: -10px;
  width: 6px;
  height: 6px;
  border-radius: 5px;
  background-color: var(--text-secondary);
  animation: dotFlashing 1s infinite alternate;
  animation-delay: 0s;
}

.dot-flashing::after {
  left: 10px;
  width: 6px;
  height: 6px;
  border-radius: 5px;
  background-color: var(--text-secondary);
  animation: dotFlashing 1s infinite alternate;
  animation-delay: 1s;
}

@keyframes dotFlashing {
  0% { background-color: var(--text-secondary); }
  50%, 100% { background-color: rgba(180, 180, 180, 0.2); }
}