/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
  --primary: #6366F1;
  --primary-hover: #4F46E5;
  --primary-light: #EEF2FF;
  --bg: #F1F5F9;
  --surface: #FFFFFF;
  --sidebar-bg: #1E1B4B;
  --sidebar-text: #E0E7FF;
  --sidebar-muted: #818CF8;
  --sidebar-border: #312E81;
  --sidebar-hover: #3730A3;
  --border: #E2E8F0;
  --text: #1E293B;
  --text-secondary: #64748B;
  --text-muted: #94A3B8;
  --success: #10B981;
  --warning: #F59E0B;
  --danger: #EF4444;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.05);
  --shadow-lg: 0 4px 20px rgba(0,0,0,0.12);
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --sidebar-width: 280px;
}

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ===========================
   App Layout
   =========================== */
.app {
  display: flex;
  flex: 1;
  min-height: 0;
  height: calc(100vh - 44px);
}

/* ===========================
   Sidebar
   =========================== */
.sidebar {
  width: var(--sidebar-width);
  background: var(--sidebar-bg);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  border-right: 1px solid var(--sidebar-border);
  overflow: hidden;
}

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

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 700;
  color: var(--sidebar-text);
}

.sidebar-search {
  padding: 10px 12px;
  border-bottom: 1px solid var(--sidebar-border);
  flex-shrink: 0;
}

.search-input {
  width: 100%;
  padding: 7px 12px;
  background: rgba(255,255,255,0.08);
  border: 1px solid var(--sidebar-border);
  border-radius: var(--radius-sm);
  color: var(--sidebar-text);
  font-family: var(--font);
  font-size: 12px;
  transition: all 0.15s;
}
.search-input::placeholder { color: var(--sidebar-muted); }
.search-input:focus { outline: none; background: rgba(255,255,255,0.12); border-color: var(--primary); }

/* Customer List in Sidebar */
.customer-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

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

.customer-empty-hint {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 32px 16px;
  color: var(--sidebar-muted);
  text-align: center;
}
.customer-empty-hint p { font-size: 13px; font-weight: 500; color: var(--sidebar-text); }
.customer-empty-hint span { font-size: 11px; }

/* Customer Item in Sidebar */
.customer-item {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s;
  margin-bottom: 4px;
  border: 1.5px solid transparent;
  position: relative;
}
.customer-item:hover { background: var(--sidebar-hover); }
.customer-item.active { background: var(--sidebar-hover); border-color: var(--primary); }
.customer-item.active::before {
  content: '';
  position: absolute;
  left: 0; top: 50%;
  transform: translateY(-50%);
  width: 3px; height: 60%;
  background: var(--primary);
  border-radius: 0 3px 3px 0;
}

.customer-item-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
}

.customer-item-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--sidebar-text);
  display: flex;
  align-items: center;
  gap: 6px;
}

.customer-level {
  font-size: 9px;
  font-weight: 700;
  padding: 2px 6px;
  border-radius: 10px;
  flex-shrink: 0;
}
.level-L5 { background: rgba(22,163,74,0.3); color: #86EFAC; }
.level-L4 { background: rgba(37,99,235,0.3); color: #93C5FD; }
.level-L3 { background: rgba(217,119,6,0.3); color: #FCD34D; }
.level-L2 { background: rgba(67,56,202,0.3); color: #A5B4FC; }
.level-L1 { background: rgba(124,58,237,0.3); color: #C4B5FD; }
.level-L0 { background: rgba(220,38,38,0.3); color: #FCA5A5; }

.customer-item-meta {
  font-size: 11px;
  color: var(--sidebar-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.customer-item-actions {
  display: flex;
  gap: 4px;
  margin-top: 6px;
}

/* Current Customer Detail (bottom of sidebar) */
.current-customer {
  border-top: 1px solid var(--sidebar-border);
  padding: 14px;
  flex-shrink: 0;
  display: none;
}
.current-customer.visible { display: block; }

.current-customer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.current-customer-name {
  font-size: 14px;
  font-weight: 700;
  color: var(--sidebar-text);
}

.current-customer-level {
  font-size: 10px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 10px;
}

.current-customer-info {
  font-size: 11px;
  color: var(--sidebar-muted);
  line-height: 1.6;
  margin-bottom: 8px;
}

.btn-edit-current {
  color: var(--sidebar-muted) !important;
  border-color: var(--sidebar-border) !important;
  width: 100%;
  justify-content: center;
}
.btn-edit-current:hover { background: var(--sidebar-hover) !important; color: var(--sidebar-text) !important; }

/* ===========================
   Main Content
   =========================== */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
}

/* Content Header */
.content-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
}

.content-header-left { display: flex; align-items: baseline; gap: 10px; }
.content-header-left h1 { font-size: 15px; font-weight: 700; color: var(--text); }
.header-subtitle { font-size: 12px; color: var(--text-muted); }
.content-header-actions { display: flex; align-items: center; gap: 8px; }

/* Chat Area */
.chat-area {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  padding: 16px 24px;
  min-height: 0;
  overflow: hidden;
}

/* ===========================
   Panel
   =========================== */
.panel {
  background: var(--surface);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.panel-header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
}
.panel-header h2 { font-size: 13px; font-weight: 600; }

/* ===========================
   Tabs
   =========================== */
.panel-tabs {
  display: flex;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.tab {
  flex: 1;
  padding: 10px 14px;
  background: none;
  border: none;
  font-family: var(--font);
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: all 0.15s;
}
.tab:hover { color: var(--text); background: var(--bg); }
.tab.active { color: var(--primary); border-bottom-color: var(--primary); }

.tab-content { display: none; flex-direction: column; flex: 1; min-height: 0; }
.tab-content.active { display: flex; }

/* ===========================
   Badges
   =========================== */
.badge {
  font-size: 10px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 20px;
  background: var(--primary-light);
  color: var(--primary);
}
.badge-ai { background: #F0FDF4; color: var(--success); }

/* ===========================
   Input Area
   =========================== */
.input-area { padding: 12px 16px; display: flex; flex-direction: column; gap: 8px; flex-shrink: 0; }

.message-input {
  width: 100%;
  min-height: 120px;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 13px;
  line-height: 1.6;
  color: var(--text);
  resize: vertical;
  transition: border-color 0.15s, box-shadow 0.15s;
  background: var(--surface);
}
.message-input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(99,102,241,0.10); }
.message-input::placeholder { color: var(--text-muted); }

.input-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 8px; flex-wrap: wrap; }
.toolbar-left { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }

.select-label { display: flex; align-items: center; gap: 4px; font-size: 11px; color: var(--text-secondary); white-space: nowrap; }
.select {
  padding: 5px 8px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 12px;
  color: var(--text);
  background: var(--surface);
  cursor: pointer;
  transition: border-color 0.15s;
}
.select:focus { outline: none; border-color: var(--primary); }

/* ===========================
   Buttons
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  border: none;
  transition: all 0.15s;
  white-space: nowrap;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-primary:active { transform: scale(0.98); }
.btn-primary:disabled { opacity: 0.6; cursor: not-allowed; }

.btn-ghost { background: transparent; color: var(--text-secondary); border: 1.5px solid var(--border); }
.btn-ghost:hover { background: var(--bg); color: var(--text); border-color: var(--text-muted); }

.btn-sm { padding: 4px 8px; font-size: 11px; }
.btn-copy { color: var(--text-muted); border-color: var(--border); }
.btn-copy:hover { color: var(--primary); border-color: var(--primary); }

/* ===========================
   Knowledge Preview
   =========================== */
.knowledge-preview {
  border-top: 1px solid var(--border);
  padding: 10px 16px;
  flex: 1;
  overflow-y: auto;
  background: #FAFAFA;
  min-height: 100px;
}

.knowledge-header {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 10px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.knowledge-count {
  margin-left: auto;
  background: var(--primary-light);
  color: var(--primary);
  padding: 1px 7px;
  border-radius: 20px;
  font-size: 9px;
}

.knowledge-chunks { display: flex; flex-direction: column; gap: 5px; }
.knowledge-empty { font-size: 11px; color: var(--text-muted); text-align: center; padding: 10px 0; }

.chunk-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 7px 10px;
  font-size: 11px;
  line-height: 1.4;
  color: var(--text);
  border-left: 3px solid var(--primary);
}
.chunk-item strong { font-size: 9px; color: var(--primary); font-weight: 600; display: block; margin-bottom: 2px; }
.chunk-item p { color: var(--text-secondary); }

/* ===========================
   Conversation Area
   =========================== */
.conversation-area {
  flex: 1;
  overflow-y: auto;
  padding: 10px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.conv-empty { font-size: 12px; color: var(--text-muted); text-align: center; padding: 40px 0; }

.conv-item {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  max-width: 88%;
}
.conv-user { align-self: flex-end; background: var(--primary-light); border: 1px solid var(--primary); }
.conv-assistant { align-self: flex-start; background: var(--bg); border: 1px solid var(--border); }
.conv-role { font-size: 9px; font-weight: 600; color: var(--text-muted); }
.conv-content { font-size: 12px; line-height: 1.5; white-space: pre-wrap; }
.conv-time { font-size: 9px; color: var(--text-muted); }

/* ===========================
   Output Panel
   =========================== */
.output-area { flex: 1; overflow-y: auto; position: relative; }

.output-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 100%;
  min-height: 200px;
  color: var(--text-muted);
  text-align: center;
  padding: 32px;
}
.placeholder-icon { opacity: 0.4; }
.output-placeholder p { font-size: 13px; font-weight: 500; color: var(--text-secondary); }
.output-placeholder span { font-size: 11px; }

.output-content { padding: 12px 16px; display: flex; flex-direction: column; gap: 8px; }
.output-header { display: flex; align-items: center; justify-content: space-between; }
.output-meta { font-size: 10px; color: var(--text-muted); }

.output-text {
  font-size: 13px;
  line-height: 1.8;
  color: var(--text);
  background: var(--primary-light);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  white-space: pre-wrap;
  border-left: 4px solid var(--primary);
}

.output-loading {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: rgba(248,250,252,0.95);
}
.output-loading p { font-size: 13px; font-weight: 500; color: var(--text-secondary); }
.output-loading span { font-size: 11px; color: var(--text-muted); }

.loading-spinner {
  width: 28px; height: 28px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ===========================
   Footer
   =========================== */
.footer {
  text-align: center;
  padding: 10px 24px;
  font-size: 10px;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  background: var(--surface);
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ===========================
   Modal
   =========================== */
.modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}
.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(4px);
}
.modal-content {
  position: relative;
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 560px;
  max-height: 88vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.modal-wide { max-width: 800px; }
.modal-header {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
}
.modal-header h3 { font-size: 15px; font-weight: 700; }
.modal-close { padding: 4px; }
.modal-body {
  padding: 16px 18px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* ===========================
   Customer Form
   =========================== */
.customer-form { display: flex; flex-direction: column; gap: 10px; }
.form-row { display: flex; flex-direction: column; gap: 4px; }
.form-row-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.form-row-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; }

.form-label { display: flex; flex-direction: column; gap: 3px; font-size: 11px; color: var(--text-secondary); font-weight: 500; }
.form-label span { font-weight: 500; }

.form-input, .form-textarea {
  padding: 7px 10px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 12px;
  color: var(--text);
  transition: border-color 0.15s;
  background: var(--surface);
}
.form-input:focus, .form-textarea:focus { outline: none; border-color: var(--primary); }
.form-textarea { resize: vertical; min-height: 56px; line-height: 1.5; }

.form-divider { font-size: 11px; font-weight: 600; color: var(--text-secondary); padding: 4px 0 2px; border-top: 1px solid var(--border); margin-top: 2px; }

.form-actions { display: flex; gap: 8px; justify-content: flex-end; padding-top: 4px; }

/* ===========================
   Knowledge Modal
   =========================== */
.knowledge-intro { font-size: 12px; color: var(--text-secondary); line-height: 1.6; }

.knowledge-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.stat-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 8px; text-align: center; }
.stat-num { font-size: 18px; font-weight: 700; color: var(--primary); display: block; }
.stat-label { font-size: 9px; color: var(--text-muted); margin-top: 1px; }

.knowledge-docs { min-height: 60px; }
.doc-empty { display: flex; flex-direction: column; align-items: center; gap: 4px; padding: 16px; color: var(--text-muted); text-align: center; }
.doc-empty p { font-size: 12px; font-weight: 500; color: var(--text-secondary); }

.doc-list { display: flex; flex-direction: column; gap: 5px; }
.doc-item { display: flex; align-items: flex-start; gap: 7px; padding: 8px; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-sm); }
.doc-icon { color: var(--primary); flex-shrink: 0; margin-top: 1px; }
.doc-info { flex: 1; min-width: 0; }
.doc-title { font-size: 11px; font-weight: 600; color: var(--text); margin-bottom: 2px; }
.doc-preview { font-size: 10px; color: var(--text-secondary); line-height: 1.4; overflow: hidden; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.doc-delete { background: none; border: none; cursor: pointer; color: var(--text-muted); padding: 2px; border-radius: 4px; transition: color 0.15s; flex-shrink: 0; }
.doc-delete:hover { color: var(--danger); }

.knowledge-add { border-top: 1px solid var(--border); padding-top: 12px; display: flex; flex-direction: column; gap: 7px; }
.knowledge-add h4 { font-size: 12px; font-weight: 600; }
.knowledge-textarea { width: 100%; min-height: 70px; padding: 8px 10px; border: 1.5px solid var(--border); border-radius: var(--radius-sm); font-family: var(--font); font-size: 12px; line-height: 1.5; color: var(--text); resize: vertical; transition: border-color 0.15s; }
.knowledge-textarea:focus { outline: none; border-color: var(--primary); }
.knowledge-add-actions { display: flex; gap: 6px; align-items: center; }
.input-title { flex: 1; padding: 6px 10px; border: 1.5px solid var(--border); border-radius: var(--radius-sm); font-family: var(--font); font-size: 12px; color: var(--text); }
.input-title:focus { outline: none; border-color: var(--primary); }

/* ===========================
   Import Modal
   =========================== */
.import-tabs { display: flex; border-bottom: 1px solid var(--border); margin-bottom: 12px; }
.import-tabs .tab { flex: 1; padding: 8px 12px; }

.import-tab-content { display: none; flex-direction: column; gap: 10px; }
.import-tab-content.active { display: flex; }

.import-tip { font-size: 12px; color: var(--text-secondary); line-height: 1.5; }

.import-image-area {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  cursor: pointer;
  transition: all 0.15s;
  min-height: 160px;
  position: relative;
}
.import-image-area:hover { border-color: var(--primary); background: var(--primary-light); }
.import-image-placeholder { display: flex; flex-direction: column; align-items: center; gap: 6px; color: var(--text-muted); }
.import-image-placeholder p { font-size: 13px; font-weight: 500; color: var(--text-secondary); }
.import-image-placeholder span { font-size: 11px; }
.import-image-preview { max-width: 100%; max-height: 200px; border-radius: var(--radius-sm); }
.import-image-preview.hidden { display: none; }

.import-image-actions, .import-text-actions { display: flex; gap: 8px; justify-content: flex-end; }

.import-textarea {
  width: 100%;
  min-height: 120px;
  padding: 10px 12px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 12px;
  line-height: 1.6;
  color: var(--text);
  resize: vertical;
  transition: border-color 0.15s;
  background: var(--surface);
}
.import-textarea:focus { outline: none; border-color: var(--primary); }
.import-textarea::placeholder { color: var(--text-muted); }

.import-result {
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  line-height: 1.5;
}
.import-result.success { background: #F0FDF4; border: 1px solid var(--success); color: var(--success); }
.import-result.error { background: #FEF2F2; border: 1px solid var(--danger); color: var(--danger); }
.import-result.info { background: var(--primary-light); border: 1px solid var(--primary); color: var(--primary); }

/* Summary Conv Item */
.conv-summary { align-self: flex-start; background: #FFFBEB; border: 1px solid #F59E0B; max-width: 90%; }
.conv-summary .conv-role { color: #D97706; }

/* ===========================
   Utilities
   =========================== */
.hidden { display: none !important; }

.toast {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: var(--text);
  color: #fff;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  z-index: 2000;
  animation: slideUp 0.2s ease;
}
@keyframes slideUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

/* Responsive */
@media (max-width: 900px) {
  .app { flex-direction: column; height: auto; }
  .sidebar { width: 100%; border-right: none; border-bottom: 1px solid var(--sidebar-border); max-height: 300px; }
  .chat-area { grid-template-columns: 1fr; padding: 12px; gap: 12px; }
  .form-row-2, .form-row-3 { grid-template-columns: 1fr; }
}