\
:root {
  --primary: #1d4ed8;
  --primary-hover: #1e40af;
  --primary-light: #dbeafe;
  --bg: #f1f5f9;
  --sidebar-bg: #0f172a;
  --sidebar-text: #cbd5e1;
  --sidebar-hover: #1e293b;
  --sidebar-active: #1d4ed8;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --text: #0f172a;
  --text-secondary: #64748b;
  --user-msg-bg: #1d4ed8;
  --ai-msg-bg: #f8fafc;
  --danger: #dc2626;
  --success: #16a34a;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.06);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: var(--bg); color: var(--text); height: 100vh; overflow: hidden; }
a { text-decoration: none; color: var(--primary); }

/* ── Login ── */
.login-wrap { display: flex; align-items: center; justify-content: center; min-height: 100vh; background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 100%); }
.login-card { background: var(--card-bg); border-radius: var(--radius); padding: 48px 40px; width: 100%; max-width: 400px; box-shadow: 0 20px 60px rgba(0,0,0,.3); }
.login-logo { text-align: center; margin-bottom: 32px; }
.login-logo h1 { font-size: 22px; font-weight: 700; color: var(--text); }
.login-logo p { font-size: 13px; color: var(--text-secondary); margin-top: 4px; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-size: 13px; font-weight: 500; color: var(--text); margin-bottom: 6px; }
.form-group input { width: 100%; padding: 11px 14px; border: 1.5px solid var(--border); border-radius: 8px; font-size: 14px; outline: none; transition: border-color .15s; }
.form-group input:focus { border-color: var(--primary); }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 11px 20px; border: none; border-radius: 8px; font-size: 14px; font-weight: 600; cursor: pointer; transition: all .15s; }
.btn-primary { background: var(--primary); color: #fff; width: 100%; }
.btn-primary:hover { background: var(--primary-hover); }
.btn-danger { background: var(--danger); color: #fff; }
.btn-secondary { background: var(--border); color: var(--text); }
.btn-sm { padding: 7px 14px; font-size: 13px; }
.error-msg { background: #fef2f2; border: 1px solid #fecaca; color: var(--danger); border-radius: 8px; padding: 10px 14px; font-size: 13px; margin-bottom: 16px; display: none; }

/* ── Layout ── */
.layout { display: flex; height: 100vh; }
.sidebar { width: 260px; background: var(--sidebar-bg); display: flex; flex-direction: column; flex-shrink: 0; }
.sidebar-head { padding: 20px 16px 16px; border-bottom: 1px solid #1e293b; }
.sidebar-head h2 { color: #f8fafc; font-size: 15px; font-weight: 700; }
.sidebar-head p { color: var(--sidebar-text); font-size: 12px; margin-top: 2px; }
.sidebar-btn { display: flex; align-items: center; gap: 10px; padding: 10px 16px; color: var(--sidebar-text); font-size: 13px; font-weight: 500; cursor: pointer; border: none; background: none; width: 100%; text-align: left; border-radius: 6px; transition: background .1s; margin: 2px 8px; width: calc(100% - 16px); }
.sidebar-btn:hover { background: var(--sidebar-hover); color: #f8fafc; }
.sidebar-btn.active { background: var(--sidebar-active); color: #fff; }
.sidebar-btn svg { flex-shrink: 0; opacity: .7; }
.conv-list { flex: 1; overflow-y: auto; padding: 8px; }
.conv-item { padding: 9px 12px; border-radius: 8px; cursor: pointer; color: var(--sidebar-text); font-size: 13px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; transition: background .1s; }
.conv-item:hover { background: var(--sidebar-hover); color: #f8fafc; }
.conv-item.active { background: var(--sidebar-active); color: #fff; }
.sidebar-footer { padding: 12px; border-top: 1px solid #1e293b; display: flex; gap: 8px; }
.sidebar-footer .sidebar-btn { margin: 0; width: 100%; }

/* ── Main area ── */
.main { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
.main-header { background: var(--card-bg); border-bottom: 1px solid var(--border); padding: 0 24px; height: 56px; display: flex; align-items: center; justify-content: space-between; flex-shrink: 0; box-shadow: var(--shadow); }
.main-header h3 { font-size: 15px; font-weight: 600; color: var(--text); }
.user-badge { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--text-secondary); }
.user-badge span { background: var(--primary-light); color: var(--primary); border-radius: 20px; padding: 4px 12px; font-weight: 600; }

/* ── Messages ── */
.messages { flex: 1; overflow-y: auto; padding: 24px; display: flex; flex-direction: column; gap: 20px; }
.msg-row { display: flex; gap: 12px; max-width: 820px; }
.msg-row.user { align-self: flex-end; flex-direction: row-reverse; }
.msg-row.ai { align-self: flex-start; }
.avatar { width: 36px; height: 36px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 14px; font-weight: 700; flex-shrink: 0; }
.avatar.user { background: var(--primary); color: #fff; }
.avatar.ai { background: var(--border); color: var(--text); font-size: 16px; }
.bubble { max-width: 680px; }
.msg-row.user .bubble { background: var(--primary); color: #fff; border-radius: 18px 18px 4px 18px; padding: 12px 16px; font-size: 14px; line-height: 1.6; }
.msg-row.ai .bubble { background: var(--card-bg); border: 1px solid var(--border); border-radius: 18px 18px 18px 4px; padding: 16px 18px; font-size: 14px; line-height: 1.7; box-shadow: var(--shadow); white-space: pre-wrap; }
.sources { margin-top: 10px; font-size: 12px; color: var(--text-secondary); }
.sources summary { cursor: pointer; font-weight: 600; color: var(--primary); }
.sources ul { margin-top: 6px; padding-left: 16px; }
.typing-indicator { display: flex; gap: 4px; padding: 16px 18px; }
.typing-indicator span { width: 8px; height: 8px; border-radius: 50%; background: var(--text-secondary); animation: bounce .9s infinite; }
.typing-indicator span:nth-child(2) { animation-delay: .15s; }
.typing-indicator span:nth-child(3) { animation-delay: .3s; }
@keyframes bounce { 0%,60%,100% { transform: translateY(0); } 30% { transform: translateY(-8px); } }
.empty-state { display: flex; flex-direction: column; align-items: center; justify-content: center; flex: 1; color: var(--text-secondary); text-align: center; gap: 12px; }
.empty-state svg { opacity: .3; }
.empty-state h3 { font-size: 18px; color: var(--text); }
.empty-state p { font-size: 14px; max-width: 400px; }

/* ── Input area ── */
.input-area { padding: 16px 24px 20px; background: var(--card-bg); border-top: 1px solid var(--border); }
.input-row { display: flex; gap: 10px; align-items: flex-end; background: var(--bg); border: 1.5px solid var(--border); border-radius: var(--radius); padding: 10px 12px; transition: border-color .15s; }
.input-row:focus-within { border-color: var(--primary); }
#msg-input { flex: 1; border: none; outline: none; background: transparent; font-size: 14px; resize: none; line-height: 1.5; max-height: 120px; font-family: inherit; }
.send-btn { background: var(--primary); color: #fff; border: none; border-radius: 8px; padding: 8px 14px; cursor: pointer; transition: background .15s; flex-shrink: 0; }
.send-btn:hover { background: var(--primary-hover); }
.send-btn:disabled { background: var(--border); cursor: default; }

/* ── Admin ── */
.admin-layout { display: flex; flex-direction: column; height: 100vh; }
.admin-header { background: var(--sidebar-bg); color: #f8fafc; padding: 14px 24px; display: flex; align-items: center; justify-content: space-between; }
.admin-header h1 { font-size: 16px; font-weight: 700; }
.admin-body { flex: 1; overflow: auto; padding: 24px; }
.tabs { display: flex; gap: 4px; margin-bottom: 24px; background: var(--card-bg); border: 1px solid var(--border); border-radius: 10px; padding: 4px; width: fit-content; }
.tab { padding: 8px 18px; border: none; border-radius: 7px; font-size: 13px; font-weight: 500; cursor: pointer; background: transparent; color: var(--text-secondary); transition: all .15s; }
.tab.active { background: var(--primary); color: #fff; }
.tab-pane { display: none; }
.tab-pane.active { display: block; }
.card { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; margin-bottom: 20px; box-shadow: var(--shadow); }
.card h3 { font-size: 15px; font-weight: 600; margin-bottom: 16px; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 12px; }
.field { display: flex; flex-direction: column; gap: 5px; }
.field.full { grid-column: 1/-1; }
.field label { font-size: 12px; font-weight: 500; color: var(--text-secondary); text-transform: uppercase; letter-spacing: .5px; }
.field input, .field select, .field textarea { border: 1.5px solid var(--border); border-radius: 8px; padding: 9px 12px; font-size: 13px; outline: none; font-family: inherit; transition: border-color .15s; }
.field input:focus, .field select:focus, .field textarea:focus { border-color: var(--primary); }
.field textarea { resize: vertical; min-height: 100px; }
table { width: 100%; border-collapse: collapse; font-size: 13px; }
th { background: var(--bg); padding: 10px 14px; text-align: left; font-weight: 600; color: var(--text-secondary); font-size: 12px; text-transform: uppercase; letter-spacing: .4px; border-bottom: 2px solid var(--border); }
td { padding: 12px 14px; border-bottom: 1px solid var(--border); vertical-align: middle; }
tr:hover td { background: var(--bg); }
.badge { display: inline-block; padding: 3px 10px; border-radius: 20px; font-size: 11px; font-weight: 600; }
.badge-green { background: #dcfce7; color: var(--success); }
.badge-gray { background: var(--border); color: var(--text-secondary); }
.badge-blue { background: var(--primary-light); color: var(--primary); }
.actions { display: flex; gap: 6px; }
.toast { position: fixed; bottom: 24px; right: 24px; background: #1e293b; color: #fff; padding: 12px 20px; border-radius: 8px; font-size: 14px; opacity: 0; transform: translateY(20px); transition: all .3s; z-index: 1000; }
.toast.show { opacity: 1; transform: translateY(0); }
.toast.error { background: var(--danger); }

/* ── Hamburger (hidden on desktop) ── */
.menu-btn { display: none; background: none; border: none; cursor: pointer; color: var(--text); padding: 6px; border-radius: 6px; flex-shrink: 0; }
.menu-btn:hover { background: var(--bg); }
.sidebar-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,.5); z-index: 99; }
.sidebar-overlay.show { display: block; }

/* ── Responsive / Mobile ── */
@media (max-width: 768px) {
  /* Sidebar as drawer */
  .sidebar { position: fixed; left: -280px; top: 0; bottom: 0; z-index: 100; transition: left .25s ease; box-shadow: none; }
  .sidebar.open { left: 0; box-shadow: 4px 0 20px rgba(0,0,0,.4); }
  .menu-btn { display: flex; align-items: center; justify-content: center; }

  /* Header */
  .main-header { padding: 0 10px; gap: 6px; }
  .main-header h3 { font-size: 13px; }
  .user-badge { font-size: 12px; }
  .user-badge span { padding: 3px 8px; font-size: 11px; }

  /* Messages */
  .messages { padding: 12px 8px; gap: 12px; }
  .msg-row { max-width: 100%; }
  .bubble { max-width: calc(100vw - 80px); }
  .avatar { width: 30px; height: 30px; font-size: 12px; }
  .msg-row.ai .bubble { padding: 10px 12px; font-size: 13px; }
  .msg-row.user .bubble { padding: 9px 12px; font-size: 13px; }
  .empty-state h3 { font-size: 15px; }
  .empty-state p { font-size: 13px; }

  /* Input */
  .input-area { padding: 8px 8px 12px; }
  .input-row { padding: 8px 10px; }
  #msg-input { font-size: 13px; }

  /* Login */
  .login-card { padding: 32px 24px; margin: 16px; max-width: none; }

  /* Admin header */
  .admin-header { flex-wrap: wrap; padding: 10px 12px; gap: 8px; }
  .admin-header h1 { font-size: 13px; }
  .admin-body { padding: 12px 8px; }

  /* Admin tabs scroll */
  .tabs { width: 100%; overflow-x: auto; -webkit-overflow-scrolling: touch; justify-content: flex-start; scrollbar-width: none; }
  .tabs::-webkit-scrollbar { display: none; }
  .tab { white-space: nowrap; flex-shrink: 0; }

  /* Admin cards + form */
  .card { padding: 14px; }
  .card h3 { font-size: 14px; }
  .field-row { grid-template-columns: 1fr; }

  /* Tables scroll */
  table { display: block; overflow-x: auto; -webkit-overflow-scrolling: touch; }
  td, th { white-space: nowrap; }

  /* Toast */
  .toast { left: 12px; right: 12px; bottom: 12px; text-align: center; }
}

@media (max-width: 400px) {
  .login-card { padding: 24px 16px; }
  .login-logo h1 { font-size: 18px; }
}