:root {
  --bg: #f0f3f8;
  --surface: #ffffff;
  --ink: #1a2332;
  --muted: #5c6b7f;
  --line: #dde3ec;
  --brand: #1f6feb;
  --brand-dark: #1557c0;
  --ok: #1a7f4b;
  --warn: #9a6700;
  --danger: #cf222e;
  --shadow: 0 10px 30px rgba(26, 35, 50, 0.08);
  --radius: 14px;
  --font: 'Noto Sans SC', system-ui, sans-serif;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: linear-gradient(160deg, #e8eef8 0%, #f5f7fb 45%, #eef2f7 100%);
}

button, input, textarea { font: inherit; }
code {
  background: #eef2f7;
  padding: 0.1em 0.4em;
  border-radius: 6px;
  font-size: 0.92em;
}

.view { min-height: 100%; }
[hidden] { display: none !important; }

/* Login */
#view-login {
  display: grid;
  place-items: center;
  padding: 2rem;
}
.login-card {
  width: min(420px, 100%);
  background: var(--surface);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: var(--shadow);
  border: 1px solid var(--line);
}
.login-brand { text-align: center; margin-bottom: 1.5rem; }
.login-brand h1 { font-size: 1.35rem; margin: 0.75rem 0 0.35rem; }
.login-brand p { margin: 0; color: var(--muted); font-size: 0.9rem; }
.logo-mark {
  width: 56px; height: 56px; margin: 0 auto;
  border-radius: 16px;
  display: grid; place-items: center;
  background: linear-gradient(145deg, var(--brand), #0b3d91);
  color: #fff; font-weight: 700; letter-spacing: 0.04em;
}
.logo-mark.sm { width: 34px; height: 34px; border-radius: 10px; font-size: 0.75rem; margin: 0; }

#login-form { display: grid; gap: 0.85rem; }
#login-form label { display: grid; gap: 0.35rem; font-weight: 600; font-size: 0.9rem; }
#login-form input {
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fafbfd;
}
.login-hint { color: var(--muted); font-size: 0.82rem; margin: 0.25rem 0 0; line-height: 1.5; }
.error { color: var(--danger); margin: 0; font-size: 0.9rem; }

.btn {
  border: none; border-radius: 10px; padding: 0.7rem 1rem;
  background: #e8eef8; color: var(--ink); cursor: pointer; font-weight: 600;
}
.btn:hover { filter: brightness(0.98); }
.btn.primary { background: var(--brand); color: #fff; }
.btn.primary:hover { background: var(--brand-dark); }
.btn.ghost { background: transparent; border: 1px solid var(--line); }
.btn.sm { padding: 0.35rem 0.65rem; font-size: 0.82rem; }
.btn.block { width: 100%; }
.btn:disabled { opacity: 0.55; cursor: not-allowed; }

/* Topbar */
.topbar {
  display: flex; align-items: center; gap: 1rem;
  padding: 0.7rem 1.1rem;
  background: rgba(255,255,255,0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 20;
}
.topbar-left { display: flex; align-items: center; gap: 0.6rem; }
.badge {
  font-size: 0.7rem; font-weight: 700; color: var(--brand);
  background: #e7f0ff; padding: 0.15rem 0.45rem; border-radius: 999px;
}
.topbar-nav { display: flex; gap: 0.35rem; margin-left: 1rem; }
.nav-btn {
  border: none; background: transparent; padding: 0.45rem 0.8rem;
  border-radius: 999px; cursor: pointer; color: var(--muted); font-weight: 600;
}
.nav-btn.active { background: #e7f0ff; color: var(--brand); }
.topbar-right { margin-left: auto; display: flex; align-items: center; gap: 0.65rem; color: var(--muted); font-size: 0.9rem; }

.main { height: calc(100vh - 58px); }
.panel { height: 100%; }

/* Chat layout */
.chat-layout { display: grid; grid-template-columns: 280px 1fr; height: 100%; }
.side {
  border-right: 1px solid var(--line);
  background: rgba(255,255,255,0.65);
  padding: 1.1rem;
  overflow: auto;
}
.side h2 { font-size: 1rem; margin: 0 0 0.6rem; }
.side h3 { font-size: 0.9rem; margin: 1.2rem 0 0.55rem; color: var(--muted); }
.capability { margin: 0; padding-left: 1.1rem; color: var(--muted); font-size: 0.9rem; line-height: 1.7; }
.hot-list { display: grid; gap: 0.45rem; }
.hot-item {
  text-align: left; border: 1px solid var(--line); background: #fff;
  border-radius: 10px; padding: 0.55rem 0.7rem; cursor: pointer;
  font-size: 0.85rem; line-height: 1.4; color: var(--ink);
}
.hot-item:hover { border-color: #b6cdf8; background: #f7faff; }
.side-note {
  margin-top: 1.25rem; padding: 0.75rem;
  background: #fff8e8; border: 1px solid #f0e0b2; border-radius: 10px;
  color: var(--warn); font-size: 0.8rem; line-height: 1.5;
}

.chat-main { display: flex; flex-direction: column; min-width: 0; }
.kb-status {
  padding: 0.45rem 1rem; font-size: 0.82rem; color: var(--muted);
  border-bottom: 1px solid var(--line); background: #fafbfd;
}
.kb-status.ok { color: var(--ok); }
.kb-status.err { color: var(--danger); }

.messages {
  flex: 1; overflow: auto; padding: 1.1rem;
  display: flex; flex-direction: column; gap: 0.9rem;
}
.msg {
  max-width: min(720px, 92%);
  padding: 0.85rem 1rem;
  border-radius: 14px;
  line-height: 1.55;
  white-space: pre-wrap;
  word-break: break-word;
}
.msg.user {
  align-self: flex-end;
  background: var(--brand); color: #fff;
  border-bottom-right-radius: 4px;
}
.msg.bot {
  align-self: flex-start;
  background: var(--surface);
  border: 1px solid var(--line);
  border-bottom-left-radius: 4px;
  box-shadow: 0 4px 14px rgba(26,35,50,0.04);
}
.msg.bot.default { border-color: #f0d9a8; background: #fffbf2; }
.msg .meta {
  margin-top: 0.65rem; padding-top: 0.55rem;
  border-top: 1px dashed var(--line);
  font-size: 0.78rem; color: var(--muted);
}
.msg .source {
  display: inline-flex; gap: 0.35rem; flex-wrap: wrap; margin-top: 0.35rem;
}
.chip {
  background: #e7f0ff; color: var(--brand);
  border-radius: 999px; padding: 0.15rem 0.55rem; font-weight: 600;
}
.msg-actions { margin-top: 0.5rem; display: flex; gap: 0.35rem; }
.thumb { font-size: 0.8rem; padding: 0.25rem 0.55rem; }

.composer {
  border-top: 1px solid var(--line);
  background: rgba(255,255,255,0.92);
  padding: 0.85rem 1rem 1rem;
}
.composer-row { display: flex; gap: 0.55rem; align-items: flex-end; }
.composer textarea {
  flex: 1; resize: none; border: 1px solid var(--line);
  border-radius: 12px; padding: 0.7rem 0.85rem; min-height: 52px;
  background: #fafbfd;
}
.upload-btn {
  width: 44px; height: 44px; display: grid; place-items: center;
  border: 1px solid var(--line); border-radius: 12px; background: #fff; cursor: pointer;
}
.composer-tip { margin: 0.45rem 0 0; color: var(--muted); font-size: 0.78rem; }
.image-preview {
  display: flex; align-items: center; gap: 0.65rem;
  margin-bottom: 0.55rem; padding: 0.5rem; background: #f7faff;
  border: 1px dashed #b6cdf8; border-radius: 10px;
}
.image-preview img { height: 56px; border-radius: 8px; }
.ocr-status { font-size: 0.8rem; color: var(--muted); }

/* History / Admin */
.page-head {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; padding: 1rem 1.2rem; border-bottom: 1px solid var(--line);
  background: rgba(255,255,255,0.8);
}
.page-head h2 { margin: 0; font-size: 1.1rem; }
.history-list { padding: 1rem; display: grid; gap: 0.75rem; overflow: auto; height: calc(100% - 64px); }
.history-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 0.9rem 1rem;
}
.history-card .q { font-weight: 600; margin-bottom: 0.35rem; }
.history-card .a { color: var(--muted); font-size: 0.9rem; white-space: pre-wrap; }
.history-card .tags { margin-top: 0.5rem; font-size: 0.78rem; color: var(--muted); }

.admin-tools { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; }
.admin-tools input[type="search"] {
  min-width: 220px; padding: 0.45rem 0.65rem; border: 1px solid var(--line); border-radius: 8px;
}
.inline { display: flex; align-items: center; gap: 0.35rem; font-size: 0.9rem; color: var(--muted); }
.inline input { width: 72px; padding: 0.35rem; border: 1px solid var(--line); border-radius: 8px; }
.admin-stats {
  display: flex; gap: 0.75rem; flex-wrap: wrap; padding: 0.85rem 1.2rem;
}
.stat {
  background: #fff; border: 1px solid var(--line); border-radius: 12px;
  padding: 0.7rem 1rem; min-width: 120px;
}
.stat b { display: block; font-size: 1.25rem; }
.stat span { color: var(--muted); font-size: 0.8rem; }
.table-wrap { overflow: auto; height: calc(100% - 130px); padding: 0 1.2rem 1.2rem; }
.faq-table { width: 100%; border-collapse: collapse; background: #fff; font-size: 0.88rem; }
.faq-table th, .faq-table td {
  border-bottom: 1px solid var(--line); text-align: left; padding: 0.55rem 0.45rem; vertical-align: top;
}
.faq-table th { position: sticky; top: 0; background: #f7f9fc; }

@media (max-width: 860px) {
  .chat-layout { grid-template-columns: 1fr; }
  .side { display: none; }
  .topbar { flex-wrap: wrap; }
  .topbar-nav { margin-left: 0; }
}