:root {
  --bg: #000000;
  --bg-raised: #0d0d0d;
  --bg-hover: #1a1a1a;
  --border: #2e2e2e;
  --border-soft: #232323;
  --fg: #ffffff;
  --fg-dim: #a3a3a3;
  --fg-faint: #6b6b6b;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #ffffff;
    --bg-raised: #f7f7f7;
    --bg-hover: #ececec;
    --border: #dcdcdc;
    --border-soft: #e7e7e7;
    --fg: #000000;
    --fg-dim: #4a4a4a;
    --fg-faint: #8a8a8a;
  }
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 14px;
}

.app {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* ---------- Sidebar ---------- */

.sidebar {
  width: 280px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--border);
  background: var(--bg-raised);
  padding: 14px 12px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 4px 6px 16px;
}

.brand-mark {
  width: 26px;
  height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--fg);
  border-radius: 6px;
  font-weight: 700;
  font-size: 13px;
}

.brand-name {
  font-weight: 600;
  letter-spacing: 0.2px;
}

.new-chat-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  justify-content: center;
  width: 100%;
  padding: 9px 10px;
  background: transparent;
  border: 1px solid var(--fg);
  color: var(--fg);
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.12s ease;
}
.new-chat-btn:hover { background: var(--bg-hover); }
.new-chat-btn .plus { font-size: 16px; line-height: 1; }

.tabs {
  display: flex;
  gap: 4px;
  margin-top: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-soft);
}

.tab-btn {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--fg-dim);
  font-size: 12px;
  font-weight: 600;
  padding: 7px 4px;
  border-radius: 6px;
  cursor: pointer;
  letter-spacing: 0.2px;
}
.tab-btn:hover { color: var(--fg); background: var(--bg-hover); }
.tab-btn.active { color: var(--bg); background: var(--fg); }

.tab-panel {
  flex: 1;
  overflow-y: auto;
  margin-top: 10px;
  padding-right: 2px;
}
.tab-panel.hidden { display: none; }

.panel-empty {
  color: var(--fg-faint);
  font-size: 12.5px;
  padding: 14px 6px;
  text-align: center;
}
.panel-empty.hidden { display: none; }

.list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.list-item {
  padding: 9px 10px;
  border-radius: 7px;
  cursor: pointer;
  border: 1px solid transparent;
}
.list-item:hover { background: var(--bg-hover); }
.list-item.active { border-color: var(--fg); }

.list-item .item-title {
  font-size: 12.5px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.list-item .item-meta {
  font-size: 11px;
  color: var(--fg-faint);
  margin-top: 2px;
  display: flex;
  gap: 8px;
}

.kb-search {
  display: flex;
  gap: 6px;
  margin-bottom: 10px;
}
.kb-search input {
  flex: 1;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--fg);
  border-radius: 6px;
  padding: 7px 8px;
  font-size: 12.5px;
}
.kb-search input:focus { outline: 1px solid var(--fg); }
.kb-search button {
  background: var(--fg);
  color: var(--bg);
  border: none;
  border-radius: 6px;
  padding: 0 12px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
}

.kb-summary {
  font-size: 11.5px;
  color: var(--fg-dim);
  border: 1px solid var(--border-soft);
  border-radius: 7px;
  padding: 8px 9px;
  margin-bottom: 10px;
  line-height: 1.5;
}
.kb-summary .cat-row {
  display: flex;
  justify-content: space-between;
}

.sidebar-footer {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 10px 6px 2px;
  border-top: 1px solid var(--border-soft);
  margin-top: 10px;
  font-size: 11px;
  color: var(--fg-faint);
}
.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--fg-faint);
  flex-shrink: 0;
}
.status-dot.live { background: var(--fg); box-shadow: 0 0 0 2px var(--border-soft); }
.footer-text code {
  color: var(--fg-dim);
  font-family: var(--mono);
}

/* ---------- Chat ---------- */

.chat {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.chat-header {
  padding: 16px 26px 12px;
  border-bottom: 1px solid var(--border);
}
.chat-header h1 {
  font-size: 15px;
  margin: 0;
  font-weight: 700;
}
.chat-header .subtitle {
  font-size: 11.5px;
  color: var(--fg-faint);
}

.messages {
  flex: 1;
  overflow-y: auto;
  padding: 22px 26px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.welcome {
  margin: auto;
  max-width: 480px;
  text-align: center;
  color: var(--fg-dim);
}
.welcome h2 { color: var(--fg); font-size: 18px; margin-bottom: 8px; }
.welcome p { font-size: 13px; line-height: 1.6; }

.msg {
  display: flex;
  flex-direction: column;
  max-width: 72%;
}
.msg.user { align-self: flex-end; align-items: flex-end; }
.msg.agent { align-self: flex-start; align-items: flex-start; }

.msg .role-label {
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.6px;
  color: var(--fg-faint);
  margin-bottom: 4px;
  padding: 0 2px;
}

.bubble {
  padding: 11px 14px;
  border-radius: 12px;
  font-size: 13.5px;
  line-height: 1.55;
  white-space: pre-wrap;
  word-wrap: break-word;
}
.msg.user .bubble {
  background: var(--fg);
  color: var(--bg);
  border-bottom-right-radius: 3px;
}
.msg.agent .bubble {
  background: var(--bg-raised);
  border: 1px solid var(--border);
  color: var(--fg);
  border-bottom-left-radius: 3px;
}
.msg.agent .bubble.error {
  border-style: dashed;
}
.msg.agent .bubble.rate-limit {
  border-style: solid;
  border-width: 2px;
  font-weight: 600;
}

.resume-btn {
  align-self: flex-start;
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--fg);
  border-radius: 8px;
  padding: 7px 14px;
  font-size: 12.5px;
  font-weight: 700;
  cursor: pointer;
}
.resume-btn:hover { background: var(--fg); color: var(--bg); }
.resume-btn:disabled { opacity: 0.5; cursor: default; }

/* live trace */
.trace {
  width: 100%;
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  background: var(--bg-raised);
  margin-bottom: 6px;
  overflow: hidden;
}
.trace-toggle {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: transparent;
  border: none;
  color: var(--fg-dim);
  font-size: 11.5px;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
}
.trace-toggle:hover { color: var(--fg); }
.trace-toggle .chev { transition: transform 0.15s ease; font-family: var(--mono); }
.trace.collapsed .chev { transform: rotate(-90deg); }
.trace.collapsed .trace-body { display: none; }

.trace-body {
  max-height: 260px;
  overflow-y: auto;
  padding: 0 12px 10px;
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--fg-dim);
  border-top: 1px solid var(--border-soft);
}
.trace-body .line {
  padding: 3px 0;
  border-bottom: 1px dotted var(--border-soft);
  white-space: pre-wrap;
  word-wrap: break-word;
}
.trace-body .line:last-child { border-bottom: none; }

.spinner {
  display: inline-block;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  border: 1.5px solid var(--fg-faint);
  border-top-color: var(--fg);
  animation: spin 0.7s linear infinite;
  margin-right: 3px;
}
@keyframes spin { to { transform: rotate(360deg); } }

.result-block { display: flex; flex-direction: column; gap: 10px; width: 100%; }

.badges { display: flex; flex-wrap: wrap; gap: 6px; }
.badge {
  font-size: 10.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.3px;
  border: 1px solid var(--fg);
  border-radius: 20px;
  padding: 3px 9px;
}
.badge.ghost { border-color: var(--border); color: var(--fg-dim); }

.plan-box {
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 12px;
}
.plan-box .plan-title { font-weight: 700; margin-bottom: 6px; }
.plan-box ol { margin: 0; padding-left: 18px; }
.plan-box li { padding: 2px 0; color: var(--fg-dim); }

.doc-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.doc-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  align-self: flex-start;
  background: transparent;
  border: 1px solid var(--fg);
  color: var(--fg);
  text-decoration: none;
  font-size: 12.5px;
  font-weight: 600;
  font-family: inherit;
  padding: 7px 12px;
  border-radius: 8px;
  cursor: pointer;
}
.doc-link:hover { background: var(--fg); color: var(--bg); }

.read-panel {
  width: 100%;
  max-height: 340px;
  overflow-y: auto;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
  background: var(--bg-raised);
}
.read-panel .read-body {
  font-size: 13px;
  line-height: 1.7;
  white-space: pre-wrap;
  word-wrap: break-word;
  color: var(--fg);
}

.clarify-box {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.clarify-q { display: flex; flex-direction: column; gap: 6px; }
.clarify-q .q-text { font-weight: 600; font-size: 13px; }
.clarify-q .q-context { font-size: 11.5px; color: var(--fg-faint); }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  border: 1px solid var(--border);
  background: transparent;
  color: var(--fg-dim);
  font-size: 11.5px;
  padding: 5px 10px;
  border-radius: 20px;
  cursor: pointer;
}
.chip:hover { border-color: var(--fg); color: var(--fg); }
.chip.selected { background: var(--fg); color: var(--bg); border-color: var(--fg); }
.clarify-q input[type="text"] {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--fg);
  border-radius: 6px;
  padding: 7px 9px;
  font-size: 12.5px;
}
.clarify-q input[type="text"]:focus { outline: 1px solid var(--fg); }
.submit-answers {
  align-self: flex-start;
  background: var(--fg);
  color: var(--bg);
  border: none;
  border-radius: 8px;
  padding: 8px 14px;
  font-size: 12.5px;
  font-weight: 700;
  cursor: pointer;
}
.submit-answers:disabled { opacity: 0.4; cursor: default; }

/* ---------- Composer ---------- */

.composer {
  display: flex;
  gap: 10px;
  align-items: flex-end;
  padding: 14px 26px 20px;
  border-top: 1px solid var(--border);
}
.composer textarea {
  flex: 1;
  resize: none;
  background: var(--bg-raised);
  border: 1px solid var(--border);
  color: var(--fg);
  border-radius: 10px;
  padding: 11px 13px;
  font-size: 13.5px;
  font-family: var(--sans);
  max-height: 160px;
}
.composer textarea:focus { outline: 1px solid var(--fg); }
.composer button {
  background: var(--fg);
  color: var(--bg);
  border: none;
  border-radius: 10px;
  padding: 0 18px;
  height: 40px;
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
}
.composer button:disabled { opacity: 0.4; cursor: default; }

.attach-btn {
  background: transparent !important;
  color: var(--fg) !important;
  border: 1px solid var(--border) !important;
  width: 40px;
  padding: 0 !important;
  font-size: 16px !important;
  flex-shrink: 0;
}
.attach-btn:hover { border-color: var(--fg) !important; background: var(--bg-hover) !important; }

.attachment-tray {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0 26px 10px;
}
.attachment-tray.hidden { display: none; }

.attachment-chip {
  display: flex;
  align-items: center;
  gap: 7px;
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 5px 8px 5px 12px;
  font-size: 12px;
  color: var(--fg-dim);
  background: var(--bg-raised);
}
.attachment-chip.uploading { border-style: dashed; color: var(--fg-faint); }
.attachment-chip .chip-name { max-width: 160px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.attachment-chip .chip-remove {
  background: transparent;
  border: none;
  color: var(--fg-faint);
  cursor: pointer;
  font-size: 13px;
  line-height: 1;
  padding: 2px 4px;
}
.attachment-chip .chip-remove:hover { color: var(--fg); }

/* scrollbars, monochrome */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-track { background: transparent; }