:root {
  --bg: #f5f5f1;
  --surface: #ffffff;
  --ink: #1b1b18;
  --muted: #6b6a64;
  --border: #e2e0d8;
  --accent: #35506b;
  --accent-ink: #ffffff;
  --good: #3f7d58;
  --bad: #b0483a;
  --warn: #c98a2c;
  --radius: 10px;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --sans: "IBM Plex Sans", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.6;
}

.shell {
  display: flex;
  height: 100vh;
}

/* ---------- sidebar ---------- */

.sidebar {
  width: 240px;
  flex-shrink: 0;
  background: var(--surface);
  border-right: 1px solid var(--border);
  padding: 24px 18px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.brand-mark {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--accent);
  display: block;
}

.brand-sub {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-top: 4px;
}

.tabs {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.tab-btn {
  text-align: left;
  padding: 9px 12px;
  border: none;
  background: transparent;
  border-radius: var(--radius);
  font-family: var(--sans);
  font-size: 14px;
  color: var(--muted);
  cursor: pointer;
}

.tab-btn:hover { background: var(--bg); color: var(--ink); }

.tab-btn.active {
  background: var(--accent);
  color: var(--accent-ink);
}

.status {
  margin-top: auto;
  border-top: 1px solid var(--border);
  padding-top: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.status-row {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 8px;
}

.dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--bad);
  flex-shrink: 0;
}

.dot.on { background: var(--good); }

/* ---------- content ---------- */

.content {
  flex: 1;
  overflow-y: auto;
  padding: 32px 40px;
}

.panel { display: none; max-width: 760px; }
.panel.active { display: block; }

h1 {
  font-size: 20px;
  font-weight: 600;
  margin: 0 0 6px;
}

.muted { color: var(--muted); font-size: 14px; }

/* ---------- chat ---------- */

#panel-chat.active {
  display: flex;
  flex-direction: column;
  height: 100%;
  max-width: 760px;
}

.chat-log {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding-bottom: 16px;
}

.empty-state { color: var(--muted); font-size: 14px; margin-top: 40px; }
.empty-state p { margin: 4px 0; }

.msg {
  max-width: 80%;
  padding: 10px 14px;
  border-radius: var(--radius);
  font-size: 14.5px;
  white-space: pre-wrap;
}

.msg.user {
  align-self: flex-end;
  background: var(--accent);
  color: var(--accent-ink);
}

.msg.assistant {
  align-self: flex-start;
  background: var(--surface);
  border: 1px solid var(--border);
}

.msg.pending { color: var(--muted); font-style: italic; }

.sources {
  align-self: flex-start;
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--muted);
  max-width: 80%;
}

.sources summary { cursor: pointer; }
.sources .src-item { padding: 6px 0 6px 12px; border-left: 2px solid var(--border); margin-top: 4px; }

.chat-input-row {
  display: flex;
  gap: 8px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

#chat-input {
  flex: 1;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: var(--sans);
  font-size: 14.5px;
  background: var(--surface);
  color: var(--ink);
}

#chat-input:focus, input:focus, select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

button {
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 500;
  padding: 10px 18px;
  border-radius: var(--radius);
  border: none;
  background: var(--accent);
  color: var(--accent-ink);
  cursor: pointer;
}

button:disabled { opacity: 0.5; cursor: default; }

/* ---------- documents ---------- */

.dropzone {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 110px;
  margin: 18px 0;
  border: 1.5px dashed var(--border);
  border-radius: var(--radius);
  color: var(--muted);
  font-size: 14px;
  cursor: pointer;
  text-align: center;
}

.dropzone.drag-over { border-color: var(--accent); color: var(--accent); }

.upload-progress {
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--muted);
  min-height: 18px;
  margin-bottom: 8px;
}

.doc-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
  font-size: 13.5px;
}

.doc-table th {
  text-align: left;
  font-family: var(--mono);
  font-weight: 500;
  font-size: 11.5px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  border-bottom: 1px solid var(--border);
  padding: 8px 6px;
}

.doc-table td {
  padding: 9px 6px;
  border-bottom: 1px solid var(--border);
}

.doc-table .delete-btn {
  background: transparent;
  color: var(--bad);
  padding: 4px 8px;
  font-size: 12.5px;
}

/* ---------- settings ---------- */

fieldset {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin: 0 0 16px;
}

legend {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  padding: 0 6px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

label {
  display: block;
  font-size: 13.5px;
  color: var(--muted);
  margin-bottom: 12px;
}

label:last-child { margin-bottom: 0; }

.optional { font-size: 11px; opacity: 0.7; }

input[type="text"], input[type="password"], select {
  display: block;
  width: 100%;
  margin-top: 5px;
  padding: 9px 11px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: var(--sans);
  font-size: 14px;
  background: var(--bg);
  color: var(--ink);
}

.saved-msg {
  margin-left: 12px;
  font-size: 13px;
  color: var(--good);
  font-family: var(--mono);
}

@media (prefers-reduced-motion: no-preference) {
  .msg { animation: rise 0.15s ease-out; }
}

@keyframes rise {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}