:root {
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface-2: #eef0f6;
  --text: #1c2030;
  --muted: #5d6478;
  --border: #dde1ea;
  --accent: #3b5bdb;
  --accent-text: #ffffff;
  --cite-bg: #e7ecff;
  --cite-text: #2c46b8;
  --warn-bg: #fff4e0;
  --warn-text: #8a5300;
  --error-bg: #fdecec;
  --error-text: #a12626;
  --radius: 12px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #12141b;
    --surface: #1b1e28;
    --surface-2: #252937;
    --text: #e6e8ef;
    --muted: #9aa1b5;
    --border: #2f3445;
    --accent: #6b8cff;
    --accent-text: #0d1020;
    --cite-bg: #26305a;
    --cite-text: #b9c7ff;
    --warn-bg: #3a2d14;
    --warn-text: #f3c77a;
    --error-bg: #3d1d1d;
    --error-text: #ffb4b4;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 10px 16px; background: var(--surface); border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 2;
}
.brand { display: flex; align-items: center; gap: 10px; min-width: 0; }
.logo { font-size: 28px; }
h1 { font-size: 18px; margin: 0; }
.docs-link {
  background: none; border: 0; padding: 0; color: var(--muted); font-size: 13px; cursor: pointer;
  text-align: left; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 45vw;
}
.docs-link:hover { color: var(--accent); text-decoration: underline; }
.controls { display: flex; gap: 8px; align-items: center; }
select, input[type="text"], input[type="password"], textarea {
  font: inherit; color: var(--text); background: var(--surface-2);
  border: 1px solid var(--border); border-radius: 8px; padding: 7px 10px;
}
select { max-width: 52vw; }
.icon-btn {
  font-size: 18px; width: 38px; height: 38px; border-radius: 8px; cursor: pointer;
  border: 1px solid var(--border); background: var(--surface-2); color: var(--text);
}

.chat {
  flex: 1; width: 100%; max-width: 820px; margin: 0 auto; padding: 20px 16px 8px;
  display: flex; flex-direction: column; gap: 16px;
}
.empty { text-align: center; color: var(--muted); margin: 8vh auto 0; max-width: 560px; }
.empty h2 { color: var(--text); font-size: 22px; margin-bottom: 6px; }
.suggestions { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-top: 16px; }
.suggestions button {
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  border-radius: 999px; padding: 6px 14px; cursor: pointer; font: inherit; font-size: 14px;
}
.suggestions button:hover { border-color: var(--accent); }

.msg { display: flex; }
.msg.user { justify-content: flex-end; }
.bubble { border-radius: var(--radius); padding: 12px 16px; max-width: 100%; overflow-wrap: anywhere; }
.msg.user .bubble { background: var(--accent); color: var(--accent-text); max-width: 85%; white-space: pre-wrap; }
.msg.bot .bubble { background: var(--surface); border: 1px solid var(--border); width: 100%; }
.bubble.abstain { background: var(--warn-bg); color: var(--warn-text); border-color: transparent; }
.bubble.error { background: var(--error-bg); color: var(--error-text); border-color: transparent; }
.answer > :first-child { margin-top: 0; }
.answer > :last-child { margin-bottom: 0; }
.answer pre { background: var(--surface-2); padding: 10px; border-radius: 8px; overflow-x: auto; }
.answer code { font-size: 0.92em; }
.answer table { border-collapse: collapse; display: block; overflow-x: auto; }
.answer th, .answer td { border: 1px solid var(--border); padding: 4px 8px; }
.cite {
  display: inline-block; background: var(--cite-bg); color: var(--cite-text);
  border-radius: 6px; padding: 0 6px; font-size: 0.82em; font-weight: 600; white-space: nowrap;
}
.meta { margin-top: 10px; font-size: 12px; color: var(--muted); }
.note { margin-top: 4px; color: var(--warn-text); }
details.sources { margin-top: 10px; border-top: 1px solid var(--border); padding-top: 8px; }
details.sources summary { cursor: pointer; font-size: 14px; color: var(--muted); }
.source { margin-top: 10px; font-size: 14px; }
.source-head { display: flex; justify-content: space-between; gap: 8px; font-weight: 600; }
.score { color: var(--muted); font-weight: 400; font-size: 12px; white-space: nowrap; }
.snippet { color: var(--muted); margin: 4px 0 0; white-space: pre-wrap; border-left: 3px solid var(--border); padding-left: 10px; }
.typing { display: inline-flex; gap: 4px; }
.typing span { width: 8px; height: 8px; border-radius: 50%; background: var(--muted); animation: blink 1.2s infinite; }
.typing span:nth-child(2) { animation-delay: .2s; }
.typing span:nth-child(3) { animation-delay: .4s; }
@keyframes blink { 0%, 80%, 100% { opacity: .25; } 40% { opacity: 1; } }

.composer {
  width: 100%; max-width: 820px; margin: 0 auto; padding: 8px 16px 4px;
  display: flex; gap: 8px; position: sticky; bottom: 0; background: var(--bg);
}
.composer textarea { flex: 1; resize: none; max-height: 180px; padding: 11px 12px; border-radius: var(--radius); }
.composer button, .dialog-actions button {
  font: inherit; font-weight: 600; border: 0; border-radius: var(--radius); padding: 0 20px;
  background: var(--accent); color: var(--accent-text); cursor: pointer;
}
.composer button:disabled { opacity: .55; cursor: default; }
.composer button.stop { background: var(--surface-2); color: var(--text); border: 1px solid var(--border); }
.text-btn {
  font: inherit; font-size: 14px; height: 38px; padding: 0 12px; border-radius: 8px; cursor: pointer;
  border: 1px solid var(--border); background: var(--surface-2); color: var(--text); white-space: nowrap;
}
.actions { margin-top: 8px; display: flex; gap: 12px; }
.link-btn { background: none; border: 0; padding: 0; font: inherit; font-size: 13px; color: var(--muted); cursor: pointer; }
.link-btn:hover { color: var(--accent); }
.cursor { display: inline-block; width: 7px; height: 1em; margin-left: 2px; vertical-align: text-bottom;
  background: var(--accent); animation: blink 1s steps(2) infinite; }
.answer .katex-display { overflow-x: auto; overflow-y: hidden; padding: 4px 0; }
.footnote { text-align: center; font-size: 12px; color: var(--muted); margin: 2px 16px 10px; }

dialog {
  border: 1px solid var(--border); border-radius: var(--radius); padding: 0;
  background: var(--surface); color: var(--text); width: min(560px, calc(100vw - 32px));
}
dialog::backdrop { background: rgb(0 0 0 / .45); }
.dialog-body { padding: 18px 20px; }
.dialog-body h2 { margin: 0 0 6px; font-size: 18px; }
.muted { color: var(--muted); font-size: 14px; }
.provider-row { border-top: 1px solid var(--border); padding: 12px 0; display: grid; gap: 6px; }
.provider-row .row-head { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; }
.provider-row label { font-size: 13px; color: var(--muted); }
.provider-row input { width: 100%; }
.badge { font-size: 12px; border-radius: 999px; padding: 1px 8px; background: var(--surface-2); color: var(--muted); }
.badge.ok { background: var(--cite-bg); color: var(--cite-text); }
.dialog-actions { display: flex; justify-content: flex-end; margin-top: 12px; }
.dialog-actions button { padding: 8px 20px; }
.doc-list { padding-left: 20px; }
.doc-list li { margin: 4px 0; }
a { color: var(--accent); }

@media (max-width: 560px) {
  .logo { display: none; }
  .docs-link { max-width: 38vw; }
}