:root {
  --bg: #faf8f5;
  --surface: #ffffff;
  --text: #22201c;
  --muted: #6f6a62;
  --border: #e6e1d8;
  --accent: #7a5c3e;
  --accent-text: #ffffff;
  --accent-soft: #f1e9df;
  --danger: #b3261e;
  --warning-bg: #fff4d6;
  --success-bg: #e6f4ea;
  --error-bg: #fde7e7;
  --highlight: rgba(255, 200, 0, 0.45);
  --radius: 10px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 4px 16px rgba(0, 0, 0, 0.04);
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #171614;
    --surface: #211f1c;
    --text: #ece8e1;
    --muted: #a19b91;
    --border: #36322d;
    --accent: #d2ad85;
    --accent-text: #1b1917;
    --accent-soft: #332b22;
    --danger: #ff8a80;
    --warning-bg: #3b3220;
    --success-bg: #1f3325;
    --error-bg: #3d2020;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
}

a { color: var(--accent); }
h1 { font-size: 1.75rem; line-height: 1.2; margin: 0.5rem 0 1rem; }
h2 { font-size: 1.15rem; margin: 0 0 0.75rem; }
.muted { color: var(--muted); font-size: 0.92rem; }
.error { color: var(--danger); }
.warning { background: var(--warning-bg); padding: 0.25rem 0.5rem; border-radius: 6px; font-size: 0.9rem; margin-top: 0.25rem; }

/* Layout */
.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  padding: 0.75rem 1rem; background: var(--surface); border-bottom: 1px solid var(--border);
}
.topbar nav { display: flex; align-items: center; gap: 1rem; white-space: nowrap; }
.brand { min-width: 0; font-weight: 700; color: var(--text); text-decoration: none; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.narrow { max-width: 640px; margin: 2rem auto; padding: 0 1rem; }
.wide { max-width: 860px; margin: 1.5rem auto; padding: 0 1rem; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 1.25rem; margin-bottom: 1.25rem; box-shadow: var(--shadow); }
main.card { padding: 1.5rem; }
.center { text-align: center; }
.hero { text-align: center; margin-top: 4rem; }
.lead { font-size: 1.15rem; color: var(--muted); }
.row { display: flex; gap: 0.5rem; align-items: center; flex-wrap: wrap; }
.row input[type=text] { flex: 1; min-width: 200px; }
.inline { display: inline; }

/* Forms */
input[type=text], input[type=email], input[type=password], textarea, select {
  font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--border); border-radius: 8px; padding: 0.55rem 0.7rem; width: 100%;
}
input[type=checkbox] { width: auto; }
input:focus, textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; }
form p label { display: block; font-weight: 600; margin-bottom: 0.25rem; }
form p:has(input[type=checkbox]) label { display: inline; }
.helptext { display: block; color: var(--muted); font-size: 0.85rem; }
.errorlist { color: var(--danger); padding-left: 1.1rem; margin: 0.25rem 0; }
.upload { display: grid; gap: 0.75rem; margin-top: 1rem; padding-top: 1rem; border-top: 1px solid var(--border); }
.upload label { display: grid; gap: 0.25rem; font-weight: 600; }

.btn {
  display: inline-block; font: inherit; font-weight: 600; cursor: pointer; text-decoration: none;
  background: var(--accent); color: var(--accent-text); border: 1px solid var(--accent);
  border-radius: 8px; padding: 0.55rem 1rem;
}
.btn:disabled { opacity: 0.55; cursor: default; }
.btn.secondary { background: transparent; color: var(--accent); }
.btn.small { padding: 0.3rem 0.7rem; font-size: 0.9rem; }
.btn.danger { background: var(--danger); border-color: var(--danger); color: #fff; }
button.link { background: none; border: 0; padding: 0; font: inherit; color: var(--accent); cursor: pointer; }
button.link.danger { color: var(--danger); }

/* Lists */
.list { list-style: none; padding: 0; margin: 0 0 1rem; }
.list li { display: flex; justify-content: space-between; align-items: center; gap: 1rem; padding: 0.75rem 0; border-bottom: 1px solid var(--border); }
.list li:last-child { border-bottom: 0; }
.list li > div { min-width: 0; overflow-wrap: anywhere; }
.list li > a + .muted { margin-left: auto; }
.qa-log { list-style: none; padding: 0; margin: 0; }
.qa-log li { padding: 0.5rem 0; border-bottom: 1px solid var(--border); }
.qa-log summary { cursor: pointer; }
.answer-text { white-space: normal; margin: 0.5rem 0 0 1rem; }

/* Flash messages */
.messages { max-width: 860px; margin: 1rem auto 0; padding: 0 1rem; }
.msg { padding: 0.6rem 0.9rem; border-radius: 8px; margin-bottom: 0.5rem; background: var(--accent-soft); }
.msg.success { background: var(--success-bg); }
.msg.error { background: var(--error-bg); color: inherit; }
.msg.warning { background: var(--warning-bg); }

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

body.chat-page { height: 100dvh; display: flex; flex-direction: column; overflow: hidden; }
.chat-page .messages { position: absolute; top: 3.5rem; left: 0; right: 0; z-index: 5; }
.chat-layout { flex: 1; display: grid; grid-template-columns: minmax(340px, 2fr) 3fr; min-height: 0; }

.chat-pane { display: flex; flex-direction: column; min-height: 0; border-right: 1px solid var(--border); background: var(--bg); }
.chat-log { flex: 1; overflow-y: auto; padding: 1rem; display: flex; flex-direction: column; gap: 0.9rem; }
.welcome { margin: auto 0; text-align: center; padding: 2rem 1rem; }
.welcome h2 { font-size: 1.3rem; }

.chat-log .msg { max-width: 92%; padding: 0.7rem 0.9rem; border-radius: 14px; margin: 0; }
.msg-user { align-self: flex-end; background: var(--accent); color: var(--accent-text); white-space: pre-wrap; border-bottom-right-radius: 4px; }
.msg-assistant { align-self: flex-start; background: var(--surface); border: 1px solid var(--border); border-bottom-left-radius: 4px; }
.msg-assistant .answer > :first-child { margin-top: 0; }
.msg-assistant .answer > :last-child { margin-bottom: 0; }
.msg-assistant ul, .msg-assistant ol { padding-left: 1.3rem; margin: 0.4rem 0; }

.cite-chip {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 1.35em; height: 1.35em; padding: 0 0.3em; margin: 0 0.1em;
  font: 600 0.72rem/1 system-ui, sans-serif; vertical-align: 0.15em;
  color: var(--accent); background: var(--accent-soft); border: 1px solid var(--accent);
  border-radius: 999px; cursor: pointer;
}
.cite-chip:hover { background: var(--accent); color: var(--accent-text); }
.cite-chip.demo { cursor: default; }

.sources { margin-top: 0.6rem; font-size: 0.88rem; border-top: 1px solid var(--border); padding-top: 0.4rem; }
.sources summary { cursor: pointer; color: var(--muted); }
.sources ol { padding-left: 1.3rem; margin: 0.4rem 0 0; }
.sources li { margin-bottom: 0.35rem; }
.sources q { color: var(--muted); }
.source-link { background: none; border: 0; padding: 0; font: inherit; font-weight: 600; color: var(--accent); cursor: pointer; text-align: left; }

.typing { display: inline-flex; gap: 4px; padding: 0.3rem 0; }
.typing i { width: 7px; height: 7px; border-radius: 50%; background: var(--muted); animation: blink 1.2s infinite both; }
.typing i:nth-child(2) { animation-delay: 0.2s; }
.typing i:nth-child(3) { animation-delay: 0.4s; }
@keyframes blink { 0%, 80%, 100% { opacity: 0.25; } 40% { opacity: 1; } }

.ask-form { display: flex; gap: 0.5rem; padding: 0.75rem 0.75rem calc(0.75rem + env(safe-area-inset-bottom)); border-top: 1px solid var(--border); background: var(--surface); align-items: flex-end; }
.ask-form textarea { resize: none; max-height: 160px; overflow-y: hidden; }

/* Viewer */
.viewer-pane { display: flex; flex-direction: column; min-height: 0; background: var(--border); }
.viewer-toolbar { display: flex; align-items: center; gap: 0.5rem; padding: 0.4rem 0.6rem; background: var(--surface); border-bottom: 1px solid var(--border); }
.doc-tabs { display: flex; gap: 0.3rem; overflow-x: auto; flex: 1; }
.doc-tabs.single .doc-tab { pointer-events: none; border-color: transparent; background: none; color: var(--text); font-weight: 600; padding-left: 0.2rem; }
.doc-tab { font: inherit; font-size: 0.9rem; white-space: nowrap; padding: 0.3rem 0.7rem; border-radius: 999px; border: 1px solid var(--border); background: var(--bg); color: var(--text); cursor: pointer; }
.doc-tab.active { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }
.close-viewer { display: none; font-weight: 600; white-space: nowrap; }

.pages { flex: 1; overflow-y: auto; padding: 12px; display: flex; flex-direction: column; align-items: center; gap: 12px; }
.page { position: relative; width: 100%; background: #fff; box-shadow: 0 1px 4px rgba(0, 0, 0, 0.18); flex-shrink: 0; transition: box-shadow 0.3s; }
.page.flash { box-shadow: 0 0 0 3px var(--accent); }
.page canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.page-label { position: absolute; top: 45%; width: 100%; text-align: center; color: #999; font-size: 0.9rem; }
.page.rendered .page-label { display: none; }

/* PDF.js text layer (subset of pdfjs-dist/web/pdf_viewer.css v4.10) */
.textLayer {
  position: absolute; inset: 0; overflow: clip; opacity: 1; line-height: 1;
  text-size-adjust: none; forced-color-adjust: none; transform-origin: 0 0; z-index: 0;
}
.textLayer :is(span, br) { color: transparent; position: absolute; white-space: pre; cursor: text; transform-origin: 0% 0%; }
.textLayer > :not(.markedContent), .textLayer .markedContent span:not(.markedContent) { z-index: 1; }
.textLayer span.markedContent { top: 0; height: 0; }
.textLayer ::selection { background: rgba(0, 100, 255, 0.25); }
.textLayer br::selection { background: transparent; }
.textLayer .endOfContent { display: block; position: absolute; inset: 100% 0 0; z-index: 0; cursor: default; user-select: none; }
.textLayer span.cite-hl { background: var(--highlight); border-radius: 2px; }

/* Mobile: the document opens as a full-screen sheet */
@media (max-width: 900px) {
  .chat-layout { grid-template-columns: 1fr; }
  .chat-pane { border-right: 0; }
  .viewer-pane {
    position: fixed; inset: 0; z-index: 20; transform: translateY(100%);
    transition: transform 0.25s ease; visibility: hidden;
  }
  .viewer-pane.open { transform: none; visibility: visible; }
  .close-viewer { display: block; }
}
@media (min-width: 901px) {
  #show-doc { display: none; }
}

.usage { display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap; }
.usage meter { width: 140px; }

@media (max-width: 600px) {
  h1 { font-size: 1.45rem; }
  .card { padding: 1rem; }
  .list li { flex-wrap: wrap; }
  .list li > a + .muted { margin-left: 0; }
  .row > .btn { flex: 1; text-align: center; }
  .chat-log .msg { max-width: 96%; }
}

/* Space management */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 0.75rem; margin-bottom: 0.75rem; }
.stat { display: flex; flex-direction: column; gap: 0.1rem; padding: 0.75rem; background: var(--bg); border: 1px solid var(--border); border-radius: 8px; }
.stat-label { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--muted); }
.stat-value { font-size: 1.5rem; font-weight: 700; }
.stat-value.small { font-size: 1.1rem; }
.badge { font-size: 0.7rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; vertical-align: middle; padding: 0.15rem 0.5rem; border-radius: 999px; background: var(--accent-soft); color: var(--accent); }
.processing { font-size: 0.9rem; color: var(--accent); margin-top: 0.25rem; }
.processing::before { content: ""; display: inline-block; width: 0.8em; height: 0.8em; margin-right: 0.4em; border: 2px solid currentColor; border-right-color: transparent; border-radius: 50%; vertical-align: -0.1em; animation: spin 0.8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.assistant-form textarea { font-size: 0.95rem; }
.row.between { justify-content: space-between; margin-top: 0.4rem; }
.file-load { font-weight: 400 !important; font-size: 0.9rem; color: var(--muted); display: inline-flex !important; gap: 0.4rem; align-items: center; flex-wrap: wrap; }
.qa-meta { display: block; font-size: 0.85rem; color: var(--muted); margin-left: 1.1rem; }
.read-mode { display: flex; flex-wrap: wrap; gap: 0.25rem 0.75rem; align-items: baseline; font-size: 0.9rem; margin-top: 0.3rem; }
.read-mode button.link { font-size: 0.9rem; }

/* Appearance settings */
.two-col { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 0 1rem; }
select { font: inherit; color: var(--text); background: var(--bg); border: 1px solid var(--border); border-radius: 8px; padding: 0.5rem 0.6rem; width: 100%; }
.presets { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 0.9rem; }
.preset { display: inline-flex; align-items: center; gap: 0.4rem; font: inherit; font-size: 0.88rem; padding: 0.3rem 0.65rem 0.3rem 0.35rem; border: 1px solid var(--border); border-radius: 999px; background: var(--surface); color: var(--text); cursor: pointer; }
.preset:hover { border-color: var(--accent); }
.swatch { width: 1.4rem; height: 1.4rem; border-radius: 50%; border: 1px solid var(--border); display: inline-flex; align-items: center; justify-content: center; }
.swatch i { width: 0.65rem; height: 0.65rem; border-radius: 50%; }
.color-field { display: flex; gap: 0.5rem; align-items: center; }
.color-field input[type=color] { width: 2.6rem; height: 2.4rem; padding: 0.15rem; border: 1px solid var(--border); border-radius: 8px; background: var(--bg); flex-shrink: 0; cursor: pointer; }
.theme-preview { border: 1px solid var(--p-border); border-radius: 12px; overflow: hidden; background: var(--p-bg); color: var(--p-text); margin: 0.25rem 0 0.75rem; font-size: 0.9rem; max-width: 420px; }
.tp-bar { padding: 0.5rem 0.8rem; font-weight: 700; background: var(--p-surface); border-bottom: 1px solid var(--p-border); }
.tp-body { padding: 0.8rem; display: flex; flex-direction: column; gap: 0.5rem; }
.tp-user { align-self: flex-end; background: var(--p-accent); color: var(--p-accent-text); padding: 0.45rem 0.7rem; border-radius: 12px 12px 4px 12px; }
.tp-bot { align-self: flex-start; background: var(--p-surface); border: 1px solid var(--p-border); padding: 0.45rem 0.7rem; border-radius: 12px 12px 12px 4px; }
.tp-chip { display: inline-block; min-width: 1.3em; margin-left: 0.15em; font-size: 0.72rem; font-weight: 600; text-align: center; color: var(--p-accent); background: var(--p-soft); border: 1px solid var(--p-accent); border-radius: 999px; }
.tp-ask { display: flex; gap: 0.4rem; align-items: center; margin-top: 0.3rem; }
.tp-ask span { flex: 1; padding: 0.4rem 0.6rem; border: 1px solid var(--p-border); border-radius: 8px; opacity: 0.7; }
.tp-ask b { background: var(--p-accent); color: var(--p-accent-text); padding: 0.4rem 0.8rem; border-radius: 8px; }
.usage-card .usage { justify-content: space-between; }
.usage-card .msg { margin: 0.75rem 0 0; }
.usage-card p.muted { margin: 0.4rem 0 0; }