:root {
  --mb-blue: #1055a5; --mb-blue-dark: #0b3d78; --mb-ink: #1f2933; --mb-muted: #5b6770;
  --mb-bg: #ffffff; --mb-soft: #f2f6fb; --mb-line: #d9e2ec; --mb-user: #1055a5; --mb-user-ink: #fff;
  --mb-warn: #fff8e6;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root { --mb-ink: #e6edf3; --mb-muted: #9aa7b2; --mb-bg: #12171d; --mb-soft: #1b232c; --mb-line: #2c3846; --mb-blue: #5aa2f0; --mb-user: #1d5fb0; --mb-warn: #3a3118; }
}
* { box-sizing: border-box; }
.mb-body { margin: 0; font: 15px/1.45 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; color: var(--mb-ink); background: var(--mb-bg); }
.mb-sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* page layouts */
.mb-fill { height: 100vh; height: 100dvh; }
.mb-fill .mb-chat { height: 100%; }
.mb-page main { max-width: 760px; margin: 0 auto; padding: 24px 16px 48px; }
.mb-page h1 { color: var(--mb-blue); margin: 0 0 4px; font-size: 1.6rem; }
.mb-page pre { background: var(--mb-soft); padding: 10px 12px; border-radius: 8px; overflow: auto; }
.mb-lede { color: var(--mb-muted); margin: 0 0 16px; }
.mb-window {
  width: 420px; height: 600px; min-width: 300px; min-height: 360px; max-width: 100%; max-height: 90vh;
  resize: both; overflow: hidden; border: 1px solid var(--mb-line); border-radius: 12px;
  box-shadow: 0 6px 24px rgba(0, 0, 0, .12);
}
.mb-window .mb-chat { height: 100%; }

/* chat */
.mb-chat { display: flex; flex-direction: column; min-height: 0; background: var(--mb-bg); }
.mb-head { display: flex; align-items: center; justify-content: space-between; padding: 10px 12px; background: var(--mb-blue-dark); color: #fff; }
.mb-chat[data-mode="frame"] .mb-head { display: none; } /* embed.js draws its own title bar */
.mb-title { font-weight: 600; }
.mb-icon { background: none; border: 0; color: inherit; cursor: pointer; font-size: 1rem; padding: 4px 8px; border-radius: 6px; }
.mb-icon:hover, .mb-icon:focus-visible { background: rgba(127, 127, 127, .2); }
.mb-audience { display: flex; gap: 6px; align-items: center; padding: 6px 12px; border-bottom: 1px solid var(--mb-line); font-size: .8rem; color: var(--mb-muted); }
.mb-audience select { flex: 1; min-width: 0; font: inherit; padding: 3px 4px; background: var(--mb-bg); color: var(--mb-ink); border: 1px solid var(--mb-line); border-radius: 6px; }
.mb-msgs { flex: 1; overflow-y: auto; padding: 12px; display: flex; flex-direction: column; gap: 10px; }
.mb-msg { max-width: 92%; }
.mb-user { align-self: flex-end; }
.mb-bubble { padding: 8px 12px; border-radius: 14px; background: var(--mb-soft); overflow-wrap: anywhere; }
.mb-user .mb-bubble { background: var(--mb-user); color: var(--mb-user-ink); white-space: pre-wrap; }
.mb-bubble p { margin: 0 0 .5em; } .mb-bubble p:last-child { margin-bottom: 0; }
.mb-bubble ul { margin: .25em 0 .5em; padding-left: 1.2em; }
.mb-bubble a { color: var(--mb-blue); }
.mb-cite { color: var(--mb-blue); cursor: pointer; font-weight: 600; margin: 0 1px; }
.mb-error .mb-bubble { background: var(--mb-warn); }
.mb-sources { font-size: .8rem; margin: 4px 4px 0; color: var(--mb-muted); }
.mb-sources summary { cursor: pointer; }
.mb-sources ol { margin: 4px 0 0; padding-left: 1.4em; }
.mb-where { color: var(--mb-muted); }
.mb-flash { background: var(--mb-warn); }
.mb-contact { margin: 6px 4px 0; padding: 6px 10px; background: var(--mb-warn); border-radius: 8px; font-size: .82rem; }
.mb-feedback { margin: 2px 2px 0; font-size: .75rem; color: var(--mb-muted); }
.mb-feedback .mb-icon { color: var(--mb-muted); filter: grayscale(1); opacity: .7; padding: 2px 6px; }
.mb-caveat { margin: 2px 4px 0; font-size: .72rem; color: var(--mb-muted); }
.mb-suggest { display: flex; flex-wrap: wrap; gap: 6px; padding: 0 12px 8px; }
.mb-suggest[hidden] { display: none; }
.mb-chip { font: inherit; font-size: .8rem; padding: 5px 10px; border-radius: 999px; border: 1px solid var(--mb-line); background: var(--mb-bg); color: var(--mb-blue); cursor: pointer; }
.mb-chip:hover { background: var(--mb-soft); }
.mb-form { display: flex; gap: 6px; padding: 8px 12px; border-top: 1px solid var(--mb-line); align-items: flex-end; }
.mb-form textarea { flex: 1; resize: none; font: inherit; padding: 8px 10px; border: 1px solid var(--mb-line); border-radius: 10px; background: var(--mb-bg); color: var(--mb-ink); max-height: 110px; }
.mb-form button { border: 0; background: var(--mb-blue-dark); color: #fff; border-radius: 10px; padding: 0 14px; height: 38px; cursor: pointer; font-size: 1rem; }
.mb-form button:disabled { opacity: .5; cursor: progress; }
.mb-foot { padding: 4px 12px 8px; font-size: .7rem; color: var(--mb-muted); text-align: center; }
:focus-visible { outline: 2px solid var(--mb-blue); outline-offset: 1px; }
.mb-typing i { display: inline-block; width: 6px; height: 6px; margin: 0 2px; border-radius: 50%; background: var(--mb-muted); animation: mb-b 1s infinite; }
.mb-typing i:nth-child(2) { animation-delay: .15s; } .mb-typing i:nth-child(3) { animation-delay: .3s; }
@keyframes mb-b { 0%, 80%, 100% { opacity: .3; } 40% { opacity: 1; } }
@media (prefers-reduced-motion: reduce) { .mb-typing i { animation: none; } }
@media (max-width: 520px) { .mb-window { width: 100%; resize: none; height: 80vh; } }