/* Bot kit UI. A shell themes it by setting the --bk-* tokens in public/brand.css; nothing here names a brand.
   Rules from David's design preferences: 16px text floor, full borders (never a one-sided stripe),
   hover lift + glow on every bordered surface, purposeful motion, reduced motion respected, no monospace
   except real code. */

:root {
  --bk-accent: #155eef;
  --bk-accent-ink: #ffffff;
  --bk-accent-soft: color-mix(in srgb, var(--bk-accent) 12%, transparent);
  --bk-bg: #ffffff;
  --bk-surface: #f5f7fa;
  --bk-surface-2: #eef1f6;
  --bk-border: #dde2ea;
  --bk-border-strong: #c5ccd8;
  --bk-text: #141a24;
  --bk-muted: #5a6475;
  --bk-user-bg: var(--bk-accent);
  --bk-user-ink: var(--bk-accent-ink);
  --bk-font: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --bk-font-display: var(--bk-font);
  --bk-radius: 18px;
  --bk-radius-sm: 12px;
  --bk-panel-w: 440px;
  --bk-panel-w-wide: 760px;
  --bk-glow: 0 0 0 1px color-mix(in srgb, var(--bk-accent) 35%, transparent), 0 8px 28px -8px color-mix(in srgb, var(--bk-accent) 45%, transparent);
  --bk-shadow: 0 1px 2px rgba(16, 24, 40, 0.06), 0 12px 40px -12px rgba(16, 24, 40, 0.22);
  --bk-ease: cubic-bezier(0.22, 1, 0.36, 1);
  --bk-fast: 160ms;
  --bk-med: 260ms;
  --bk-good: #12805c;
  --bk-warn: #b54708;
  --bk-bad: #c01048;
}

.bk-root, .bk-launcher { font-family: var(--bk-font); color: var(--bk-text); font-size: 16px; line-height: 1.55; -webkit-font-smoothing: antialiased; }
.bk-root *, .bk-root *::before, .bk-root *::after, .bk-launcher * { box-sizing: border-box; }
.bk-ico { width: 20px; height: 20px; flex: none; }
.bk-root [hidden] { display: none !important; }

/* ---------- buttons ---------- */
.bk-icon-btn {
  display: inline-grid; place-items: center; width: 38px; height: 38px; border-radius: 10px;
  border: 1px solid transparent; background: transparent; color: var(--bk-muted); cursor: pointer;
  transition: background var(--bk-fast), color var(--bk-fast), border-color var(--bk-fast), transform var(--bk-fast), box-shadow var(--bk-fast);
}
.bk-icon-btn:hover { background: var(--bk-surface); color: var(--bk-text); border-color: var(--bk-border); transform: translateY(-1px); }
.bk-icon-btn:active { transform: translateY(0); }
.bk-icon-btn[aria-expanded="true"] { background: var(--bk-accent-soft); color: var(--bk-accent); border-color: color-mix(in srgb, var(--bk-accent) 35%, transparent); }
.bk-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 40px; padding: 8px 16px;
  border-radius: 999px; border: 1px solid var(--bk-border-strong); background: var(--bk-bg); color: var(--bk-text);
  font: 600 15px/1.2 var(--bk-font); cursor: pointer;
  transition: transform var(--bk-fast), box-shadow var(--bk-fast), background var(--bk-fast), border-color var(--bk-fast);
}
.bk-btn:hover { transform: translateY(-1px); box-shadow: var(--bk-glow); border-color: var(--bk-accent); }
.bk-btn:active { transform: translateY(0); box-shadow: none; }
.bk-btn-primary { background: var(--bk-accent); color: var(--bk-accent-ink); border-color: var(--bk-accent); }
.bk-btn-primary:hover { filter: brightness(1.06); }
.bk-btn.is-done { background: var(--bk-good); border-color: var(--bk-good); color: #fff; }
.bk-root :focus-visible, .bk-launcher:focus-visible { outline: 2px solid var(--bk-accent); outline-offset: 2px; }

/* ---------- launcher (panel layout) ---------- */
.bk-launcher {
  position: fixed; right: 24px; bottom: 24px; z-index: 2147482000; display: inline-flex; align-items: center; gap: 10px;
  padding: 14px 20px 14px 16px; border-radius: 999px; border: 1px solid color-mix(in srgb, var(--bk-accent) 60%, #000 0%);
  background: var(--bk-accent); color: var(--bk-accent-ink); font: 600 16px/1 var(--bk-font); cursor: pointer;
  box-shadow: var(--bk-shadow), var(--bk-glow);
  transition: transform var(--bk-med) var(--bk-ease), opacity var(--bk-med), box-shadow var(--bk-fast);
  animation: bk-pop 500ms var(--bk-ease) both 300ms;
}
.bk-launcher .bk-ico { width: 22px; height: 22px; }
.bk-launcher:hover { transform: translateY(-2px) scale(1.02); }
html.bk-panel-open .bk-launcher { opacity: 0; transform: translateY(12px) scale(0.9); pointer-events: none; }

/* ---------- panel layout ---------- */
.bk-panel {
  position: fixed; top: 12px; right: 12px; bottom: 12px; width: min(var(--bk-panel-w), calc(100vw - 24px)); z-index: 2147482001;
  transform: translateX(calc(100% + 24px)); opacity: 0; visibility: hidden;
  transition: transform var(--bk-med) var(--bk-ease), opacity var(--bk-med), visibility 0s linear var(--bk-med), width var(--bk-med) var(--bk-ease);
}
.bk-panel[data-open="true"] { transform: none; opacity: 1; visibility: visible; transition-delay: 0s; }
.bk-panel.bk-wide { width: min(var(--bk-panel-w-wide), calc(100vw - 24px)); }
.bk-panel .bk-main {
  position: relative; display: flex; flex-direction: column; height: 100%; background: var(--bk-bg);
  border: 1px solid var(--bk-border); border-radius: var(--bk-radius); box-shadow: var(--bk-shadow); overflow: hidden;
}

/* ---------- page layout ---------- */
.bk-page { display: grid; grid-template-columns: var(--bk-side-w, 300px) 1fr; grid-template-rows: minmax(0, 1fr); height: 100dvh; background: var(--bk-surface); }
.bk-page .bk-main { display: flex; flex-direction: column; min-width: 0; min-height: 0; height: 100dvh; background: var(--bk-bg); border-left: 1px solid var(--bk-border); }
.bk-page .bk-body, .bk-page .bk-foot > *, .bk-page .bk-history { width: 100%; }
.bk-page .bk-log, .bk-page .bk-empty, .bk-page .bk-form, .bk-page .bk-meta, .bk-page .bk-disclaimer { max-width: 800px; margin-inline: auto; }
.bk-side { display: flex; flex-direction: column; gap: 14px; padding: 20px 16px; background: var(--bk-surface); overflow-y: auto; }
.bk-side-brand { display: flex; align-items: center; gap: 12px; padding: 4px 6px 10px; }
.bk-side-brand strong { display: block; font: 700 18px/1.2 var(--bk-font-display); }
.bk-side-brand span { display: block; color: var(--bk-muted); font-size: 15px; }
.bk-side-new { width: 100%; border-radius: var(--bk-radius-sm); }
.bk-side-label { margin-top: 8px; color: var(--bk-muted); font-size: 14px; font-weight: 600; letter-spacing: 0.02em; text-transform: uppercase; padding-inline: 6px; }
.bk-side-note { margin-top: auto; color: var(--bk-muted); font-size: 15px; padding: 12px; border: 1px solid var(--bk-border); border-radius: var(--bk-radius-sm); background: var(--bk-bg); }
.bk-menu-btn { display: none; }

/* ---------- header ---------- */
.bk-head { display: flex; align-items: center; gap: 10px; padding: 14px 14px 12px 18px; border-bottom: 1px solid var(--bk-border); background: var(--bk-bg); }
.bk-title { display: flex; align-items: center; gap: 12px; min-width: 0; margin-right: auto; }
.bk-title > div { min-width: 0; }
.bk-panel .bk-head { flex-wrap: wrap; row-gap: 10px; }
.bk-panel .bk-title { flex: 1 1 0; }
.bk-panel .bk-modes { order: 3; }
.bk-panel .bk-head::after { content: ""; order: 2; flex-basis: 100%; height: 0; }
.bk-panel .bk-modes button { padding: 7px 14px; }
.bk-title strong { display: block; font: 700 18px/1.2 var(--bk-font-display); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bk-title span { display: block; color: var(--bk-muted); font-size: 14px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bk-avatar { width: 40px; height: 40px; border-radius: 12px; object-fit: cover; flex: none; border: 1px solid var(--bk-border); background: var(--bk-surface); }
.bk-avatar-fallback { display: inline-grid; place-items: center; color: var(--bk-accent); background: var(--bk-accent-soft); }
.bk-actions { display: flex; gap: 2px; }
.bk-modes { display: inline-flex; padding: 3px; border-radius: 999px; border: 1px solid var(--bk-border); background: var(--bk-surface); }
.bk-modes button {
  border: 0; background: transparent; color: var(--bk-muted); font: 600 14px/1 var(--bk-font); padding: 8px 12px; border-radius: 999px; cursor: pointer;
  transition: background var(--bk-fast), color var(--bk-fast), box-shadow var(--bk-fast);
}
.bk-modes button:hover { color: var(--bk-text); }
.bk-modes button[aria-checked="true"] { background: var(--bk-accent); color: var(--bk-accent-ink); box-shadow: 0 2px 10px -2px color-mix(in srgb, var(--bk-accent) 60%, transparent); }

/* ---------- history ---------- */
.bk-history {
  position: absolute; top: 68px; left: 12px; right: 12px; z-index: 5; max-height: 55%; overflow-y: auto; padding: 8px;
  background: var(--bk-bg); border: 1px solid var(--bk-border); border-radius: var(--bk-radius-sm); box-shadow: var(--bk-shadow);
  animation: bk-drop var(--bk-fast) var(--bk-ease);
}
.bk-hist-item { display: flex; align-items: center; gap: 4px; border-radius: 10px; border: 1px solid transparent; transition: background var(--bk-fast), border-color var(--bk-fast); }
.bk-hist-item:hover, .bk-hist-item.is-active { background: var(--bk-accent-soft); border-color: color-mix(in srgb, var(--bk-accent) 25%, transparent); }
.bk-hist-open { flex: 1; min-width: 0; text-align: left; border: 0; background: none; color: var(--bk-text); font: 500 15px/1.35 var(--bk-font); padding: 10px 10px; cursor: pointer; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bk-hist-open small { display: block; color: var(--bk-muted); font-size: 13px; }
.bk-hist-del { opacity: 0; width: 32px; height: 32px; }
.bk-hist-item:hover .bk-hist-del, .bk-hist-del:focus-visible { opacity: 1; }
.bk-hist-empty { margin: 8px; color: var(--bk-muted); font-size: 15px; }

/* ---------- body + messages ---------- */
.bk-body { flex: 1; overflow-y: auto; padding: 20px 18px 8px; scroll-behavior: smooth; overscroll-behavior: contain; }
.bk-empty { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 10px; padding: 32px 4px 16px; animation: bk-rise 420ms var(--bk-ease) both; }
.bk-body.has-messages .bk-empty { display: none; }
.bk-empty-avatar .bk-avatar { width: 64px; height: 64px; border-radius: 20px; box-shadow: var(--bk-glow); }
.bk-empty h3 { margin: 6px 0 0; font: 700 22px/1.3 var(--bk-font-display); max-width: 30ch; }
.bk-empty p { margin: 0; color: var(--bk-muted); max-width: 42ch; }
.bk-starters { display: flex; flex-direction: column; gap: 8px; width: 100%; max-width: 420px; margin-top: 14px; }
.bk-page .bk-starters { display: grid; grid-template-columns: 1fr 1fr; max-width: 680px; }
.bk-starter {
  text-align: left; padding: 12px 16px; border-radius: var(--bk-radius-sm); border: 1px solid var(--bk-border); background: var(--bk-bg);
  color: var(--bk-text); font: 500 15.5px/1.4 var(--bk-font); cursor: pointer;
  transition: transform var(--bk-fast), box-shadow var(--bk-fast), border-color var(--bk-fast);
  animation: bk-rise 420ms var(--bk-ease) both;
}
.bk-starter:nth-child(2) { animation-delay: 60ms; } .bk-starter:nth-child(3) { animation-delay: 120ms; } .bk-starter:nth-child(4) { animation-delay: 180ms; }
.bk-starter:hover { transform: translateY(-2px); border-color: var(--bk-accent); box-shadow: var(--bk-glow); }

.bk-log { display: flex; flex-direction: column; gap: 18px; }
.bk-msg { display: flex; gap: 10px; animation: bk-rise 280ms var(--bk-ease) both; }
.bk-user { justify-content: flex-end; }
.bk-bubble {
  max-width: 82%; padding: 11px 16px; border-radius: 18px 18px 6px 18px; background: var(--bk-user-bg); color: var(--bk-user-ink);
  white-space: pre-wrap; overflow-wrap: anywhere;
}
.bk-user.is-failed .bk-bubble { opacity: 0.6; }
.bk-msg-avatar .bk-avatar { width: 32px; height: 32px; border-radius: 10px; }
.bk-msg-main { flex: 1; min-width: 0; }
.bk-md { overflow-wrap: anywhere; }
.bk-md > :first-child { margin-top: 2px; }
.bk-md p { margin: 0 0 10px; }
.bk-md ul, .bk-md ol { margin: 0 0 10px; padding-left: 22px; }
.bk-md li { margin: 4px 0; }
.bk-md h4 { margin: 14px 0 6px; font: 700 17px/1.3 var(--bk-font-display); }
.bk-md a { color: var(--bk-accent); text-underline-offset: 3px; }
.bk-md code { font-family: ui-monospace, "Cascadia Code", Consolas, monospace; font-size: 0.9em; padding: 2px 6px; border-radius: 6px; background: var(--bk-surface-2); border: 1px solid var(--bk-border); }
.bk-md pre { margin: 0 0 10px; padding: 12px 14px; overflow-x: auto; border-radius: var(--bk-radius-sm); background: var(--bk-surface-2); border: 1px solid var(--bk-border); }
.bk-md pre code { padding: 0; border: 0; background: none; }
.bk-md strong { font-weight: 650; }
.bk-caret { display: inline-block; width: 8px; height: 1.05em; margin-left: 2px; vertical-align: -2px; border-radius: 2px; background: var(--bk-accent); animation: bk-blink 1s steps(2) infinite; }
.bk-cite {
  display: inline-grid; place-items: center; min-width: 22px; height: 22px; margin: 0 2px; padding: 0 6px; vertical-align: 2px;
  border-radius: 999px; border: 1px solid color-mix(in srgb, var(--bk-accent) 40%, transparent); background: var(--bk-accent-soft); color: var(--bk-accent);
  font: 700 12.5px/1 var(--bk-font); cursor: pointer; transition: transform var(--bk-fast), box-shadow var(--bk-fast);
}
.bk-cite:hover { transform: translateY(-1px); box-shadow: var(--bk-glow); }

.bk-typing { display: inline-flex; gap: 5px; padding: 12px 2px; }
.bk-typing i { width: 8px; height: 8px; border-radius: 50%; background: var(--bk-muted); opacity: 0.4; animation: bk-dot 1.1s infinite var(--bk-ease); }
.bk-typing i:nth-child(2) { animation-delay: 0.15s; } .bk-typing i:nth-child(3) { animation-delay: 0.3s; }
.bk-status { display: inline-flex; align-items: center; gap: 10px; margin: 2px 0 10px; padding: 7px 14px; border-radius: 999px; border: 1px solid var(--bk-border); background: var(--bk-surface); color: var(--bk-muted); font-size: 15px; }
.bk-spin { width: 14px; height: 14px; border-radius: 50%; border: 2px solid var(--bk-border-strong); border-top-color: var(--bk-accent); animation: bk-spin 0.7s linear infinite; }

.bk-sources { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin-top: 6px; }
.bk-sources-label { color: var(--bk-muted); font-size: 14px; font-weight: 600; margin-right: 2px; }
.bk-source {
  display: inline-flex; align-items: center; gap: 7px; max-width: 100%; padding: 5px 12px 5px 6px; border-radius: 999px;
  border: 1px solid var(--bk-border); background: var(--bk-bg); color: var(--bk-text); font-size: 14px; text-decoration: none;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis; transition: transform var(--bk-fast), box-shadow var(--bk-fast), border-color var(--bk-fast);
}
.bk-source b { display: inline-grid; place-items: center; min-width: 20px; height: 20px; border-radius: 999px; background: var(--bk-accent-soft); color: var(--bk-accent); font-size: 12px; }
.bk-source small { color: var(--bk-muted); font-size: 13px; }
a.bk-source:hover { transform: translateY(-1px); border-color: var(--bk-accent); box-shadow: var(--bk-glow); }
.bk-source.is-flash { animation: bk-flash 900ms var(--bk-ease); }
.bk-msg-tools { display: flex; gap: 2px; margin-top: 4px; opacity: 0; transition: opacity var(--bk-fast); }
.bk-msg-tools .bk-icon-btn { width: 32px; height: 32px; }
.bk-msg-tools .bk-ico { width: 17px; height: 17px; }
.bk-bot:hover .bk-msg-tools, .bk-bot:focus-within .bk-msg-tools { opacity: 1; }

.bk-system { justify-content: center; }
.bk-notice { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 10px; padding: 10px 16px; border-radius: var(--bk-radius-sm); border: 1px solid var(--bk-border); background: var(--bk-surface); color: var(--bk-text); font-size: 15px; text-align: center; }
.bk-notice[data-tone="warn"] { border-color: color-mix(in srgb, var(--bk-warn) 40%, transparent); background: color-mix(in srgb, var(--bk-warn) 8%, var(--bk-bg)); }
.bk-notice[data-tone="limit"] { border-color: color-mix(in srgb, var(--bk-accent) 40%, transparent); background: var(--bk-accent-soft); }
.bk-retry { min-height: 34px; padding: 6px 12px; font-size: 14px; }
.bk-retry .bk-ico { width: 16px; height: 16px; }

/* ---------- blocks ---------- */
.bk-blocks { display: flex; flex-direction: column; gap: 12px; }
.bk-blocks:not(:empty) { margin: 6px 0 10px; }
.bk-block-title { font: 700 16px/1.3 var(--bk-font-display); margin-bottom: 8px; }
.bk-enter { animation: bk-rise 360ms var(--bk-ease) both; }
.bk-cards-row { display: grid; grid-auto-flow: column; grid-auto-columns: minmax(200px, 72%); gap: 12px; overflow-x: auto; padding: 2px 2px 8px; scroll-snap-type: x mandatory; }
.bk-wide .bk-cards-row, .bk-page .bk-cards-row { grid-auto-flow: row; grid-template-columns: repeat(auto-fill, minmax(210px, 1fr)); overflow: visible; }
.bk-card {
  display: flex; flex-direction: column; scroll-snap-align: start; border: 1px solid var(--bk-border); border-radius: var(--bk-radius-sm);
  background: var(--bk-bg); overflow: hidden; transition: transform var(--bk-fast), box-shadow var(--bk-fast), border-color var(--bk-fast);
}
.bk-card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--bk-accent) 55%, var(--bk-border)); box-shadow: var(--bk-glow); }
.bk-card-media { aspect-ratio: 4 / 3; background: var(--bk-surface); overflow: hidden; }
.bk-card-media img { width: 100%; height: 100%; object-fit: cover; transition: transform 500ms var(--bk-ease); }
.bk-card:hover .bk-card-media img { transform: scale(1.04); }
.bk-card-body { display: flex; flex-direction: column; gap: 6px; padding: 12px 14px 14px; flex: 1; }
.bk-card h5 { margin: 0; font: 650 16px/1.3 var(--bk-font-display); }
.bk-card p { margin: 0; color: var(--bk-muted); font-size: 15px; line-height: 1.45; }
.bk-card-foot { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-top: auto; padding-top: 4px; }
.bk-price { font-size: 17px; font-variant-numeric: tabular-nums; }
.bk-rating { color: var(--bk-muted); font-size: 14px; font-variant-numeric: tabular-nums; }
.bk-badge { align-self: flex-start; padding: 3px 10px; border-radius: 999px; border: 1px solid color-mix(in srgb, var(--bk-accent) 35%, transparent); background: var(--bk-accent-soft); color: var(--bk-accent); font-size: 13px; font-weight: 650; }
.bk-card-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.bk-card-actions .bk-btn { flex: 1; min-height: 38px; padding: 7px 12px; font-size: 14.5px; }

.bk-summary { padding: 16px 18px; border: 1px solid var(--bk-border); border-radius: var(--bk-radius-sm); background: var(--bk-bg); box-shadow: var(--bk-shadow); transition: transform var(--bk-fast), box-shadow var(--bk-fast); }
.bk-summary:hover { transform: translateY(-2px); box-shadow: var(--bk-shadow), var(--bk-glow); }
.bk-summary-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; margin-bottom: 8px; }
.bk-summary-sub { margin: -4px 0 0; color: var(--bk-muted); font-size: 15px; }
.bk-status-pill { flex: none; padding: 4px 12px; border-radius: 999px; font-size: 13.5px; font-weight: 700; border: 1px solid; }
.bk-status-pill[data-tone="good"] { color: var(--bk-good); border-color: color-mix(in srgb, var(--bk-good) 40%, transparent); background: color-mix(in srgb, var(--bk-good) 10%, transparent); }
.bk-status-pill[data-tone="warn"] { color: var(--bk-warn); border-color: color-mix(in srgb, var(--bk-warn) 40%, transparent); background: color-mix(in srgb, var(--bk-warn) 10%, transparent); }
.bk-status-pill[data-tone="bad"] { color: var(--bk-bad); border-color: color-mix(in srgb, var(--bk-bad) 40%, transparent); background: color-mix(in srgb, var(--bk-bad) 10%, transparent); }
.bk-summary dl { margin: 0; display: grid; gap: 0; }
.bk-summary dl > div { display: grid; grid-template-columns: minmax(110px, 38%) 1fr; gap: 12px; padding: 9px 0; border-top: 1px solid var(--bk-border); }
.bk-summary dt { color: var(--bk-muted); font-size: 15px; }
.bk-summary dd { margin: 0; font-size: 15.5px; font-weight: 550; }
.bk-summary-note { margin: 10px 0 0; padding: 10px 12px; border-radius: 10px; background: var(--bk-surface); border: 1px solid var(--bk-border); color: var(--bk-muted); font-size: 15px; }

.bk-steps ol { list-style: none; counter-reset: s; margin: 0; padding: 0; display: grid; gap: 8px; }
.bk-steps li { counter-increment: s; display: flex; gap: 12px; align-items: flex-start; padding: 10px 12px; border: 1px solid var(--bk-border); border-radius: 12px; background: var(--bk-bg); }
.bk-steps li::before { content: counter(s); flex: none; display: grid; place-items: center; width: 26px; height: 26px; border-radius: 50%; background: var(--bk-accent); color: var(--bk-accent-ink); font-weight: 700; font-size: 14px; }

.bk-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.bk-chip {
  padding: 9px 16px; border-radius: 999px; border: 1px solid var(--bk-border-strong); background: var(--bk-bg); color: var(--bk-text);
  font: 550 15px/1.2 var(--bk-font); cursor: pointer; transition: transform var(--bk-fast), box-shadow var(--bk-fast), border-color var(--bk-fast), background var(--bk-fast);
}
.bk-chip:hover:not(:disabled) { transform: translateY(-1px); border-color: var(--bk-accent); box-shadow: var(--bk-glow); }
.bk-chip:disabled { cursor: default; opacity: 0.5; }
.bk-chip.is-picked { opacity: 1; background: var(--bk-accent); color: var(--bk-accent-ink); border-color: var(--bk-accent); }

/* ---------- composer ---------- */
.bk-foot { padding: 10px 16px 12px; border-top: 1px solid var(--bk-border); background: var(--bk-bg); }
.bk-form { display: flex; align-items: flex-end; gap: 10px; }
.bk-form textarea {
  flex: 1; resize: none; min-height: 50px; max-height: 180px; padding: 13px 16px; border-radius: 16px; border: 1px solid var(--bk-border-strong);
  background: var(--bk-surface); color: var(--bk-text); font: 16px/1.45 var(--bk-font); outline: none;
  transition: border-color var(--bk-fast), box-shadow var(--bk-fast), background var(--bk-fast);
}
.bk-form textarea::placeholder { color: var(--bk-muted); }
.bk-form textarea:focus { border-color: var(--bk-accent); background: var(--bk-bg); box-shadow: 0 0 0 4px var(--bk-accent-soft); }
.bk-send {
  flex: none; display: grid; place-items: center; width: 50px; height: 50px; border-radius: 50%; border: 1px solid var(--bk-accent);
  background: var(--bk-accent); color: var(--bk-accent-ink); cursor: pointer; box-shadow: var(--bk-glow);
  transition: transform var(--bk-fast), filter var(--bk-fast), opacity var(--bk-fast);
}
.bk-send:hover:not(:disabled) { transform: translateY(-1px) scale(1.04); filter: brightness(1.06); }
.bk-send:disabled { opacity: 0.55; cursor: progress; box-shadow: none; }
.bk-meta { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-top: 8px; font-size: 14px; color: var(--bk-muted); }
.bk-full-link { color: var(--bk-accent); font-weight: 600; text-decoration: none; }
.bk-full-link:hover { text-decoration: underline; text-underline-offset: 3px; }
.bk-remaining[data-low="true"] { color: var(--bk-warn); font-weight: 600; }
.bk-disclaimer { margin: 4px 0 0; color: var(--bk-muted); font-size: 13.5px; line-height: 1.4; }

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .bk-page { grid-template-columns: 1fr; }
  .bk-page .bk-side { position: fixed; inset: 0 auto 0 0; width: min(320px, 86vw); z-index: 20; transform: translateX(-100%); transition: transform var(--bk-med) var(--bk-ease); box-shadow: var(--bk-shadow); }
  .bk-page.bk-side-open .bk-side { transform: none; }
  .bk-menu-btn { display: inline-grid; }
  .bk-page .bk-main { border-left: 0; }
  .bk-page .bk-starters { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .bk-panel, .bk-panel.bk-wide { top: 0; right: 0; bottom: 0; width: 100vw; }
  .bk-panel .bk-main { border-radius: 0; border: 0; }
  .bk-expand-btn { display: none; }
  .bk-launcher { right: 16px; bottom: 16px; }
  .bk-launcher span { display: none; }
  .bk-launcher { padding: 16px; }
  .bk-head { padding: 12px 10px 10px 14px; flex-wrap: wrap; }
  .bk-modes { order: 3; width: 100%; justify-content: center; }
  .bk-modes button { flex: 1; }
  .bk-bubble { max-width: 90%; }
  .bk-page .bk-title { flex: 1 1 0; }
  .bk-page .bk-actions { order: 2; }
}

/* ---------- motion ---------- */
@keyframes bk-rise { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
@keyframes bk-pop { from { opacity: 0; transform: translateY(16px) scale(0.92); } to { opacity: 1; transform: none; } }
@keyframes bk-drop { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }
@keyframes bk-dot { 0%, 80%, 100% { opacity: 0.25; transform: translateY(0); } 40% { opacity: 1; transform: translateY(-4px); } }
@keyframes bk-blink { 50% { opacity: 0; } }
@keyframes bk-spin { to { transform: rotate(360deg); } }
@keyframes bk-flash { 0% { box-shadow: 0 0 0 0 var(--bk-accent); } 100% { box-shadow: 0 0 0 10px transparent; } }
@media (prefers-reduced-motion: reduce) {
  .bk-root *, .bk-launcher, .bk-panel { animation: none !important; transition-duration: 0ms !important; }
  .bk-body { scroll-behavior: auto; }
}