:root {
  --bg: #f4f6fb;
  --surface: #ffffff;
  --surface-2: #f0f3f9;
  --border: #dfe4ee;
  --text: #161d2b;
  --text-muted: #5d6880;
  --brand: #0b5fff;
  --brand-soft: #e8f0ff;
  --bot-bubble: #ffffff;
  --customer-bubble: #0b5fff;
  --customer-text: #ffffff;
  --warn-bg: #fff4e5;
  --warn-border: #f0a92c;
  --warn-text: #7a4a00;
  --danger: #c0392b;
  --ok: #1f9254;
  --radius: 12px;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.06), 0 4px 12px rgba(16, 24, 40, 0.05);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1420;
    --surface: #171d2b;
    --surface-2: #1e2536;
    --border: #2a3244;
    --text: #e8ecf5;
    --text-muted: #9aa5bd;
    --brand: #5b8dff;
    --brand-soft: #1c2740;
    --bot-bubble: #1e2536;
    --customer-bubble: #3b6fe0;
    --customer-text: #ffffff;
    --warn-bg: #33270f;
    --warn-border: #b5811f;
    --warn-text: #ffd79a;
    --danger: #ef6a5c;
    --ok: #4ec27f;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 4px 14px rgba(0, 0, 0, 0.25);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family:
    system-ui,
    -apple-system,
    'Segoe UI',
    Roboto,
    'Helvetica Neue',
    Arial,
    sans-serif;
  font-size: 15px;
  line-height: 1.5;
}

.app {
  max-width: 860px;
  margin: 0 auto;
  padding: 20px 16px 40px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-height: 100vh;
}

/* ---------- masthead ---------- */

.masthead {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand__mark {
  width: 42px;
  height: 42px;
  border-radius: 11px;
  background: var(--brand);
  color: #fff;
  display: grid;
  place-items: center;
  font-weight: 700;
  letter-spacing: 0.5px;
  flex: none;
}

.brand__text h1 {
  margin: 0;
  font-size: 19px;
  letter-spacing: -0.2px;
}

.brand__text p {
  margin: 1px 0 0;
  font-size: 12.5px;
  color: var(--text-muted);
}

.masthead__meta {
  display: flex;
  align-items: center;
  gap: 8px;
}

.pill {
  font-size: 11.5px;
  font-weight: 600;
  padding: 4px 9px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--text-muted);
  border: 1px solid var(--border);
  white-space: nowrap;
}

.pill--phase {
  background: var(--brand-soft);
  color: var(--brand);
  border-color: transparent;
}

.status-dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--text-muted);
  flex: none;
}

.status-dot.is-ok {
  background: var(--ok);
}

.status-dot.is-down {
  background: var(--danger);
}

/* ---------- controls ---------- */

.controls {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  box-shadow: var(--shadow);
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.control-group--end {
  flex-direction: row;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.control-label {
  font-size: 11.5px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-muted);
}

.segmented {
  display: inline-flex;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 9px;
  padding: 3px;
  gap: 2px;
}

.segmented__item {
  border: 0;
  background: transparent;
  color: var(--text-muted);
  font: inherit;
  font-size: 13.5px;
  font-weight: 600;
  padding: 6px 14px;
  border-radius: 7px;
  cursor: pointer;
}

.segmented__item:hover {
  color: var(--text);
}

.segmented__item.is-active {
  background: var(--surface);
  color: var(--brand);
  box-shadow: var(--shadow);
}

.checkbox {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  font-size: 13.5px;
  color: var(--text-muted);
  cursor: pointer;
  user-select: none;
}

.btn {
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  border-radius: 9px;
  padding: 9px 18px;
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn--primary {
  background: var(--brand);
  color: #fff;
}

.btn--primary:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.btn--ghost {
  background: var(--surface);
  border-color: var(--border);
  color: var(--text-muted);
  padding: 7px 13px;
  font-size: 13px;
}

.btn--ghost:hover {
  color: var(--text);
  border-color: var(--text-muted);
}

/* ---------- handoff banner ---------- */

.handoff-banner {
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-left-width: 4px;
  color: var(--warn-text);
  border-radius: var(--radius);
  padding: 11px 14px;
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex-wrap: wrap;
  font-size: 14px;
}

.handoff-banner strong {
  letter-spacing: 0.6px;
  font-size: 13px;
}

.handoff-banner span {
  font-size: 13px;
  opacity: 0.9;
}

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

.chat {
  flex: 1;
  min-height: 320px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  overflow-y: auto;
  max-height: 56vh;
  box-shadow: var(--shadow);
}

.empty-state {
  margin: auto;
  text-align: center;
  color: var(--text-muted);
  font-size: 14px;
  max-width: 380px;
}

.turn {
  display: flex;
  flex-direction: column;
  gap: 5px;
  max-width: 82%;
}

.turn--customer {
  align-self: flex-end;
  align-items: flex-end;
}

.turn--bot {
  align-self: flex-start;
  align-items: flex-start;
}

.turn__bubble {
  padding: 10px 14px;
  border-radius: 14px;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.turn--customer .turn__bubble {
  background: var(--customer-bubble);
  color: var(--customer-text);
  border-bottom-right-radius: 4px;
}

.turn--bot .turn__bubble {
  background: var(--bot-bubble);
  border: 1px solid var(--border);
  border-bottom-left-radius: 4px;
}

.turn--error .turn__bubble {
  border-color: var(--danger);
  color: var(--danger);
}

.turn__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  font-size: 11px;
}

.tag {
  padding: 2px 7px;
  border-radius: 5px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-weight: 600;
  white-space: nowrap;
}

.tag--lang {
  background: var(--brand-soft);
  color: var(--brand);
  border-color: transparent;
}

.tag--handoff {
  background: var(--warn-bg);
  color: var(--warn-text);
  border-color: var(--warn-border);
}

.tag--safety {
  background: var(--warn-bg);
  color: var(--warn-text);
  border-color: var(--warn-border);
}

.tag--review {
  background: var(--surface-2);
  color: var(--text-muted);
  border-style: dashed;
}

/* ---------- composer + samples ---------- */

.composer {
  display: flex;
  gap: 10px;
}

.composer__input {
  flex: 1;
  font: inherit;
  padding: 11px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
}

.composer__input:focus {
  outline: 2px solid var(--brand);
  outline-offset: -1px;
}

.samples {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.samples__label {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 600;
}

.chip {
  font: inherit;
  font-size: 12px;
  padding: 5px 11px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  cursor: pointer;
}

.chip:hover {
  color: var(--brand);
  border-color: var(--brand);
}

@media (max-width: 600px) {
  .turn {
    max-width: 92%;
  }

  .controls {
    flex-direction: column;
    align-items: stretch;
  }
}