:root {
  --brand-dark: #0A1C40;
  --brand: #1352B4;
  --brand-light: #E8F0FE;
  --surface: #FFFFFF;
  --surface-2: #F4F6F9;
  --text: #1A202C;
  --text-muted: #54627B;
  --border: #E2E8F0;
  --success: #10B981;
  --warning: #F59E0B;
  --danger: #EF4444;
  --warning-bg: #FEF3C7;
  --danger-bg: #FEE2E2;
}

@media (prefers-color-scheme: dark) {
  :root {
    --brand-dark: #F8FAFC;
    --surface: #1E293B;
    --surface-2: #0F172A;
    --text: #F8FAFC;
    --text-muted: #94A3B8;
    --border: #334155;
    --brand: #3B82F6;
    --warning-bg: #451A03;
    --danger-bg: #7F1D1D;
  }
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: system-ui, -apple-system, sans-serif;
  background-color: var(--surface-2);
  color: var(--text);
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

header {
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 12px 16px;
  flex-shrink: 0;
  z-index: 10;
}

.logo {
  color: var(--brand-dark);
  font-weight: 700;
  font-size: 1.1rem;
}

.brand-amp {
  color: var(--brand);
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 4px;
}

.status-dot {
  width: 8px;
  height: 8px;
  background-color: var(--success);
  border-radius: 50%;
  display: inline-block;
}

.warning-bar {
  background-color: var(--warning-bg);
  color: var(--text);
  font-size: 0.75rem;
  padding: 8px 16px;
  text-align: center;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

main {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
}

#messages {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.message {
  display: flex;
  flex-direction: column;
  max-width: 85%;
}

.message.user {
  align-self: flex-end;
}

.message.bot {
  align-self: flex-start;
}

.message.error {
  align-self: center;
  max-width: 90%;
  align-items: center;
}

.bubble {
  padding: 12px 16px;
  border-radius: 16px;
  font-size: 0.95rem;
  line-height: 1.4;
  word-break: break-word;
}

.user .bubble {
  background-color: var(--brand);
  color: #FFFFFF;
  border-bottom-right-radius: 4px;
}

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

.error .bubble {
  background-color: var(--danger-bg);
  color: var(--text);
  border: 1px solid var(--danger);
  border-radius: 8px;
  text-align: center;
}

.search-cards {
  display: flex;
  gap: 12px;
  overflow-x: auto;
  padding: 8px 0;
  margin-top: 4px;
  scroll-snap-type: x mandatory;
}

.search-card {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  min-width: 200px;
  max-width: 280px;
  flex-shrink: 0;
  scroll-snap-align: start;
  cursor: pointer;
  transition: all 0.2s ease;
}

.card-title {
  font-weight: 600;
  font-size: 0.85rem;
  margin-bottom: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.card-source {
  color: var(--brand);
  font-size: 0.75rem;
  font-weight: 500;
  margin-bottom: 2px;
}

.card-excerpt {
  margin-top: 8px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.card-link {
  display: inline-block;
  margin-top: 8px;
  font-size: 0.8rem;
  color: var(--brand);
  text-decoration: none;
}

.card-link:hover {
  text-decoration: underline;
}

.search-card.expanded .card-title {
  white-space: normal;
}

.search-card.expanded .card-excerpt,
.search-card.expanded .card-link {
  display: block;
}

footer {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  padding: 12px 16px;
  flex-shrink: 0;
}

#chat-form {
  display: flex;
  gap: 8px;
}

input {
  flex: 1;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background-color: var(--surface-2);
  color: var(--text);
  font-size: 1rem;
  outline: none;
}

input:focus {
  border-color: var(--brand);
}

button {
  background-color: var(--brand);
  color: #FFFFFF;
  border: none;
  border-radius: 24px;
  padding: 0 20px;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  outline: none;
}

button:focus-visible {
  box-shadow: 0 0 0 2px var(--surface), 0 0 0 4px var(--brand);
}

.retry-btn {
  margin-top: 8px;
  background-color: var(--danger);
  color: #FFFFFF;
  border: none;
  border-radius: 24px;
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  outline: none;
}

.retry-btn:focus-visible {
  box-shadow: 0 0 0 2px var(--danger-bg), 0 0 0 4px var(--danger);
}

.hidden {
  display: none !important;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

#typing-indicator {
  align-self: flex-start;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  border-bottom-left-radius: 4px;
  padding: 12px 16px;
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 16px;
}

#typing-text {
  transition: opacity 0.3s ease;
  display: inline-block;
}

.typing-dots::after {
  content: "";
  animation: dots 1.5s steps(4, end) infinite;
}

@keyframes dots {
  0%, 20% { content: ""; }
  40% { content: "."; }
  60% { content: ".."; }
  80%, 100% { content: "..."; }
}

#handoff-message {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
  padding: 8px 0;
}