:root {
  color-scheme: light;
  --bg: #f4fbf9;
  --panel: #ffffff;
  --ink: #11201d;
  --muted: #60726e;
  --brand: #0f766e;
  --brand-dark: #115e59;
  --line: #dce9e6;
  --soft: #e7f5f2;
  --shadow: 0 14px 32px rgba(15, 118, 110, 0.14);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

body {
  display: flex;
  justify-content: center;
}

button,
input {
  font: inherit;
}

.app-shell {
  width: min(100%, 520px);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: linear-gradient(180deg, #eefaf7 0%, #ffffff 42%);
}

.topbar {
  display: flex;
  gap: 12px;
  align-items: center;
  padding: 18px 18px 12px;
  position: sticky;
  top: 0;
  z-index: 2;
  background: rgba(244, 251, 249, 0.96);
  border-bottom: 1px solid rgba(220, 233, 230, 0.7);
  backdrop-filter: blur(10px);
}

.brand-mark {
  width: 44px;
  height: 44px;
  border-radius: 8px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  background: var(--brand);
  color: #fff;
  font-weight: 800;
  font-size: 22px;
}

h1 {
  margin: 0;
  font-size: 20px;
  line-height: 1.2;
}

.topbar p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.quick-area {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 12px 18px 8px;
  scrollbar-width: none;
}

.quick-area::-webkit-scrollbar {
  display: none;
}

.quick-area button {
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--brand-dark);
  border-radius: 999px;
  padding: 9px 12px;
  white-space: nowrap;
  box-shadow: 0 3px 12px rgba(17, 32, 29, 0.04);
}

.chat {
  flex: 1;
  padding: 10px 18px 96px;
}

.message {
  display: flex;
  margin: 12px 0;
}

.message.user {
  justify-content: flex-end;
}

.bubble {
  max-width: 88%;
  padding: 12px 14px;
  border-radius: 16px;
  line-height: 1.55;
  font-size: 15px;
}

.assistant .bubble {
  background: var(--panel);
  border: 1px solid var(--line);
  border-top-left-radius: 8px;
  box-shadow: 0 8px 20px rgba(17, 32, 29, 0.06);
}

.user .bubble {
  background: var(--brand);
  color: #fff;
  border-top-right-radius: 8px;
}

.book-list {
  display: grid;
  gap: 10px;
  margin-top: 12px;
}

.book-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  box-shadow: 0 8px 20px rgba(17, 32, 29, 0.06);
}

.book-card h2 {
  margin: 0 0 6px;
  font-size: 16px;
}

.book-meta {
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 8px;
}

.book-card p {
  margin: 0 0 10px;
  color: #2a3d39;
  line-height: 1.5;
  font-size: 14px;
}

.book-actions {
  display: flex;
  gap: 8px;
}

.book-actions a {
  flex: 1;
  text-align: center;
  text-decoration: none;
  border-radius: 8px;
  padding: 10px;
  background: var(--soft);
  color: var(--brand-dark);
  font-weight: 700;
}

.book-actions a.primary {
  background: var(--brand);
  color: #fff;
}

.composer {
  position: fixed;
  left: 50%;
  bottom: 0;
  transform: translateX(-50%);
  width: min(100%, 520px);
  display: flex;
  gap: 8px;
  padding: 12px 14px calc(12px + env(safe-area-inset-bottom));
  background: rgba(255, 255, 255, 0.96);
  border-top: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.composer input {
  min-width: 0;
  flex: 1;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  outline: none;
}

.composer input:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.12);
}

.composer button {
  border: 0;
  border-radius: 8px;
  padding: 0 16px;
  color: #fff;
  background: var(--brand);
  font-weight: 800;
}

.typing {
  color: var(--muted);
}

.error {
  color: #9f1239;
}