:root {
  --goto-green: #00ad3d;
  --pure-white: #ffffff;
  --light-mint: #e6f8ed;
  --dark-slate: #0f172a;
  --soft-gray: #f1f5f9;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", "Inter", system-ui, -apple-system, sans-serif;
  background: var(--soft-gray);
  color: var(--dark-slate);
}

.app {
  max-width: 560px;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--pure-white);
  box-shadow: 0 0 24px rgba(15, 23, 42, 0.06);
}

/* ---------- Header ---------- */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px;
  background: var(--goto-green);
  color: var(--pure-white);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.2px;
}

.brand-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--pure-white);
  box-shadow: 0 0 0 4px rgba(255, 255, 255, 0.25);
}

.engine-badge {
  font-size: 0.72rem;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.18);
  color: var(--pure-white);
  font-weight: 600;
}

/* ---------- Chat area ---------- */
.chat-shell {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.chat-window {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: var(--pure-white);
}

.msg {
  display: flex;
}

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

.msg-bot {
  justify-content: flex-start;
}

.bubble {
  max-width: 80%;
  padding: 12px 16px;
  border-radius: 16px;
  line-height: 1.45;
  font-size: 0.95rem;
  white-space: pre-wrap;
}

.msg-bot .bubble {
  background: var(--light-mint);
  color: var(--dark-slate);
  border-bottom-left-radius: 4px;
}

.msg-user .bubble {
  background: var(--goto-green);
  color: var(--pure-white);
  border-bottom-right-radius: 4px;
}

.bubble.payload {
  background: var(--dark-slate);
  color: var(--pure-white);
  font-family: "Consolas", monospace;
  font-size: 0.82rem;
  border-radius: 12px;
}

.typing .bubble {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 14px 16px;
}

.typing .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--goto-green);
  opacity: 0.4;
  animation: blink 1.2s infinite ease-in-out;
}

.typing .dot:nth-child(2) { animation-delay: 0.2s; }
.typing .dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes blink {
  0%, 80%, 100% { opacity: 0.25; transform: translateY(0); }
  40% { opacity: 1; transform: translateY(-2px); }
}

/* ---------- Quick replies ---------- */
.quick-replies {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 0 20px 12px;
  background: var(--pure-white);
}

.chip {
  border: 1px solid var(--light-mint);
  background: var(--light-mint);
  color: var(--goto-green);
  font-weight: 600;
  font-size: 0.8rem;
  padding: 8px 12px;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}

.chip:hover {
  background: #d3f3e0;
}

.chip:active {
  transform: scale(0.97);
}

/* ---------- Composer ---------- */
.composer {
  display: flex;
  gap: 8px;
  padding: 14px 16px;
  border-top: 1px solid var(--soft-gray);
  background: var(--pure-white);
}

#messageInput {
  flex: 1;
  border: 1px solid var(--soft-gray);
  background: var(--soft-gray);
  border-radius: 12px;
  padding: 12px 14px;
  font-size: 0.95rem;
  color: var(--dark-slate);
  outline: none;
  transition: border-color 0.15s ease, background 0.15s ease;
}

#messageInput:focus {
  border-color: var(--goto-green);
  background: var(--pure-white);
}

#sendButton {
  background: var(--goto-green);
  color: var(--pure-white);
  border: none;
  border-radius: 12px;
  padding: 0 20px;
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  transition: opacity 0.15s ease;
}

#sendButton:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

#sendButton:not(:disabled):hover {
  opacity: 0.9;
}

#resetButton {
  background: var(--soft-gray);
  color: var(--dark-slate);
  border: none;
  border-radius: 12px;
  padding: 0 16px;
  font-weight: 600;
  font-size: 0.85rem;
  cursor: pointer;
}

#resetButton:hover {
  background: #e3e9ef;
}

/* ---------- Scrollbar ---------- */
.chat-window::-webkit-scrollbar {
  width: 6px;
}

.chat-window::-webkit-scrollbar-thumb {
  background: var(--light-mint);
  border-radius: 999px;
}