:root {
  --bg: #0b1021;
  --card: #141b34;
  --muted: #9aa4c7;
  --text: #e8ecff;
  --primary: #5f7cff;
  --primary-dark: #4f68d4;
  --chip: #1f2950;
  --user: #1f7a5b;
  --bot: #2b3565;
  --danger: #ff6b6b;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: radial-gradient(circle at top, #111a36, var(--bg));
  color: var(--text);
  font-family: Arial, Helvetica, sans-serif;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 16px;
}

.app {
  width: min(900px, 100%);
  background: var(--card);
  border: 1px solid #26305d;
  border-radius: 14px;
  padding: 18px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.28);
}

.header h1 {
  margin: 0;
  font-size: 1.5rem;
}

.subtitle {
  margin: 6px 0 8px;
  color: var(--muted);
}

.active-persona {
  margin: 0;
  color: var(--muted);
}

#activePersonaLabel {
  color: #9fc5ff;
  font-weight: 700;
}

.persona-switcher {
  margin-top: 14px;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.persona-btn {
  border: 1px solid #30417c;
  background: #1a2447;
  color: var(--text);
  padding: 9px 12px;
  border-radius: 9px;
  cursor: pointer;
}

.persona-btn.active {
  background: var(--primary);
  border-color: var(--primary);
}

.suggestions {
  margin-top: 14px;
}

.suggestions-title {
  margin: 0 0 8px;
  color: var(--muted);
}

.chips {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.chip {
  border: 1px solid #30417c;
  background: var(--chip);
  color: var(--text);
  border-radius: 999px;
  padding: 7px 10px;
  font-size: 0.9rem;
  cursor: pointer;
}

.chat-box {
  margin-top: 14px;
  border: 1px solid #2b396d;
  border-radius: 10px;
  min-height: 340px;
  max-height: 420px;
  overflow-y: auto;
  padding: 12px;
  background: #0f1630;
}

.msg {
  max-width: 85%;
  padding: 9px 11px;
  border-radius: 10px;
  margin-bottom: 10px;
  line-height: 1.4;
  white-space: pre-wrap;
}

.msg.user {
  margin-left: auto;
  background: var(--user);
}

.msg.bot {
  margin-right: auto;
  background: var(--bot);
}

.msg.error {
  margin-right: auto;
  background: #4a1f2a;
  border: 1px solid #7f3142;
  color: #ffd4da;
}

.typing {
  margin-top: 10px;
  color: var(--muted);
  font-style: italic;
}

.hidden {
  display: none;
}

.input-area {
  margin-top: 10px;
  display: flex;
  gap: 8px;
}

#userInput {
  flex: 1;
  padding: 11px;
  border-radius: 10px;
  border: 1px solid #30417c;
  background: #111b3b;
  color: var(--text);
}

#sendBtn {
  border: none;
  padding: 0 16px;
  border-radius: 10px;
  background: var(--primary);
  color: white;
  cursor: pointer;
  font-weight: 700;
}

#sendBtn:disabled {
  background: var(--primary-dark);
  opacity: 0.7;
  cursor: not-allowed;
}

@media (max-width: 640px) {
  .app {
    padding: 14px;
  }

  .header h1 {
    font-size: 1.2rem;
  }

  .chat-box {
    min-height: 300px;
  }

  .input-area {
    flex-direction: column;
  }

  #sendBtn {
    height: 42px;
  }
}