:root {
  --bg: #0e1117;
  --fg: #e6edf3;
  --accent: #00ff9c;
  --user: #00ff9c;
  --bot: #36c9ff;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "Inter", sans-serif;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

.app {
  display: flex;
  flex-direction: column;
  height: 90vh;
  width: 100%;
  max-width: 800px;
  border: 1px solid #222;
  border-radius: 12px;
  overflow: hidden;
  background: #1a1e27;
}

header {
  padding: 1rem;
  background: #111;
  border-bottom: 1px solid #222;
}
header h1 {
  margin: 0;
  color: var(--accent);
}
.subtitle {
  font-size: 0.9rem;
  color: #aaa;
}

#chat {
  flex: 1;
  padding: 1rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}
.msg {
  margin: 0.5rem 0;
  padding: 0.6rem 0.8rem;
  border-radius: 6px;
  line-height: 1.4;
  max-width: 80%;
}
.user {
  background: rgba(0, 255, 156, 0.1);
  color: var(--user);
  align-self: flex-end;
}
.bot {
  background: rgba(54, 201, 255, 0.1);
  color: var(--bot);
  align-self: flex-start;
}

footer {
  display: flex;
  padding: 0.6rem;
  border-top: 1px solid #222;
  background: #111;
}
textarea {
  flex: 1;
  resize: none;
  border: none;
  background: #1a1e27;
  color: var(--fg);
  padding: 0.6rem;
  border-radius: 6px;
}
button {
  margin-left: 0.6rem;
  padding: 0 1.2rem;
  border: none;
  border-radius: 6px;
  background: var(--accent);
  color: #000;
  font-weight: bold;
  cursor: pointer;
}