:root {
  color-scheme: dark;
  --bg: #0b1020;
  --panel: #121a2f;
  --panel2: #17213b;
  --text: #eef3ff;
  --muted: #9da9c5;
  --accent: #70e1b5;
  --accent2: #7da5ff;
  --danger: #ff8b8b;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at top left, #193259, var(--bg) 42%);
  color: var(--text);
}
.shell { max-width: 980px; margin: 0 auto; padding: 32px 18px; }
.hero { display: flex; justify-content: space-between; gap: 20px; align-items: flex-start; margin-bottom: 18px; }
.eyebrow { color: var(--accent); text-transform: uppercase; letter-spacing: .14em; font-size: 12px; margin: 0 0 8px; }
h1 { margin: 0; font-size: clamp(32px, 5vw, 54px); line-height: 1; }
h2 { margin: 0 0 14px; font-size: 18px; }
.subtle { color: var(--muted); max-width: 720px; line-height: 1.5; }
.badge { border: 1px solid rgba(112,225,181,.35); color: var(--accent); padding: 10px 14px; border-radius: 999px; white-space: nowrap; background: rgba(112,225,181,.08); }
.panel { background: rgba(18,26,47,.86); border: 1px solid rgba(255,255,255,.08); border-radius: 18px; padding: 18px; margin: 14px 0; box-shadow: 0 20px 60px rgba(0,0,0,.22); }
.hidden { display: none; }
label { display: block; color: var(--muted); margin-bottom: 8px; }
input, textarea { width: 100%; background: var(--panel2); color: var(--text); border: 1px solid rgba(255,255,255,.12); border-radius: 14px; padding: 13px 14px; font: inherit; outline: none; }
textarea { resize: vertical; }
input:focus, textarea:focus { border-color: var(--accent2); }
.prompts { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 10px; }
.prompt { text-align: left; background: rgba(125,165,255,.1); color: var(--text); border: 1px solid rgba(125,165,255,.24); border-radius: 14px; padding: 12px; cursor: pointer; line-height: 1.35; }
.prompt:hover { border-color: var(--accent2); }
.messages { min-height: 300px; max-height: 560px; overflow: auto; display: flex; flex-direction: column; gap: 12px; padding-right: 4px; }
.message { padding: 14px 15px; border-radius: 16px; line-height: 1.48; white-space: pre-wrap; }
.user { align-self: flex-end; max-width: 78%; background: #244578; }
.assistant { align-self: flex-start; max-width: 88%; background: #16243f; border: 1px solid rgba(255,255,255,.08); }
.error { color: var(--danger); }
.composer { display: grid; grid-template-columns: 1fr auto; gap: 10px; margin-top: 14px; align-items: end; }
button { background: linear-gradient(135deg, var(--accent), var(--accent2)); color: #07101f; border: 0; border-radius: 14px; padding: 13px 18px; font-weight: 800; cursor: pointer; }
button:disabled { opacity: .55; cursor: wait; }
@media (max-width: 720px) { .hero { flex-direction: column; } .composer { grid-template-columns: 1fr; } .user, .assistant { max-width: 100%; } }