:root {
  --bg: #0e1116; --panel: #161b22; --border: #2a3139;
  --text: #e6edf3; --dim: #8b949e; --accent: #f6821f; --ok: #3fb950; --err: #f85149;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); }
main { max-width: 760px; margin: 0 auto; padding: 24px 16px 48px; }
header h1 { margin: 0; font-size: 28px; letter-spacing: .5px; }
.tagline { color: var(--dim); margin-top: 4px; }
section { background: var(--panel); border: 1px solid var(--border); border-radius: 10px; padding: 16px; margin-top: 16px; }
button {
  background: var(--accent); color: #111; border: 0; border-radius: 8px;
  padding: 10px 18px; font-size: 15px; font-weight: 600; cursor: pointer;
}
button:hover { filter: brightness(1.08); }
button:disabled { opacity: .45; cursor: not-allowed; }
button.ghost { background: transparent; color: var(--text); border: 1px solid var(--border); font-weight: 400; padding: 6px 12px; font-size: 13px; }
.hint { color: var(--dim); font-size: 13px; }
code { background: #21262d; padding: 2px 6px; border-radius: 5px; font-size: 13px; }

#chat-form { display: flex; gap: 8px; margin-top: 12px; }
#prompt { flex: 1; background: #0d1117; border: 1px solid var(--border); color: var(--text); border-radius: 8px; padding: 10px 12px; font-size: 15px; }
#log { display: flex; flex-direction: column; gap: 8px; max-height: 340px; overflow-y: auto; }
.msg { padding: 8px 12px; border-radius: 8px; max-width: 85%; white-space: pre-wrap; word-break: break-word; font-size: 14px; line-height: 1.45; }
.msg.user { align-self: flex-end; background: #1f3a5f; }
.msg.assistant { align-self: flex-start; background: #21262d; }
.msg.error { align-self: stretch; background: #3d1418; color: #ffb4ae; font-family: ui-monospace, monospace; font-size: 12px; }
.msg.pending { color: var(--dim); font-style: italic; }

#proof-table { width: 100%; border-collapse: collapse; font-size: 13px; }
#proof-table td { padding: 5px 8px; border-bottom: 1px solid var(--border); vertical-align: top; }
#proof-table td:first-child { color: var(--dim); white-space: nowrap; width: 40%; }
#proof-table td:last-child { word-break: break-all; }
.proof-actions { display: flex; gap: 8px; margin-top: 12px; flex-wrap: wrap; }
#experiment-out { background: #0d1117; border: 1px solid var(--border); border-radius: 8px; padding: 12px; font-size: 12px; overflow-x: auto; margin-top: 12px; }
.ok { color: var(--ok); } .err { color: var(--err); } .warn { color: #d29922; }
footer { margin-top: 24px; text-align: center; font-size: 12px; }
footer a { color: var(--dim); }