:root {
  --bg: #0b0d10;
  --panel: #14171c;
  --line: #262b33;
  --text-1: #e8ebef;
  --text-2: #9aa3ae;
  --accent: #63e6a8;
  --danger: #ff7a7a;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text-1);
  font: 15px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  display: flex;
  flex-direction: column;
}

#top {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 8px; color: var(--text-1); text-decoration: none; letter-spacing: .04em; }
.brand strong { color: var(--accent); }
.tagline { color: var(--text-2); font-size: 13px; }

main {
  flex: 1;
  display: grid;
  grid-template-columns: minmax(320px, 420px) 1fr;
  min-height: 0;
}

#chat-col {
  display: flex;
  flex-direction: column;
  border-right: 1px solid var(--line);
  padding: 14px;
  gap: 12px;
  min-height: 0;
}

#messages { flex: 1; overflow-y: auto; display: flex; flex-direction: column; gap: 10px; }
.msg { padding: 10px 12px; border-radius: 10px; max-width: 92%; white-space: pre-wrap; }
.msg.user { background: var(--panel); align-self: flex-end; }
.msg.system { color: var(--text-2); font-size: 13.5px; align-self: stretch; }
.msg.error { color: var(--danger); }
.msg .retry { margin-left: 8px; }

.rev {
  align-self: flex-start;
  background: none;
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--text-1);
  padding: 8px 12px;
  cursor: pointer;
  font: inherit;
}
.rev.active { border-color: var(--accent); color: var(--accent); }
.rev .size { color: var(--text-2); font-size: 12.5px; margin-left: 8px; }

#composer { display: flex; gap: 8px; align-items: flex-end; }
#prompt {
  flex: 1;
  resize: none;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 10px;
  color: var(--text-1);
  padding: 10px 12px;
  font: inherit;
}
#prompt:focus { outline: none; border-color: var(--accent); }

.pill-btn {
  background: var(--accent);
  color: #06281a;
  border: none;
  border-radius: 999px;
  padding: 10px 18px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
.pill-btn:disabled { opacity: .45; cursor: default; }

#actions { display: flex; gap: 8px; flex-wrap: wrap; }
.ghost-btn {
  background: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--text-1);
  padding: 7px 14px;
  font: inherit;
  font-size: 13.5px;
  cursor: pointer;
}
.ghost-btn:hover { border-color: var(--accent); color: var(--accent); }

#settings { border-top: 1px solid var(--line); padding-top: 10px; color: var(--text-2); }
#settings summary { cursor: pointer; }
#settings label { display: block; margin: 10px 0 4px; font-size: 13.5px; }
#byok {
  width: 100%;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text-1);
  padding: 8px 10px;
  font: inherit;
}
.hint { color: var(--text-2); font-size: 12.5px; margin: 6px 0 0; }

#preview-col { display: flex; flex-direction: column; min-height: 0; padding: 14px; gap: 10px; }
#preview-strip { display: flex; align-items: center; gap: 10px; }
#scene {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text-1);
  padding: 7px 10px;
  font: inherit;
}
#ambient { flex: 1; accent-color: var(--accent); }
#ambient-lbl { color: var(--text-2); font-size: 13px; min-width: 76px; text-align: right; }
#sim { flex: 1; width: 100%; border: 1px solid var(--line); border-radius: 12px; background: #000; }
#preview-col .hint { text-align: center; }

@media (max-width: 860px) {
  main { grid-template-columns: 1fr; grid-template-rows: minmax(300px, 45vh) 1fr; }
  #preview-col { order: -1; border-bottom: 1px solid var(--line); }
  #chat-col { border-right: none; }
}