:root {
  --canvas: #f7f7f5;
  --paper: #ffffff;
  --ink: #171817;
  --muted: #747873;
  --line: #dedfdb;
  --line-strong: #c9cbc6;
  --soft: #f0f1ee;
  --accent: #1d6751;
  --accent-soft: #e4f2ed;
  --warn: #936b0b;
  --warn-soft: #fff4d8;
  --danger: #a7433d;
  --danger-soft: #fae9e7;
  --code: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box }

html, body { height: 100% }

body {
  margin: 0;
  color: var(--ink);
  background: var(--canvas);
  font: 14px/1.45 var(--sans);
}

button, textarea, input { font: inherit }
button { cursor: pointer }

.shell {
  height: 100vh;
  display: grid;
  grid-template-columns: minmax(480px, 1fr) minmax(420px, 46vw);
}

.workspace {
  min-width: 0;
  display: grid;
  grid-template-rows: 58px 1fr auto;
  background: var(--paper);
}

.topbar {
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-weight: 760;
  letter-spacing: -0.01em;
}

.mark {
  width: 25px;
  height: 25px;
  display: grid;
  place-items: center;
  border: 1px solid var(--ink);
  border-radius: 7px;
  font: 700 13px var(--code);
}

.meta {
  color: var(--muted);
  font: 12px var(--code);
}

.meta a {
  color: inherit;
  text-decoration: underline;
  text-underline-offset: 0.12em;
}

.meta a:hover { color: var(--accent) }

.button {
  border: 1px solid var(--line-strong);
  background: var(--paper);
  color: var(--ink);
  border-radius: 7px;
  padding: 7px 11px;
  font-weight: 620;
}

.button:hover { background: var(--soft) }

.button.primary {
  color: white;
  border-color: var(--accent);
  background: var(--accent);
}

.button.primary:hover { background: #165441 }

.button:disabled {
  opacity: 0.55;
  cursor: wait;
}

.article-pane {
  min-height: 0;
  display: grid;
  grid-template-rows: 42px 1fr;
}

.pane-head {
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 14px;
}

.pane-title { font-weight: 680 }

.pane-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--muted);
  font-size: 12px;
}

.text-button {
  border: 0;
  background: transparent;
  color: var(--accent);
  padding: 3px;
  font-weight: 640;
}

textarea.article {
  width: 100%;
  height: 100%;
  resize: none;
  display: block;
  border: 0;
  outline: 0;
  color: #2f3430;
  background: #fbfbfa;
  padding: 16px 18px;
  font: 14px/1.6 var(--sans);
}

textarea.article:focus { box-shadow: inset 3px 0 var(--accent) }

.askbar {
  border-top: 1px solid var(--line);
  padding: 12px 14px;
  display: grid;
  gap: 8px;
}

.ask-row { display: flex; gap: 8px }

.ask-row .button.primary {
  margin-left: auto;
  padding: 8px 14px;
}

.hint { color: var(--muted); font-size: 12px }
.hint.error { color: var(--danger) }

.response {
  min-width: 0;
  border-left: 1px solid var(--line);
  background: var(--paper);
  display: grid;
  grid-template-rows: 58px 1fr;
}

.response-head {
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 18px;
}

.response-title {
  font-size: 12px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 750;
}

.response-body {
  min-height: 0;
  overflow: auto;
  padding: 18px;
}

.empty {
  height: 100%;
  display: grid;
  place-items: center;
  color: var(--muted);
  text-align: center;
}

.empty strong {
  display: block;
  color: #555a55;
  font-size: 18px;
  margin-bottom: 5px;
}

.para {
  margin: 0;
  color: #2f3430;
  font: 14px/1.6 var(--sans);
  animation: para-in 280ms ease both;
}

.para + .para {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--soft);
}

@keyframes para-in {
  from { opacity: 0; transform: translateY(4px) }
  to { opacity: 1; transform: none }
}

.foot {
  margin: 16px 0 0;
  color: var(--muted);
  font: 11px var(--code);
}

.error {
  color: var(--danger);
  margin: 0;
}

@media (max-width: 900px) {
  .shell { display: block; height: auto }
  .workspace { height: 80vh }
  .response {
    min-height: 70vh;
    border-left: 0;
    border-top: 1px solid var(--line);
  }
}