:root {
  --bg: #f7f8fa;
  --panel: #ffffff;
  --field: #fafbfc;
  --text: #1b1f26;
  --muted: #737b8a;
  --accent: #4c6ef5;
  --accent-soft: #eef1fe;
  --danger-bg: #fdecec;
  --danger-text: #a02020;
  --content-rgb: 148 163 184;
  --content-alpha: 16%;
  --radius: 12px;
  --shadow-sm: 0 1px 2px rgba(20, 26, 40, 0.06);
  --shadow-md: 0 10px 30px -18px rgba(20, 26, 40, 0.45), 0 1px 2px rgba(20, 26, 40, 0.04);
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --editor-height: clamp(360px, calc(100dvh - 272px), 960px);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  max-width: 1800px;
  margin: 0 auto;
  padding: 24px 32px 28px;
  background: var(--bg);
  color: var(--text);
  font: 14px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

.masthead {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
}

.mode-tabs {
  display: inline-flex;
  gap: 3px;
  flex: 0 0 auto;
  padding: 3px;
  border: 1px solid #dce1eb;
  border-radius: 11px;
  background: #e9edf5;
}

.mode-tab {
  min-width: 76px;
  padding: 6px 20px;
  border: 0;
  border-radius: 7px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
  transition: background 120ms ease, color 120ms ease;
}

.mode-tab:hover { color: var(--accent); background: var(--accent-soft); }
.mode-tab.active { color: #fff; background: var(--accent); }

.masthead h1 {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand { color: var(--text); }

@supports (background-clip: text) or (-webkit-background-clip: text) {
  .brand {
    background-image: linear-gradient(96deg, #4c6ef5, #8a3ffc 58%, #0e8aa8);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }
}

.badge {
  padding: 3px 9px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: #3b57c5;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.toolbar {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 18px;
}

.toolbar-divider {
  width: 1px;
  height: 24px;
  background: #dce1eb;
  flex: 0 0 auto;
}

.tabs {
  display: inline-flex;
  padding: 3px;
  gap: 2px;
  background: transparent;
  border-radius: 10px;
}

.tab {
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  padding: 6px 14px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 120ms ease, color 120ms ease;
}

.tab:hover { color: var(--text); }

.tab.active {
  background: var(--panel);
  color: var(--text);
  box-shadow: var(--shadow-sm);
  font-weight: 600;
}

.actions { display: flex; align-items: center; flex: 0 0 auto; gap: 8px; }

button.primary {
  border: 0;
  font: inherit;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 9px;
  cursor: pointer;
  white-space: nowrap;
  background: var(--accent);
  color: #fff;
  box-shadow: 0 6px 14px -8px rgba(76, 110, 245, 0.9);
  transition: background 120ms ease, box-shadow 120ms ease, transform 60ms ease;
}

button.primary:hover { background: #3f5ee0; }

button:active { transform: translateY(1px); }

.error {
  margin-bottom: 12px;
  padding: 11px 14px;
  background: var(--danger-bg);
  color: var(--danger-text);
  border-radius: 10px;
  font-family: var(--mono);
  font-size: 12.5px;
  white-space: pre-wrap;
  word-break: break-word;
}

.grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 16px;
  align-items: start;
}

.pane { min-width: 0; }

.pane-header {
  display: flex;
  min-height: 56px;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 0 12px;
}

.pane-heading { display: flex; min-width: 0; flex-direction: column; gap: 5px; }

.pane h2 {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 4px 8px;
  margin: 0;
  font-size: 12px;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.03em;
}

.meta {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 400;
  color: var(--muted);
  text-transform: none;
  letter-spacing: 0;
}

#input,
.prompt {
  height: var(--editor-height);
  min-height: 360px;
  padding: 16px 18px;
  border: 0;
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow-md);
  font-family: var(--mono);
  font-size: 12.5px;
}

#input {
  width: 100%;
  resize: vertical;
  line-height: 1.6;
  color: var(--text);
  background: var(--field);
  tab-size: 2;
}

#input:focus {
  outline: 0;
  background: var(--panel);
  box-shadow: var(--shadow-md), 0 0 0 3px var(--accent-soft);
}

.prompt {
  margin: 0;
  overflow: auto;
  line-height: 1.9;
  white-space: pre-wrap;
  word-break: break-word;
}

.model-editor {
  position: relative;
  height: var(--editor-height);
  min-height: 360px;
  overflow: hidden;
  resize: vertical;
  border-radius: var(--radius);
  background: var(--field);
  box-shadow: var(--shadow-md);
}

.model-editor:focus-within {
  background: var(--panel);
  box-shadow: var(--shadow-md), 0 0 0 3px var(--accent-soft);
}

#model-output,
#model-output-preview {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 16px 18px;
  border: 0;
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 400;
  font-variant-ligatures: none;
  line-height: 1.6;
  letter-spacing: normal;
  tab-size: 2;
  white-space: pre-wrap;
  overflow-wrap: break-word;
  word-break: normal;
  scrollbar-gutter: stable;
}

#model-output-preview {
  overflow: hidden;
  color: var(--text);
  pointer-events: none;
}

#model-output-preview .sp,
#model-output-preview .tx {
  padding: 0;
  font-weight: inherit;
}

#model-output {
  overflow: auto;
  resize: none;
  outline: 0;
  background: transparent;
  color: transparent;
  -webkit-text-fill-color: transparent;
  caret-color: var(--text);
}

#model-output::selection { background: rgb(76 110 245 / 25%); }

button:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.response { line-height: 1.6; }
.response[aria-busy="true"] { opacity: 0.6; }

@media (max-width: 900px) {
  :root { --editor-height: 52dvh; }
  .grid { grid-template-columns: minmax(0, 1fr); gap: 14px; }
  .toolbar { gap: 12px; }
}

@media (max-width: 600px) {
  body { padding: 18px 16px 24px; }
  .masthead { flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
  .masthead h1 { font-size: 20px; }
  .badge { font-size: 10px; }
  .toolbar { flex-wrap: wrap; gap: 10px; margin-bottom: 12px; }
  .toolbar-divider { display: none; }
  .mode-tabs { width: 100%; }
  .mode-tab { flex: 1; }
  .tabs { width: 100%; padding: 0; }
  .tab { flex: 1; padding: 7px 6px; font-size: 12px; white-space: nowrap; }
  .pane-header { gap: 8px; }
  button.primary { padding: 8px 10px; font-size: 12px; }
  .pane h2 { letter-spacing: 0.02em; }
  #input, .prompt, #model-output, #model-output-preview { padding: 14px; }
}

@media (max-width: 360px) {
  body { padding-inline: 12px; }
  .tab { padding-inline: 4px; font-size: 11px; }
}

.sp {
  --rgb: 148 163 184;
  --alpha: 32%;
  padding: 1px 5px;
  font-weight: 600;
  background: rgb(var(--rgb) / var(--alpha));
  color: var(--text);
}

.sp {
  cursor: help;
  transition: background 120ms ease;
}

.sp:hover { background: rgb(var(--rgb) / 85%); }

[data-name="bos"] { --rgb: 165 180 252; }
[data-name="system"] { --rgb: 252 211 77; }
[data-name="user"] { --rgb: 134 239 172; }
[data-name="assistant"] { --rgb: 216 180 254; }
[data-name="thinking_start"] { --rgb: 103 232 249; }
[data-name="thinking_end"] { --rgb: 125 211 252; }
[data-name="latest_reminder"] { --rgb: 249 168 212; }
[data-name="eos"] { --rgb: 203 213 225; }

[data-name="dsml"] { --rgb: 190 242 100; --alpha: 26%; }
[data-name="tool_result"] { --rgb: 253 186 116; --alpha: 26%; }
[data-name="system_reminder"] { --rgb: 240 171 252; --alpha: 26%; }

.tx {
  padding: 1px 0;
  background: rgb(var(--content-rgb) / var(--content-alpha));
  color: var(--text);
}

.tooltip {
  position: fixed;
  z-index: 50;
  max-width: 360px;
  padding: 7px 11px;
  background: #1b1f26;
  color: #fff;
  font-family: var(--mono);
  font-size: 11.5px;
  line-height: 1.5;
  white-space: normal;
  border-radius: 8px;
  box-shadow: 0 12px 28px -14px rgba(0, 0, 0, 0.7);
  pointer-events: none;
}