:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b7280;
  --border: #e5e7eb;
  --panel: #f9fafb;
  --add-bg: #e6ffed;
  --add-line: #acf2bd;
  --del-bg: #ffeef0;
  --del-line: #fdb8c0;
  --gutter: #f3f4f6;
  --accent: #013EDE;
  color-scheme: light;
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
/* Header */
header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
header h1 {
  font-size: 16px;
  margin: 0;
  font-weight: 600;
  letter-spacing: -0.01em;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--fg);
}
header h1 svg {
  width: 22px;
  height: 22px;
  color: var(--accent);
  flex-shrink: 0;
}
header .spacer { flex: 1; }

/* Buttons */
button {
  background: var(--accent);
  color: white;
  border: none;
  padding: 7px 14px;
  border-radius: 4px;
  font-size: 13px;
  cursor: pointer;
  font-weight: 500;
}
button.secondary {
  background: transparent;
  color: var(--fg);
  border: 1px solid var(--border);
}
button:hover { filter: brightness(0.92); }
button.secondary:hover { filter: none; background: var(--bg); }
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Options bar */
.optionsbar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 18px;
  padding: 8px 16px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.optionsbar label {
  font-size: 13px;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
}
.optionsbar .divider {
  width: 1px;
  height: 18px;
  background: var(--border);
}

/* Input panes */
.inputs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  border-bottom: 1px solid var(--border);
}
.pane {
  background: var(--bg);
  display: flex;
  flex-direction: column;
  min-height: 220px;
}
.pane-title {
  padding: 6px 10px;
  font-size: 12px;
  color: var(--muted);
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
textarea {
  flex: 1;
  width: 100%;
  border: none;
  outline: none;
  resize: vertical;
  padding: 10px;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  background: var(--bg);
  color: var(--fg);
  min-height: 200px;
  line-height: 1.5;
}
textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}

/* Stats bar */
.stats {
  padding: 8px 16px;
  font-size: 12px;
  color: var(--muted);
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
}
.stats .stats-text { flex: 1; }
.stats .add { color: #16a34a; font-weight: 600; }
.stats .del { color: #dc2626; font-weight: 600; }

/* Explain button + panel */
.explain-btn {
  display: none;
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  cursor: pointer;
}
.explain-btn:hover { background: rgba(1, 62, 222, 0.06); filter: none; }
.explain-btn[disabled] { opacity: 0.5; cursor: not-allowed; }
.explain-btn.visible { display: inline-flex; align-items: center; gap: 6px; }
.explain-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: 400px;
  max-width: 100vw;
  height: 100vh;
  background: #ffffff;
  border-left: 1px solid var(--border);
  box-shadow: -8px 0 24px rgba(0, 0, 0, 0.06);
  padding: 16px 18px;
  font-size: 13px;
  line-height: 1.55;
  color: #000;
  transform: translateX(100%);
  transition: transform 220ms ease;
  z-index: 60;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}
.explain-panel.open { transform: translateX(0); }
.explain-panel .head {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
  font-weight: 600;
}
.explain-panel .head .title {
  color: #000;
  font-size: 13px;
}
.explain-panel .head .est {
  font-size: 10px;
  font-weight: 600;
  color: var(--muted);
  letter-spacing: 0.04em;
  padding: 2px 6px;
  border-radius: 999px;
  background: var(--panel);
  display: none;
}
.explain-panel .head .est:not(:empty) { display: inline-block; }
.explain-panel .head .spacer { flex: 1; }
.explain-panel .head button {
  background: transparent;
  border: none;
  color: var(--muted);
  font-size: 11px;
  padding: 4px 8px;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
  border-radius: 4px;
}
.explain-panel .head button:hover { color: var(--accent); filter: none; background: var(--panel); }
.explain-panel .body { flex: 1; overflow-y: auto; }
.explain-panel pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
  font-family: inherit;
  font-size: 13px;
}
.explain-panel .loading {
  color: var(--muted);
  font-style: italic;
}
.explain-panel.error pre { color: #dc2626; }
.explain-panel .disclaimer {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--border);
  font-size: 11px;
  color: var(--muted);
}
.explain-panel .copy-ok {
  color: #16a34a;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
}
.explain-panel .cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  text-transform: none;
  letter-spacing: 0;
  margin-top: 8px;
}
.explain-panel .cta:hover { filter: brightness(0.92); }
.explain-panel .confirm {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
  background: var(--panel);
}
.explain-panel .confirm h4 {
  margin: 0 0 6px;
  font-size: 14px;
  font-weight: 600;
}
.explain-panel .confirm p {
  margin: 0 0 12px;
  font-size: 13px;
  color: rgba(0,0,0,0.7);
  line-height: 1.5;
}
.explain-panel .confirm label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 12px;
  cursor: pointer;
}
.explain-panel .confirm .row {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
}
@media (max-width: 540px) {
  .explain-panel { width: 100vw; border-left: none; }
}

/* Diff output */
.diff {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  line-height: 1.5;
}
.diff-side {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
}
.diff-col { background: var(--bg); overflow-x: auto; }
.row {
  display: grid;
  grid-template-columns: 48px 1fr;
  min-height: 1.5em;
}
.gutter {
  background: var(--gutter);
  color: var(--muted);
  text-align: right;
  padding: 0 8px;
  user-select: none;
  border-right: 1px solid var(--border);
  font-size: 11px;
  line-height: 1.5;
  padding-top: 1px;
}
.line {
  padding: 0 8px;
  white-space: pre-wrap;
  word-break: break-word;
}
.row.add { background: var(--add-bg); }
.row.add .line { background: var(--add-bg); }
.row.del { background: var(--del-bg); }
.row.del .line { background: var(--del-bg); }
.row.empty { background: var(--panel); }
.row.empty .gutter { background: var(--panel); }
.row.empty .line { color: var(--muted); }
.intra-add { background: var(--add-line); border-radius: 2px; }
.intra-del { background: var(--del-line); border-radius: 2px; }
.empty-state {
  padding: 40px 20px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
}

/* Hero */
.hero {
  background: #ffffff;
  text-align: center;
  padding: 56px 24px 48px;
  border-bottom: 1px solid var(--border);
  position: relative;
}
.hero h2 {
  margin: 0 0 12px;
  font-size: 38px;
  line-height: 1.1;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: #000000;
}
.hero h2 .accent { color: var(--accent); }
.hero p {
  margin: 0 auto;
  max-width: 560px;
  font-size: 16px;
  line-height: 1.5;
  color: #000000;
  opacity: 0.7;
}
.hero .pills {
  margin-top: 22px;
  display: inline-flex;
  gap: 8px;
  flex-wrap: wrap;
  justify-content: center;
}
.hero .pill {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--accent);
  color: #ffffff;
}
.hero .pill.outline {
  background: #ffffff;
  color: #000000;
  border: 1px solid #000000;
}
.hero .attribution {
  margin-top: 24px;
  font-size: 12px;
  color: rgba(0, 0, 0, 0.5);
  letter-spacing: 0.01em;
}
.hero .attribution a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 0, 0, 0.2);
  transition: color 120ms ease, border-color 120ms ease;
}
.hero .attribution a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}
@media (max-width: 540px) {
  .hero { padding: 36px 16px 32px; }
  .hero h2 { font-size: 28px; }
  .hero p { font-size: 14px; }
}

/* Gear, modals, feedback */
.gear-btn {
  background: transparent;
  border: none;
  padding: 6px;
  border-radius: 4px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: rgba(0, 0, 0, 0.55);
  transition: color 120ms ease, background 120ms ease;
  position: relative;
}
.gear-btn:hover { color: var(--accent); background: var(--panel); filter: none; }
.gear-btn svg { width: 18px; height: 18px; }
.gear-btn .dot {
  position: absolute;
  top: 4px;
  right: 4px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  display: none;
}
.gear-btn.has-key .dot { display: block; }

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 16px;
}
.modal-backdrop.open { display: flex; }
.modal {
  background: #ffffff;
  border-radius: 8px;
  width: 100%;
  max-width: 440px;
  padding: 20px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}
.modal h3 {
  margin: 0 0 4px;
  font-size: 16px;
  font-weight: 600;
}
.modal .sub {
  margin: 0 0 16px;
  font-size: 12px;
  color: var(--muted);
}
.modal .field { margin-bottom: 14px; }
.modal .field label.tag {
  display: block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--muted);
  margin-bottom: 6px;
  font-weight: 600;
}
.modal .radios { display: flex; gap: 12px; }
.modal .radios label {
  flex: 1;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
}
.modal .radios label:has(input:checked) {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(1, 62, 222, 0.04);
}
.modal input[type="password"],
.modal input[type="text"],
.modal select {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 13px;
  font-family: "SF Mono", Menlo, Consolas, monospace;
  background: #ffffff;
  color: var(--fg);
}
.modal select { font-family: inherit; }
.modal .status {
  margin: 4px 0 14px;
  font-size: 12px;
  color: var(--muted);
}
.modal .status.set { color: #16a34a; }
.modal .actions {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
  margin-top: 6px;
}
.modal .actions .left { margin-right: auto; }
.modal button.danger {
  background: transparent;
  color: #dc2626;
  border: 1px solid var(--border);
}
.modal button.danger:hover { background: rgba(220, 38, 38, 0.06); filter: none; }

.feedback-corner {
  position: fixed;
  right: 16px;
  bottom: 60px;
  font-size: 12px;
  color: var(--accent);
  text-decoration: none;
  background: #ddefff;
  padding: 6px 10px;
  border: 1px solid var(--accent);
  border-radius: 999px;
  transition: color 120ms ease, border-color 120ms ease;
  z-index: 50;
}
.feedback-corner:hover {
  color: var(--accent);
  border-color: var(--accent);
}
@media (max-width: 540px) {
  .feedback-corner { right: 10px; bottom: 56px; font-size: 11px; padding: 5px 9px; }
}
</content>
</invoke>