/* ===== Base layout ===== */
* { box-sizing: border-box; }
html, body { height: 100%; }
body { margin: 0; font-family: system-ui, Segoe UI, Arial, sans-serif; }

/* ===== Top bar ===== */
.top {
  position: sticky;
  top: 0;
  z-index: 10;
  background: #fff;
  border-bottom: 1px solid #ddd;
  padding: 8px 10px;
  display: flex;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
}

.controls button { margin-right: 8px; }

/* ===== Panes + splitter ===== */
.panes {
  display: flex;
  align-items: stretch;
  gap: 0;
  height: calc(100vh - 80px);
  min-height: 300px;
  box-sizing: border-box;
}

.pane {
  display: flex;
  flex-direction: column;
  min-width: 120px;
  overflow: hidden;
}

.pane-title {
  flex: 0 0 auto;
  font-weight: 600;
  text-align: center;
  padding: 6px 8px;
  border-bottom: 1px solid #ddd;
  background: #f7f7f7;
}

#leftPane,
#rightPane {
  flex: 1 1 auto;
  border: 0;
  padding: 10px;
  overflow: auto;
  background: #fafafa;
  white-space: pre-wrap;
  word-break: break-word;
  position: relative;          /* stabilizes offset/geometry math for JS */
  scroll-behavior: smooth;     /* nicer auto-centering on Next/Prev */
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  font-size: 13px;
  line-height: 1.5;
}

/* Draggable splitter between panes */
.splitter {
  flex: 0 0 8px;
  cursor: col-resize;
  background: linear-gradient(90deg, #e9e9e9 0, #dcdcdc 50%, #e9e9e9 100%);
  border-left: 1px solid #d0d0d0;
  border-right: 1px solid #d0d0d0;
}
.splitter:focus { outline: 2px solid #66aaff; outline-offset: -2px; }

/* During drag: optional global cursor + no text-select feel */
body.resizing, body.resizing * { cursor: col-resize !important; user-select: none !important; }

/* ===== Inline diff colors ===== */
.editOldInline { background: #FFE6E6; }  /* left old (red-ish) */
.editNewInline { background: #E6FFE6; }  /* right new (green-ish) */

/* Current diff focus anchor (both panes) */
.focusTarget {
  outline: 2px dashed #999;
  outline-offset: 2px;
  background: #fff6cc;
}

/* ===== Buttons & inputs tweaks ===== */
button {
  appearance: none;
  border: 1px solid #ccc;
  background: #fff;
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
}
button:hover { background: #f6f6f6; }
button:active { background: #eee; }
button:disabled { opacity: 0.6; cursor: default; }

input[type="file"] {
  border: 1px solid #ddd;
  padding: 4px 6px;
  border-radius: 6px;
  background: #fff;
}

/* ===== Small screens: stack panes vertically (optional) ===== */
@media (max-width: 800px) {
  .panes { flex-direction: column; }
  .splitter { height: 8px; width: 100%; cursor: row-resize; }
  button { padding: 4px 8px; font-size: 12px; }
  input[type="file"] { padding: 2px 4px; font-size: 12px; }
}

/* Tablet: 768px - 1023px (horizontal, optimized for tablets) */
@media (min-width: 768px) and (max-width: 1023px) {
  .top { padding: 6px 12px; }
  .panes { height: calc(100vh - 70px); }
  .pane-title { padding: 8px 10px; font-size: 16px; }
  #leftPane, #rightPane { padding: 12px; font-size: 14px; }
  .splitter { flex: 0 0 10px; }
}

/* Desktop: 1024px - 1439px (standard desktop) */
@media (min-width: 1024px) and (max-width: 1439px) {
  .top { padding: 8px 16px; }
  .panes { height: calc(100vh - 80px); }
  .pane-title { padding: 10px 12px; }
  #leftPane, #rightPane { padding: 15px; font-size: 14px; }
  .splitter { flex: 0 0 12px; }
}

/* Large Desktop: 1440px - 2559px (larger screens) */
@media (min-width: 1440px) and (max-width: 2559px) {
  .top { padding: 10px 20px; }
  .panes { height: calc(100vh - 90px); }
  .pane-title { padding: 12px 15px; font-size: 18px; }
  #leftPane, #rightPane { padding: 20px; font-size: 15px; line-height: 1.6; }
  .splitter { flex: 0 0 15px; }
}

/* 4K: 2560px+ (high resolution) */
@media (min-width: 2560px) {
  .top { padding: 12px 24px; }
  .panes { height: calc(100vh - 100px); }
  .pane-title { padding: 15px 20px; font-size: 20px; }
  #leftPane, #rightPane { padding: 25px; font-size: 16px; line-height: 1.7; }
  .splitter { flex: 0 0 20px; }
  button { padding: 8px 12px; font-size: 16px; }
  input[type="file"] { padding: 6px 8px; font-size: 16px; }
}

/* Disable smooth behavior during forced jumps */
.no-smooth { scroll-behavior: auto !important; }