:root {
  --bg: #f2f4f8;
  --panel: #ffffff;
  --panel-2: #e9edf4;
  --border: #d5dbe5;
  --text: #1f2733;
  --muted: #5c697a;
  --accent: #2563b5;
  --accent-2: #1d6fbd;
  --ok: #1d9752;
  --err: #c0392b;
  --warn: #b9770b;
  --code-bg: #ffffff;
  --mono: "Cascadia Code", Consolas, "SF Mono", Menlo, monospace;
  /* Panel widths (adjustable via the draggable dividers). */
  --files-w: 260px;
  --output-w: 430px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body { height: 100%; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 13px;
  display: flex;
  flex-direction: column;
}

/* ---------- top bar ---------- */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 14px;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}
.brand { display: flex; align-items: center; gap: 8px; font-size: 15px; }
.logo { color: var(--accent); font-weight: 700; font-size: 20px; }
.title { font-weight: 600; letter-spacing: 0.2px; }
.toolbar { display: flex; align-items: center; gap: 8px; }

.btn {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 13px;
  transition: background 0.15s, border-color 0.15s;
}
.btn:hover { background: #f4f6fa; border-color: #c3ccd9; }
.btn:disabled { opacity: 0.5; cursor: default; }
.btn.primary { background: var(--accent-2); border-color: var(--accent-2); }
.btn.primary:hover { background: var(--accent); }
.btn.build { background: var(--ok); border-color: var(--ok); color: #fff; font-weight: 600; }
.btn.build:hover { filter: brightness(1.08); }
.btn.small { padding: 3px 8px; font-size: 12px; }
.mini {
  background: transparent; border: 1px solid var(--border); color: var(--muted);
  border-radius: 5px; padding: 2px 7px; cursor: pointer; font-size: 12px;
}
.mini:hover { color: var(--text); border-color: #9aa6b8; }
.mini.danger:hover { color: var(--err); border-color: var(--err); }
.engine-badge {
  font-size: 11px; color: var(--muted); background: var(--panel-2);
  border: 1px solid var(--border); border-radius: 999px; padding: 4px 10px;
}
.engine-badge.ok { color: var(--ok); border-color: var(--ok); }
.engine-badge.warn { color: var(--warn); border-color: var(--warn); }

/* ---------- layout ---------- */
.layout {
  flex: 1;
  display: grid;
  /* Five children flow left-to-right in one row: files, divider, editor,
     divider, output. All are explicitly placed below so they never wrap. */
  grid-template-columns: var(--files-w) 5px 1fr 5px var(--output-w);
  grid-template-rows: 1fr;
  min-height: 0;
}
.panel.files  { grid-column: 1; }
.divider[data-dir="files"]  { grid-column: 2; }
.panel.editor { grid-column: 3; }
.divider[data-dir="output"] { grid-column: 4; }
.panel.output { grid-column: 5; }

.panel {
  background: var(--panel);
  min-width: 0;
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.panel.files { border-right: 1px solid var(--border); }
.panel.output { border-left: 1px solid var(--border); }
.divider {
  width: 100%;
  height: 100%;
  cursor: col-resize;
  flex: none;
  background: transparent;
  transition: background 0.15s;
  z-index: 5;
  touch-action: none; /* keep touch drags from being cancelled by scrolling */
}
.divider:hover, .divider.dragging { background: var(--accent); }

.head-actions { display: flex; align-items: center; gap: 4px; }

/* ---------- foldable files panel ---------- */
/* Folded state overrides the grid template directly (not --files-w), so it
   wins over any inline width the resize drag has set on :root. */
.layout.folded-files { grid-template-columns: 36px 0 1fr 5px var(--output-w); }
.layout.folded-files .divider[data-dir="files"] { display: none; }
.panel.files.folded .tree,
.panel.files.folded .panel-foot { display: none; }
.panel.files.folded .panel-head {
  flex-direction: column;
  justify-content: flex-start;
  gap: 10px;
  padding: 8px 6px;
  border-bottom: none;
  flex: 1;
  min-height: 0;
}
.panel.files.folded .panel-head > span:first-child {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-height: 55%;
}
.panel.files.folded .head-actions { flex-direction: column; }
.panel-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 8px 10px; border-bottom: 1px solid var(--border);
  color: var(--muted); font-weight: 600; text-transform: uppercase;
  font-size: 11px; letter-spacing: 0.6px; background: var(--panel-2);
}
.panel-foot { border-top: 1px solid var(--border); padding: 8px 10px; }
.pathinfo { color: var(--muted); font-size: 12px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* ---------- file tree ---------- */
.tree { flex: 1; overflow: auto; padding: 6px; }
.tree-node { user-select: none; }
.tree-row {
  display: flex; align-items: center; gap: 6px; padding: 3px 6px; border-radius: 5px;
  cursor: pointer; color: var(--text); white-space: nowrap;
}
.tree-row:hover { background: var(--panel-2); }
.tree-row.active { background: var(--accent-2); color: #fff; }
.tree-row .caret { width: 14px; color: var(--muted); display: inline-block; text-align: center; font-size: 10px; }
.tree-row .icon { color: var(--muted); width: 16px; text-align: center; }
.tree-row.active .icon, .tree-row.active .caret { color: #fff; }
.tree-row .fname { flex: 1; overflow: hidden; text-overflow: ellipsis; }
.tree-row .row-action { font-size: 10px; color: var(--muted); border: 1px solid var(--muted); border-radius: 4px; padding: 0 5px; cursor: pointer; white-space: nowrap; }
.tree-row .row-action:hover { color: var(--accent-2); border-color: var(--accent-2); }
.tree-row.active .row-action { color: #fff; border-color: #fff; }
.tree-children { padding-left: 14px; }
.tree-empty { color: var(--muted); padding: 10px; font-style: italic; }

/* Per-row "⋯" button revealing the labeled action menu (Google-Drive style).
   Semi-transparent when idle so it stays reachable on touch devices. */
.tree-row .row-more {
  flex: none; width: 18px; height: 18px; padding: 0; margin-left: 2px;
  border: 0; border-radius: 4px; background: transparent; color: var(--muted);
  font-size: 14px; line-height: 1; text-align: center; cursor: pointer;
  opacity: 0.35; transition: opacity 0.12s, background 0.12s, color 0.12s;
}
.tree-row:hover .row-more, .tree-row.active .row-more { opacity: 1; }
.tree-row .row-more:hover { background: var(--panel-2); color: var(--text); }
.tree-row.active .row-more { color: #fff; }
.tree-row.active .row-more:hover { background: rgba(255, 255, 255, 0.22); color: #fff; }

/* Floating context menu for tree rows (right-click). */
.ctx-menu {
  position: fixed; z-index: 200; min-width: 170px;
  background: var(--panel); border: 1px solid var(--border); border-radius: 8px;
  box-shadow: 0 10px 32px rgba(15, 23, 42, 0.18);
  padding: 4px; display: flex; flex-direction: column; gap: 1px;
}
.ctx-item {
  text-align: left; border: 0; background: transparent; cursor: pointer;
  font-size: 12.5px; color: var(--text); padding: 6px 10px; border-radius: 5px; white-space: nowrap;
}
.ctx-item:hover { background: var(--panel-2); }
.ctx-item.danger:hover { color: var(--err); background: #fbeeed; }

/* ---------- editor ---------- */
.editor-wrap { flex: 1; display: flex; position: relative; min-height: 0; background: var(--code-bg); }
.linenums {
  flex: none; text-align: right; padding: 8px 8px 8px 0;
  color: #6b7686; background: var(--code-bg); font-family: var(--mono);
  font-size: 12.5px; line-height: 1.5; overflow: hidden; user-select: none;
  border-right: 1px solid var(--border);
  white-space: pre;                 /* keep each number on its own row */
  min-width: 30px;
}
.code {
  flex: 1; min-width: 0; resize: none; border: none; outline: none;
  background: var(--code-bg); color: #1f2733; font-family: var(--mono);
  font-size: 12.5px; line-height: 1.5; padding: 8px 10px; tab-size: 2;
}
.filename {
  background: transparent; border: 1px solid transparent; color: var(--text);
  font-size: 12.5px; font-weight: 600; text-transform: none; letter-spacing: 0;
  width: 55%; padding: 2px 6px; border-radius: 4px;
}
.filename:hover, .filename:focus { border-color: var(--border); background: var(--panel); }
.editor-actions { display: flex; gap: 6px; }
.statusbar {
  display: flex; align-items: center; gap: 14px; padding: 5px 10px;
  border-top: 1px solid var(--border); color: var(--muted); font-size: 11.5px;
  background: var(--panel-2);
}
.statusbar .spacer { flex: 1; }
.statusbar .dirty { color: var(--warn); }

/* ---------- output ---------- */
.tabs { display: flex; border-bottom: 1px solid var(--border); background: var(--panel-2); }
.tab {
  background: transparent; border: none; color: var(--muted); padding: 8px 14px;
  cursor: pointer; font-size: 12px; border-bottom: 2px solid transparent;
}
.tab:hover { color: var(--text); }
.tab.active { color: var(--text); border-bottom-color: var(--accent); }
.tab-body { flex: 1; min-height: 0; display: flex; flex-direction: column; }
.tabpane { display: none; flex: 1; min-height: 0; overflow: auto; }
.tabpane.active { display: flex; flex-direction: column; }
.console {
  padding: 8px 10px; font-family: var(--mono); font-size: 11.5px; line-height: 1.5;
  white-space: pre-wrap; word-break: break-word; color: #1f2733; flex: 1;
}
.console .e { color: var(--err); }
.console .m { color: var(--accent); font-style: italic; }
.console .ok { color: var(--ok); }

/* issues list */
.issues { list-style: none; flex: 1; padding: 6px; }
.issues li {
  display: flex; gap: 8px; align-items: flex-start; padding: 6px 8px;
  border-radius: 6px; border-left: 3px solid transparent; margin-bottom: 4px;
  cursor: pointer; background: var(--panel-2);
}
.issues li:hover { background: #f4f6fa; }
.issues li.lvl-error { border-left-color: var(--err); }
.issues li.lvl-warning { border-left-color: var(--warn); }
.issues li.lvl-notice { border-left-color: var(--accent); }
.issues .lvl {
  font-size: 10px; text-transform: uppercase; font-weight: 700; letter-spacing: 0.5px;
  flex: none; padding: 2px 6px; border-radius: 4px; margin-top: 1px;
}
.lvl-error { color: var(--err); }
.lvl-warning { color: var(--warn); }
.lvl-notice { color: var(--accent); }
.issues .msg { flex: 1; }
.issues .loc { color: var(--muted); font-size: 11px; font-family: var(--mono); flex: none; }
.issues-empty { color: var(--muted); padding: 12px; text-align: center; font-style: italic; }
.badge {
  background: var(--err); color: #fff; border-radius: 999px; font-size: 10px;
  padding: 1px 6px; margin-left: 4px; font-weight: 700; display: none;
}
.badge.show { display: inline-block; }

/* pdf */
.pdf-pane { background: #eef1f6; min-height: 0; }
.pdf-placeholder { padding: 20px; text-align: center; color: var(--muted); }
.pdf-viewer {
  display: block; flex: 1 1 auto; border: none; width: 100%;
  height: 100%; min-height: 0; background: #fff;
}
.pdf-pane .btn { align-self: center; margin: 8px; }

/* Image preview tab */
.pdf-pane .image-viewer { max-width: 92%; max-height: 82%; object-fit: contain; background:
  repeating-conic-gradient(#eef0f4 0% 25%, #fff 0% 50%) 50% / 24px 24px; border: 1px solid var(--border); }
.pdf-pane .image-name { font-size: 12px; color: var(--muted); margin-top: 6px; }

#toast {
  position: fixed; bottom: 18px; left: 50%; transform: translateX(-50%);
  background: var(--panel-2); border: 1px solid var(--border); color: var(--text);
  padding: 8px 16px; border-radius: 8px; box-shadow: 0 8px 24px rgba(0,0,0,0.12);
  opacity: 0; pointer-events: none; transition: opacity 0.2s; z-index: 100;
}
#toast.show { opacity: 1; }
#toast.err { border-color: var(--err); color: var(--err); }

/* ---------- new-file template picker modal ---------- */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(15, 23, 42, 0.45);
  display: flex; align-items: center; justify-content: center; z-index: 90;
}
.modal-overlay[hidden] { display: none; }
.modal {
  background: var(--panel); border: 1px solid var(--border); border-radius: 10px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.25);
  width: min(680px, calc(100vw - 32px));
  max-height: min(560px, calc(100vh - 48px));
  display: flex; flex-direction: column; overflow: hidden;
}
.modal-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 14px; border-bottom: 1px solid var(--border);
  font-weight: 600; background: var(--panel-2);
}
.tpl-list {
  overflow: auto; padding: 10px; display: grid; gap: 8px;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}
.tpl-card {
  border: 1px solid var(--border); border-radius: 8px; padding: 8px 10px;
  cursor: pointer; background: var(--panel);
  transition: border-color 0.15s, background 0.15s;
}
.tpl-card:hover { background: var(--panel-2); }
.tpl-card.selected { border-color: var(--accent-2); background: #edf4fc; }
.tpl-card:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
.tpl-name { font-weight: 600; margin-bottom: 2px; }
.tpl-desc { color: var(--muted); font-size: 11.5px; line-height: 1.35; }
.modal-foot {
  display: flex; align-items: center; gap: 8px;
  padding: 10px 14px; border-top: 1px solid var(--border);
}
.modal-foot input[type="text"] {
  flex: 1; min-width: 0; border: 1px solid var(--border); border-radius: 6px;
  padding: 6px 8px; font-size: 13px; color: var(--text); background: var(--panel);
  font-family: var(--mono);
}
.modal-foot input[type="text"]:focus { outline: none; border-color: var(--accent-2); }

@media (max-width: 1100px) {
  .layout {
    grid-template-columns: var(--files-w) 5px 1fr;
    grid-template-rows: 1fr auto;
  }
  .divider[data-dir="output"] { grid-column: 1 / -1; grid-row: 2; height: 5px; width: 100%; cursor: row-resize; }
  .panel.output { grid-column: 1 / -1; grid-row: 3; border-left: none; border-top: 1px solid var(--border); max-height: 40vh; }
}

/* ---------- narrow screens (tablets): keep side-by-side layout -------------
   The desktop folded rule reserves five tracks (incl. a fixed 430px output
   column), which makes no sense once the output panel moves below the editor,
   so shrink the folded files column to a rail within this layout instead. */
@media (max-width: 1100px) {
  .layout.folded-files { grid-template-columns: 36px 5px 1fr; }
}

/* ---------- phones: stack Files / Editor / Output vertically ----------------
   Breakpoint intentionally matches MOBILE_MQ in app.js. Folding collapses the
   files panel to just its header bar in this stacked layout. */
@media (max-width: 768px) {
  .topbar { flex-wrap: wrap; row-gap: 6px; }
  .toolbar { flex-wrap: wrap; row-gap: 6px; }

  .layout,
  .layout.folded-files {
    grid-template-columns: 1fr;
    grid-template-rows: auto minmax(0, 1fr) minmax(140px, 42%);
  }
  .divider[data-dir="files"],
  .divider[data-dir="output"] { display: none; }

  .panel.files {
    grid-column: 1;
    grid-row: 1;
    max-height: 34vh;              /* cap unfolded height; tree scrolls */
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .panel.editor {
    grid-column: 1;
    grid-row: 2;
  }
  .panel.output {
    grid-column: 1;
    grid-row: 3;
    max-height: none;
  }

  /* Folded files = header bar only: undo the vertical-rail presentation. */
  .panel.files.folded .panel-head {
    flex-direction: row;
    justify-content: space-between;
    gap: 4px;
    padding: 8px 10px;
    border-bottom: 1px solid var(--border);
    flex: none;
    min-height: 0;
  }
  .panel.files.folded .panel-head > span:first-child {
    writing-mode: horizontal-tb;
    transform: none;
    max-height: none;
  }
  .panel.files.folded .head-actions { flex-direction: row; }
}