/* ==========================================================================
   plc.css: the pop-out PLC / digital-twin takeover
   ========================================================================== */
.plc-takeover {
  position: fixed; inset: 0; z-index: 100;
  background: var(--paper); color: var(--ink);
  display: grid; grid-template-rows: auto 1fr;
  animation: plc-in .22s ease-out;
}
.plc-takeover[hidden] { display: none; }
@keyframes plc-in { from { transform: translateY(100%); } to { transform: none; } }
body.plc-open { overflow: hidden; }
@media (prefers-reduced-motion: reduce) { .plc-takeover { animation: none; } }

.plc-bar {
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
  padding: 8px 14px; border-bottom: var(--line) solid var(--ink); background: var(--yellow);
}
.plc-bar .title { font-family: var(--font-display); font-size: 1.3rem; text-transform: uppercase; }
.plc-bar .spacer { flex: 1; }
.plc-bar .btn { font-size: 0.9rem; padding: 6px 12px; box-shadow: 3px 3px 0 var(--ink); }
.plc-bar .btn:hover { box-shadow: 1px 1px 0 var(--ink); }
.plc-mode { display: inline-flex; border: var(--line) solid var(--ink); overflow: hidden; font-family: var(--font-mono); font-size: 0.8rem; }
.plc-mode button { border: 0; background: var(--white); padding: 6px 12px; font: inherit; cursor: pointer; letter-spacing: 0.12em; }
.plc-mode button + button { border-left: var(--line) solid var(--ink); }
.plc-mode button[aria-pressed="true"] { background: var(--ink); color: var(--yellow); }
.plc-status { font-family: var(--font-mono); font-size: 0.75rem; letter-spacing: 0.08em; display: flex; gap: 14px; }
.plc-status .led { display: inline-block; width: 10px; height: 10px; border: 2px solid var(--ink); border-radius: 50%; background: var(--paper-2); vertical-align: -1px; margin-right: 4px; }
.plc-status .led.on { background: #38e04b; box-shadow: 0 0 6px #38e04b; }
.plc-status .led.fault { background: var(--magenta); }

.plc-split { display: grid; grid-template-columns: minmax(380px, 1fr) minmax(320px, 1fr); min-height: 0; }
.plc-pane { min-height: 0; display: flex; flex-direction: column; overflow: hidden; }
.plc-pane + .plc-pane { border-left: var(--line) solid var(--ink); }
.pane-head { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 8px; padding: 6px 10px; border-bottom: 2px solid var(--ink); background: var(--paper-2); font-family: var(--font-caption); font-weight: 700; text-transform: uppercase; font-size: 0.85rem; }
.pane-head .spacer { flex: 1; }
.pane-head select, .pane-head button { font: inherit; font-size: 0.78rem; border: 2px solid var(--ink); background: var(--white); padding: 3px 7px; cursor: pointer; white-space: nowrap; }
.pane-head select { max-width: 150px; text-overflow: ellipsis; }
.pane-head label { display: inline-flex; align-items: center; gap: 4px; white-space: nowrap; }
.pane-head button:hover { background: var(--yellow); }

/* ---- Ladder pane: rendered ladder on top, properties drawer below, optional text view ---- */
.ladder-editor { display: grid; grid-template-rows: minmax(0, 1fr) auto auto; min-height: 0; flex: 1; }
.ladder-wrap { min-height: 0; display: flex; flex-direction: row; overflow: hidden; position: relative; }
.ladder-col { flex: 1; min-width: 0; min-height: 0; display: flex; flex-direction: column; }
.ladder-col .ladder { flex: 1; }

/* Dockable instruction palette (drag source) */
.palette-pop { flex: none; width: 232px; min-height: 0; display: flex; flex-direction: column; border-left: var(--line) solid var(--ink); background: var(--paper); }
.palette-pop[hidden] { display: none; }
.palette-pop-head { display: flex; align-items: center; gap: 8px; padding: 6px 8px 6px 12px; background: var(--yellow); border-bottom: 2px solid var(--ink); font-family: var(--font-caption); font-weight: 700; text-transform: uppercase; font-size: 0.85rem; }
.palette-pop-head .spacer { flex: 1; }
.palette-pop-head .dbtn { padding: 2px 8px; min-height: 0; }
.palette-pop-hint { padding: 6px 12px; font-family: var(--font-mono); font-size: 0.64rem; line-height: 1.4; color: var(--ink-soft); border-bottom: 2px solid var(--ink); background: var(--paper-2); }
.palette-pop-body { overflow: auto; padding: 8px 10px 14px; display: grid; gap: 8px; align-content: start; }
.palette-pop-body .ops { display: grid; gap: 4px; }
.pitem, .pbtn {
  font: inherit; border: 2px solid var(--ink); background: var(--white); cursor: grab; text-align: left;
  display: grid; grid-template-columns: 12px 1fr; grid-template-rows: auto auto; column-gap: 6px; align-items: center;
  padding: 4px 8px 4px 6px; user-select: none; -webkit-user-select: none; touch-action: pan-y;
}
.pitem .grip, .pbtn .grip { grid-row: 1 / span 2; color: var(--ink-soft); font-size: 11px; letter-spacing: -3px; line-height: 1; }
.pitem b, .pbtn b { font-family: var(--font-display); font-size: 0.95rem; letter-spacing: 0.05em; }
.pitem small, .pbtn small { font-size: 0.62rem; color: var(--ink-soft); font-family: var(--font-mono); }
.pitem:hover, .pbtn:hover { background: var(--yellow); }
.pitem:active, .pbtn:active { cursor: grabbing; }

/* Drag & drop feedback */
.instr { touch-action: pan-y; user-select: none; -webkit-user-select: none; }
.drag-ghost { position: fixed; z-index: 1000; pointer-events: none; transform: translate(-50%, -50%) rotate(-2deg); border: 3px solid var(--ink); background: var(--yellow); box-shadow: 5px 5px 0 var(--ink); padding: 5px 10px; display: grid; font-family: var(--font-mono); font-size: 0.66rem; color: var(--ink); }
.drag-ghost b { font-family: var(--font-display); font-size: 1rem; letter-spacing: 0.05em; }
body.plc-dragging, body.plc-dragging * { cursor: grabbing !important; }
body.plc-dragging { user-select: none; -webkit-user-select: none; }
.instr.drag-source { opacity: 0.35; }
.rung.drop-target { background: rgba(255, 217, 0, 0.3); }
.drop-marker { position: absolute; top: 12px; bottom: 6px; width: 6px; margin-left: -3px; background: var(--magenta); box-shadow: 0 0 0 2px var(--white); z-index: 3; pointer-events: none; }
.drop-marker::before, .drop-marker::after { content: ""; position: absolute; left: -4px; border: 7px solid transparent; }
.drop-marker::before { top: -8px; border-top-color: var(--magenta); }
.drop-marker::after { bottom: -8px; border-bottom-color: var(--magenta); }
.drop-newrung { display: none; margin: 12px 20px 4px 34px; border: 2px dashed var(--ink); padding: 12px; text-align: center; font-family: var(--font-caption); font-weight: 700; text-transform: uppercase; font-size: 0.75rem; color: var(--ink-soft); }
body.plc-dragging .drop-newrung { display: block; }
.drop-newrung.drop-target { background: var(--yellow); color: var(--ink); border-style: solid; }
.ladder-errors { font-family: var(--font-mono); font-size: 0.75rem; color: var(--white); background: var(--magenta); padding: 4px 12px; display: none; }
.ladder-errors.show { display: block; }

/* Text view (import / export) */
.ladder-textwrap { border-top: var(--line) solid var(--ink); display: grid; grid-template-rows: minmax(110px, 150px) auto; }
.ladder-textwrap[hidden] { display: none; }
.ladder-text {
  margin: 0; width: 100%; height: 100%; resize: none; border: 0;
  font-family: var(--font-mono); font-size: 16px; line-height: 1.45;   /* ≥16px: iOS does not zoom on focus */
  padding: 10px 14px; background: var(--ink); color: var(--paper); outline: none;
  tab-size: 4; white-space: pre; overflow: auto;
}
.ladder-text:focus { box-shadow: inset 0 0 0 3px var(--cyan); }
.ladder-textbar { display: flex; align-items: center; gap: 8px; padding: 4px 12px; background: var(--paper-2); border-top: 2px solid var(--ink); font-family: var(--font-mono); font-size: 0.72rem; }
.ladder-textbar .spacer { flex: 1; }
.ladder-textbar code { background: var(--white); padding: 0 4px; }
.ladder-textbar button { font: inherit; font-size: 0.75rem; border: 2px solid var(--ink); background: var(--yellow); padding: 3px 10px; cursor: pointer; text-transform: uppercase; letter-spacing: 0.06em; }

/* Editing affordances on the ladder */
.rung { cursor: default; }
.rung.selected { background: rgba(0, 174, 239, 0.14); box-shadow: inset 4px 0 0 var(--cyan); }
.rung-num { cursor: pointer; border: 2px solid transparent; border-radius: 2px; text-align: center; }
.rung-num:hover, .rung-num:focus-visible { border-color: var(--ink); background: var(--yellow); color: var(--ink); outline: none; }
.rung.heading { min-height: 0; padding: 12px 0 0 34px; font-family: var(--font-caption); font-weight: 700; font-size: 0.78rem; text-transform: uppercase; color: var(--ink-soft); cursor: pointer; }
.rung.heading:hover, .rung.heading.selected { color: var(--ink); }
.rung.has-error .wire { background: var(--magenta); }
.rung-error { position: absolute; right: 8px; top: 0; font-family: var(--font-mono); font-size: 0.66rem; color: var(--white); background: var(--magenta); padding: 1px 6px; max-width: 60%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.instr { cursor: pointer; padding: 3px; border-radius: 2px; }
.instr:hover { background: rgba(255, 217, 0, 0.4); }
.instr:focus-visible { outline: 3px solid var(--cyan); }
.instr.selected { outline: 3px solid var(--magenta); outline-offset: 1px; background: rgba(236, 0, 140, 0.08); }
.add-instr {
  flex: none; width: 30px; height: 30px; margin: 0 6px; cursor: pointer;
  border: 2px dashed var(--ink); background: var(--white); color: var(--ink);
  font: 700 18px/1 var(--font-mono); opacity: 0.5;
}
.rung:hover .add-instr, .rung.selected .add-instr, .add-instr:focus-visible { opacity: 1; }
.add-instr:hover { background: var(--yellow); border-style: solid; }

/* Properties drawer */
.ladder-drawer { border-top: var(--line) solid var(--ink); background: var(--paper-2); padding: 8px 12px 10px; font-family: var(--font-mono); font-size: 0.78rem; max-height: min(45vh, 340px); overflow: auto; }
.drawer-idle { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.drawer-idle .hint { flex: 1; text-transform: none; letter-spacing: 0; }
.drawer-head { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; font-family: var(--font-caption); font-weight: 700; text-transform: uppercase; font-size: 0.8rem; }
.drawer-head .op { font-family: var(--font-display); font-size: 1.05rem; letter-spacing: 0.04em; background: var(--ink); color: var(--yellow); padding: 1px 8px; }
.drawer-head .spacer { flex: 1; }
.drawer-fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 6px 12px; }
.drawer-fields .field:has(.joints-grid) { grid-column: 1 / -1; }
.field { display: grid; gap: 3px; }
.field > span { font-size: 0.66rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--ink-soft); }
.field input, .field select { font: inherit; font-size: 16px; border: 2px solid var(--ink); padding: 5px 7px; background: var(--white); width: 100%; min-width: 0; border-radius: 0; }
.field input:focus, .field select:focus { outline: none; box-shadow: 0 0 0 3px var(--cyan); }
.joints-grid { display: grid; grid-template-columns: repeat(6, 1fr); gap: 4px; }
.field-error { display: none; margin-top: 6px; font-size: 0.72rem; color: var(--white); background: var(--magenta); padding: 2px 8px; }
.field-error.show { display: block; }
.drawer-actions { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 10px; }
.dbtn { font: inherit; font-size: 0.72rem; letter-spacing: 0.06em; text-transform: uppercase; border: 2px solid var(--ink); background: var(--white); padding: 6px 10px; cursor: pointer; min-height: 32px; }
.dbtn:hover:not(:disabled) { background: var(--yellow); }
.dbtn.primary { background: var(--yellow); }
.dbtn.danger:hover:not(:disabled) { background: var(--magenta); color: var(--white); border-color: var(--ink); }
.dbtn:disabled { opacity: 0.4; cursor: default; }
.palette { display: grid; gap: 8px; }
.palette-group h4 { margin: 0 0 4px; font-family: var(--font-caption); font-size: 0.7rem; letter-spacing: 0.14em; text-transform: uppercase; color: var(--magenta); }
.palette-group .ops { display: flex; flex-wrap: wrap; gap: 4px; }
.palette .pbtn { min-width: 118px; }

.ladder { overflow: auto; padding: 14px 16px 30px; background:
  repeating-linear-gradient(0deg, transparent 0 23px, rgba(20,20,20,0.06) 23px 24px); }
.rung { display: flex; align-items: center; min-height: 86px; position: relative; padding-top: 18px; }
.rung-comment { position: absolute; top: 0; left: 18px; font-family: var(--font-caption); font-weight: 700; font-size: 0.72rem; text-transform: uppercase; color: var(--ink-soft); }
.rung-num { font-family: var(--font-mono); font-size: 0.7rem; width: 28px; color: var(--ink-soft); flex: none; }
.rail { width: 6px; align-self: stretch; background: var(--ink); flex: none; }
.rail.hot { background: var(--yellow); box-shadow: 0 0 6px var(--yellow); }
.wire { flex: 1 0 18px; height: 4px; background: var(--ink); }
.wire.hot { background: var(--yellow); box-shadow: 0 0 6px var(--yellow); }
.instr { flex: none; display: flex; flex-direction: column; align-items: center; gap: 2px; position: relative; }
.instr .sym { width: 60px; height: 40px; display: block; }
.instr .sym .stroke { stroke: var(--ink); stroke-width: 4; fill: none; stroke-linecap: square; }
.instr .sym .fillbox { fill: var(--white); stroke: var(--ink); stroke-width: 3; }
.instr.hot .sym .stroke { stroke: var(--yellow); filter: drop-shadow(0 0 3px var(--yellow)); }
.instr.hot .sym .fillbox { fill: var(--yellow); }
.instr .tag { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.04em; white-space: nowrap; }
.instr .val { font-family: var(--font-mono); font-size: 10px; color: var(--ink-soft); white-space: nowrap; }
.instr.block { align-items: stretch; }
.instr.block .box { border: 3px solid var(--ink); background: var(--white); min-width: 118px; font-family: var(--font-mono); font-size: 11px; line-height: 1.35; padding: 4px 8px; }
.instr.block .box .hd { font-weight: 700; font-size: 12px; letter-spacing: 0.1em; border-bottom: 2px solid var(--ink); margin-bottom: 3px; padding-bottom: 2px; display: flex; justify-content: space-between; gap: 8px; }
.instr.block .box .row { display: flex; justify-content: space-between; gap: 10px; }
.instr.block .box .row .bit { font-weight: 700; }
.instr.block .box .row .bit.on { color: #0a7f1e; }
.instr.block.hot .box { background: var(--yellow); box-shadow: 0 0 8px var(--yellow); }
.instr.block.done .box .hd { background: var(--cyan); margin: -4px -8px 3px; padding: 2px 8px; }
.instr.err .box, .instr.err .sym .stroke { stroke: var(--magenta); border-color: var(--magenta); }
.rung.empty .wire { background: var(--ink-soft); opacity: 0.4; }

/* ---- Viewport pane ---- */
.plc-viewport { position: relative; flex: 1; min-height: 240px; background: var(--paper); }
.plc-viewport canvas { position: absolute; inset: 0; width: 100% !important; height: 100% !important; }
.plc-controls { border-top: var(--line) solid var(--ink); padding: 10px 14px; display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 8px 16px; background: var(--paper-2); max-height: 42%; overflow: auto; }
.joint { display: grid; grid-template-columns: 34px 1fr 52px; gap: 8px; align-items: center; font-family: var(--font-mono); font-size: 0.75rem; }
.joint input[type=range] { width: 100%; accent-color: var(--magenta); }
.joint .deg { text-align: right; }
.plc-controls .full { grid-column: 1 / -1; display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }

/* ---- Tag monitor ---- */
.tag-monitor { font-family: var(--font-mono); font-size: 0.75rem; border-collapse: collapse; width: 100%; }
.tag-monitor th, .tag-monitor td { border-bottom: 1px solid rgba(20,20,20,0.25); padding: 3px 8px; text-align: left; }
.tag-monitor th { background: var(--paper-2); font-family: var(--font-caption); text-transform: uppercase; font-size: 0.72rem; position: sticky; top: 0; }
.tag-monitor td.v1 { color: #0a7f1e; font-weight: 700; }
.tag-monitor .btn-toggle { font: inherit; font-size: 0.7rem; border: 2px solid var(--ink); background: var(--white); padding: 0 6px; cursor: pointer; }
.tag-monitor .btn-toggle:hover { background: var(--yellow); }
.tag-wrap { overflow: auto; max-height: 220px; border-top: var(--line) solid var(--ink); }
.plc-help { padding: 10px 14px; font-size: 0.82rem; font-family: var(--font-body); border-top: 2px solid var(--ink); background: var(--white); max-height: 200px; overflow: auto; }
.plc-help code { font-family: var(--font-mono); background: var(--paper-2); padding: 0 4px; }
.plc-help[hidden] { display: none; }

.plc-takeover { grid-template-rows: auto minmax(0, 1fr) auto; }
.plc-mobilebar, .plc-backdrop { display: none; }
.palette-pop-body { min-height: 0; }

/* ======================================================================
   Phones and small tablets: twin on top, ladder below, and a bottom bar
   that opens the palette, joint sliders, tag monitor, text view and help
   as bottom sheets. Instruction properties open as a sheet too.
   ====================================================================== */
@media (max-width: 860px) {
  .plc-bar { padding: 6px 10px; gap: 6px 10px; }
  .plc-bar .title { font-size: 1rem; }
  .plc-bar .btn { font-size: 0.72rem; padding: 5px 9px; }
  .plc-mode button { padding: 5px 10px; font-size: 0.72rem; }
  #plc-help-btn { display: none; }                                   /* lives in the bottom bar */
  .plc-status { order: 10; width: 100%; font-size: 0.64rem; gap: 10px; }

  .plc-split { display: flex; flex-direction: column; overflow: hidden; }
  .plc-pane + .plc-pane { border-left: 0; }
  .plc-pane.pane-twin { order: -1; flex: none; height: 34vh; min-height: 190px; position: relative; border-bottom: var(--line) solid var(--ink); }
  .plc-pane.pane-twin .twin-head { position: absolute; top: 6px; right: 6px; z-index: 2; background: transparent; border: 0; padding: 0; gap: 6px; }
  .plc-pane.pane-twin .twin-head .pane-title, .plc-pane.pane-twin .twin-head .spacer { display: none; }
  .plc-viewport { flex: 1; height: auto; min-height: 0; }
  .tags-head { display: none; }
  .plc-pane.pane-ladder { flex: 1; min-height: 0; }
  #plc-palette-btn, #plc-text-btn { display: none; }                 /* also in the bottom bar */
  .pane-head { padding: 4px 8px; }

  /* Bottom sheets (above the bottom bar) */
  .plc-controls, #tag-wrap, .ladder-textwrap, .plc-help, .palette-pop, .ladder-drawer {
    position: fixed; left: 0; right: 0; top: auto; bottom: calc(54px + env(safe-area-inset-bottom)); z-index: 120;
    width: auto; max-height: 58vh; overflow: auto; margin: 0;
    background: var(--paper); border: 0; border-top: var(--line-heavy) solid var(--ink);
    box-shadow: 0 -10px 0 rgba(20, 20, 20, 0.12);
    padding-bottom: 14px;
    animation: sheet-in .18s ease-out;
  }
  @keyframes sheet-in { from { transform: translateY(100%); } to { transform: none; } }
  @media (prefers-reduced-motion: reduce) {
    .plc-controls, #tag-wrap, .ladder-textwrap, .plc-help, .palette-pop, .ladder-drawer { animation: none; transition: none; }
  }
  .plc-controls[hidden], #tag-wrap[hidden], .ladder-textwrap[hidden], .plc-help[hidden], .palette-pop[hidden] { display: none; }
  .ladder-drawer { display: none; z-index: 130; max-height: 52vh; padding: 10px 12px 14px; }
  .ladder-drawer.open { display: block; }
  .palette-pop.drag-hidden, .ladder-drawer.drag-hidden { transform: translateY(120%); transition: transform .15s; }
  .palette-pop { padding-bottom: 0; }
  .palette-pop-head { position: sticky; top: 0; z-index: 1; }
  .palette-pop-body .ops { grid-template-columns: 1fr 1fr; }
  .plc-controls { display: grid; grid-template-columns: 1fr; gap: 10px; padding: 12px 14px 16px; }   /* one slider per row */
  .joint { grid-template-columns: 44px 1fr 64px; font-size: 0.85rem; }
  .joint input[type=range] { height: 34px; }
  .tag-monitor { font-size: 0.85rem; }
  .tag-monitor th, .tag-monitor td { padding: 8px 10px; }
  .tag-monitor .btn-toggle { font-size: 0.85rem; padding: 4px 10px; min-height: 36px; }
  .ladder-textwrap { grid-template-rows: minmax(120px, 34vh) auto; }
  .plc-help { font-size: 0.9rem; line-height: 1.5; padding: 12px 14px 16px; }

  .plc-backdrop { display: block; position: fixed; inset: 0; z-index: 110; background: rgba(20, 20, 20, 0.28); }
  .plc-backdrop[hidden] { display: none; }
  .plc-mobilebar { display: flex; height: calc(54px + env(safe-area-inset-bottom)); padding-bottom: env(safe-area-inset-bottom); border-top: var(--line) solid var(--ink); background: var(--yellow); }
  .plc-mobilebar button { flex: 1; min-width: 0; font: 700 0.72rem/1 var(--font-caption); text-transform: uppercase; letter-spacing: 0.04em; border: 0; border-right: 2px solid var(--ink); background: transparent; color: var(--ink); padding: 0 4px; cursor: pointer; }
  .plc-mobilebar button:last-child { border-right: 0; }
  .plc-mobilebar button[aria-pressed="true"] { background: var(--ink); color: var(--yellow); }
}
}