:root {
  color-scheme: dark;
  --bg: #0d1110;
  --panel: #151b19;
  --panel-edge: #232c29;
  --text: #d6e2dc;
  --muted: #7d8c86;
  --screen-bg: #050806;
  --screen-edge: #1d2622;
  --key-top: #2a3330;
  --key-bottom: #1c2321;
  --key-edge: #0a0d0c;
  --key-text: #e3ebe7;
  --key-dim: #6f7d77;
  --accent: #4fe08a;
  --warn: #ffcc4d;
  --err: #ff6b6b;
  /* 5250 colors (3179-2 color display) */
  --c-green: #4fe08a;
  --c-white: #f2f5f3;
  --c-red: #ff5f5f;
  --c-turquoise: #3fd6d9;
  --c-yellow: #ffe066;
  --c-pink: #ff8ad8;
  --c-blue: #6ea8ff;
  --mono: ui-monospace, "Cascadia Mono", "SF Mono", Menlo, Consolas, "DejaVu Sans Mono", "Liberation Mono", monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --cell: 16px;
}
:root[data-theme="dark"] { color-scheme: dark; }
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #e9eeec;
    --panel: #f7faf9;
    --panel-edge: #cfd8d4;
    --text: #1d2523;
    --muted: #5d6b65;
    --key-top: #ffffff;
    --key-bottom: #e4e9e7;
    --key-edge: #a9b4af;
    --key-text: #1d2523;
    --key-dim: #8a9690;
    --accent: #128a47;
  }
}
:root[data-theme="light"] {
  --bg: #e9eeec;
  --panel: #f7faf9;
  --panel-edge: #cfd8d4;
  --text: #1d2523;
  --muted: #5d6b65;
  --key-top: #ffffff;
  --key-bottom: #e4e9e7;
  --key-edge: #a9b4af;
  --key-text: #1d2523;
  --key-dim: #8a9690;
  --accent: #128a47;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  min-height: 100vh;
}
.app {
  max-width: 1180px;
  margin: 0 auto;
  padding: 12px 16px 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.top { display: flex; align-items: center; justify-content: space-between; }
.brand { font-weight: 650; letter-spacing: .02em; }
.brand-sub { color: var(--muted); font-weight: 500; margin-left: 2px; }
.conn { font-size: 13px; color: var(--muted); display: inline-flex; align-items: center; gap: 6px; }
.conn::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--muted); }
.conn[data-state="open"]::before { background: var(--accent); }
.conn[data-state="closed"]::before { background: var(--err); }

/* Keyboard */
.keyboard {
  display: flex;
  gap: 18px;
  align-items: stretch;
  background: var(--panel);
  border: 1px solid var(--panel-edge);
  border-radius: 10px;
  padding: 10px 12px;
  overflow-x: auto;
}
.fkeys { display: flex; flex-direction: column; gap: 6px; flex: 1 1 auto; min-width: 0; }
.fkey-row { display: grid; grid-template-columns: repeat(4, 1fr) 10px repeat(4, 1fr) 10px repeat(4, 1fr); gap: 5px; }
.gap { width: 10px; }
.cluster {
  display: grid;
  grid-template-columns: repeat(4, minmax(48px, auto)) minmax(60px, auto);
  grid-template-rows: 1fr 1fr;
  gap: 5px 6px;
  flex: 0 0 auto;
}
.key-enter { grid-column: 5; grid-row: 1 / span 2; }

.key {
  appearance: none;
  font: inherit;
  color: var(--key-text);
  background: linear-gradient(var(--key-top), var(--key-bottom));
  border: 1px solid var(--key-edge);
  border-radius: 6px;
  /* The key's depth is a shadow, not a border, so pressing it moves only
     the key's picture and never the layout below the keyboard. */
  box-shadow: 0 2px 0 var(--key-edge);
  min-height: 42px;
  min-width: 0;
  padding: 4px 6px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: space-between;
  cursor: pointer;
  text-align: left;
  user-select: none;
  transition: transform .04s ease, box-shadow .04s ease, filter .1s;
}
.key:hover { filter: brightness(1.12); }
.key:focus-visible { outline: 2px solid var(--accent); outline-offset: 1px; }
.key:active, .key.pressed { transform: translateY(2px); box-shadow: 0 0 0 var(--key-edge); }
.key .cap { font-size: 12px; font-weight: 650; line-height: 1.1; }
.key .lbl {
  font-size: 11px;
  line-height: 1.1;
  color: var(--accent);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 100%;
}
.fkey:not(.active) .cap { color: var(--key-dim); }

.key.active { border-color: color-mix(in srgb, var(--accent) 55%, var(--key-edge)); }
.key-enter { justify-content: center; align-items: center; }
.key-enter .cap { font-size: 13px; }
.keyboard.shift #row-shift .key { filter: brightness(1.25); }

/* Screen */
.screen-wrap { position: relative; overflow-x: auto; }
.screen {
  background: var(--screen-bg);
  border: 1px solid var(--screen-edge);
  border-radius: 8px;
  padding: calc(var(--cell) * .6) calc(var(--cell) * .8);
  font-family: var(--mono);
  font-size: var(--cell);
  line-height: 1.32;
  color: var(--c-green);
  white-space: pre;
  width: max-content;
  min-width: 100%;
  outline: none;
  cursor: text;
  box-shadow: inset 0 0 40px rgba(0, 0, 0, .55);
}
.screen:focus-visible { border-color: var(--accent); }
.row { height: calc(var(--cell) * 1.32); width: 80ch; margin-inline: auto; }
.screen span { display: inline; }
.a-green { color: var(--c-green); }
.a-white { color: var(--c-white); }
.a-red { color: var(--c-red); }
.a-turquoise { color: var(--c-turquoise); }
.a-yellow { color: var(--c-yellow); }
.a-pink { color: var(--c-pink); }
.a-blue { color: var(--c-blue); }
.a-ul { text-decoration: underline; text-underline-offset: 3px; text-decoration-thickness: 1px; }
.a-rev { color: var(--screen-bg) !important; }
.a-rev.a-green { background: var(--c-green); }
.a-rev.a-white { background: var(--c-white); }
.a-rev.a-red { background: var(--c-red); }
.a-rev.a-turquoise { background: var(--c-turquoise); }
.a-rev.a-yellow { background: var(--c-yellow); }
.a-rev.a-pink { background: var(--c-pink); }
.a-rev.a-blue { background: var(--c-blue); }
.a-field { background: rgba(79, 224, 138, .06); }
.hot { cursor: pointer; }
.hot:hover { background: rgba(110, 168, 255, .18); border-radius: 2px; }
.cur { background: var(--c-green); color: var(--screen-bg) !important; animation: blink 1.1s steps(1) infinite; }
.screen-wrap:not(:focus-within) .cur { background: transparent; color: inherit !important; outline: 1px solid var(--c-green); animation: none; }
@keyframes blink { 50% { background: transparent; color: inherit; } }
.screen.locked { cursor: progress; }
/* The keyboard input field: invisible, kept at the cursor so the phone
   scrolls to the cursor and an input method shows its suggestions there.
   16px, or iOS Safari zooms the page when it gets the focus. */
.kbd-input {
  position: absolute; left: 0; top: 0;
  width: 1px; height: 1px;
  margin: 0; padding: 0; border: 0;
  opacity: 0; resize: none; overflow: hidden;
  font-size: 16px; line-height: 1;
  color: transparent; background: transparent; caret-color: transparent;
  white-space: pre;
}

.overlay {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 12px;
  background: rgba(5, 8, 6, .82);
  border-radius: 8px;
  color: #e3ebe7;
}
.overlay[hidden] { display: none; }
.overlay .key { min-height: 36px; padding: 6px 14px; align-items: center; }

/* Operator information area */
.oia {
  display: flex; gap: 16px; align-items: center;
  font-family: var(--mono); font-size: 13px;
  color: var(--muted);
  padding: 0 4px;
  min-height: 20px;
}
#oia-lock { color: var(--warn); min-width: 9ch; }
#oia-msg { color: var(--err); flex: 1; }
.oia-right { display: inline-flex; gap: 14px; }
#oia-ins { color: var(--warn); }


@media (max-width: 760px) {
  .keyboard { flex-direction: column; gap: 8px; }
  .fkey-row { grid-template-columns: repeat(4, 1fr) 4px repeat(4, 1fr) 4px repeat(4, 1fr); gap: 3px; }
  .key { min-height: 36px; padding: 3px 4px; }
  .key .cap { font-size: 11px; }
  .key .lbl { display: none; }
}