/* Fetch–Execute simulator */
.fe { --addr: var(--accent); --data: var(--good); --ctrl: var(--warn); --bad: #c8362f; }
@media (prefers-color-scheme: dark) { .fe { --bad: #ff7b72; } }
.fe .small-text { font: 14px/1.5 var(--sans); }
.fe .h2 { font-size: 1.7rem; margin-bottom: 8px; }
.fe .block { padding: 40px 0 8px; border-top: 1px solid var(--line); margin-top: 40px; }
.fe .muted { color: var(--muted); }

.lab { font-family: var(--sans); }
.preset-row { display: flex; gap: 12px; align-items: end; flex-wrap: wrap; }
.field { display: flex; flex-direction: column; gap: 4px; font: 600 12px var(--sans); color: var(--muted); letter-spacing: 0.04em; text-transform: uppercase; }
.field.inline { flex-direction: row; align-items: center; gap: 8px; text-transform: none; letter-spacing: 0; font-weight: 500; font-size: 13.5px; }
.lab select, .lab input[type="number"], .lab input[type="text"], .lab textarea {
  font: 14.5px var(--sans); color: var(--ink); background: var(--card); border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px;
}
.lab select { min-width: min(100%, 360px); }
.lab input[type="number"] { width: 4.6em; }
.lab :disabled { opacity: 0.55; cursor: not-allowed; }
.btn.small { padding: 7px 12px; font-size: 13px; cursor: pointer; }
.lab .btn { cursor: pointer; }
.lab .btn:disabled { cursor: not-allowed; }
.preset-desc { color: var(--muted); font: 15px/1.55 var(--sans); margin: 12px 0 8px; max-width: 60em; }
.spoiler { margin: 0 0 12px; font: 14.5px/1.55 var(--sans); background: var(--card); border: 1px dashed var(--line); border-radius: 8px; padding: 8px 14px; }
.spoiler summary { cursor: pointer; font-weight: 600; }
.toolbar { display: flex; flex-wrap: wrap; gap: 8px 10px; align-items: center; margin: 14px 0 10px; padding: 12px; background: var(--card); border: 1px solid var(--line); border-radius: 12px; }
.toolbar input[type="range"] { width: 110px; accent-color: var(--accent); }
.toolbar output { min-width: 2.6em; font-variant-numeric: tabular-nums; }
.notation { border: 0; padding: 0; margin: 0 0 0 auto; display: flex; gap: 12px; align-items: center; font: 13.5px var(--sans); }
.notation legend { float: left; padding: 0; margin-right: 10px; color: var(--muted); }
.notation label { display: flex; gap: 4px; align-items: center; cursor: pointer; }
.scroll-hint { display: none; font-size: 12.5px; color: var(--muted); margin: 0 0 6px; }

/* machine */
.machine-scroll { overflow-x: auto; padding-bottom: 6px; }
.machine { position: relative; min-width: 860px; display: grid; grid-template-columns: minmax(400px, 1.05fr) 96px minmax(360px, 0.95fr); grid-template-rows: auto auto; align-items: stretch; }
.machine .cpu { grid-column: 1; grid-row: 1; }
.machine .mem { grid-column: 3; grid-row: 1 / span 2; display: flex; flex-direction: column; }
.machine .io { grid-column: 1; grid-row: 2; display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 10px; }
.bus-layer { position: absolute; left: 0; top: 0; pointer-events: none; z-index: 1; overflow: visible; }
.bus line { stroke-width: 6; stroke-linecap: round; opacity: 0.28; transition: opacity 0.15s, stroke-width 0.15s; }
.bus text { font: 600 10px var(--sans); letter-spacing: 0.08em; fill: var(--muted); }
.bus .sig { font-size: 12px; font-weight: 700; fill: var(--ctrl); letter-spacing: 0.06em; }
.bus-addr-line line { stroke: var(--addr); }
.bus-data-line line { stroke: var(--data); }
.bus-ctrl-line line { stroke: var(--ctrl); }
.bus.is-on line { opacity: 1; stroke-width: 8; }
.bus.is-on text { fill: var(--ink); }

.panel { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 14px; }
.cpu { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; align-content: start; }
.panel-title { grid-column: 1 / -1; font: 600 12px var(--sans); letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); margin: 0 0 2px; }
.panel-title .muted { letter-spacing: 0; text-transform: none; font-weight: 400; margin-left: 6px; }
.node { background: var(--bg); border: 1.5px solid var(--line); border-radius: 10px; padding: 9px 11px; transition: border-color 0.15s, background 0.15s, box-shadow 0.15s; }
.node.is-active { border-color: var(--accent); background: var(--accent-soft); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 22%, transparent); }
.cu { grid-column: 1 / -1; }
.alu { grid-column: 1; }
.reg { display: flex; flex-direction: column; gap: 1px; }
.reg-name { font: 700 15px var(--sans); }
.reg-full { font: 11.5px var(--sans); color: var(--muted); }
.reg-val { font: 600 17px ui-monospace, Menlo, Consolas, monospace; margin-top: 4px; letter-spacing: 0.02em; word-break: break-all; }
.reg-alt { font: 12px var(--sans); color: var(--muted); min-height: 1.2em; }
.reg-asm { font: 600 12.5px ui-monospace, Menlo, Consolas, monospace; color: var(--accent); min-height: 1.2em; }
.node-head { display: flex; gap: 8px; align-items: baseline; flex-wrap: wrap; font: 14px var(--sans); }
.node-head .muted { font-size: 12px; }
.kv { margin: 6px 0 0; display: grid; gap: 2px; font: 13px var(--sans); }
.kv > div { display: flex; justify-content: space-between; gap: 10px; }
.kv dt { color: var(--muted); }
.kv dd { margin: 0; font: 600 13px ui-monospace, Menlo, Consolas, monospace; text-align: right; }
.cu .kv { grid-template-columns: repeat(3, 1fr); gap: 4px 14px; }
.cu .kv > div { flex-direction: column; justify-content: flex-start; gap: 0; }
.cu .kv dd { text-align: left; }
.phase-pills { display: flex; gap: 6px; margin-top: 6px; }

.pill { display: inline-block; font: 600 10.5px var(--sans); letter-spacing: 0.06em; text-transform: uppercase; padding: 2px 8px; border-radius: 99px; background: var(--accent-soft); color: var(--muted); border: 1px solid transparent; }
.phase-pills .pill { opacity: 0.55; }
.phase-pills .pill.on { opacity: 1; color: #fff; }
.ph-fetch.on, li .ph-fetch { --p: var(--addr); }
.ph-decode.on, li .ph-decode { --p: var(--ctrl); }
.ph-execute.on, li .ph-execute { --p: var(--data); }
.phase-pills .pill.on { background: var(--p); }
.pill.ph-fetch, .pill.ph-decode, .pill.ph-execute { }
li .pill, .now-title .pill { color: #fff; background: var(--p, var(--muted)); }
.now-title .pill { margin-right: 6px; }
.pill.ph-fetch { --p: var(--addr); } .pill.ph-decode { --p: var(--ctrl); } .pill.ph-execute { --p: var(--data); }
@media (prefers-color-scheme: dark) { li .pill, .now-title .pill, .phase-pills .pill.on { color: #0d1320; } }

/* memory */
.mem-table { width: 100%; border-collapse: collapse; font: 13px var(--sans); }
.mem-table th { text-align: left; font: 600 11px var(--sans); letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); padding: 4px 6px; }
.mem-table td { padding: 2px 6px; border-top: 1px solid var(--line); vertical-align: middle; }
.mem-row { transition: background 0.15s; }
.mem-row .ptr { width: 14px; color: var(--accent); font-size: 12px; padding: 0 0 0 2px; }
.mem-row.is-pc .ptr::before { content: "▶"; }
.mem-row.is-pc { background: color-mix(in srgb, var(--accent) 7%, transparent); }
.mem-row.is-mar { box-shadow: inset 3px 0 0 var(--addr); }
.mem-row.is-read { background: color-mix(in srgb, var(--addr) 22%, transparent); }
.mem-row.is-write { background: color-mix(in srgb, var(--ctrl) 28%, transparent); }
.mem-row.has-warn .addr small::after { content: " ⚠"; color: var(--bad); }
.addr code, .bits code { font: 12.5px ui-monospace, Menlo, Consolas, monospace; }
.addr small { color: var(--muted); margin-left: 5px; }
.mem-row input { width: 100%; min-width: 7.5em; font: 600 13px ui-monospace, Menlo, Consolas, monospace; padding: 3px 6px; border-radius: 6px; border: 1px solid transparent; background: transparent; color: var(--ink); }
.mem-row input:hover:not(:disabled) { border-color: var(--line); }
.mem-row input:focus { background: var(--card); border-color: var(--accent); outline: none; }
.mem-row input.is-code { color: var(--accent); }
.mem-row input.bad { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, transparent); }
.ascode { font: italic 11.5px var(--sans); color: var(--muted); white-space: nowrap; }
.mem-help { margin: 10px 2px 0; font: 12.5px/1.5 var(--sans); color: var(--muted); }
.mem-help code, .preset-desc code, .try code, .warn-list code { font-size: 0.92em; }

.io-box { display: flex; flex-direction: column; gap: 4px; font: 13px var(--sans); min-height: 62px; }
.io-box input { width: 4.4em; margin-left: 6px; padding: 3px 6px; }
.out-list { display: flex; flex-wrap: wrap; gap: 4px; }
.out-chip { font: 600 13px ui-monospace, Menlo, Consolas, monospace; background: var(--accent-soft); color: var(--accent); border-radius: 6px; padding: 1px 8px; }
[hidden] { display: none !important; }

/* travelling value */
.chip { position: absolute; z-index: 5; left: 0; top: 0; transform: translate(-50%, -50%); opacity: 0; pointer-events: none; padding: 3px 10px; border-radius: 99px; color: #fff; font: 700 13px ui-monospace, Menlo, Consolas, monospace; box-shadow: 0 2px 10px rgba(0, 0, 0, 0.25); white-space: nowrap; background: var(--ink); }
.chip.bus-addr { background: var(--addr); } .chip.bus-data { background: var(--data); } .chip.bus-io { background: var(--ctrl); }
@media (prefers-color-scheme: dark) { .chip { color: #0d1320; } }

/* tools */
.edit-tools { display: flex; flex-wrap: wrap; gap: 8px; align-items: flex-start; margin: 12px 0 18px; }
.port { flex: 1 1 320px; background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 8px 12px; font: 14px var(--sans); }
.port summary { cursor: pointer; font-weight: 600; }
.port textarea { width: 100%; margin-top: 8px; font: 13px/1.5 ui-monospace, Menlo, Consolas, monospace; resize: vertical; }
.port-actions { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin-top: 8px; }

/* explanation + warnings */
.grid2 { display: grid; grid-template-columns: 1.15fr 1fr; gap: 16px; margin-bottom: 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 16px 18px; }
.card-title { font: 600 12px var(--sans); letter-spacing: 0.14em; text-transform: uppercase; color: var(--muted); margin: 0 0 10px; display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.card-title .stats { margin-left: auto; letter-spacing: 0; text-transform: none; font-weight: 500; font-size: 13px; }
.card-sub { font: 600 13px var(--sans); margin: 14px 0 6px; }
.now-title { font: 600 16px var(--sans); margin: 0 0 6px; }
.now p, .now #now-text { font: 15.5px/1.6 var(--serif); margin: 0 0 4px; }
.now code, .warn-list code { background: var(--accent-soft); }
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 2px; font: 13.5px var(--sans); }
.steps li { padding: 3px 8px; border-radius: 6px; display: flex; gap: 8px; align-items: baseline; }
.steps li.done { color: var(--muted); }
.steps li.done .pill { opacity: 0.55; }
.steps li.next { background: var(--accent-soft); font-weight: 600; }
.steps li.todo.muted { color: var(--muted); font-style: italic; }
.badge-count { font: 700 12px var(--sans); letter-spacing: 0; background: var(--accent-soft); color: var(--muted); border-radius: 99px; padding: 1px 9px; }
.badge-count.has { background: var(--bad); color: #fff; }
.warn-list { list-style: none; margin: 8px 0 0; padding: 0; display: grid; gap: 8px; max-height: 420px; overflow: auto; }
.warn-list li { display: grid; grid-template-columns: 4.6em 1fr; gap: 10px; font: 14px/1.5 var(--sans); padding: 8px 10px; border-radius: 8px; border-left: 4px solid var(--muted); background: var(--bg); }
.warn-list .wn { font: 600 11.5px var(--sans); color: var(--muted); padding-top: 2px; }
.warn-list .lvl-bad { border-color: var(--bad); }
.warn-list .lvl-warn { border-color: var(--ctrl); }
.warn-list .lvl-info { border-color: var(--addr); }

.table-scroll { overflow-x: auto; }
table.log { width: 100%; border-collapse: collapse; font: 13.5px var(--sans); }
table.log th { text-align: left; font: 600 11px var(--sans); letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted); padding: 6px 8px; }
table.log td { padding: 6px 8px; border-top: 1px solid var(--line); vertical-align: top; }
table.log code { font: 600 12.5px ui-monospace, Menlo, Consolas, monospace; }
.trace .table-scroll { max-height: 320px; overflow-y: auto; }
.isa td:nth-child(4) { color: var(--muted); }
.try { font: 16px/1.6 var(--serif); padding-left: 1.2em; display: grid; gap: 8px; max-width: 52em; }
.try code { background: var(--accent-soft); padding: 0 5px; border-radius: 4px; }

@media (max-width: 900px) {
  .grid2 { grid-template-columns: 1fr; }
  .scroll-hint { display: block; }
  .notation { margin-left: 0; }
}

/* polish */
.bits code, .addr code { white-space: nowrap; }
.card-title .stats { white-space: nowrap; }
.fe p.muted, .fe #log-empty, .fe #warn-empty, .fe #out-empty { font-family: var(--sans); font-size: 14px; }
.trace .card-title { justify-content: space-between; }
.trace .card-title .stats { margin-left: 0; }
.lab select { min-width: 0; width: 100%; max-width: 100%; }
.preset-row .field { flex: 1 1 260px; min-width: 0; max-width: 520px; }