:root {
  --bg: #0d0e0c;
  --panel: #161813;
  --box: #1e211a;
  --border: #2f3328;
  --text: #e2e0d2;
  --muted: #8b8a78;
  --accent: #ffb000;
  --accent-dim: #8a6200;
  --green: #7fdc6a;
  --sel: #ffd666;
  --bad: #ff6b5b;
  --info: #6cc4ff;
  --term-bg: #0a0b09;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; }
body {
  background: var(--bg); color: var(--text);
  font: 14px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  display: flex; flex-direction: column;
}
code, pre { font-family: var(--mono); }
code { font-size: 0.9em; background: #262a20; padding: 1px 4px; border-radius: 4px; color: #f3dfa6; }
a { color: var(--accent); }
.hidden { display: none !important; }
.muted { color: var(--muted); }
.small { font-size: 12px; }
.spacer { flex: 1; }

button, select {
  background: var(--box); color: var(--text); border: 1px solid var(--border); border-radius: 6px;
  padding: 5px 10px; font: inherit; cursor: pointer;
}
button:hover:not(:disabled), select:hover { border-color: var(--accent); }
button:disabled { opacity: 0.4; cursor: default; }
button.primary { background: #4a3500; border-color: var(--accent-dim); }
button.danger { border-color: #6b2c25; color: #ffb3aa; }
input.filter {
  background: var(--term-bg); color: var(--text); border: 1px solid var(--border); border-radius: 6px;
  padding: 3px 8px; font: 12px var(--mono); width: 110px;
}
input.filter.addr { width: 70px; }

/* ---------- Top bar ---------- */

.topbar {
  display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
  padding: 8px 14px; border-bottom: 1px solid var(--border); background: #11130f;
}
.brand { font-weight: 700; font-size: 16px; white-space: nowrap; }
.brand small { color: var(--muted); font-weight: 400; margin-left: 6px; }
.logo { color: var(--accent); }
.toolbar { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-left: auto; }
.machine-pick { display: flex; align-items: center; gap: 6px; color: var(--muted); }
.divider { width: 1px; height: 24px; background: var(--border); }
.progress { font-family: var(--mono); color: var(--green); }

/* ---------- Layout ---------- */

.layout {
  flex: 1; min-height: 0;
  display: grid; gap: 10px; padding: 10px;
  grid-template-columns: minmax(340px, 430px) minmax(380px, 1fr) 360px;
}
.panel {
  background: var(--panel); border: 1px solid var(--border); border-radius: 10px;
  padding: 10px 12px; min-width: 0;
}
.panel-head { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; flex-wrap: wrap; }
h2 { font-size: 12px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin: 0; }
h3 { font-size: 11px; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); margin: 0 0 4px; font-weight: 600; }
.badge { font-size: 11px; padding: 1px 7px; border-radius: 10px; border: 1px solid var(--border); color: var(--muted); font-family: var(--mono); }
.badge.run { color: var(--accent); border-color: var(--accent-dim); }
.badge.compile { color: var(--info); border-color: #2c5878; }
.badge.err { color: var(--bad); border-color: #6b2c25; }

/* ---------- Lesson ---------- */

.p-lesson { display: flex; flex-direction: column; min-height: 0; padding: 0; }
.lesson-nav { display: flex; gap: 6px; padding: 10px 12px; border-bottom: 1px solid var(--border); }
.lesson-nav select { flex: 1; min-width: 0; }
.lesson { overflow-y: auto; padding: 4px 16px 24px; flex: 1; }
.lesson h1 { font-size: 22px; margin: 14px 0 0; color: var(--accent); }
.lesson .subtitle { color: var(--muted); margin: 2px 0 12px; }
.lesson h3 { font-size: 12px; color: var(--accent); margin: 20px 0 6px; }
.lesson p, .lesson li { color: #d6d4c4; }
.lesson ul, .lesson ol { padding-left: 22px; }
.lesson li { margin: 3px 0; }
.lesson b { color: #fff3d1; }
.lesson .note {
  border-left: 3px solid var(--accent-dim); background: #1c1a10; padding: 8px 10px; border-radius: 0 6px 6px 0;
  font-size: 13px;
}
.lesson blockquote {
  margin: 12px 0; padding: 8px 12px; border-left: 3px solid var(--green); background: #141b12; font-style: italic;
  border-radius: 0 6px 6px 0;
}
.lesson blockquote cite { display: block; font-style: normal; font-size: 11px; color: var(--muted); margin-top: 4px; }
.lesson table.sig { border-collapse: collapse; margin: 8px 0; font-size: 13px; }
.lesson table.sig td { padding: 3px 10px 3px 0; vertical-align: top; }
.snippet { position: relative; margin: 8px 0; }
.snippet pre {
  margin: 0; padding: 8px 40px 8px 12px; background: var(--term-bg); border: 1px solid var(--border); border-radius: 6px;
  color: #f3dfa6; white-space: pre-wrap; font-size: 13px;
}
.snippet button.play {
  position: absolute; top: 5px; right: 5px; padding: 2px 8px; font-size: 12px;
  background: #4a3500; border-color: var(--accent-dim); color: var(--accent);
}
.snippet.err pre { border-color: #4a2420; }
.mode-banner {
  margin: 12px 0; padding: 10px 12px; border: 1px solid var(--accent-dim); border-radius: 8px; background: #221a05;
  display: flex; gap: 10px; align-items: center; flex-wrap: wrap;
}
.mode-banner.ok { border-color: #2f5a27; background: #121c10; color: var(--green); }
.layout-diagram { display: flex; flex-wrap: wrap; gap: 3px; margin: 8px 0; font: 12px var(--mono); }
.layout-diagram span { padding: 4px 8px; border-radius: 4px; }
.b-name, .m-name { background: #3d2f5c; }
.b-prev, .m-prev { background: #1f4660; }
.b-len, .m-len { background: #5a3a1c; }
.m-type { background: #6b5200; }
.b-body, .m-body { background: #24462a; }
.b-lit { background: #3e4a1d; }

.challenges { margin-top: 26px; border-top: 1px solid var(--border); padding-top: 4px; }
.challenge { border: 1px solid var(--border); border-radius: 8px; padding: 10px 12px; margin: 10px 0; background: var(--box); }
.challenge.done { border-color: #2f5a27; }
.challenge .ch-head { display: flex; gap: 8px; align-items: flex-start; }
.challenge .mark { font-size: 16px; line-height: 1.2; color: var(--muted); }
.challenge.done .mark { color: var(--green); }
.challenge .ch-text { flex: 1; }
.challenge .hint { color: var(--sel); font-size: 13px; margin-top: 6px; }
.challenge .hint.good { color: var(--green); }
.challenge .actions { display: flex; gap: 6px; margin-top: 8px; flex-wrap: wrap; align-items: center; }
.challenge details { margin-top: 6px; font-size: 13px; }
.challenge details pre { background: var(--term-bg); padding: 6px 8px; border-radius: 6px; white-space: pre-wrap; margin: 6px 0 0; }
.quiz-opts { display: flex; flex-direction: column; gap: 5px; margin-top: 8px; }
.quiz-opts button { text-align: left; }
.quiz-opts button.right { border-color: var(--green); color: var(--green); }
.quiz-opts button.wrong { border-color: var(--bad); color: var(--bad); }
.todo-check { display: flex; gap: 8px; align-items: center; cursor: pointer; }
.todo-check input { accent-color: var(--green); width: 16px; height: 16px; }
.lesson-foot { display: flex; justify-content: space-between; margin-top: 20px; }

/* ---------- Terminal ---------- */

.p-center { display: grid; grid-template-rows: minmax(260px, 1fr) minmax(180px, 38%); gap: 10px; min-height: 0; min-width: 0; }
.p-term { display: flex; flex-direction: column; min-height: 0; }
.tabs { display: flex; gap: 2px; }
.tabs button { border-radius: 6px 6px 0 0; border-bottom: none; padding: 4px 12px; }
.tabs button.active { background: var(--term-bg); color: var(--accent); border-color: var(--accent-dim); }
.toggle { display: flex; align-items: center; gap: 5px; color: var(--muted); cursor: pointer; font-size: 13px; }
.toggle input { accent-color: var(--accent); }
.term-view { flex: 1; min-height: 0; display: flex; flex-direction: column; background: var(--term-bg); border: 1px solid var(--border); border-radius: 8px; }
.output {
  flex: 1; min-height: 0; overflow-y: auto; margin: 0; padding: 10px 12px; white-space: pre-wrap; word-break: break-word;
  font-size: 13.5px; color: #e9d9a8; text-shadow: 0 0 6px rgba(255, 176, 0, 0.15);
}
.output .in { color: #fff; }
.output .ok { color: var(--green); }
.output .err { color: var(--bad); }
.output .sys { color: var(--muted); }
.output .gen { color: var(--info); }
.input-line { display: flex; align-items: center; border-top: 1px solid var(--border); padding: 6px 10px; gap: 8px; }
.prompt { color: var(--accent); font-family: var(--mono); }
.prompt.compile { color: var(--info); }
#input { flex: 1; background: transparent; border: none; outline: none; color: #fff; font: 14px var(--mono); }

.blocks-view { flex: 1; min-height: 0; display: flex; flex-direction: column; gap: 6px; }
.blk-bar { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }
.blk-editor { display: flex; flex: 1; min-height: 0; background: var(--term-bg); border: 1px solid var(--border); border-radius: 8px; overflow: auto; }
.blk-gutter { margin: 0; padding: 8px 6px; color: var(--muted); text-align: right; user-select: none; font-size: 13px; line-height: 1.45; }
.blk-gutter .over { color: var(--bad); }
#blk-text {
  flex: 1; min-width: 64ch; background: transparent; color: #e9d9a8; border: none; outline: none; resize: none;
  font: 13px/1.45 var(--mono); padding: 8px; white-space: pre;
  background-image: linear-gradient(to right, transparent calc(64ch + 8px), #3a1d18 calc(64ch + 8px), #3a1d18 calc(64ch + 9px), transparent calc(64ch + 9px));
}

/* ---------- Inspector ---------- */

.p-inspect { display: flex; flex-direction: column; min-height: 0; }
.insp-title { font-family: var(--mono); color: var(--accent); }
.inspector { overflow: auto; flex: 1; font: 12.5px var(--mono); }
.inspector .hdr { display: flex; flex-wrap: wrap; gap: 3px; margin-bottom: 8px; }
.inspector .hdr span { padding: 3px 6px; border-radius: 4px; }
.inspector .desc { color: var(--muted); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-size: 12.5px; margin-bottom: 6px; }
.inspector table { border-collapse: collapse; }
.inspector td { padding: 1px 10px 1px 0; white-space: nowrap; }
.inspector td.a { color: var(--muted); }
.inspector td.b { color: #9d9a80; }
.inspector tr.ip td { background: #4a3500; color: #fff; }
.inspector tr.ip td:first-child::before { content: "IP▶ "; color: var(--accent); }
.inspector .op-call { color: #f3dfa6; }
.inspector .op-lit { color: #c5e88a; }
.inspector .op-br { color: var(--info); }
.inspector .op-exit { color: var(--bad); }
.inspector .clickable { cursor: pointer; text-decoration: underline dotted; }

/* ---------- Machine ---------- */

.p-machine { display: flex; flex-direction: column; gap: 10px; min-height: 0; overflow-y: auto; }
.stacks { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.stack {
  list-style: none; margin: 0; padding: 0; min-height: 60px; max-height: 150px; overflow-y: auto;
  font: 12.5px var(--mono); display: flex; flex-direction: column;
}
.stack li { padding: 2px 6px; border: 1px solid var(--border); border-radius: 4px; margin-bottom: 2px; background: var(--box); display: flex; justify-content: space-between; gap: 6px; }
.stack li:first-child { border-color: var(--accent-dim); }
.stack li .h { color: var(--muted); }
.stack li .ann { color: var(--info); font-size: 11px; }
.stack li.empty { color: var(--muted); border: 1px dashed var(--border); background: none; }
.regs { display: grid; grid-template-columns: auto 1fr; gap: 1px 10px; margin-top: 8px; font: 12px var(--mono); }
.regs .k { color: var(--muted); }

.io { display: flex; flex-direction: column; gap: 8px; }
.leds, .switches { display: flex; gap: 6px; justify-content: space-between; }
.led { width: 26px; height: 26px; border-radius: 50%; background: #2a1410; border: 2px solid #3b2420; position: relative; }
.led.on { background: #ff4d2e; border-color: #ff8a70; box-shadow: 0 0 12px #ff4d2e, 0 0 3px #fff inset; }
.led span, .sw span { position: absolute; bottom: -15px; left: 0; right: 0; text-align: center; font: 9px var(--mono); color: var(--muted); }
.leds { margin-bottom: 12px; }
.sw { width: 26px; height: 34px; border-radius: 5px; background: #20231c; border: 1px solid var(--border); position: relative; cursor: pointer; padding: 0; }
.sw::after { content: ""; position: absolute; left: 4px; right: 4px; height: 12px; top: 17px; background: #6d6b5c; border-radius: 3px; transition: top 0.1s; }
.sw.on::after { top: 3px; background: var(--accent); }
.switches { margin-bottom: 14px; }

.p-dict { min-height: 180px; display: flex; flex-direction: column; }
.dict { list-style: none; margin: 0; padding: 0; overflow-y: auto; max-height: 220px; display: flex; flex-wrap: wrap; gap: 3px; align-content: flex-start; font: 12px var(--mono); }
.dict li { padding: 1px 6px; border-radius: 4px; border: 1px solid var(--border); cursor: pointer; color: var(--muted); }
.dict li.user { color: var(--accent); border-color: var(--accent-dim); }
.dict li.imm { font-style: italic; }
.dict li.sel { background: #4a3500; color: #fff; }
.dict li:hover { border-color: var(--accent); }

.mem-jump { display: flex; gap: 3px; align-items: center; }
.mem-jump button { padding: 1px 6px; font-size: 11px; }
.memory { font: 11.5px/1.5 var(--mono); overflow-x: auto; }
.memory .row { white-space: nowrap; }
.memory .addr { color: var(--muted); margin-right: 6px; }
.memory .byte { padding: 0 1px; border-radius: 2px; }
.memory .ascii { color: var(--muted); margin-left: 6px; }
.memory .m-here { outline: 1px solid var(--accent); }
.memory .m-ps { background: #4b2c45; }
.memory .zero { color: #4a4b40; }
.legend { display: flex; flex-wrap: wrap; gap: 4px; margin-top: 6px; }
.legend span { padding: 0 5px; border-radius: 3px; }
.legend .m-here { outline: 1px solid var(--accent); }
.legend .m-ps { background: #4b2c45; }

/* ---------- Responsive ---------- */

@media (max-width: 1250px) {
  .layout { grid-template-columns: minmax(320px, 400px) 1fr; }
  .p-machine { grid-column: 1 / -1; overflow: visible; display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
}
@media (max-width: 800px) {
  body { height: auto; }
  .layout { grid-template-columns: 1fr; }
  .p-lesson { max-height: 70vh; }
  .p-center { grid-template-rows: 420px 300px; }
  .brand small { display: none; }
}