.alu-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem 1rem;
  align-items: end;
  margin-bottom: 0.85rem;
}

.alu-field {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}
.alu-field label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.alu-field select,
.alu-field input {
  font-family: var(--mono);
  font-size: 0.9rem;
  padding: 0.4rem 0.55rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  min-width: 5.5rem;
}

.op-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 0.85rem;
}
.op-grid button {
  font-family: var(--mono);
  font-size: 0.82rem;
  padding: 0.4rem 0.55rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  cursor: pointer;
  color: var(--ink);
}
.op-grid button.active {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 18%, var(--surface));
  font-weight: 700;
}

.alu-stage {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 1rem;
  background:
    linear-gradient(160deg, color-mix(in srgb, var(--accent) 7%, var(--surface)), var(--surface) 55%);
}

.alu-expr {
  font-family: var(--mono);
  font-size: 1.15rem;
  font-weight: 650;
  margin: 0 0 0.65rem;
}

.alu-y {
  font-family: var(--mono);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  margin: 0 0 0.75rem;
}

.flag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}
.flag {
  font-family: var(--mono);
  font-size: 0.9rem;
  padding: 0.4rem 0.6rem;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--surface2);
  color: var(--muted);
  min-width: 3.2rem;
  text-align: center;
}
.flag.on {
  background: color-mix(in srgb, var(--accent) 20%, var(--surface));
  border-color: var(--accent);
  color: var(--ink);
  font-weight: 700;
}

.alu-meta {
  margin: 0.55rem 0 0;
  font-size: 0.88rem;
  color: var(--muted);
}

.bit-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.35rem 0 0.75rem;
}
.bit-btn {
  font-family: var(--mono);
  font-size: 0.82rem;
  min-width: 3.2rem;
  padding: 0.35rem 0.45rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  cursor: pointer;
}
.bit-btn.on {
  background: color-mix(in srgb, var(--accent) 22%, var(--surface));
  border-color: var(--accent);
  font-weight: 700;
}

.quiz-choices {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin: 0.5rem 0;
}
.quiz-choices label {
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
  font-family: var(--mono);
  font-size: 0.88rem;
  padding: 0.45rem 0.55rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  cursor: pointer;
}
.quiz-choices label:has(input:checked) {
  outline: 2px solid var(--accent);
  outline-offset: -1px;
}