.controls {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0;
  border: 1px solid var(--ink);
  border-radius: 2px;
  background: var(--paper-3);
  overflow: hidden;
}
.ctl {
  padding: 16px 18px 14px;
  border-right: 1px solid var(--rule-2);
  display: flex;
  flex-direction: column;
  gap: 6px;
  position: relative;
}
.ctl:last-child { border-right: 0; }
.ctl label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.22em;
  color: var(--ink-3);
  font-weight: 600;
}
.ctl-input {
  display: flex;
  align-items: baseline;
  gap: 4px;
}
.ctl input[type="number"],
.ctl select {
  width: 100%;
  background: transparent;
  border: none;
  outline: none;
  padding: 0;
  font-family: "Fraunces", serif;
  font-variation-settings: "opsz" 72, "SOFT" 60;
  font-weight: 400;
  font-size: 32px;
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums lining-nums;
}
.ctl select {
  font-size: 22px;
  font-style: italic;
  font-variation-settings: "opsz" 36, "SOFT" 80;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  padding-right: 18px;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'><path d='M1 1l4 4 4-4' stroke='%231a1410' stroke-width='1.4' fill='none' stroke-linecap='round'/></svg>");
  background-repeat: no-repeat;
  background-position: right 2px center;
}
.ctl .unit {
  font-family: "Fraunces", serif;
  font-style: italic;
  font-variation-settings: "opsz" 24;
  font-size: 24px;
  color: var(--stamp);
  line-height: 1;
}
.ctl input::-webkit-outer-spin-button,
.ctl input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }

/* ─── Formula row ─── */
.formula-row {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin: 26px 0 6px;
  padding: 0 2px;
}
.formula-label {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.32em;
  color: var(--stamp);
  font-weight: 700;
  flex-shrink: 0;
  padding-top: 4px;
}
.formula {
  margin: 0;
  font-family: "Fraunces", serif;
  font-variation-settings: "opsz" 36, "SOFT" 50;
  font-style: italic;
  font-weight: 400;
  font-size: 22px;
  color: var(--ink-2);
  line-height: 1.35;
}
.formula b {
  font-style: normal;
  font-weight: 600;
  color: var(--ink);
  font-variation-settings: "opsz" 36, "SOFT" 0;
  border-bottom: 2px solid var(--stamp);
  padding-bottom: 1px;
}