.desk {
  display: grid;
  grid-template-columns: 7fr 5fr;
  gap: 20px;
  align-items: stretch;
}
.desk-inputs,
.desk-result,
.formula-strip,
.cat-index,
.mini-desk,
.vis-panel,
.chart-sheet,
.formula-entry,
.example-card {
  background: var(--paper);
  border: 1px solid var(--border);
  padding: 22px;
}
.desk-inputs {
  background-image: repeating-linear-gradient(
    90deg,
    transparent,
    transparent 9px,
    rgba(41, 56, 60, 0.05) 9px,
    rgba(41, 56, 60, 0.05) 10px
  );
  background-size: 100% 12px;
  background-repeat: no-repeat;
  background-position: top;
}
.controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.controls .span-2 { grid-column: 1 / -1; }
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.desk-result {
  background: var(--result);
  color: #F4F2EB;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.desk-result .kicker { color: #C9D4D1; }
.result-num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(52px, 8vw, 100px);
  line-height: 0.95;
  letter-spacing: -0.03em;
  word-break: break-all;
  color: #FFFEFA;
}
.desk-result p { margin: 0; font-size: 14px; color: #D7E0DD; }
.desk-result .precision { margin-top: auto; }
.desk-result select {
  background: #1c2d32;
  color: #FFFEFA;
  border-color: #3d555c;
}

.formula-strip {
  background: var(--formula);
  margin-top: 16px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 16px;
  align-items: start;
}
.formula-text { font-family: var(--mono); font-size: 16px; }

.cat-index { margin-top: 28px; }
.cat-tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.cat-tab {
  appearance: none;
  text-align: left;
  border: 1px solid var(--border);
  background: #fff;
  padding: 12px;
  cursor: pointer;
  min-height: 88px;
  color: inherit;
  text-decoration: none;
  display: block;
}
.cat-tab strong { display: block; font-family: var(--serif); font-size: 18px; }
.cat-tab span { display: block; font-size: 13px; color: var(--muted); }
.cat-tab.is-active,
.cat-tab[aria-current="true"] {
  border-color: var(--accent);
  box-shadow: inset 3px 0 0 var(--accent);
}

.mini-desk { margin-top: 16px; }
.mini-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr 1fr auto;
  gap: 10px;
  align-items: end;
}
.meta-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-top: 14px;
  font-size: 14px;
}
.meta-grid div {
  border-top: 1px solid var(--border);
  padding-top: 8px;
}

.length-layout .ruler {
  height: 28px;
  margin: 12px 0 0;
  background:
    repeating-linear-gradient(90deg, var(--ink) 0 1px, transparent 1px 10px),
    repeating-linear-gradient(90deg, var(--accent) 0 1px, transparent 1px 50px);
  opacity: 0.45;
}
.mass-layout { background-image: linear-gradient(#fff 0, var(--paper) 40%); }
.temp-layout .thermo-track {
  position: relative;
  height: 18px;
  margin: 28px 0 36px;
  background: linear-gradient(90deg, #6aa7c2, #b4634a);
  border: 1px solid var(--border);
}
.temp-layout .mark {
  position: absolute;
  top: -22px;
  transform: translateX(-50%);
  font-size: 11px;
  font-family: var(--mono);
  white-space: nowrap;
}
.temp-layout .zero { top: 20px; color: var(--muted); }
.volume-layout .grad {
  height: 12px;
  background: repeating-linear-gradient(90deg, var(--secondary) 0 2px, transparent 2px 16px);
  opacity: 0.5;
  margin-top: 10px;
}
.area-layout .grid-illus {
  height: 72px;
  background:
    repeating-linear-gradient(0deg, transparent, transparent 11px, var(--border) 11px 12px),
    repeating-linear-gradient(90deg, transparent, transparent 11px, var(--border) 11px 12px);
}
.speed-layout .speed-scale {
  height: 10px;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
  margin-top: 10px;
}
.time-layout .time-strip {
  display: flex;
  gap: 6px;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}
.storage-layout .bin-dec {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  font-size: 13px;
}

.vis-panel { margin-top: 16px; }
.bar-row { margin: 10px 0; }
.bar {
  height: 16px;
  background: var(--secondary);
  min-width: 2px;
  max-width: 100%;
}
.bar.to { background: var(--accent); }
.bar-lab { font-family: var(--mono); font-size: 13px; margin-bottom: 4px; }

.table-scroll { overflow-x: auto; }
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
th, td {
  border-bottom: 1px solid var(--border);
  text-align: left;
  padding: 8px 10px;
  font-variant-numeric: tabular-nums;
}
th {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 600;
}

.quick-row { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.example-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}
.example-q { font-family: var(--serif); font-size: 18px; margin: 0 0 8px; }
.example-a {
  font-family: var(--mono);
  font-size: 22px;
  margin: 4px 0 10px;
}

.formula-list { display: grid; gap: 16px; }
.formula-entry h3 { margin-bottom: 8px; }

.reg-marks {
  display: flex;
  justify-content: space-between;
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  opacity: 0.7;
}

@media (max-width: 760px) {
  .desk { grid-template-columns: 1fr; }
  .controls, .mini-grid, .meta-grid, .cat-tabs, .example-grid, .storage-layout .bin-dec {
    grid-template-columns: 1fr;
  }
  .cat-tabs {
    display: flex;
    overflow-x: auto;
    gap: 8px;
    padding-bottom: 8px;
  }
  .cat-tab { min-width: 210px; flex: 0 0 auto; }
  .formula-strip { grid-template-columns: 1fr; }
  .result-num { font-size: clamp(52px, 12vw, 70px); }
}

@media (max-width: 375px) {
  input[type="text"], select { font-size: 16px; }
}