* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  overflow: hidden;
  display: flex;
  flex-direction: column;
  height: 100vh;
  user-select: none;
  -webkit-user-select: none;
}

/* ---- Calculator body ---- */
#calc-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 4px;
  overflow: hidden;
}

.hidden {
  display: none !important;
}

/* ---- Base display (programmer) ---- */
.base-display {
  margin-bottom: 4px;
  background: var(--sz-color-window);
  border: 2px inset;
  border-color: var(--sz-color-button-shadow) var(--sz-color-button-highlight) var(--sz-color-button-highlight) var(--sz-color-button-shadow);
  padding: 2px 4px;
  font-family: 'Lucida Console', 'Consolas', 'Courier New', monospace;
  font-size: 10px;
  color: var(--sz-color-window-text);
}

.base-row {
  display: flex;
  align-items: center;
  padding: 1px 0;
}

.base-label {
  width: 28px;
  font-weight: bold;
  flex-shrink: 0;
  font-size: 9px;
  opacity: 0.7;
}

.base-value {
  flex: 1;
  text-align: right;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  word-break: break-all;
}

/* ---- Main display ---- */
#display-container {
  margin-bottom: 4px;
  background: var(--sz-color-window);
  border: 2px inset;
  border-color: var(--sz-color-button-shadow) var(--sz-color-button-highlight) var(--sz-color-button-highlight) var(--sz-color-button-shadow);
  padding: 2px 4px;
  min-height: 28px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex-shrink: 0;
}

#display {
  font-family: 'Lucida Console', 'Consolas', 'Courier New', monospace;
  font-size: 20px;
  color: var(--sz-color-window-text);
  text-align: right;
  overflow: hidden;
  white-space: nowrap;
  width: 100%;
  direction: rtl;
  text-overflow: clip;
}

/* ---- Selector rows (programmer + scientific) ---- */
#programmer-selectors {
  margin-bottom: 4px;
  flex-shrink: 0;
}

.selector-group {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-bottom: 2px;
  flex-wrap: wrap;
}

.selector-label {
  font-size: 10px;
  font-weight: bold;
  width: 30px;
  flex-shrink: 0;
}

.radio-label {
  font-size: 10px;
  cursor: default;
  display: flex;
  align-items: center;
  gap: 1px;
  padding: 1px 3px;
}

.radio-label input[type="radio"] {
  margin: 0;
  cursor: default;
}

#angle-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 4px;
  flex-shrink: 0;
}

/* ---- Button area ---- */
#button-area {
  flex: 1;
  display: grid;
  gap: 2px;
  min-height: 0;
}

/* Standard: 4 columns */
body.mode-standard #button-area {
  grid-template-columns: repeat(4, 1fr);
}

/* Scientific: 8 columns (4 sci + 4 standard) */
body.mode-scientific #button-area {
  grid-template-columns: repeat(8, 1fr);
}

/* Programmer: 8 columns (4 bitwise + 4 standard) */
body.mode-programmer #button-area {
  grid-template-columns: repeat(8, 1fr);
}

.btn {
  font-size: 12px;
  font-weight: bold;
  cursor: default;
  padding: 2px 1px;
  min-height: 24px;
  text-align: center;
  outline: none;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.btn.op {
  color: #c00;
}

.btn.special {
  color: #009;
}

.btn.equals {
  color: #c00;
}

.btn.sci {
  color: #630;
  font-size: 11px;
}

.btn.prog {
  color: #063;
  font-size: 11px;
}

.btn.hex-digit {
  color: #306;
}

.btn:disabled {
  opacity: 0.4;
  cursor: default;
}

.btn.span2 {
  grid-column: span 2;
}

/* ---- Bit toggle display ---- */
#bit-display {
  margin-top: 4px;
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  justify-content: flex-end;
  flex-shrink: 0;
}

.bit-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 0 2px;
}

.bit-group-label {
  font-size: 8px;
  color: var(--sz-color-gray-text);
  margin-bottom: 1px;
}

.bit-group-bits {
  display: flex;
  gap: 1px;
}

.bit-cell {
  width: 10px;
  height: 12px;
  font-size: 8px;
  font-family: 'Lucida Console', 'Consolas', monospace;
  text-align: center;
  line-height: 12px;
  cursor: pointer;
  border: 1px solid var(--sz-color-button-shadow);
  background: var(--sz-color-window);
  color: var(--sz-color-window-text);
}

.bit-cell:hover {
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
}

.bit-cell.on {
  background: var(--sz-color-highlight);
  color: var(--sz-color-highlight-text);
  font-weight: bold;
}