/* ============================================================
   Calculator Decoy — Styles
   Must look convincingly like a native iOS/Android calculator
   ============================================================ */

.calculator {
  display: flex;
  flex-direction: column;
  height: 100%;
  background-color: var(--surface-0);
  padding-top: var(--safe-area-top);
  padding-bottom: var(--safe-area-bottom);
}

/* --- Display Area --- */
.calc-display {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: flex-end;
  padding: var(--space-lg) var(--space-lg) var(--space-md);
  min-height: 120px;
  overflow: hidden;
}

.calc-expression {
  font-size: var(--font-size-lg);
  color: var(--text-tertiary);
  font-weight: var(--font-weight-light);
  letter-spacing: 0.5px;
  min-height: 1.5em;
  text-align: right;
  width: 100%;
  word-break: break-all;
}

.calc-result {
  font-size: var(--font-size-display);
  font-weight: var(--font-weight-light);
  color: var(--text-primary);
  letter-spacing: -1px;
  line-height: var(--line-height-tight);
  text-align: right;
  width: 100%;
  transition: font-size var(--transition-fast);
  word-break: break-all;
}

.calc-result.shrink-1 {
  font-size: 2.8rem;
}

.calc-result.shrink-2 {
  font-size: 2.2rem;
}

.calc-result.shrink-3 {
  font-size: 1.8rem;
}

/* --- Button Grid --- */
.calc-buttons {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  padding: var(--space-md) var(--space-md) var(--space-lg);
}

/* --- Base Button --- */
.calc-btn {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1 / 1;
  border-radius: var(--radius-full);
  font-size: 1.75rem;
  font-weight: var(--font-weight-medium);
  transition: background-color var(--transition-fast), transform var(--transition-fast);
  overflow: hidden;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

.calc-btn::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: white;
  opacity: 0;
  transition: opacity var(--transition-fast);
  pointer-events: none;
}

.calc-btn:active {
  transform: scale(0.92);
}

.calc-btn:active::after {
  opacity: 0.15;
}

/* --- Number Buttons --- */
.calc-btn.number {
  background-color: var(--btn-number);
  color: var(--text-primary);
}

.calc-btn.number:hover {
  background-color: var(--btn-number-hover);
}

/* Zero button spans 2 columns */
.calc-btn.zero {
  grid-column: span 2;
  border-radius: 36px;
  aspect-ratio: auto;
  justify-content: flex-start;
  padding-left: 30px;
}

/* --- Operator Buttons --- */
.calc-btn.operator {
  background-color: var(--btn-operator);
  color: var(--text-primary);
}

.calc-btn.operator:hover {
  background-color: var(--btn-operator-hover);
}

.calc-btn.operator:active {
  background-color: var(--btn-operator-active);
}

.calc-btn.operator.active {
  background-color: var(--text-primary);
  color: var(--btn-operator);
}

/* --- Function Buttons (AC, ±, %) --- */
.calc-btn.function {
  background-color: var(--btn-function);
  color: var(--text-inverse);
}

.calc-btn.function:hover {
  background-color: var(--btn-function-hover);
}

.calc-btn.function:active {
  background-color: var(--btn-function-active);
}

/* --- Responsive adjustments --- */
@media (max-height: 600px) {
  .calc-btn {
    aspect-ratio: auto;
    height: 52px;
    font-size: 1.4rem;
  }
  
  .calc-result {
    font-size: 2.5rem;
  }

  .calc-display {
    min-height: 80px;
  }
}

/* Small phones (iPhone SE) */
@media (max-width: 375px) {
  .calc-buttons {
    gap: 10px;
    padding: var(--space-sm) var(--space-sm) var(--space-md);
  }

  .calc-btn {
    font-size: 1.5rem;
  }

  .calc-result {
    font-size: 3rem;
  }
}

/* Large phones */
@media (min-width: 430px) {
  .calc-buttons {
    gap: 14px;
    padding: var(--space-md) var(--space-lg) var(--space-xl);
  }

  .calc-btn {
    font-size: 2rem;
  }
}