.tsa-calc {
  display: flex;
  flex-direction: column;
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  background: linear-gradient(160deg, rgba(8, 12, 26, 0.95), rgba(5, 6, 18, 0.95));
  color: #fdfdff;
  font-family: 'Inter', 'SF Pro Display', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  box-sizing: border-box;
}

.tsa-calc__display {
  position: relative;
  padding: 18px 24px 12px;
  min-height: 120px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 8px;
}

.tsa-calc__memory-indicator {
  position: absolute;
  top: 12px;
  left: 20px;
  font-size: 0.8rem;
  letter-spacing: 0.3em;
  color: rgba(173, 228, 255, 0.8);
}

.tsa-calc__expression {
  min-height: 24px;
  font-size: 1rem;
  color: rgba(221, 235, 255, 0.8);
  text-align: right;
  word-break: break-all;
}

.tsa-calc__output {
  font-size: 2.4rem;
  font-weight: 600;
  text-align: right;
}

.tsa-calc__keypad {
  flex: 1;
  padding: 12px 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.tsa-calc__row {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 10px;
}

.tsa-calc__key {
  border: 1px solid rgba(255, 255, 255, 0.08);
  background: rgba(255, 255, 255, 0.04);
  color: inherit;
  border-radius: 12px;
  padding: 10px 8px;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: transform 120ms ease, border-color 120ms ease, background 120ms ease;
}

.tsa-calc__key:hover {
  transform: translateY(-1px);
  border-color: rgba(0, 187, 255, 0.35);
}

.tsa-calc__key--operator {
  background: rgba(255, 255, 255, 0.08);
}

.tsa-calc__key--danger {
  color: #ff9f9f;
}

.tsa-calc__key--function,
.tsa-calc__key--utility,
.tsa-calc__key--constant,
.tsa-calc__key--memory {
  color: #96caff;
}

.tsa-calc__key--equals {
  background: linear-gradient(135deg, #37b4ff, #7a5bff);
  color: #06070f;
  font-weight: 700;
}

@media (max-width: 480px) {
  .tsa-calc__row {
    grid-template-columns: repeat(4, 1fr);
  }
}