@media (max-width: 1040px) {
  .tool-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  .app-shell {
    width: min(100% - 24px, 680px);
    padding-top: 18px;
  }

  .hero {
    grid-template-columns: 1fr;
    padding-top: 18px;
  }

  .hero-panel {
    min-width: 0;
  }

  .tool-grid {
    grid-template-columns: 1fr;
  }

  .calculator-card {
    grid-row: auto;
  }
}

@media (max-width: 480px) {
  .app-shell {
    width: min(100% - 18px, 460px);
  }

  h1 {
    font-size: 36px;
  }

  .hero-copy {
    font-size: 16px;
  }

  .tool-card {
    padding: 16px;
  }

  .tool-heading {
    gap: 10px;
  }

  .split {
    grid-template-columns: 1fr;
  }

  #calcDisplay {
    font-size: 34px;
  }

  .calc-keys {
    gap: 8px;
  }

  .calc-keys button {
    min-height: 50px;
    aspect-ratio: auto;
    font-size: 16px;
  }
}