/* ==========================================================================
   TIP CALCULATOR - RESPONSIVE STYLESHEET
   Breakpoints:
   - Mobile Small: 320px - 374px
   - Mobile Standard: 375px - 767px
   - Tablet: 768px - 1023px
   - Laptop / Small Desktop: 1024px - 1279px
   - Desktop Standard: 1280px - 1439px
   - Desktop Large: 1440px+
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. Laptop & Tablet (max-width: 1023px)
   -------------------------------------------------------------------------- */
@media (max-width: 1023px) {
  .calculator-layout {
    grid-template-columns: 1fr;
  }

  .calc-inputs-panel {
    border-right: none;
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-6);
  }

  .calc-results-panel {
    padding: var(--space-6);
  }

  .calc-secondary-container {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }

  .footer-brand {
    grid-column: span 2;
  }
}

/* --------------------------------------------------------------------------
   2. Mobile & Small Tablet (max-width: 767px)
   -------------------------------------------------------------------------- */
@media (max-width: 767px) {
  :root {
    --space-8: 1.5rem;
    --space-10: 2rem;
    --space-12: 2.5rem;
  }

  body {
    padding-bottom: 74px; /* Space for mobile sticky summary bar */
  }

  .container {
    padding-left: var(--space-3);
    padding-right: var(--space-3);
  }

  /* Header adjustments */
  .nav-desktop {
    display: none;
  }

  .menu-toggle {
    display: flex;
  }

  .header-cta .btn-primary {
    display: none;
  }

  /* Hero adjustments */
  .hero-section {
    padding: var(--space-6) 0 var(--space-4);
  }

  .hero-title {
    font-size: 2.1rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  /* Calculator layout adjustments */
  .calculator-card {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    margin: 0 auto;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
  }

  .calc-inputs-panel {
    padding: var(--space-4);
    gap: var(--space-4);
    box-sizing: border-box;
  }

  .calc-results-panel {
    padding: var(--space-4);
    box-sizing: border-box;
  }

  /* Bill input & Currency wrapper */
  .currency-select-container {
    padding: 0 var(--space-2);
    max-width: 110px;
  }

  .currency-select {
    font-size: 0.85rem;
  }

  .currency-symbol-display {
    padding-left: var(--space-2);
    font-size: 1.15rem;
  }

  .calc-input-bill {
    font-size: 1.35rem;
    padding: var(--space-3);
  }

  /* Quick bill preset chips */
  .quick-bill-chips {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 6px;
    width: 100%;
  }

  .quick-chip {
    padding: 6px 2px;
    font-size: 0.78rem;
    text-align: center;
    min-width: 0;
  }

  /* Tip preset grid: 3 columns on standard mobile, Custom spans all 3 */
  .tip-preset-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    width: 100%;
  }

  .tip-btn {
    padding: var(--space-3) var(--space-2);
    font-size: 0.95rem;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 0;
  }

  .tip-btn[data-tip="custom"] {
    grid-column: span 3;
    font-weight: var(--font-weight-semibold);
  }

  /* Stepper on mobile */
  .stepper-btn {
    width: 48px;
    height: 48px;
    min-width: 44px;
    min-height: 44px;
    font-size: 1.25rem;
  }

  .stepper-input {
    font-size: 1.2rem;
    min-width: 0;
  }

  /* Tax toggle header */
  .tax-toggle-header {
    padding: var(--space-3);
  }

  .tax-toggle-label {
    font-size: 0.9rem;
  }

  /* Rounding options: 2x2 grid on mobile */
  .rounding-options-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
    width: 100%;
  }

  .rounding-btn {
    padding: var(--space-3) var(--space-2);
    font-size: 0.85rem;
    min-height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 0;
  }

  /* Results card typography on mobile */
  .results-header {
    margin-bottom: var(--space-3);
    padding-bottom: var(--space-2);
  }

  .results-title {
    font-size: 1.05rem;
  }

  .results-meta {
    font-size: 0.75rem;
  }

  .result-highlight-card {
    padding: var(--space-4);
    margin-bottom: var(--space-4);
  }

  .result-highlight-value {
    font-size: 2.1rem;
    min-width: 0;
  }

  .results-grid {
    grid-template-columns: 1fr;
    gap: var(--space-2);
    margin-bottom: var(--space-4);
  }

  .result-item {
    padding: var(--space-3) var(--space-4);
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-2);
    min-width: 0;
  }

  .result-item-label {
    font-size: 0.85rem;
    margin-bottom: 0;
    min-width: 0;
    flex: 1 1 auto;
  }

  .result-item-value {
    font-size: 1.15rem;
    text-align: right;
    flex-shrink: 0;
    min-width: 0;
  }

  .result-item-tax {
    grid-column: span 1;
  }

  /* Buttons on mobile */
  .action-buttons-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    width: 100%;
  }

  .action-buttons-row .btn {
    width: 100%;
    min-height: 44px;
    padding: 10px 6px;
    font-size: 0.85rem;
    justify-content: center;
  }

  /* Comparison table spacing */
  .comparison-table th,
  .comparison-table td {
    padding: var(--space-2) var(--space-2);
    font-size: 0.85rem;
  }

  /* Footer adjustments */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .footer-brand {
    grid-column: span 1;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-3);
  }

  /* Mobile Sticky Bottom Summary Bar */
  .mobile-sticky-bar {
    display: block;
  }

  /* Customizer full width drawer on mobile */
  .customizer-panel {
    max-width: 100%;
    width: 100%;
  }

  .receipt-modal-card {
    margin: var(--space-2);
    max-width: 100%;
    width: 100%;
  }
}

/* --------------------------------------------------------------------------
   3. Small Mobile Viewports (< 480px)
   -------------------------------------------------------------------------- */
@media (max-width: 480px) {
  .quick-bill-chips {
    grid-template-columns: repeat(3, 1fr);
    gap: 6px;
  }

  .action-buttons-row {
    grid-template-columns: 1fr;
    gap: 8px;
  }
}

/* --------------------------------------------------------------------------
   4. Small Mobile Phones (320px - 374px)
   -------------------------------------------------------------------------- */
@media (max-width: 374px) {
  .hero-title {
    font-size: 1.75rem;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .btn {
    width: 100%;
  }

  /* Tip preset grid: 2 columns on very narrow screens */
  .tip-preset-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 6px;
  }

  .tip-btn[data-tip="custom"] {
    grid-column: span 2;
  }

  .calc-inputs-panel,
  .calc-results-panel {
    padding: var(--space-3);
    gap: var(--space-3);
  }

  .currency-select-container {
    max-width: 95px;
    padding: 0 4px;
  }

  .currency-select {
    font-size: 0.8rem;
  }

  .calc-input-bill {
    font-size: 1.2rem;
    padding: 8px 10px;
  }

  .stepper-btn {
    width: 42px;
    height: 42px;
    min-width: 42px;
  }

  .stepper-input {
    font-size: 1.1rem;
  }

  .rounding-btn {
    font-size: 0.78rem;
    padding: 8px 4px;
  }

  .result-highlight-value {
    font-size: 1.85rem;
  }

  .comparison-table th,
  .comparison-table td {
    font-size: 0.78rem;
    padding: var(--space-2) 4px;
  }

  .theme-options-grid {
    grid-template-columns: 1fr;
  }
}

/* --------------------------------------------------------------------------
   5. High Resolution / Large Screens (1440px+)
   -------------------------------------------------------------------------- */
@media (min-width: 1440px) {
  .calculator-card {
    max-width: 1020px;
  }

  .hero-title {
    font-size: 3.25rem;
  }
}