/* Date Difference Calculator — Custom Styles */

    .calc-form {
      display: grid;
      grid-template-columns: 1fr auto 1fr;
      gap: 20px;
      align-items: end;
    }

    .calc-form .input-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .calc-form .input-group.full-width {
      grid-column: 1 / -1;
    }

    .calc-form label {
      font-size: 0.8rem;
      font-weight: 600;
      color: var(--color-text-secondary);
      text-transform: uppercase;
      letter-spacing: 0.05em;
    }

    .calc-form input[type="date"] {
      padding: 12px 16px;
      border: 1px solid var(--color-border);
      border-radius: var(--radius-sm);
      font-family: var(--font-body);
      font-size: 1rem;
      color: var(--color-text);
      background: var(--color-surface);
      transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
      outline: none;
    }

    .calc-form input[type="date"]:focus {
      border-color: var(--color-primary);
      box-shadow: 0 0 0 3px var(--color-primary-light);
    }

    .swap-btn {
      padding: 12px 16px;
      border: 1px solid var(--color-border);
      border-radius: var(--radius-sm);
      background: var(--color-surface);
      cursor: pointer;
      color: var(--color-text-secondary);
      font-size: 1.1rem;
      transition: border-color var(--transition-fast), background var(--transition-fast), color var(--transition-fast);
      display: flex;
      align-items: center;
      justify-content: center;
      height: 46px;
      width: 46px;
    }

    .swap-btn:hover {
      border-color: var(--color-primary);
      background: var(--color-primary-light);
      color: var(--color-primary);
    }

    /* Results Section */
    .results-section {
      display: none;
      margin-top: 32px;
      padding-top: 28px;
      border-top: 1px solid var(--color-border-light);
      animation: fadeInUp 0.4s cubic-bezier(0.16, 1, 0.3, 1) both;
    }

    .results-section.visible {
      display: block;
    }

    .results-header {
      text-align: center;
      margin-bottom: 28px;
    }

    .diff-display {
      display: inline-flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
      padding: 28px 48px;
      border-radius: var(--radius-lg);
      background: var(--color-primary-light);
      border: 1px solid var(--color-primary-subtle);
      min-width: 280px;
    }

    .diff-display .diff-label {
      font-size: 0.75rem;
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.08em;
      color: var(--color-primary);
      opacity: 0.85;
    }

    .diff-display .diff-value {
      font-size: 2.2rem;
      font-weight: 700;
      line-height: 1.2;
      color: var(--color-primary);
      font-family: var(--font-body);
      letter-spacing: -0.02em;
      text-align: center;
    }

    /* Result Cards Grid */
    .result-cards {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 12px;
      margin-top: 24px;
    }

    .result-card {
      padding: 16px;
      background: var(--color-bg);
      border: 1px solid var(--color-border-light);
      border-radius: var(--radius-sm);
      text-align: center;
    }

    .result-card .card-label {
      font-size: 0.7rem;
      font-weight: 600;
      text-transform: uppercase;
      letter-spacing: 0.05em;
      color: var(--color-text-muted);
      margin-bottom: 6px;
    }

    .result-card .card-value {
      font-size: 1.25rem;
      font-weight: 700;
      color: var(--color-text);
      font-family: var(--font-mono);
    }

    .result-card .card-sub {
      font-size: 0.75rem;
      color: var(--color-text-muted);
      margin-top: 4px;
    }

    .result-card.highlight {
      background: var(--color-success-bg);
      border-color: #a7f3d0;
    }

    .result-card.highlight .card-value {
      color: #059669;
    }

    /* Responsive */
    @media (max-width: 768px) {
      .calc-form {
        grid-template-columns: 1fr;
      }

      .swap-btn {
        justify-self: center;
        transform: rotate(90deg);
      }

      .result-cards {
        grid-template-columns: 1fr 1fr;
      }

      .diff-display {
        padding: 24px 36px;
      }

      .diff-display .diff-value {
        font-size: 1.7rem;
      }
    }

    @media (max-width: 480px) {
      .result-cards {
        grid-template-columns: 1fr;
      }
    }