:root{--primary-color:#4e73df;--secondary-color:#f8f9fc;--accent-color:#2e59d9;--light-color:#fff;--dark-color:#5a5c69;--success-color:#1cc88a;--warning-color:#f6c23e;--danger-color:#e74a3b;--text-color:#333;--text-light:#666;--border-color:#e3e6f0;--bg-light:#f8f9fc}*{box-sizing:border-box;margin:0;padding:0}.containert{max-width:1200px;margin:100px auto 40px auto;padding:20px}.card{border:0;border-radius:.5rem;overflow:hidden;box-shadow:0 .15rem 1.75rem 0 rgba(58,59,69,0.15)}.upload-area{background-color:var(--secondary-color);text-align:center;cursor:pointer;transition:all .3s ease;height:100%;display:flex;flex-direction:column;justify-content:center;align-items:center;min-height:350px;border-radius:.5rem;border:2px dashed #d1d3e2}.upload-area:hover{background-color:#e9ecef;border-color:var(--primary-color)}.upload-area.highlight{background-color:#e2f0fd;border:2px dashed var(--primary-color)}.settings-area{background-color:var(--light-color);height:100%}.preview-area{background-color:var(--light-color);padding:1.5rem;border-radius:.5rem;border:1px solid var(--border-color);max-height:500px;overflow-y:auto}.file-info{font-size:.9rem;color:var(--text-light);padding:10px;background:var(--bg-light);border-radius:.5rem}.preview-table{width:100%;border-collapse:collapse;font-size:.85rem}.preview-table th,.preview-table td{border:1px solid #ddd;padding:8px;text-align:left}.preview-table th{background-color:#f2f2f2;font-weight:600}.preview-table tr:nth-child(even){background-color:#f9f9f9}.btn-primary{background-color:var(--primary-color);border-color:var(--primary-color)}.btn-primary:hover{background-color:var(--accent-color);border-color:var(--accent-color)}.btn-success{background-color:var(--success-color);border-color:var(--success-color)}.btn-success:hover{background-color:#17a673;border-color:#169b6b}.btn-warning{background-color:var(--warning-color);border-color:var(--warning-color);color:#000}.btn-warning:hover{background-color:#dda20a;border-color:#d29410;color:#000}.btn-danger{background-color:var(--danger-color);border-color:var(--danger-color)}.btn-danger:hover{background-color:#be2617;border-color:#b32112}.btn:disabled{opacity:.6;cursor:not-allowed}.progress{height:1rem;border-radius:.35rem}.progress-bar{background-color:var(--primary-color)}.modal-content{border-radius:.5rem}.modal-header{background-color:var(--primary-color);color:white;border-bottom:0}.modal-header .btn-close{filter:brightness(0) invert(1)}.format-badge{font-size:.75rem;margin-right:5px;margin-bottom:5px}#columnSelection{border:1px solid var(--border-color);border-radius:.25rem;padding:10px}#columnSelection .form-check{margin-bottom:8px}#columnSelection .form-check:last-child{margin-bottom:0}#base64Result{font-family:monospace;font-size:12px;resize:vertical}.toast-notification{position:fixed;bottom:20px;right:20px;background-color:var(--success-color);color:white;padding:12px 20px;border-radius:8px;z-index:9999;animation:slideIn .3s ease}.toast-notification.error{background-color:var(--danger-color)}@keyframes slideIn{from{transform:translateX(100%);opacity:0}to{transform:translateX(0);opacity:1}}.how-to-section-wrapper{max-width:1200px;margin:60px auto;padding:0 20px}.how-to-section-wrapper h2{font-family:'Space Grotesk',sans-serif;text-align:center;font-size:2.2rem;color:#333;line-height:1.6;margin-bottom:40px}.steps-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:30px}.step-card{background-color:#fff;padding:30px;border-radius:12px;border:1px solid #e9ecef;text-align:left;box-shadow:0 5px 15px rgba(0,0,0,0.05);transition:transform .3s ease}.step-card:hover{transform:translateY(-5px)}.step-card .step-number{font-size:1.5rem;font-weight:700;color:#fff;background-color:#0d47a1;width:45px;height:45px;border-radius:50%;display:flex;align-items:center;justify-content:center;margin-bottom:20px}.step-card h3{font-family:'Space Grotesk',sans-serif;font-size:1.3rem;margin-bottom:10px;color:#222;line-height:1.6}.step-card p{color:#666;line-height:1.6;font-size:1rem;margin:0}.content-wrapper{max-width:1200px;margin:60px auto;padding:0 20px;font-family:'Segoe UI',Tahoma,Geneva,Verdana,sans-serif;line-height:1.7;color:#333}.content-wrapper h2{font-size:2rem;margin:30px 0 15px;color:#0d47a1;font-weight:700;text-align:left;border-left:4px solid var(--primary-color);padding-left:15px}.content-wrapper h3{font-size:1.3rem;margin:25px 0 10px;font-weight:600;color:#222}.content-wrapper p{margin-bottom:18px;font-size:1rem;color:#555}.content-wrapper ul{margin:15px 0 25px 25px}.content-wrapper li{margin-bottom:12px;font-size:1rem;color:#444}.content-wrapper a{color:#0d47a1;text-decoration:none;font-weight:600;transition:all .2s ease}.content-wrapper a:hover{text-decoration:underline;color:#2e59d9}.feature-icon{color:#0d47a1;margin-right:10px;width:20px;text-align:center}@media(max-width:1024px){.containert{margin:80px auto 30px auto;padding:15px}.steps-grid{gap:20px}}@media(max-width:768px){.containert{margin:60px auto 20px auto;padding:10px}.card-body{padding:1rem}.upload-area{padding:1.5rem;min-height:250px}.settings-area{padding:1.5rem;margin-top:20px}.preview-area{padding:1rem}.steps-grid{grid-template-columns:1fr}.content-wrapper h2{font-size:1.5rem}.content-wrapper h3{font-size:1.2rem}.preview-table{font-size:.75rem}.preview-table th,.preview-table td{padding:4px}}@media(max-width:480px){.containert{margin:50px auto 15px auto;padding:5px}.upload-area h4{font-size:1rem}.upload-area p{font-size:.85rem}.btn{font-size:.85rem;padding:8px 16px}.how-to-section-wrapper h2{font-size:1.5rem}.step-card{padding:20px}}@media(prefers-color-scheme:dark){:root{--secondary-color:#1f2937;--light-color:#1f2937;--bg-light:#111827;--border-color:#374151;--text-color:#f9fafb;--text-light:#9ca3af}body{background-color:#111827}.card{background-color:#1f2937}.upload-area{background-color:#1f2937;border-color:#4b5563}.upload-area:hover{background-color:#374151}.settings-area{background-color:#1f2937}.preview-area{background-color:#1f2937;border-color:#4b5563}.file-info{background-color:#111827}.preview-table th{background-color:#374151;color:#f9fafb}.preview-table td{border-color:#4b5563;color:#d1d5db}.preview-table tr:nth-child(even){background-color:#1f2937}.step-card{background-color:#1f2937;border-color:#374151}.step-card h3{color:#f9fafb}.step-card p{color:#9ca3af}.how-to-section-wrapper h2{color:#f9fafb}.content-wrapper{color:#e5e7eb}.content-wrapper h2{color:#818cf8}.content-wrapper h3{color:#f9fafb}.content-wrapper p{color:#9ca3af}.content-wrapper li{color:#9ca3af}#columnSelection{background-color:#1f2937;border-color:#4b5563}#base64Result{background-color:#1f2937;color:#f9fafb;border-color:#4b5563}}@media print{.upload-area,.settings-area,.action-buttons,.how-to-section-wrapper,.content-wrapper,.modal{display:none !important}.preview-area{display:block !important;max-height:none}.containert{margin:0;padding:0}}.btn:focus-visible,.form-control:focus-visible,.form-select:focus-visible{outline:2px solid var(--primary-color);outline-offset:2px}@keyframes fadeIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.preview-area{animation:fadeIn .3s ease}