:root{--primary-color:#46757e;--primary-hover:#5a8d99;--accent-color:#93d9d7;--bg-light:#f8fafb;--text-main:#333;--text-muted:#666;--border-color:#e1e8ed;--white:#fff;--shadow:0 4px 15px rgba(0,0,0,.05);--transition:all .3s ease}.bg-remover-container{max-width:650px;margin:40px auto;padding:30px;background-color:var(--white);border-radius:16px;box-shadow:var(--shadow);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;color:var(--text-main);line-height:1.6}.bg-remover-container h1{font-size:1.75rem;font-weight:700;text-align:center;color:var(--primary-color);margin-bottom:25px;letter-spacing:-.5px}.drop-area{position:relative;border:2px dashed var(--border-color);border-radius:12px;padding:50px 20px;text-align:center;background-color:var(--bg-light);transition:var(--transition);cursor:pointer;margin-bottom:25px}.drop-area:hover,.drop-area.highlight{border-color:var(--primary-color);background-color:rgba(70,117,126,.05)}.drop-area p{margin:10px 0;font-weight:500}.drop-area p:first-child{font-size:1.1rem;color:var(--primary-color)}.btn-select{display:inline-block;padding:8px 24px;background-color:var(--white);border:1px solid var(--primary-color);color:var(--primary-color);border-radius:25px;font-weight:600;cursor:pointer;transition:var(--transition)}.btn-select:hover{background-color:var(--primary-color);color:var(--white)}.preview-container{margin-bottom:25px;text-align:center;padding:20px;border:1px solid var(--border-color);border-radius:12px;background-color:var(--white);box-shadow:inset 0 2px 4px rgba(0,0,0,.02)}.preview-label{font-size:.85rem;font-weight:600;color:var(--text-muted);margin-bottom:15px;text-transform:uppercase;letter-spacing:.5px}#image-preview{max-width:100%;max-height:350px;border-radius:8px;object-fit:contain;display:block;margin:0 auto;border:1px solid #f0f0f0}.bg-remover-form{display:flex;flex-direction:column;gap:20px}.form-group label{display:block;font-size:.9rem;font-weight:600;margin-bottom:8px}.form-control{width:100%;padding:12px;border:1px solid var(--border-color);border-radius:8px;font-size:1rem;background-color:var(--white);transition:var(--transition)}.form-control:focus{outline:none;border-color:var(--primary-color);box-shadow:0 0 0 3px rgba(70,117,126,.1)}#alpha-matting-settings{background:var(--bg-light);padding:20px;border-radius:10px;display:grid;grid-template-columns:1fr 1fr;gap:15px}#alpha-matting-settings .form-group:last-child{grid-column:span 2}.btn-submit{width:100%;padding:16px;background-color:var(--primary-color);color:var(--white);border:none;border-radius:8px;font-size:1.1rem;font-weight:700;cursor:pointer;transition:var(--transition);box-shadow:0 4px 10px rgba(70,117,126,.2)}.btn-submit:hover{background-color:var(--primary-hover);transform:translateY(-1px);box-shadow:0 6px 15px rgba(70,117,126,.3)}.status-log{margin:20px 0 10px;text-align:center;font-size:.95rem;font-weight:600;color:var(--primary-color);min-height:1.5em}#bg-remover-progress-container{width:100%;height:10px;background-color:var(--bg-light);border-radius:5px;overflow:hidden;margin-bottom:30px}.progress-bar{height:100%;background-color:var(--accent-color);width:0%;transition:width .4s cubic-bezier(.4,0,.2,1)}.bg-remover-result{margin-top:30px;padding-top:30px;border-top:2px solid var(--bg-light);text-align:center}.bg-remover-result h3{margin-bottom:20px;font-size:1.25rem;color:var(--text-main)}.bg-remover-result img{max-width:100%;height:auto;border-radius:12px;box-shadow:var(--shadow);margin-bottom:25px;background-image:linear-gradient(45deg,#e0e0e0 25%,transparent 25%) , linear-gradient(-45deg,#e0e0e0 25%,transparent 25%) , linear-gradient(45deg,transparent 75%,#e0e0e0 75%) , linear-gradient(-45deg,transparent 75%,#e0e0e0 75%);background-size:20px 20px;background-position:0 0 , 0 10px , 10px -10px , -10px 0}.btn-download{display:inline-block;padding:14px 40px;background-color:#2c3e50;color:var(--white);text-decoration:none;border-radius:30px;font-weight:700;transition:var(--transition)}.btn-download:hover{background-color:#1a252f;transform:scale(1.05)}@media (max-width:600px){.bg-remover-container{margin:20px 10px;padding:20px}#alpha-matting-settings{grid-template-columns:1fr}#alpha-matting-settings .form-group:last-child{grid-column:span 1}}