:root{color:#172033;background:#f4f6fb;font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}*{box-sizing:border-box}body{margin:0}button,input,textarea,select{font:inherit}.app-shell{min-height:100vh}.header{color:#fff;background:#111827;padding:28px clamp(16px,4vw,56px)}.header h1{margin:0 0 8px;font-size:clamp(28px,4vw,44px)}.header p{color:#cbd5e1;max-width:850px;margin:0}.main{grid-template-columns:minmax(280px,380px) 1fr;gap:24px;padding:28px clamp(16px,4vw,56px);display:grid}.card{background:#fff;border:1px solid #e5e7eb;border-radius:18px;padding:22px;box-shadow:0 10px 30px #0f172a14}.card h2,.card h3{margin-top:0}.form-field{gap:8px;margin-bottom:14px;display:grid}.form-field label{font-size:14px;font-weight:700}input,textarea,select{background:#fff;border:1px solid #cbd5e1;border-radius:12px;padding:11px 12px}textarea{resize:vertical;min-height:220px}button{color:#fff;cursor:pointer;background:#2563eb;border:0;border-radius:12px;padding:12px 16px;font-weight:800}button.secondary{background:#334155}button:disabled{opacity:.55;cursor:not-allowed}.course-list,.lesson-list{gap:10px;display:grid}.list-item{text-align:left;color:#172033;background:#f8fafc;border:1px solid #e2e8f0;width:100%}.list-item.active{background:#dbeafe;border-color:#60a5fa}.workspace{gap:24px;display:grid}.tabs{flex-wrap:wrap;gap:8px;margin-bottom:16px;display:flex}.tabs button{color:#172033;background:#e2e8f0;padding:8px 12px}.tabs button.active{color:#fff;background:#111827}.output-box{color:#e5e7eb;white-space:pre-wrap;background:#0f172a;border-radius:14px;padding:18px;overflow-x:auto}.grid-two{grid-template-columns:1fr 1fr;gap:16px;display:grid}.error{color:#b91c1c;font-weight:700}.success{color:#166534;font-weight:700}.upload-panel{background:#eff6ff;border:1px dashed #60a5fa;border-radius:14px;margin-bottom:20px;padding:16px}.batch-status{gap:10px;margin-bottom:22px;display:grid}.batch-status progress{width:100%;height:12px}.file-status-list{gap:6px;max-height:280px;display:grid;overflow:auto}.file-status{background:#f1f5f9;border-radius:8px;justify-content:space-between;gap:12px;padding:8px 10px;font-size:13px;display:flex}.file-status.completed{background:#dcfce7}.file-status.failed{color:#991b1b;background:#fee2e2}.file-status.processing{background:#fef3c7}.retry-button{margin-left:10px;padding:5px 8px;font-size:12px}.processing-message{color:#92400e;background:#fef3c7;border-radius:10px;padding:10px 12px;font-weight:700}.language-card,.study-card{background:#fff;border:1px solid #dbe3ef;border-radius:14px;padding:18px;position:relative;box-shadow:0 5px 18px #0f172a0d}.language-card h4,.study-card h4{margin:4px 0 12px}.language-card p,.study-card p{line-height:1.65}.language-tag,.card-number{color:#1d4ed8;background:#dbeafe;border-radius:999px;margin-bottom:10px;padding:4px 9px;font-size:12px;font-weight:800;display:inline-block}.notes-card>div{white-space:pre-wrap;line-height:1.65}.study-grid{grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:14px;display:grid}.stack-list{gap:16px;display:grid}.translation{color:#64748b;font-weight:500}.flashcard{padding:0;overflow:hidden}.flashcard summary{cursor:pointer;gap:8px;padding:18px;list-style:none;display:grid}.flashcard summary::-webkit-details-marker{display:none}.flashcard summary:after{content:"Mostrar respuesta";color:#2563eb;font-size:13px;font-weight:800}.flashcard[open] summary:after{content:"Ocultar respuesta"}.flashcard .answer{background:#f8fafc;border-top:1px solid #e2e8f0;padding:4px 18px 18px}.option-list{gap:8px;padding-left:26px;display:grid}.option-list li{background:#f8fafc;border-radius:9px;padding:9px 12px}.option-list li span{color:#64748b;margin-top:3px;font-size:13px;display:block}.answer-reveal{border-top:1px solid #e2e8f0;margin-top:14px;padding-top:12px}.answer-reveal summary{cursor:pointer;color:#2563eb;font-weight:800}.exercise-card h5{margin-bottom:6px}.exercise-card li{margin-bottom:7px;line-height:1.5}.checklist{gap:10px;display:grid}.check-item{cursor:pointer;background:#fff;border:1px solid #dbe3ef;border-radius:12px;align-items:flex-start;gap:12px;padding:14px;display:flex}.check-item input{accent-color:#2563eb;width:20px;height:20px;margin:1px 0 0}.check-item span{gap:4px;display:grid}.check-item small{color:#64748b}.check-item:has(input:checked){background:#dcfce7;border-color:#86efac}.check-item:has(input:checked) strong{color:#166534;text-decoration:line-through}@media (width<=900px){.main,.grid-two{grid-template-columns:1fr}}