*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}:root{--bg: #ffffff;--bg-subtle: #f9fafb;--bg-muted: #f3f4f6;--border: #e5e7eb;--border-focus: #6366f1;--text: #111827;--text-secondary: #6b7280;--text-muted: #9ca3af;--accent: #4f46e5;--accent-hover: #4338ca;--accent-light: #eef2ff;--green: #059669;--green-light: #ecfdf5;--green-border: #a7f3d0;--red: #dc2626;--red-light: #fef2f2;--red-border: #fecaca;--yellow: #d97706;--yellow-light: #fffbeb;--radius: 12px;--radius-sm: 8px;--shadow-sm: 0 1px 2px 0 rgb(0 0 0 / .05);--shadow: 0 1px 3px 0 rgb(0 0 0 / .1), 0 1px 2px -1px rgb(0 0 0 / .1);--shadow-md: 0 4px 6px -1px rgb(0 0 0 / .1), 0 2px 4px -2px rgb(0 0 0 / .1);--transition: .15s ease;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,system-ui,sans-serif}html,body,#root{height:100%;background-color:var(--bg);color:var(--text)}body{min-height:100vh;background:var(--bg);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}.app{min-height:100vh;display:flex;flex-direction:column}.header{padding:16px 32px;display:flex;align-items:center;gap:10px;border-bottom:1px solid var(--border);background:var(--bg);position:sticky;top:0;z-index:100}.logo{width:32px;height:32px;background:var(--accent);border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:15px;color:#fff}.header h1{font-size:1.1rem;font-weight:600;color:var(--text);letter-spacing:-.3px}.header .tagline{margin-left:auto;font-size:.75rem;color:var(--text-muted);font-weight:400}.main{flex:1;max-width:720px;margin:0 auto;padding:48px 24px 80px;width:100%}.step-indicator{display:flex;align-items:center;justify-content:center;gap:0;margin-bottom:40px}.step-item{display:flex;align-items:center;gap:8px;font-size:.8rem;font-weight:500;color:var(--text-muted);transition:var(--transition)}.step-item.active{color:var(--accent)}.step-item.done{color:var(--green)}.step-dot{width:28px;height:28px;border-radius:50%;border:2px solid var(--border);display:flex;align-items:center;justify-content:center;font-size:.75rem;font-weight:600;background:var(--bg);transition:var(--transition)}.step-item.active .step-dot{border-color:var(--accent);background:var(--accent-light);color:var(--accent)}.step-item.done .step-dot{border-color:var(--green);background:var(--green-light);color:var(--green)}.step-line{width:40px;height:2px;background:var(--border);margin:0 8px;border-radius:1px;transition:var(--transition)}.step-line.done{background:var(--green)}.upload-section{text-align:center}.upload-section h2{font-size:1.5rem;font-weight:700;margin-bottom:6px;letter-spacing:-.4px;color:var(--text)}.upload-section p{color:var(--text-secondary);font-size:.9rem;margin-bottom:28px;line-height:1.5}.drop-zone{border:2px dashed var(--border);border-radius:var(--radius);padding:48px 32px;cursor:pointer;transition:var(--transition);background:var(--bg-subtle)}.drop-zone:hover{border-color:var(--accent);background:var(--accent-light)}.drop-zone-icon{font-size:2.5rem;margin-bottom:12px;display:block}.drop-zone h3{font-size:1rem;font-weight:600;margin-bottom:4px;color:var(--text)}.drop-zone p{font-size:.8rem;color:var(--text-muted);margin-bottom:0}.preview-container{position:relative;display:inline-block;width:100%}.preview-image{width:100%;max-height:360px;object-fit:contain;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-muted)}.preview-remove{position:absolute;top:8px;right:8px;background:#fff;border:1px solid var(--border);color:var(--text-secondary);width:28px;height:28px;border-radius:50%;cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:14px;transition:var(--transition);box-shadow:var(--shadow-sm)}.preview-remove:hover{background:var(--red-light);border-color:var(--red-border);color:var(--red)}.btn-primary{width:100%;margin-top:20px;padding:12px 24px;background:var(--accent);color:#fff;border:none;border-radius:var(--radius-sm);font-size:.9rem;font-weight:600;cursor:pointer;transition:var(--transition)}.btn-primary:hover:not(:disabled){background:var(--accent-hover)}.btn-primary:active:not(:disabled){transform:scale(.99)}.btn-primary:disabled{opacity:.5;cursor:not-allowed}.btn-secondary{padding:12px 24px;background:var(--bg);color:var(--text-secondary);border:1px solid var(--border);border-radius:var(--radius-sm);font-size:.9rem;font-weight:500;cursor:pointer;transition:var(--transition)}.btn-secondary:hover{background:var(--bg-subtle);color:var(--text);border-color:var(--text-muted)}.btn-link{background:none;border:none;color:var(--text-muted);font-size:.8rem;cursor:pointer;text-decoration:underline;padding:0;transition:var(--transition)}.btn-link:hover{color:var(--text-secondary)}.loading-container{text-align:center;padding:48px 0}.loading-spinner{width:36px;height:36px;border:3px solid var(--border);border-top-color:var(--accent);border-radius:50%;animation:spin .7s linear infinite;margin:0 auto 20px}@keyframes spin{to{transform:rotate(360deg)}}.loading-container h3{font-size:.95rem;font-weight:600;margin-bottom:4px;color:var(--text)}.loading-container p{color:var(--text-muted);font-size:.8rem}.results-section{animation:fadeIn .3s ease}@keyframes fadeIn{0%{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}.results-section h2{font-size:1.5rem;font-weight:700;margin-bottom:6px;letter-spacing:-.4px}.results-section>p{color:var(--text-secondary);font-size:.9rem;margin-bottom:24px}.score-card{display:flex;align-items:center;gap:24px;padding:28px;background:var(--bg-subtle);border:1px solid var(--border);border-radius:var(--radius);margin-bottom:28px}.score-ring{width:88px;height:88px;border-radius:50%;display:flex;flex-direction:column;align-items:center;justify-content:center;flex-shrink:0;position:relative}.score-ring:before{content:"";position:absolute;top:0;right:0;bottom:0;left:0;border-radius:50%;background:conic-gradient(var(--grade-color) var(--score-deg),var(--border) 0deg)}.score-ring-inner{width:calc(100% - 8px);height:calc(100% - 8px);border-radius:50%;background:var(--bg-subtle);display:flex;flex-direction:column;align-items:center;justify-content:center;position:relative;z-index:1}.score-letter{font-size:1.5rem;font-weight:800;line-height:1}.score-pct{font-size:.65rem;color:var(--text-muted);font-weight:500;margin-top:2px}.score-details h3{font-size:1.2rem;font-weight:700;margin-bottom:8px;color:var(--text)}.score-pills{display:flex;gap:8px}.pill{display:inline-flex;align-items:center;gap:4px;padding:4px 10px;border-radius:20px;font-size:.78rem;font-weight:500}.pill.correct{background:var(--green-light);color:var(--green)}.pill.incorrect{background:var(--red-light);color:var(--red)}.word-bank-box{background:var(--bg-subtle);border:1px solid var(--border);border-radius:var(--radius-sm);padding:14px 18px;margin-bottom:20px}.word-bank-box strong{font-size:.75rem;text-transform:uppercase;letter-spacing:.5px;color:var(--text-muted);display:block;margin-bottom:6px}.word-bank-box 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1fr;gap:10px;font-size:.82rem}.detail-item label{display:block;font-size:.65rem;text-transform:uppercase;letter-spacing:.4px;color:var(--text-muted);font-weight:600;margin-bottom:2px}.detail-item.student-answer span{color:var(--text)}.detail-item.correct-answer span{color:var(--green);font-weight:500}.explanation{grid-column:1 / -1;font-size:.78rem;color:var(--text-secondary);font-style:italic;line-height:1.5}.override-btn{margin-top:10px;padding:4px 10px;font-size:.75rem;border:1px solid var(--border);border-radius:6px;background:var(--bg);color:var(--text-muted);cursor:pointer;transition:var(--transition)}.override-btn:hover{border-color:var(--yellow);color:var(--yellow);background:var(--yellow-light)}.overridden-badge{font-size:.7rem;color:var(--yellow);font-weight:500;margin-top:6px;display:block}.key-card{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);padding:16px 18px;transition:var(--transition);display:flex;flex-direction:column;gap:10px}.key-card:hover{box-shadow:var(--shadow-sm)}.key-card .field-label{font-size:.65rem;text-transform:uppercase;letter-spacing:.4px;color:var(--text-muted);font-weight:600;margin-bottom:2px;display:block}.key-card input[type=text]{width:100%;padding:8px 12px;border:1px solid var(--border);border-radius:6px;font-size:.85rem;color:var(--text);background:var(--bg);transition:var(--transition);font-family:inherit}.key-card input[type=text]:focus{outline:none;border-color:var(--border-focus);box-shadow:0 0 0 3px #6366f11a}.key-card input.answer-field{border-color:var(--green-border);background:var(--green-light)}.key-card input.answer-field:focus{border-color:var(--green);box-shadow:0 0 0 3px #0596691a}.status-badge{display:inline-flex;align-items:center;gap:6px;padding:6px 14px;border-radius:20px;font-size:.78rem;font-weight:500;background:var(--green-light);color:var(--green);border:1px solid var(--green-border);margin-bottom:20px}.error-box{background:var(--red-light);border:1px solid var(--red-border);border-radius:var(--radius-sm);padding:12px 16px;color:var(--red);margin-top:12px;font-size:.85rem;display:flex;align-items:center;gap:8px}.divider{border:none;border-top:1px solid var(--border);margin:24px 0}.action-bar{display:flex;gap:10px;margin-top:24px}.action-bar .btn-primary{flex:2;margin-top:0}.action-bar .btn-secondary{flex:1}@media(max-width:640px){.header{padding:14px 16px}.header .tagline{display:none}.main{padding:28px 16px 60px}.drop-zone{padding:32px 20px}.score-card{flex-direction:column;align-items:flex-start;gap:16px;padding:20px}.question-details{grid-template-columns:1fr}.step-item span:not(.step-dot){display:none}.step-line{width:24px}.action-bar{flex-direction:column}}