:root{--bg: #f7f8ff;--surface: #ffffff;--surface-alt: #eef1ff;--border: #d8deff;--border-strong: #b9c3ff;--text: #1f2343;--text-muted: #5f6593;--text-soft: #9ba2c4;--primary: #A4BEFF;--primary-dark: #7d9bf0;--primary-light: #e4ebff;--primary-soft: #f0f4ff;--accent: #8a9a5b;--danger: #b54842;--success: #7a9159;--radius: 14px;--radius-sm: 10px;--radius-lg: 18px;--font-serif: "Georgia", "Playfair Display", "Cambria", serif;--font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", sans-serif}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font-sans);background:var(--bg);color:var(--text);line-height:1.65;-webkit-font-smoothing:antialiased}.app{max-width:980px;margin:0 auto;padding:32px 20px;min-height:100vh}.app-header{text-align:center;margin-bottom:32px}.app-header h1{font-family:var(--font-serif);font-size:34px;font-weight:600;letter-spacing:-.5px;color:var(--text)}.subtitle{color:var(--text-muted);font-size:15px;margin-top:6px;font-style:italic}.tabs{display:flex;gap:6px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:6px;margin-bottom:24px}.tab{flex:1;padding:11px 16px;border:none;background:transparent;border-radius:var(--radius-sm);font-size:14px;font-weight:500;color:var(--text-muted);cursor:pointer;transition:all .2s ease;display:flex;align-items:center;justify-content:center;gap:8px;font-family:var(--font-sans)}.tab:hover{color:var(--text);background:var(--primary-soft)}.tab.active{background:var(--primary);color:#1f2343}.badge{background:#ffffff40;padding:1px 8px;border-radius:99px;font-size:12px;font-weight:600}.tab:not(.active) .badge{background:var(--primary-light);color:var(--primary)}.dropzone{border:2px dashed var(--border-strong);border-radius:var(--radius);padding:56px 24px;text-align:center;cursor:pointer;transition:all .25s ease;background:var(--surface)}.dropzone:hover,.dropzone.dragging{border-color:var(--primary);background:var(--primary-soft)}.dropzone.has-preview{padding:18px;cursor:default;border-style:solid}.dropzone-icon{font-size:40px;margin-bottom:14px;opacity:.8}.dropzone-text{font-size:15px;font-weight:500;color:var(--text);font-family:var(--font-serif)}.dropzone-hint{font-size:13px;color:var(--text-soft);margin-top:6px}.preview-container{position:relative}.preview-image{max-width:100%;max-height:420px;border-radius:var(--radius-sm);object-fit:contain}.clear-btn{position:absolute;top:10px;right:10px;width:30px;height:30px;border-radius:50%;border:none;background:#2d2823bf;color:var(--surface);font-size:17px;cursor:pointer;display:flex;align-items:center;justify-content:center;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.clear-btn:hover{background:#2d2823e6}.upload-controls{display:flex;gap:12px;margin-top:18px}.subject-select{flex:1;padding:11px 14px;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:14px;background:var(--surface);color:var(--text);font-family:var(--font-sans);cursor:pointer}.subject-select:focus{outline:none;border-color:var(--primary)}.submit-btn{padding:11px 28px;background:var(--primary);color:#1f2343;border:none;border-radius:var(--radius-sm);font-size:14px;font-weight:600;cursor:pointer;transition:all .2s ease;min-width:150px;font-family:var(--font-sans)}.submit-btn:disabled{opacity:.5;cursor:not-allowed}.submit-btn:hover:not(:disabled){background:var(--primary-dark)}.spinner{display:inline-block;width:16px;height:16px;border:2px solid rgba(255,255,255,.3);border-top-color:var(--surface);border-radius:50%;animation:spin .7s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.error-message{margin-top:14px;padding:11px 15px;background:#fbeff0;border:1px solid #e8c4c0;border-radius:var(--radius-sm);color:var(--danger);font-size:13px}.analyses-list{margin-top:36px}.analyses-list h3{font-family:var(--font-serif);font-size:18px;font-weight:600;margin-bottom:18px;color:var(--text)}.analysis-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:22px;margin-bottom:18px}.analysis-meta{display:flex;align-items:center;gap:14px;margin-bottom:16px;padding-bottom:16px;border-bottom:1px solid var(--border)}.analysis-thumb{width:84px;height:62px;object-fit:cover;border-radius:8px}.subject-badge{display:inline-block;padding:3px 12px;background:var(--primary-light);color:var(--primary-dark);border-radius:99px;font-size:12px;font-weight:600;letter-spacing:.3px}.chunk-count{display:block;font-size:12px;color:var(--text-soft);margin-top:5px}.analysis-content{font-size:14px;max-height:320px;overflow-y:auto;color:var(--text)}.chat-section{display:flex;flex-direction:column;height:calc(100vh - 180px);min-height:640px}.chat-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:18px}.chat-header h3{font-family:var(--font-serif);font-size:18px;font-weight:600;color:var(--text)}.chat-controls{display:flex;gap:10px;align-items:center}.filter-select{padding:7px 12px;border:1px solid var(--border);border-radius:8px;font-size:13px;background:var(--surface);color:var(--text);cursor:pointer;font-family:var(--font-sans)}.filter-select:focus{outline:none;border-color:var(--primary)}.clear-chat-btn{padding:7px 14px;border:1px solid var(--border);border-radius:8px;background:var(--surface);font-size:13px;cursor:pointer;color:var(--text-muted);font-family:var(--font-sans);transition:all .2s}.clear-chat-btn:hover{border-color:var(--primary);color:var(--primary)}.messages-container{flex:1;overflow-y:auto;padding:28px 32px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius) var(--radius) 0 0}.message{margin-bottom:24px;max-width:94%}.message.user{margin-left:auto;max-width:80%}.message.user .message-content{background:var(--primary);color:#1f2343;border-radius:var(--radius) var(--radius) 4px var(--radius);padding:14px 20px;font-size:15px;line-height:1.6}.message.assistant .message-content{background:var(--surface-alt);border-radius:var(--radius) var(--radius) var(--radius) 4px;padding:20px 24px;font-size:15px;line-height:1.75;color:var(--text)}.message.assistant.loading .message-content{background:transparent}.markdown-content h1,.markdown-content h2,.markdown-content h3,.markdown-content h4{margin:16px 0 10px;font-weight:600;font-family:var(--font-serif);color:var(--text);letter-spacing:-.2px}.markdown-content h2{font-size:19px}.markdown-content h3{font-size:17px}.markdown-content h4{font-size:15px}.markdown-content p{margin-bottom:12px}.markdown-content ul{padding-left:24px;margin:12px 0}.markdown-content li{margin-bottom:6px}.markdown-content code{background:#8b92d11a;color:var(--primary-dark);padding:2px 6px;border-radius:4px;font-size:13px;font-family:SF Mono,Monaco,Courier New,monospace}.markdown-content pre{background:#2d2823;color:#f5efe5;padding:16px;border-radius:10px;overflow-x:auto;margin:10px 0}.markdown-content pre code{background:none;padding:0;color:inherit}.markdown-content strong{font-weight:600;color:var(--text)}.sources{margin-top:12px;padding-top:12px;border-top:1px solid var(--border)}.sources-label{font-size:11px;color:var(--text-soft);display:block;margin-bottom:8px;letter-spacing:.4px;text-transform:uppercase;font-weight:600}.source-chips{display:flex;flex-wrap:wrap;gap:6px}.source-chip{display:inline-flex;align-items:center;gap:6px;padding:4px 12px;background:var(--surface);border:1px solid var(--border);border-radius:99px;font-size:12px;color:var(--text)}.relevance{background:var(--primary-light);color:var(--primary-dark);padding:1px 7px;border-radius:99px;font-size:11px;font-weight:600}.empty-state{text-align:center;padding:56px 24px}.empty-title{font-family:var(--font-serif);font-size:20px;font-weight:600;color:var(--text)}.empty-hint{font-size:14px;color:var(--text-muted);margin-top:10px;max-width:440px;margin-left:auto;margin-right:auto;line-height:1.6}.example-queries{display:flex;flex-direction:column;gap:10px;margin-top:26px;max-width:480px;margin-left:auto;margin-right:auto}.example-query{padding:12px 18px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);font-size:13px;text-align:left;cursor:pointer;color:var(--text);transition:all .2s;font-family:var(--font-sans)}.example-query:hover{border-color:var(--primary);background:var(--primary-soft);color:var(--primary-dark)}.typing-indicator{display:flex;gap:6px;padding:10px 2px}.typing-indicator span{width:8px;height:8px;background:var(--primary);opacity:.6;border-radius:50%;animation:bounce 1.3s infinite}.typing-indicator span:nth-child(2){animation-delay:.15s}.typing-indicator span:nth-child(3){animation-delay:.3s}@keyframes bounce{0%,60%,to{transform:translateY(0);opacity:.4}30%{transform:translateY(-7px);opacity:1}}.chat-input-form{display:flex;gap:10px;padding:14px;background:var(--surface);border:1px solid var(--border);border-top:none;border-radius:0 0 var(--radius) var(--radius);align-items:center}.chat-input{flex:1;padding:13px 18px;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:15px;outline:none;transition:border-color .2s;background:var(--bg);color:var(--text);font-family:var(--font-sans)}.chat-input::placeholder{color:var(--text-soft)}.chat-input:focus{border-color:var(--primary);background:var(--surface)}.send-btn{padding:11px 20px;background:var(--primary);color:#1f2343;border:none;border-radius:var(--radius-sm);font-size:18px;cursor:pointer;transition:all .2s;min-width:48px}.send-btn:hover:not(:disabled){background:var(--primary-dark)}.send-btn:disabled{opacity:.35;cursor:not-allowed}.textbook-dropzone{border:2px dashed var(--border-strong);border-radius:var(--radius);padding:42px 24px;text-align:center;cursor:pointer;transition:all .25s ease;background:var(--surface)}.textbook-dropzone:hover{border-color:var(--primary);background:var(--primary-soft)}.file-selected{display:flex;align-items:center;justify-content:center;gap:10px;font-size:14px;color:var(--text)}.file-icon{font-size:22px}.file-name{font-weight:500}.file-size{color:var(--text-soft);font-size:13px}.file-icon-large{font-size:30px}.textbook-controls{display:flex;flex-direction:column;gap:12px;margin-top:16px}.title-input{padding:11px 14px;border:1px solid var(--border);border-radius:var(--radius-sm);font-size:14px;width:100%;background:var(--surface);color:var(--text);font-family:var(--font-sans)}.title-input:focus{outline:none;border-color:var(--primary)}.textbook-row{display:flex;gap:12px}.progress-message{margin-top:14px;padding:11px 15px;background:var(--primary-soft);border:1px solid var(--primary-light);border-radius:var(--radius-sm);color:var(--primary-dark);font-size:13px}.text-preview{font-size:13px;color:var(--text-muted);line-height:1.6;font-style:italic}.source-chip .source-type{font-size:13px}.chat-image{max-width:100%;max-height:320px;border-radius:10px;margin-bottom:10px;object-fit:contain;border:1px solid var(--border)}.image-preview-bar{display:flex;align-items:center;gap:12px;padding:10px 14px;background:var(--primary-soft);border:1px solid var(--border);border-bottom:none}.preview-thumb{width:52px;height:38px;object-fit:cover;border-radius:6px}.preview-name{flex:1;font-size:13px;color:var(--text-muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.preview-remove{width:26px;height:26px;border:none;background:var(--surface);border-radius:50%;font-size:15px;cursor:pointer;color:var(--text-muted);display:flex;align-items:center;justify-content:center;transition:all .15s}.preview-remove:hover{background:var(--danger);color:var(--surface)}.attach-btn{width:40px;height:40px;border:1px solid var(--border);background:var(--surface);border-radius:50%;font-size:22px;cursor:pointer;color:var(--text-muted);display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:all .2s;font-weight:300}.attach-btn:hover:not(:disabled){border-color:var(--primary);color:var(--primary);background:var(--primary-soft)}.attach-btn:disabled{opacity:.4;cursor:not-allowed}.indexed-badge{margin-top:8px;padding:5px 12px;background:#eef2e4;color:var(--accent);border-radius:99px;font-size:11px;font-weight:600;display:inline-block;letter-spacing:.3px}.stream-cursor{display:inline-block;width:8px;height:16px;background:var(--primary);vertical-align:text-bottom;margin-left:3px;animation:blink 1s step-end infinite;border-radius:1px}@keyframes blink{0%,50%{opacity:1}51%,to{opacity:0}}@media (max-width: 600px){.app{padding:20px 14px}.app-header h1{font-size:28px}.upload-controls{flex-direction:column}.chat-header{flex-direction:column;gap:10px;align-items:flex-start}.message{max-width:96%}}