:root{--bg-primary: #ffffff;--bg-secondary: #f8fafc;--bg-tertiary: #f1f5f9;--bg-accent: #e2e8f0;--text-primary: #1e293b;--text-secondary: #475569;--text-muted: #64748b;--border-color: #e2e8f0;--border-light: #f1f5f9;--accent-color: #3b82f6;--accent-hover: #2563eb;--accent-light: #dbeafe;--success-color: #10b981;--success-light: #d1fae5;--warning-color: #f59e0b;--warning-light: #fef3c7;--error-color: #ef4444;--error-light: #fee2e2;--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);--shadow-lg: 0 10px 15px -3px rgb(0 0 0 / .1), 0 4px 6px -4px rgb(0 0 0 / .1);--shadow-xl: 0 20px 25px -5px rgb(0 0 0 / .1), 0 8px 10px -6px rgb(0 0 0 / .1);--radius-sm: .375rem;--radius: .5rem;--radius-md: .75rem;--radius-lg: 1rem}[data-theme=dark]{--bg-primary: #0f172a;--bg-secondary: #1e293b;--bg-tertiary: #334155;--bg-accent: #475569;--text-primary: #f8fafc;--text-secondary: #cbd5e1;--text-muted: #94a3b8;--border-color: #334155;--border-light: #475569;--accent-color: #60a5fa;--accent-hover: #3b82f6;--accent-light: #1e3a8a;--success-color: #34d399;--success-light: #064e3b;--warning-color: #fbbf24;--warning-light: #451a03;--error-color: #f87171;--error-light: #450a0a}*{margin:0;padding:0;box-sizing:border-box}body{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,Fira Sans,Droid Sans,Helvetica Neue,sans-serif;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background-color:var(--bg-primary);color:var(--text-primary);line-height:1.6;transition:background-color .3s ease,color .3s ease;font-size:14px}.container{max-width:1280px;margin:0 auto;padding:0 24px}.header{background-color:var(--bg-primary);border-bottom:1px solid var(--border-color);padding:1rem 0;position:sticky;top:0;z-index:100;box-shadow:var(--shadow-sm);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px)}.header-content{display:flex;justify-content:space-between;align-items:center}.logo{font-size:1.75rem;font-weight:700;color:var(--accent-color);text-decoration:none;transition:color .3s ease;display:flex;align-items:center;gap:.5rem}.logo:hover{color:var(--accent-hover)}.nav{display:flex;gap:2rem;align-items:center}.nav-link{color:var(--text-secondary);text-decoration:none;font-weight:500;padding:.5rem 1rem;border-radius:var(--radius);transition:all .3s ease;position:relative}.nav-link:hover{color:var(--accent-color);background-color:var(--accent-light)}.nav-link.active{color:var(--accent-color);background-color:var(--accent-light);font-weight:600}.theme-toggle{background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:var(--radius);width:40px;height:40px;cursor:pointer;display:flex;align-items:center;justify-content:center;color:var(--text-primary);transition:all .3s ease;font-size:1.1rem}.theme-toggle:hover{background-color:var(--bg-tertiary);transform:scale(1.05);box-shadow:var(--shadow)}.main-content{min-height:calc(100vh - 80px);padding:2rem 0}.search-container{max-width:900px;margin:0 auto;text-align:center;padding:2rem 0}.search-title{font-size:3rem;font-weight:800;margin-bottom:1rem;background:linear-gradient(135deg,var(--accent-color),var(--success-color));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.search-subtitle{font-size:1.125rem;color:var(--text-secondary);margin-bottom:3rem;font-weight:400}.search-form{background:linear-gradient(135deg,var(--bg-secondary),var(--bg-tertiary));padding:2.5rem;border-radius:var(--radius-lg);box-shadow:var(--shadow-xl);margin-bottom:2rem;border:1px solid var(--border-color);position:relative;overflow:hidden}.search-form:before{content:"";position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,var(--accent-color),var(--success-color),var(--accent-color));background-size:200% 100%;animation:shimmer 2s linear infinite}@keyframes shimmer{0%{background-position:-200% 0}to{background-position:200% 0}}.search-input-group{display:flex;gap:.75rem;margin-bottom:2rem;align-items:stretch}.search-input{flex:1;padding:1rem 1.25rem;border:2px solid var(--border-color);border-radius:var(--radius);font-size:1rem;background-color:var(--bg-primary);color:var(--text-primary);transition:all .3s ease;font-weight:400}.search-input:focus{outline:none;border-color:var(--accent-color);box-shadow:0 0 0 3px var(--accent-light)}.search-input::placeholder{color:var(--text-muted)}.search-button{padding:1rem 2.5rem;background:linear-gradient(135deg,var(--accent-color),var(--accent-hover));color:#fff;border:none;border-radius:var(--radius);font-size:1rem;font-weight:600;cursor:pointer;transition:all .3s ease;white-space:nowrap;box-shadow:var(--shadow)}.search-button:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}.search-button:active{transform:translateY(0)}.search-button:disabled{background:var(--text-muted);cursor:not-allowed;transform:none;box-shadow:none}.filter-toggle{display:flex;gap:1rem;align-items:center;justify-content:center;margin:1.5rem 0;padding-top:1.5rem;border-top:1px solid var(--border-color)}.filter-toggle-button{padding:.75rem 1.5rem;background:linear-gradient(135deg,var(--bg-tertiary),var(--bg-accent));color:var(--text-primary);border:1px solid var(--border-color);border-radius:var(--radius);cursor:pointer;font-size:.875rem;font-weight:600;transition:all .3s ease;text-transform:uppercase;letter-spacing:.025em;position:relative;overflow:hidden}.filter-toggle-button:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(59,130,246,.1),transparent);transition:left .5s}.filter-toggle-button:hover:before{left:100%}.filter-toggle-button:hover{background:linear-gradient(135deg,var(--accent-color),var(--accent-hover));color:#fff;transform:translateY(-2px);box-shadow:var(--shadow-md)}.clear-filters-button{padding:.75rem 1.5rem;background:linear-gradient(135deg,var(--warning-color),#f59e0b);color:#fff;border:none;border-radius:var(--radius);cursor:pointer;font-size:.875rem;font-weight:600;transition:all .3s 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var(--border-color)}.filter-group{display:flex;flex-direction:column;gap:.5rem}.filter-label{font-weight:600;color:var(--text-secondary);font-size:.875rem;text-transform:uppercase;letter-spacing:.025em}.filter-input,.filter-select{padding:.75rem 1rem;border:2px solid var(--border-color);border-radius:var(--radius);background-color:var(--bg-primary);color:var(--text-primary);font-size:.875rem;transition:all .3s ease;font-weight:500}.filter-input:focus,.filter-select:focus{outline:none;border-color:var(--accent-color);box-shadow:0 0 0 3px var(--accent-light);transform:translateY(-1px)}.filter-input::placeholder{color:var(--text-muted);font-style:italic}.filter-select{cursor:pointer;background-image:url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");background-position:right .5rem center;background-repeat:no-repeat;background-size:1.5em 1.5em;padding-right:2.5rem;-webkit-appearance:none;-moz-appearance:none;appearance:none}.filter-checkbox-group{display:flex;align-items:center;gap:.75rem;padding:.75rem 1rem;background-color:var(--bg-primary);border:2px solid var(--border-color);border-radius:var(--radius);transition:all .3s ease;cursor:pointer}.filter-checkbox-group:hover{border-color:var(--accent-color);background-color:var(--accent-light)}.filter-checkbox{width:1.25rem;height:1.25rem;accent-color:var(--accent-color);cursor:pointer}.results-container{max-width:1100px;margin:0 auto}.results-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem;flex-wrap:wrap;gap:1rem;padding:1.5rem 2rem;background-color:var(--bg-secondary);border-radius:var(--radius-lg);border:1px solid var(--border-color);box-shadow:var(--shadow)}.results-info{color:var(--text-secondary);font-size:.875rem;font-weight:500}.results-stats{display:flex;gap:2rem;color:var(--text-muted);font-size:.875rem}.export-controls{display:flex;gap:.75rem;flex-wrap:wrap}.export-button{padding:.75rem 1.5rem;background:linear-gradient(135deg,var(--success-color),#059669);color:#fff;border:none;border-radius:var(--radius);font-size:.875rem;font-weight:600;cursor:pointer;transition:all .3s ease;box-shadow:var(--shadow);position:relative;overflow:hidden}.export-button:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.2),transparent);transition:left .5s}.export-button:hover:before{left:100%}.export-button:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}.export-button:disabled{background:var(--text-muted);cursor:not-allowed;transform:none;box-shadow:none}.export-button:disabled:before{display:none}.paper-card{background:linear-gradient(135deg,var(--bg-secondary),var(--bg-primary));border:1px solid var(--border-color);border-radius:var(--radius-lg);padding:2rem;margin-bottom:1.5rem;transition:all .4s ease;position:relative;overflow:hidden}.paper-card:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(59,130,246,.05),transparent);transition:left .6s}.paper-card:hover:before{left:100%}.paper-card:hover{box-shadow:var(--shadow-xl);transform:translateY(-6px) scale(1.02);border-color:var(--accent-color);background:linear-gradient(135deg,var(--bg-primary),var(--accent-light))}.paper-title{font-size:1.25rem;font-weight:700;margin-bottom:1rem;line-height:1.4}.paper-title a{color:var(--accent-color);text-decoration:none;transition:color .3s ease}.paper-title a:hover{color:var(--accent-hover);text-decoration:underline}.paper-meta{display:flex;gap:1.5rem;margin-bottom:1.5rem;flex-wrap:wrap;color:var(--text-secondary);font-size:.875rem}.paper-meta-item{display:flex;align-items:center;gap:.375rem;padding:.25rem .75rem;background-color:var(--bg-tertiary);border-radius:var(--radius);font-weight:500}.paper-authors{color:var(--text-primary);font-weight:600}.paper-year{color:var(--accent-color);font-weight:600}.paper-citations{color:var(--success-color);font-weight:700}.paper-abstract{color:var(--text-secondary);line-height:1.7;margin-bottom:1.5rem;font-size:.95rem}.paper-actions{display:flex;gap:1rem;align-items:center;flex-wrap:wrap}.paper-source{display:inline-flex;align-items:center;padding:.375rem .75rem;background-color:var(--bg-accent);color:var(--text-muted);border-radius:var(--radius);font-size:.75rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em}.bookmark-button,.action-button{padding:.5rem 1rem;border:2px solid var(--border-color);background-color:var(--bg-primary);color:var(--text-secondary);border-radius:var(--radius);cursor:pointer;font-size:.875rem;font-weight:600;transition:all .3s ease;text-decoration:none;display:inline-flex;align-items:center;gap:.375rem;position:relative;overflow:hidden}.bookmark-button:before,.action-button:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(59,130,246,.1),transparent);transition:left .5s}.bookmark-button:hover:before,.action-button:hover:before{left:100%}.bookmark-button:hover,.action-button:hover{background:linear-gradient(135deg,var(--accent-color),var(--accent-hover));color:#fff;border-color:var(--accent-color);transform:translateY(-2px);box-shadow:var(--shadow-md)}.bookmark-button.bookmarked{background:linear-gradient(135deg,var(--warning-color),#f59e0b);color:#fff;border-color:var(--warning-color)}.bookmark-button.bookmarked:hover{background:linear-gradient(135deg,#f59e0b,#d97706);border-color:#d97706}.loading{text-align:center;padding:4rem 2rem;color:var(--text-secondary)}.loading-spinner{width:48px;height:48px;border:4px solid var(--border-color);border-top:4px solid var(--accent-color);border-radius:50%;animation:spin 1s linear infinite;margin:0 auto 1.5rem}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.error{background-color:var(--error-light);border:1px solid var(--error-color);color:var(--error-color);padding:2rem;border-radius:var(--radius-lg);margin:2rem 0;text-align:center}.pagination{display:flex;justify-content:center;gap:.5rem;margin:3rem 0;flex-wrap:wrap}.pagination-button{padding:.75rem 1rem;border:1px solid var(--border-color);background-color:var(--bg-primary);color:var(--text-primary);border-radius:var(--radius);cursor:pointer;transition:all .3s ease;font-weight:500;min-width:44px}.pagination-button:hover{background-color:var(--bg-tertiary);border-color:var(--accent-color)}.pagination-button.active{background-color:var(--accent-color);color:#fff;border-color:var(--accent-color)}.pagination-button:disabled{background-color:var(--bg-tertiary);color:var(--text-muted);cursor:not-allowed}.chart-section{background:var(--card-background);border-radius:12px;padding:1.5rem;margin:2rem 0;border:1px solid var(--border-color);box-shadow:0 2px 8px #0000001a}.chart-section h3{margin:0 0 1rem;color:var(--text-primary);font-size:1.25rem;font-weight:600}.chart-loading{display:flex;flex-direction:column;align-items:center;padding:2rem;margin:2rem 0;background:var(--card-background);border-radius:12px;border:1px solid var(--border-color)}.chart-loading p{margin-top:1rem;color:var(--text-secondary);font-size:.95rem}.chart-container{background-color:var(--bg-secondary);padding:2rem;border-radius:var(--radius-lg);margin:2rem 0;box-shadow:var(--shadow);border:1px solid var(--border-color)}.chart-title{font-size:1.25rem;font-weight:700;margin-bottom:1.5rem;color:var(--text-primary);text-align:center}.paper-detail-container{max-width:1000px;margin:0 auto;padding:2rem 0}.paper-detail-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:2rem;padding-bottom:1rem;border-bottom:1px solid var(--border-color)}.header-actions{display:flex;gap:1rem}.paper-detail-content{background:linear-gradient(135deg,var(--bg-secondary),var(--bg-primary));border-radius:var(--radius-lg);box-shadow:var(--shadow-xl);overflow:hidden}.paper-title-section{padding:3rem 3rem 2rem;background:linear-gradient(135deg,var(--accent-color),var(--accent-hover));color:#fff;position:relative;overflow:hidden}.paper-title-section:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.1),transparent);animation:shimmer 3s linear infinite}.paper-detail-title{font-size:2.25rem;font-weight:800;line-height:1.3;margin-bottom:1.5rem;color:#fff}.paper-badges{display:flex;gap:1rem;flex-wrap:wrap}.badge{padding:.5rem 1rem;border-radius:var(--radius);font-size:.875rem;font-weight:600;background:#fff3;color:#fff;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);border:1px solid rgba(255,255,255,.3)}.paper-metrics{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:1.5rem;padding:2rem 3rem;background:var(--bg-primary)}.metric-card{display:flex;align-items:center;gap:1rem;padding:1.5rem;background:linear-gradient(135deg,var(--bg-secondary),var(--bg-tertiary));border-radius:var(--radius-lg);border:1px solid var(--border-color);transition:all .3s ease}.metric-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg);border-color:var(--accent-color)}.metric-icon{font-size:2rem;opacity:.8}.metric-content{flex:1}.metric-value{font-size:1.75rem;font-weight:700;color:var(--accent-color);margin-bottom:.25rem}.metric-label{font-size:.875rem;color:var(--text-secondary);text-transform:uppercase;letter-spacing:.05em;font-weight:600}.detail-section{padding:2rem 3rem;border-top:1px solid var(--border-color)}.section-title{display:flex;align-items:center;gap:.75rem;font-size:1.5rem;font-weight:700;color:var(--text-primary);margin-bottom:1.5rem}.section-icon{font-size:1.25rem;opacity:.8}.authors-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:1rem}.author-card{padding:1.25rem;background:var(--bg-secondary);border-radius:var(--radius);border:1px solid var(--border-color);transition:all .3s ease}.author-card:hover{transform:translateY(-1px);box-shadow:var(--shadow);border-color:var(--accent-color)}.author-name{font-weight:600;color:var(--text-primary);margin-bottom:.5rem}.author-affiliation{font-size:.875rem;color:var(--text-secondary);display:flex;align-items:center;gap:.375rem}.abstract-content{font-size:1.1rem;line-height:1.8;color:var(--text-primary);background:var(--bg-secondary);padding:2rem;border-radius:var(--radius-lg);border:1px solid var(--border-color);text-align:justify}.details-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:1.25rem}.detail-item{display:flex;flex-direction:column;gap:.5rem;padding:1.25rem;background:var(--bg-secondary);border-radius:var(--radius);border:1px solid var(--border-color);transition:all .3s ease}.detail-item:hover{border-color:var(--accent-color);box-shadow:var(--shadow)}.detail-label{font-size:.875rem;font-weight:600;color:var(--text-secondary);text-transform:uppercase;letter-spacing:.05em}.detail-value{font-weight:500;color:var(--text-primary)}.doi-link{color:var(--accent-color);text-decoration:none;font-weight:600;transition:color .3s ease}.doi-link:hover{color:var(--accent-hover);text-decoration:underline}.oa-info{display:flex;align-items:center;justify-content:space-between;padding:1.5rem;background:var(--bg-secondary);border-radius:var(--radius-lg);border:1px solid var(--border-color)}.oa-status{display:flex;align-items:center;gap:1rem}.oa-indicator{padding:.5rem 1rem;border-radius:var(--radius);font-weight:600;font-size:.875rem}.oa-indicator.available{background:var(--success-light);color:var(--success-color);border:1px solid var(--success-color)}.oa-indicator.unavailable{background:var(--error-light);color:var(--error-color);border:1px solid var(--error-color)}.oa-label{font-weight:600;color:var(--text-secondary)}.oa-link{padding:.75rem 1.5rem;background:linear-gradient(135deg,var(--success-color),#059669);color:#fff;text-decoration:none;border-radius:var(--radius);font-weight:600;transition:all .3s ease}.oa-link:hover{transform:translateY(-1px);box-shadow:var(--shadow-md)}.action-button{padding:.75rem 1.5rem;border-radius:var(--radius);font-size:.875rem;font-weight:600;cursor:pointer;transition:all .3s ease;text-decoration:none;display:inline-flex;align-items:center;gap:.5rem;border:2px solid transparent;position:relative;overflow:hidden}.action-button:before{content:"";position:absolute;top:0;left:-100%;width:100%;height:100%;background:linear-gradient(90deg,transparent,rgba(255,255,255,.2),transparent);transition:left .5s}.action-button:hover:before{left:100%}.action-button.primary{background:linear-gradient(135deg,var(--accent-color),var(--accent-hover));color:#fff;border-color:var(--accent-color)}.action-button.secondary{background:var(--bg-secondary);color:var(--text-primary);border-color:var(--border-color)}.action-button.bookmark{background:linear-gradient(135deg,var(--warning-color),#f59e0b);color:#fff;border-color:var(--warning-color)}.action-button.bookmarked{background:linear-gradient(135deg,#f59e0b,#d97706);color:#fff;border-color:#d97706}.action-button:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg)}.paper-detail-error{text-align:center;padding:4rem 2rem;background:linear-gradient(135deg,var(--bg-secondary),var(--bg-tertiary));border-radius:var(--radius-lg);box-shadow:var(--shadow-lg);border:1px solid var(--border-color)}.error-icon{font-size:4rem;margin-bottom:1rem;opacity:.6}.paper-detail-error h2{font-size:1.75rem;font-weight:700;color:var(--text-primary);margin-bottom:1rem}.paper-detail-error p{font-size:1.1rem;color:var(--text-secondary);margin-bottom:2rem}.error-actions{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}@media (max-width: 768px){.paper-detail-container{padding:1rem 0}.paper-detail-header{flex-direction:column;gap:1rem;align-items:stretch}.header-actions{justify-content:center}.paper-title-section,.paper-metrics,.detail-section{padding:1.5rem}.paper-detail-title{font-size:1.75rem}.paper-metrics,.authors-grid,.details-grid{grid-template-columns:1fr}.oa-info{flex-direction:column;gap:1rem;align-items:stretch}}@media (max-width: 768px){.container{padding:0 16px}.header-content{flex-direction:column;gap:1rem}.nav{gap:1rem}.search-title{font-size:2rem}.search-form{padding:1.5rem}.search-input-group{flex-direction:column}.filters,.advanced-filters{grid-template-columns:1fr}.results-header{flex-direction:column;align-items:flex-start;padding:1rem}.paper-card{padding:1.5rem}.paper-meta{flex-direction:column;gap:.75rem}.paper-actions{flex-direction:column;align-items:flex-start}.pagination{gap:.25rem}.pagination-button{padding:.5rem;font-size:.875rem;min-width:36px}}