:root {
        --primary: #4361ee;
        --primary-light: #4895ef;
        --secondary: #3f37c9;
        --dark: #1a1a2e;
        --light: #f8f9fa;
        --gray: #6c757d;
        --success: #4bb543;
        --warning: #fca311;
        --danger: #f72525;
    }
    
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    }
    
    body {
        background-color: #f5f7fa;
        color: #333;
        line-height: 1.6;
    }
    
    .container {
        max-width: 1200px;
        margin: 0 auto;
        padding: 20px;
    }
    
    header {
        text-align: center;
        margin-bottom: 30px;
        padding: 20px 0;
        border-bottom: 1px solid #e0e0e0;
    }
    
    .logo {
        font-size: 3rem;
        color: var(--primary);
        margin-bottom: 15px;
    }
    
    h1 {
        font-size: 2.2rem;
        color: var(--dark);
        margin-bottom: 10px;
    }
    
    .subtitle {
        color: var(--gray);
        font-size: 1.1rem;
    }
    
    .filter-card {
        background-color: white;
        border-radius: 10px;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        padding: 25px;
        margin-bottom: 30px;
    }
    
    .filter-card h2 {
        font-size: 1.3rem;
        color: var(--dark);
        margin-bottom: 15px;
        display: flex;
        align-items: center;
    }
    
    .filter-card h2 i {
        margin-right: 10px;
        color: var(--primary);
    }
    
    .date-range-picker {
        display: flex;
        gap: 20px;
        margin-bottom: 25px;
    }
    
    .date-input {
        flex: 1;
    }
    
    .date-input label {
        display: block;
        margin-bottom: 8px;
        font-weight: 500;
        color: var(--dark);
    }
    
    .date-input input {
        width: 100%;
        padding: 10px;
        border: 1px solid #ddd;
        border-radius: 5px;
        font-size: 1rem;
    }
    
    .category-selector {
        margin-bottom: 15px;
    }
    
    .category-options {
        display: flex;
        flex-wrap: wrap;
        gap: 15px;
        margin-top: 10px;
    }
    
    .category-group {
        flex: 1;
        min-width: 250px;
    }
    
    .category-group h3 {
        font-size: 1rem;
        color: var(--dark);
        margin-bottom: 8px;
        padding-bottom: 5px;
        border-bottom: 1px solid #eee;
    }
    
    .category-checkboxes {
        display: flex;
        flex-direction: column;
        gap: 6px;
    }
    
    .category-checkboxes label {
        display: flex;
        align-items: center;
        cursor: pointer;
        font-size: 0.9rem;
    }
    
    .category-checkboxes input {
        margin-right: 8px;
    }
    
    .prompt-editor {
        margin-bottom: 25px;
    }
    
    .prompt-editor p {
        margin-bottom: 10px;
        color: var(--gray);
        font-size: 0.9rem;
    }
    
    .prompt-textarea {
        width: 100%;
        min-height: 300px;
        padding: 15px;
        border: 1px solid #ddd;
        border-radius: 5px;
        font-family: 'Courier New', Courier, monospace;
        font-size: 0.9rem;
        line-height: 1.5;
        resize: vertical;
    }
    
    .ai-filter-section {
        margin-top: 30px;
    }
    
    .api-selector {
        display: flex;
        gap: 10px;
        margin-bottom: 20px;
    }
    
    .api-btn {
        flex: 1;
        padding: 12px;
        border: 1px solid #ddd;
        border-radius: 5px;
        background-color: white;
        cursor: pointer;
        font-weight: 500;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 8px;
        transition: all 0.2s;
    }
    
    .api-btn i {
        font-size: 1.1rem;
    }
    
    .api-btn.active {
        background-color: var(--primary);
        color: white;
        border-color: var(--primary);
    }
    
    .api-key-input {
        margin-bottom: 20px;
    }
    
    .api-key-input label {
        display: block;
        margin-bottom: 8px;
        font-weight: 500;
        color: var(--dark);
        font-size: 0.9rem;
    }
    
    .api-key-input input {
        width: 100%;
        padding: 10px;
        border: 1px solid #ddd;
        border-radius: 5px;
        font-size: 0.9rem;
    }
    
    .ai-filter-btn {
        width: 100%;
        padding: 15px;
        background-color: var(--primary);
        color: white;
        border: none;
        border-radius: 5px;
        font-size: 1.1rem;
        font-weight: 600;
        cursor: pointer;
        display: flex;
        align-items: center;
        justify-content: center;
        gap: 10px;
        transition: background-color 0.2s;
    }
    
    .ai-filter-btn:hover {
        background-color: var(--secondary);
    }
    
    .ai-filter-btn.loading {
        background-color: var(--gray);
        cursor: not-allowed;
    }
    
    .status-message {
        padding: 15px;
        border-radius: 5px;
        margin-bottom: 20px;
        display: flex;
        align-items: center;
    }
    
    .status-message.success {
        background-color: rgba(75, 181, 67, 0.1);
        border-left: 4px solid var(--success);
    }
    
    .status-message.error {
        background-color: rgba(247, 37, 37, 0.1);
        border-left: 4px solid var(--danger);
    }
    
    .status-indicator {
        display: inline-block;
        width: 10px;
        height: 10px;
        border-radius: 50%;
        margin-right: 10px;
    }
    
    .status-indicator.success {
        background-color: var(--success);
    }
    
    .status-indicator.error {
        background-color: var(--danger);
    }
    
    .hide {
        display: none;
    }
    
    .results-section {
        background-color: white;
        border-radius: 10px;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        padding: 25px;
    }
    
    .papers-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        margin-bottom: 20px;
        padding-bottom: 15px;
        border-bottom: 1px solid #eee;
    }
    
    .papers-header h2 {
        font-size: 1.5rem;
        color: var(--dark);
        display: flex;
        align-items: center;
        gap: 10px;
    }
    
    .paper-date {
        color: var(--gray);
        font-size: 0.9rem;
    }
    
    .papers-container {
        display: flex;
        flex-direction: column;
        gap: 15px;
    }
    
    .paper-item {
        border: 1px solid #eee;
        border-radius: 8px;
        overflow: hidden;
        transition: box-shadow 0.2s;
    }
    
    .paper-item:hover {
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    }
    
    .paper-header {
        padding: 15px;
        cursor: pointer;
        background-color: #f9f9f9;
    }
    
    .paper-title {
        font-size: 1.1rem;
        font-weight: 600;
        color: var(--dark);
        margin-bottom: 8px;
        display: flex;
        align-items: center;
        flex-wrap: wrap;
        gap: 10px;
    }
    
    .paper-title span {
        flex: 1;
    }
    
    .paper-category {
        background-color: var(--primary-light);
        color: white;
        padding: 3px 8px;
        border-radius: 4px;
        font-size: 0.8rem;
        font-weight: 500;
    }
    
    .relevance-tag {
        padding: 3px 8px;
        border-radius: 4px;
        font-size: 0.8rem;
        font-weight: 500;
    }
    
    .relevance-tag.high {
        background-color: rgba(75, 181, 67, 0.2);
        color: var(--success);
    }
    
    .relevance-tag.medium {
        background-color: rgba(252, 163, 17, 0.2);
        color: var(--warning);
    }
    
    .relevance-tag.low {
        background-color: rgba(247, 37, 37, 0.2);
        color: var(--danger);
    }
    
    .paper-meta {
        display: flex;
        gap: 15px;
        font-size: 0.9rem;
        color: var(--gray);
    }
    
    .paper-meta i {
        margin-right: 5px;
    }
    
    .paper-content {
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease-out;
    }
    
    .paper-abstract {
        padding: 0 15px;
    }
    
    .paper-abstract.expanded {
        padding: 15px;
        border-top: 1px solid #eee;
    }
    
    .loading {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        padding: 40px;
        color: var(--gray);
    }
    
    .loading .spinner {
        width: 50px;
        height: 50px;
        border: 5px solid rgba(67, 97, 238, 0.2);
        border-radius: 50%;
        border-top-color: var(--primary);
        animation: spin 1s ease-in-out infinite;
        margin-bottom: 20px;
    }
    
    @keyframes spin {
        to { transform: rotate(360deg); }
    }
    
    .time-btn {
        padding: 8px 15px;
        background-color: white;
        border: 1px solid #ddd;
        border-radius: 5px;
        cursor: pointer;
        display: inline-flex;
        align-items: center;
        gap: 8px;
        transition: all 0.2s;
    }
    
    .time-btn:hover {
        background-color: #f0f0f0;
    }
    
    .time-btn.active {
        background-color: var(--primary);
        color: white;
        border-color: var(--primary);
    }
    
    footer.citation {
        text-align: center;
        margin-top: 30px;
        padding: 20px 0;
        color: var(--gray);
        font-size: 0.9rem;
        border-top: 1px solid #e0e0e0;
    }
    
    pre {
        white-space: pre-wrap;
        word-wrap: break-word;
        font-family: 'Courier New', Courier, monospace;
        font-size: 0.9rem;
    }
    
    .api-settings {
        background-color: #f8f9fa;
        border-radius: 8px;
        padding: 15px;
        margin-bottom: 20px;
        border: 1px solid #eee;
    }
    
    .api-settings h3 {
        margin-bottom: 15px;
        font-size: 1.1rem;
        color: var(--dark);
        display: flex;
        align-items: center;
        gap: 10px;
    }
    
    .api-settings h3 i {
        color: var(--primary);
    }
    
    .model-selector {
        margin-bottom: 15px;
    }
    
    .model-selector label {
        display: block;
        margin-bottom: 8px;
        font-weight: 500;
        color: var(--dark);
        font-size: 0.9rem;
    }
    
    .model-selector select {
        width: 100%;
        padding: 10px;
        border: 1px solid #ddd;
        border-radius: 5px;
        font-size: 0.9rem;
    }
    .paper-item {
    border: 1px solid #eaeaea;
    border-radius: 8px;
    overflow: hidden;
    transition: all 0.2s ease;
    margin-bottom: 15px;
    background-color: white;
}

.paper-item:hover {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    transform: translateY(-2px);
}

.paper-header {
    padding: 18px 20px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.paper-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--dark);
    line-height: 1.4;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
}

.paper-title-text {
    flex: 1;
    min-width: 70%;
}

.paper-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    font-size: 0.85rem;
    color: var(--gray);
    align-items: center;
}

.paper-meta-item {
    display: flex;
    align-items: center;
    gap: 5px;
}

.paper-meta i {
    color: var(--primary-light);
}

.paper-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.paper-category {
    background-color: #f0f4ff;
    color: var(--primary);
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    white-space: nowrap;
}

.relevance-tag {
    padding: 3px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    white-space: nowrap;
}

.relevance-tag.high {
    background-color: rgba(75, 181, 67, 0.1);
    color: var(--success);
    border: 1px solid rgba(75, 181, 67, 0.3);
}

.relevance-tag.medium {
    background-color: rgba(252, 163, 17, 0.1);
    color: var(--warning);
    border: 1px solid rgba(252, 163, 17, 0.3);
}

.relevance-tag.low {
    background-color: rgba(247, 37, 37, 0.1);
    color: var(--danger);
    border: 1px solid rgba(247, 37, 37, 0.3);
}

.paper-abstract {
    padding: 0 20px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease;
    font-size: 0.95rem;
    line-height: 1.6;
    color: #555;
}

.paper-abstract.expanded {
    padding: 0 20px 20px;
    max-height: 500px;
    border-top: 1px solid #f0f0f0;
    margin-top: 10px;
}

.no-results {
    text-align: center;
    padding: 50px 20px;
    color: var(--gray);
}

.no-results i {
    font-size: 3rem;
    opacity: 0.3;
    margin-bottom: 20px;
}

.no-results h3 {
    margin-bottom: 10px;
    font-weight: 500;
}

.results-count {
    font-size: 0.9rem;
    color: var(--gray);
    background-color: #f8f9fa;
    padding: 5px 10px;
    border-radius: 4px;
}
.category-checkboxes {
    display: grid;
    grid-template-columns: repeat(4, 1fr); /* 每行4列 */
    gap: 10px; /* 选项间距 */
    margin-bottom: 10px;
}

.category-checkboxes label {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-size: 0.9rem;
    white-space: nowrap; /* 防止文字换行 */
    padding: 5px 8px;
    background-color: #f5f7fa;
    border-radius: 4px;
    transition: background-color 0.2s;
}

.category-checkboxes label:hover {
    background-color: #e9ecef;
}

.category-checkboxes input {
    margin-right: 6px;
}
@media (max-width: 768px) {
    .category-checkboxes {
        grid-template-columns: repeat(2, 1fr);
    }
}
.api-key-input a {
    color: var(--primary);
    text-decoration: none;
    font-size: 0.8rem;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    transition: color 0.2s;
}

.api-key-input a:hover {
    color: var(--secondary);
    text-decoration: underline;
}