* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

.header p {
    font-size: 1.1em;
    opacity: 0.9;
}

.search-section {
    padding: 40px;
}

.search-form {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
}

.search-input {
    flex: 1;
    padding: 15px 20px;
    border: 2px solid #e1e5e9;
    border-radius: 10px;
    font-size: 16px;
    transition: all 0.3s ease;
}

.search-input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-btn {
    padding: 15px 30px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.search-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(102, 126, 234, 0.3);
}

.search-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.loading {
    display: none;
    text-align: center;
    padding: 20px;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 15px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.results-section {
    padding: 0 40px 40px;
}

.results-section h2 {
    color: #2c3e50;
    margin-bottom: 20px;
    font-size: 1.8em;
}

.result-card {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 20px;
    border-left: 4px solid #667eea;
    transition: all 0.3s ease;
}

.result-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.result-title {
    font-size: 1.2em;
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 10px;
    line-height: 1.4;
}

.result-authors {
    color: #7f8c8d;
    margin-bottom: 8px;
    font-style: italic;
}

.result-journal {
    color: #667eea;
    font-weight: 500;
    margin-bottom: 8px;
}

.result-abstract {
    color: #34495e;
    line-height: 1.6;
    margin-bottom: 10px;
}

.result-link {
    display: inline-block;
    margin-top: 10px;
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
    padding: 8px 16px;
    border: 2px solid #667eea;
    border-radius: 6px;
    transition: all 0.3s ease;
}

.result-link:hover {
    background: #667eea;
    color: white;
    text-decoration: none;
}

.error-message {
    background: #fee;
    color: #c33;
    padding: 15px;
    border-radius: 8px;
    border-left: 4px solid #c33;
    margin-bottom: 20px;
}

.info-section {
    background: #e8f4fd;
    border-radius: 10px;
    padding: 20px;
    margin-bottom: 20px;
    border-left: 4px solid #3498db;
}

.info-title {
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 10px;
}

.info-content {
    color: #34495e;
    line-height: 1.6;
}

.query-display {
    background: #f0f8ff;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 20px;
    border-left: 4px solid #4CAF50;
}

.query-label {
    font-weight: 600;
    color: #2c3e50;
    margin-bottom: 5px;
}

.query-text {
    color: #34495e;
    font-family: monospace;
    background: white;
    padding: 8px;
    border-radius: 4px;
    border: 1px solid #ddd;
    word-break: break-all;
    line-height: 1.4;
}

.stats-section {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 20px;
    border-left: 4px solid #ffc107;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-top: 10px;
}

.stat-item {
    text-align: center;
    padding: 10px;
    background: white;
    border-radius: 6px;
    border: 1px solid #e1e5e9;
}

.stat-number {
    font-size: 1.5em;
    font-weight: 600;
    color: #667eea;
}

.stat-label {
    font-size: 0.9em;
    color: #7f8c8d;
    margin-top: 5px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        margin: 10px;
        border-radius: 10px;
    }
    
    .header h1 {
        font-size: 2em;
    }
    
    .search-form {
        flex-direction: column;
    }
    
    .search-section {
        padding: 20px;
    }
    
    .results-section {
        padding: 0 20px 20px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }
    
    .header {
        padding: 20px;
    }
    
    .header h1 {
        font-size: 1.8em;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}