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

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

.container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

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

.main-content {
    padding: 30px;
}

.display-area {
    margin-bottom: 30px;
}

.student-display {
    background: #f8f9fa;
    border: 3px dashed #dee2e6;
    border-radius: 10px;
    padding: 40px;
    text-align: center;
    min-height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.student-display .placeholder {
    color: #6c757d;
    font-size: 1.2em;
}

.student-info {
    color: #333;
}

.student-info h2 {
    font-size: 2em;
    color: #007bff;
    margin-bottom: 10px;
}

.student-info p {
    font-size: 1.1em;
    margin: 5px 0;
}

.control-buttons {
    text-align: center;
    margin-bottom: 20px;
}

.btn {
    padding: 12px 24px;
    margin: 0 10px;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: #007bff;
    color: white;
}

.btn-primary:hover {
    background: #0056b3;
    transform: translateY(-2px);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #545b62;
    transform: translateY(-2px);
}

.btn-success {
    background: #28a745;
    color: white;
}

.btn-warning {
    background: #ffc107;
    color: black;
}

.btn-info {
    background: #17a2b8;
    color: white;
}

.btn-danger {
    background: #dc3545;
    color: white;
}

.btn-outline {
    background: transparent;
    border: 2px solid #007bff;
    color: #007bff;
}

.btn-outline:hover {
    background: #007bff;
    color: white;
}

.score-controls, .file-import, .data-actions {
    margin: 20px 0;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 10px;
}

.score-controls h3, .file-import h3 {
    margin-bottom: 15px;
    color: #333;
}

.score-buttons {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.score-buttons .btn {
    flex: 1;
    min-width: 120px;
}

.file-import input {
    padding: 8px;
    margin-right: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
}

.data-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.ranking-display {
    margin-top: 20px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 10px;
}

.ranking-item {
    display: flex;
    justify-content: space-between;
    padding: 10px;
    margin: 5px 0;
    background: white;
    border-radius: 5px;
    border-left: 4px solid #007bff;
}

.ranking-number {
    font-weight: bold;
    color: #007bff;
}

#importMessage {
    margin-top: 10px;
    padding: 10px;
    border-radius: 5px;
}

.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}