/* 拖拽上传区域 */
.drop-zone {
    border: 3px dashed #ccc;
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafbfc;
    color: #6c757d;
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: #0d6efd;
    background: #e8f0fe;
    color: #0d6efd;
}

.drop-zone-text p {
    margin-bottom: 0;
}

/* 统计卡片 */
.stats-card {
    border: none;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: transform 0.2s;
}

.stats-card:hover {
    transform: translateY(-2px);
}

/* 表格优化 */
.table th {
    white-space: nowrap;
    font-weight: 600;
}

.table td {
    vertical-align: middle;
}

/* 导航栏 */
.navbar-brand {
    font-weight: 700;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .drop-zone {
        padding: 40px 15px;
    }

    .display-6 {
        font-size: 1.5rem;
    }
}