.upload-area {
    border: 2px dashed #17a2b8;
    border-radius: 10px;
    transition: all 0.3s ease;
    cursor: pointer;
}

.upload-area:hover {
    border-color: #138496;
    background-color: #ffffff;
}

.upload-area.dragover {
    border-color: #28a745;
    background-color: #d4edda;
}

.csv-preview {
    background-color: #ffffff;
    padding: 1.5rem;
    border-radius: 10px;
    border: 1px solid var(--border-color);
}

.conversion-settings {
    background-color: #ffffff;
    padding: 1.5rem;
    border-radius: 10px;
    border: 1px solid var(--border-color);
}

.conversion-result {
    background-color: #d4edda;
    padding: 1.5rem;
    border-radius: 10px;
    border: 1px solid #c3e6cb;
}

#previewTable {
    background-color: var(--bg-card);
    font-size: 0.875rem;
}

#previewTable th {
    background-color: #e9ecef !important;
    font-weight: 600;
    position: sticky;
    top: 0;
    z-index: 10;
}

#previewTable td {
    max-width: 200px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.table-responsive {
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

@media (max-width: 768px) {
    .conversion-settings .row {
        flex-direction: column;
    }
    
    #previewTable {
        font-size: 0.75rem;
    }
    
    #previewTable td {
        max-width: 100px;
    }
}

/* 도구 페이지 다크 테마 (숨겨진 UI: csvPreview, conversionSettings, conversionResult 포함) */
.tool-page .card {
    background: var(--bg-card);
    border-color: var(--border-color);
}

.tool-page .card-body {
    color: var(--text-primary);
}

.tool-page .csv-preview,
.tool-page .conversion-settings {
    background: var(--gradient-card) !important;
    border-color: var(--border-color-light) !important;
}

.tool-page .csv-preview h5,
.tool-page .conversion-settings h5 {
    color: var(--accent-primary);
}

.tool-page .conversion-result {
    background: rgba(16, 185, 129, 0.12) !important;
    border-color: var(--accent-success) !important;
}

.tool-page .conversion-result h5 {
    color: var(--accent-success);
}

.tool-page .alert-success,
.tool-page .alert.alert-success {
    background: rgba(16, 185, 129, 0.15) !important;
    border-color: var(--accent-success);
    color: var(--text-primary) !important;
}

.tool-page .alert-success .text-muted,
.tool-page .alert.alert-success .text-muted {
    color: var(--text-secondary) !important;
}

.tool-page .table-light,
.tool-page #previewTable thead.table-light {
    background: var(--bg-tertiary) !important;
    color: var(--text-primary) !important;
    border-color: var(--border-color-light);
}

.tool-page #previewTable,
.tool-page #previewTable td {
    color: var(--text-primary);
    border-color: var(--border-color-light);
}