body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: #f7f7f7;
    color: #333;
    margin: 0;
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    width: 100%;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    padding: 24px;
    box-sizing: border-box;
}

h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 0 0 20px;
    color: #1a1a1a;
}

.file-input-wrapper {
    margin-bottom: 24px;
    display: flex;
    justify-content: center;
}

input[type="file"] {
    padding: 12px;
    font-size: 1rem;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    background: #fafafa;
    cursor: pointer;
    transition: border-color 0.3s, background 0.3s;
}

input[type="file"]:hover {
    border-color: #007bff;
    background: #f0f0f0;
}

input[type="file"]::-webkit-file-upload-button {
    background: #007bff;
    color: #fff;
    border: none;
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background 0.3s;
}

input[type="file"]::-webkit-file-upload-button:hover {
    background: #0056b3;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

th, td {
    padding: 12px 16px;
    text-align: left;
    font-size: 0.9rem;
    border-bottom: 1px solid #eee;
}

th {
    background: #f4f4f4;
    font-weight: 600;
    color: #1a1a1a;
    text-transform: uppercase;
    font-size: 0.85rem;
}

td {
    color: #333;
}

tr:hover {
    background: #f9f9f9;
}

.no-data {
    text-align: center;
    padding: 20px;
    font-size: 1rem;
    color: #666;
}

.preloader {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.preloader-spinner {
    width: 32px;
    height: 32px;
    border: 4px solid #e0e0e0;
    border-top: 4px solid #007bff;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

@media (max-width: 768px) {
    .container {
        padding: 16px;
    }

    h2 {
        font-size: 1.3rem;
    }

    th, td {
        padding: 10px;
        font-size: 0.85rem;
    }

    input[type="file"] {
        font-size: 0.9rem;
        padding: 10px;
    }
}

@media (max-width: 480px) {
    table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
    }

    th, td {
        min-width: 100px;
    }
}