body {
    font-family: 'Inter', sans-serif;
    background-color: #f0f2f5;
    display: flex;
    justify-content: center;
    align-items: flex-start; /* Align to top to allow scrolling for longer content */
    min-height: 100vh;
    padding: 20px;
    box-sizing: border-box;
}
.container {
    background-color: #ffffff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    max-width: 900px;
    width: 100%;
    text-align: center;
}
.file-input-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    margin-bottom: 30px;
}
.custom-file-upload {
    border: 2px dashed #cbd5e0; /* gray-300 */
    border-radius: 8px;
    padding: 20px;
    cursor: pointer;
    width: 100%;
    max-width: 400px;
    transition: all 0.2s ease-in-out;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: #4a5568; /* gray-700 */
}
.custom-file-upload:hover {
    border-color: #a0aec0; /* gray-400 */
    background-color: #edf2f7; /* gray-100 */
}
.custom-file-upload input[type="file"] {
    display: none;
}
.btn-primary {
    background-color: #4c51bf; /* indigo-700 */
    color: white;
    padding: 12px 25px;
    border-radius: 8px;
    font-weight: 600;
    transition: background-color 0.2s ease-in-out;
    cursor: pointer;
    border: none;
}
.btn-primary:hover {
    background-color: #3c418f; /* darker indigo */
}
.btn-remove {
    background-color: #ef4444; /* red-500 */
    color: white;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.875rem; /* text-sm */
    font-weight: 500;
    transition: background-color 0.2s ease-in-out;
    cursor: pointer;
    border: none;
}
.btn-remove:hover {
    background-color: #dc2626; /* red-600 */
}
.loading-spinner {
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-left-color: #4c51bf; /* indigo-700 */
    border-radius: 50%;
    width: 30px;
    height: 30px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}
@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}
.message-box {
    background-color: #fff3cd; /* yellow-100 */
    color: #664d03; /* yellow-800 */
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    border: 1px solid #ffecb5; /* yellow-200 */
    text-align: left;
}
.error-box {
    background-color: #f8d7da; /* red-100 */
    color: #721c24; /* red-800 */
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    border: 1px solid #f5c6cb; /* red-200 */
    border-left: 4px solid #dc3545; /* red-600 */
    text-align: left;
}
.warning-box {
    background-color: #fff3cd; /* yellow-100 */
    color: #856404; /* yellow-800 */
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    border: 1px solid #ffeaa7; /* yellow-200 */
    border-left: 4px solid #ffc107; /* yellow-500 */
    text-align: left;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 30px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    border-radius: 8px;
    overflow: hidden; /* Ensures rounded corners apply to table content */
}
th, td {
    padding: 15px;
    border: 1px solid #e2e8f0; /* gray-200 */
    text-align: left;
}
th {
    background-color: #ebf4ff; /* blue-50 */
    font-weight: 700;
    color: #2d3748; /* gray-800 */
}
td {
    background-color: #ffffff;
    color: #4a5568; /* gray-700 */
}
td select {
    width: 100%;
    padding: 8px;
    border-radius: 6px;
    border: 1px solid #cbd5e0; /* gray-300 */
    background-color: #ffffff;
    font-size: 1rem;
    color: #4a5568;
    appearance: none; /* Remove default arrow */
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='currentColor'%3E%3Cpath fill-rule='evenodd' d='M5.293 7.293a1 1 0 011.414 0L10 10.586l3.293-3.293a1 1 0 111.414 1.414l-4 4a1 1 0 01-1.414 0l-4-4a1 1 0 010-1.414z' clip-rule='evenodd'%3E%3C/path%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.7rem center;
    background-size: 1.5em 1.5em;
}
td select:focus {
    outline: none;
    border-color: #667eea; /* indigo-500 */
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.3);
}
.net-owed-display {
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    font-size: 1.25rem; /* text-xl */
    font-weight: 600; /* font-semibold */
    text-align: center;
    border: 1px solid;
}
.net-owed-display.text-red-700 {
    background-color: #f8d7da; /* red-100 */
    border-color: #f5c6cb; /* red-200 */
    color: #721c24; /* red-800 */
}
.net-owed-display.text-green-700 {
    background-color: #d4edda; /* green-100 */
    border-color: #c3e6cb; /* green-200 */
    color: #155724; /* green-800 */
}
.net-owed-display.text-gray-700 {
    background-color: #e2e8f0; /* gray-200 */
    border-color: #cbd5e0; /* gray-300 */
    color: #4a5568; /* gray-700 */
}
.currency-summary {
    margin-bottom: 10px;
}