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

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

.container {
    max-width: 600px;
    margin: 0 auto;
}

.header {
    text-align: center;
    color: white;
    margin-bottom: 30px;
}

.header h1 {
    font-size: 28px;
    margin-bottom: 10px;
}

.header p {
    opacity: 0.9;
    font-size: 14px;
}

.form-section {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    margin-bottom: 20px;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #333;
    font-size: 14px;
}

.form-group select,
.form-group input {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.3s;
}

.form-group select:focus,
.form-group input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.file-drop-zone {
    border: 2px dashed #667eea;
    border-radius: 8px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    background: #f8f9fa;
}

.file-drop-zone:hover,
.file-drop-zone.dragover {
    border-color: #764ba2;
    background: #f0f3ff;
}

.file-drop-zone p {
    font-weight: 600;
    color: #333;
    margin-bottom: 5px;
}

.file-drop-zone small {
    color: #999;
    display: block;
}

.file-list {
    margin-top: 15px;
}

.file-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px;
    background: #f0f3ff;
    border-radius: 6px;
    margin-bottom: 8px;
    font-size: 13px;
}

.file-item span {
    color: #333;
    word-break: break-all;
}

.btn-remove {
    background: #ff6b6b;
    color: white;
    border: none;
    padding: 5px 10px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 18px;
    margin-left: 10px;
    transition: background 0.3s;
}

.btn-remove:hover {
    background: #ff5252;
}

.btn {
    width: 100%;
    padding: 12px;
    font-size: 16px;
    font-weight: 600;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: #6c757d;
    color: white;
    margin-top: 15px;
}

.btn-secondary:hover {
    background: #5a6268;
}

/* Loading State */
.loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: white;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin-bottom: 15px;
}

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

/* Results Section */
.results-section {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.results-section h2 {
    margin-bottom: 20px;
    color: #333;
    font-size: 20px;
}

.result-summary {
    background: #e7f5ff;
    border-left: 4px solid #339af0;
    padding: 15px;
    border-radius: 4px;
    margin-bottom: 15px;
    font-size: 14px;
}

.result-summary p {
    color: #1e78d2;
    margin: 0;
}

.result-item {
    display: flex;
    gap: 15px;
    padding: 15px;
    border-radius: 6px;
    margin-bottom: 10px;
    font-size: 13px;
}

.result-item.success {
    background: #e6ffed;
    border-left: 4px solid #51cf66;
}

.result-item.error {
    background: #ffe6e6;
    border-left: 4px solid #ff6b6b;
}

.result-icon {
    font-size: 20px;
    font-weight: bold;
    min-width: 30px;
    text-align: center;
}

.result-item.success .result-icon {
    color: #51cf66;
}

.result-item.error .result-icon {
    color: #ff6b6b;
}

.result-content {
    flex: 1;
}

.result-old {
    color: #666;
    margin-bottom: 5px;
    word-break: break-all;
}

.result-arrow {
    color: #aaa;
    font-size: 12px;
    margin: 3px 0;
}

.result-new {
    color: #333;
    font-weight: 600;
    word-break: break-all;
}

.result-error {
    color: #ff6b6b;
    font-weight: 500;
}

.result-item small {
    display: block;
    color: #666;
    margin-top: 5px;
}

@media (max-width: 600px) {
    .header h1 {
        font-size: 22px;
    }

    .form-section {
        padding: 20px;
    }

    .file-drop-zone {
        padding: 30px 15px;
    }
}