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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
}

header {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    margin-bottom: 30px;
    text-align: center;
}

h1 {
    color: #333;
    font-size: 2.5em;
    margin-bottom: 10px;
}

.subtitle {
    color: #666;
    font-size: 1.1em;
}

.loading {
    background: white;
    padding: 60px 30px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    text-align: center;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

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

.tabs {
    background: white;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.tab-buttons {
    display: flex;
    background: #f5f5f5;
    border-bottom: 2px solid #e0e0e0;
}

.tab-button {
    flex: 1;
    padding: 15px 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    color: #666;
    transition: all 0.3s;
}

.tab-button:hover {
    background: #eee;
}

.tab-button.active {
    background: white;
    color: #667eea;
    border-bottom: 3px solid #667eea;
}

.tab-content {
    display: none;
    padding: 30px;
}

.tab-content.active {
    display: block;
}

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

h2 {
    color: #333;
    margin-bottom: 10px;
}

.card > p {
    color: #666;
    margin-bottom: 30px;
}

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

label {
    display: block;
    color: #333;
    font-weight: 500;
    margin-bottom: 8px;
}

input[type="number"],
input[type="file"] {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 5px;
    font-size: 16px;
    transition: border-color 0.3s;
}

input[type="number"]:focus,
input[type="file"]:focus {
    outline: none;
    border-color: #667eea;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(102, 126, 234, 0.3);
}

.btn-primary:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
}

.status {
    margin-top: 20px;
    padding: 15px;
    border-radius: 5px;
    display: none;
}

.status.success {
    display: block;
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.status.error {
    display: block;
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.status.info {
    display: block;
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

.output {
    margin-top: 20px;
}

.file-download {
    display: inline-block;
    margin: 10px 10px 0 0;
    padding: 10px 20px;
    background: #28a745;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    transition: all 0.3s;
}

.file-download:hover {
    background: #218838;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(40, 167, 69, 0.3);
}

footer {
    text-align: center;
    color: white;
    margin-top: 30px;
    padding: 20px;
}

footer a {
    color: white;
    text-decoration: underline;
}