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

:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #6b7280;
    --success-color: #10b981;
    --error-color: #ef4444;
    --bg-color: #f9fafb;
    --card-bg: #ffffff;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: var(--text-primary);
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

header {
    text-align: center;
    color: white;
    margin-bottom: 40px;
    padding: 20px;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

main {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 40px;
    box-shadow: var(--shadow-lg);
    margin-bottom: 20px;
}

.upload-area {
    border: 3px dashed var(--border-color);
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    background: var(--bg-color);
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: #f3f4f6;
}

.upload-area.dragover {
    border-color: var(--primary-color);
    background: #eef2ff;
    transform: scale(1.02);
}

.upload-icon {
    color: var(--primary-color);
    margin-bottom: 20px;
}

.upload-area h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.upload-area p {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 32px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: var(--shadow);
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    padding: 12px 32px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-left: 10px;
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
}

.status-card,
.result-card {
    text-align: center;
    padding: 40px 20px;
}

.status-card h2,
.result-card h2 {
    margin: 20px 0 10px;
    font-size: 1.5rem;
}

.status-card p,
.result-card p {
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.spinner {
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--primary-color);
    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); }
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    margin-top: 20px;
}

.progress-fill {
    height: 100%;
    background: var(--primary-color);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 4px;
}

.success-icon {
    color: var(--success-color);
    margin-bottom: 20px;
}

.error-icon {
    color: var(--error-color);
    margin-bottom: 20px;
}

.result-card.success {
    color: var(--success-color);
}

.result-card.error {
    color: var(--error-color);
}

.result-card.error p {
    color: var(--error-color);
}

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

.footer-links {
    margin-top: 10px;
}

.footer-links a {
    color: white;
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.footer-links a:hover {
    opacity: 1;
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 600px) {
    header h1 {
        font-size: 2rem;
    }

    main {
        padding: 20px;
    }

    .upload-area {
        padding: 40px 20px;
    }

    .btn-secondary {
        margin-left: 0;
        margin-top: 10px;
        display: block;
        width: 100%;
    }
}