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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --success: #10b981;
    --error: #ef4444;
    --bg-dark: #0f172a;
    --bg-card: rgba(30, 41, 59, 0.8);
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --border: rgba(148, 163, 184, 0.2);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-dark);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background-image:
        radial-gradient(ellipse at top left, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at bottom right, rgba(16, 185, 129, 0.1) 0%, transparent 50%);
}

.container {
    width: 100%;
    max-width: 600px;
}

.card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    border-radius: 24px;
    border: 1px solid var(--border);
    padding: 48px;
    box-shadow:
        0 25px 50px -12px rgba(0, 0, 0, 0.5),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

.header {
    text-align: center;
    margin-bottom: 40px;
}

.logo {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 20px;
    margin-bottom: 24px;
    color: white;
    box-shadow: 0 10px 40px rgba(99, 102, 241, 0.3);
}

h1 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    letter-spacing: -0.5px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 400;
}

.dropzone {
    border: 2px dashed var(--border);
    border-radius: 16px;
    padding: 48px 24px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: rgba(99, 102, 241, 0.05);
}

.dropzone:hover,
.dropzone.dragover {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.1);
    transform: translateY(-2px);
}

.upload-icon {
    color: var(--primary-light);
    margin-bottom: 16px;
}

.dropzone-text {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.dropzone-subtext {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 16px;
}

.file-types {
    display: inline-block;
    padding: 6px 12px;
    background: rgba(99, 102, 241, 0.2);
    border-radius: 20px;
    font-size: 12px;
    color: var(--primary-light);
    font-weight: 500;
}

.hidden {
    display: none !important;
}

.processing-section {
    text-align: center;
    padding: 48px 24px;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    margin: 0 auto 24px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.progress-bar-container {
    width: 100%;
    max-width: 300px;
    height: 8px;
    background: var(--border);
    border-radius: 4px;
    margin: 16px auto;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--primary), var(--success));
    border-radius: 4px;
    transition: width 0.3s ease;
}

.processing-text {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.processing-subtext {
    color: var(--text-secondary);
    font-size: 14px;
}

.results-section {
    text-align: center;
}

.success-icon {
    color: var(--success);
    margin-bottom: 16px;
}

.results-section h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 32px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-bottom: 32px;
}

.stat-card {
    background: rgba(15, 23, 42, 0.5);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-card.highlight {
    grid-column: span 2;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2), rgba(16, 185, 129, 0.2));
    border-color: var(--primary);
}

.stat-value {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
}

.stat-card.highlight .stat-value {
    background: linear-gradient(135deg, var(--primary-light), var(--success));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 13px;
    color: var(--text-secondary);
    font-weight: 500;
}

.stat-card.full-width {
    grid-column: span 2;
}

.csv-warning .stat-label {
    color: var(--primary-light);
    font-style: italic;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    padding: 16px 32px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(99, 102, 241, 0.5);
}

.reset-btn {
    display: block;
    width: 100%;
    margin-top: 16px;
    padding: 14px;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 12px;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.reset-btn:hover {
    border-color: var(--text-secondary);
    color: var(--text-primary);
}

.error-section {
    text-align: center;
    padding: 24px 0;
}

.error-icon {
    color: var(--error);
    margin-bottom: 16px;
}

.error-section h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.error-message {
    color: var(--text-secondary);
    margin-bottom: 24px;
    font-size: 14px;
}

footer {
    text-align: center;
    margin-top: 24px;
    color: var(--text-secondary);
    font-size: 13px;
}

@media (max-width: 480px) {
    .card {
        padding: 32px 24px;
    }

    h1 {
        font-size: 24px;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .stat-card.highlight {
        grid-column: span 1;
    }
}