:root {
    --bg-dark: #0a0a0c;
    --bg-card: #16161a;
    --bg-card-hover: #1c1c21;
    --border: #2a2a30;
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --text-main: #ededef;
    --text-muted: #8d8d96;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

    --shadow-card: 0 20px 40px -10px rgba(0, 0, 0, 0.5);
    --radius-lg: 16px;
    --radius-md: 8px;
    --radius-sm: 4px;
}

body {
    margin: 0;
    font-family: var(--font-sans);
    background-color: var(--bg-dark);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* Background Gradient */
.bg-gradient {
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at 50% 50%, rgba(99, 102, 241, 0.15) 0%, rgba(10, 10, 12, 0) 50%);
    z-index: -1;
    pointer-events: none;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 2rem 1rem;
    width: 100%;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 3rem;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 100px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.logo-text {
    font-weight: 600;
    letter-spacing: -0.01em;
    font-size: 0.9rem;
}

h1 {
    font-size: 2.5rem;
    line-height: 1.2;
    font-weight: 700;
    margin: 0 0 1rem 0;
    letter-spacing: -0.02em;
}

.text-gradient {
    background: linear-gradient(135deg, #a5b4fc 0%, #6366f1 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.subtitle {
    color: var(--text-muted);
    line-height: 1.6;
    margin: 0;
    font-size: 1.1rem;
}

/* Card */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    padding: 2rem;
    position: relative;
    overflow: hidden;
    transition: height 0.3s ease;
}

.step.hidden {
    display: none;
}

/* Upload Zone */
.upload-zone {
    border: 2px dashed var(--border);
    border-radius: var(--radius-md);
    padding: 4rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
}

.upload-zone:hover,
.upload-zone.dragover {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.05);
}

.upload-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.upload-zone h3 {
    margin: 0 0 0.5rem 0;
    font-weight: 600;
}

.upload-zone p {
    margin: 0;
    color: var(--text-muted);
}

/* Step Header */
.step-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.step-indicator {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.step-header h2 {
    margin: 0;
    font-size: 1.4rem;
}

.step-desc {
    color: var(--text-muted);
    margin-top: -1rem;
    /* Visual tweak */
    margin-bottom: 2rem;
}

/* Column Selection */
.column-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 0.75rem;
    margin-bottom: 2rem;
    max-height: 200px;
    overflow-y: auto;
}

.column-option {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border);
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.9rem;
    text-overflow: ellipsis;
    overflow: hidden;
    white-space: nowrap;
    transition: all 0.2s;
    text-align: center;
}

.column-option:hover {
    background: rgba(255, 255, 255, 0.07);
}

.column-option.selected {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

/* Buttons */
.btn {
    border: none;
    border-radius: var(--radius-md);
    padding: 0.75rem 1.5rem;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    font-family: var(--font-sans);
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    transform: translateY(-1px);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-main);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
}

.btn-sm {
    padding: 0.4rem 0.8rem;
    font-size: 0.85rem;
}

.btn-text {
    background: transparent;
    color: var(--primary);
    padding: 0.5rem;
}

.btn-text:hover {
    text-decoration: underline;
}

.btn-text.text-muted {
    color: var(--text-muted);
}

.actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 1rem;
}

.actions.vertical {
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.secondary-actions {
    display: flex;
    gap: 1rem;
    margin-top: 0.5rem;
}

.full-width {
    width: 100%;
}

/* Stats */
.stats-grid {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: rgba(255, 255, 255, 0.03);
    padding: 1rem;
    border-radius: var(--radius-md);
    text-align: center;
    border: 1px solid transparent;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-success .stat-value {
    color: var(--success);
}

.stat-success {
    border-color: rgba(16, 185, 129, 0.2);
}

.stat-warning .stat-value {
    color: var(--warning);
}

.stat-warning {
    border-color: rgba(245, 158, 11, 0.2);
}

.stat-error .stat-value {
    color: var(--error);
}

.stat-error {
    border-color: rgba(239, 68, 68, 0.2);
}

/* Fix Section */
.fix-section {
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid rgba(245, 158, 11, 0.3);
    border-radius: var(--radius-md);
    padding: 1rem 1.5rem;
    margin-bottom: 2rem;
}

.fix-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.fix-header h3 {
    margin: 0;
    font-size: 1rem;
    color: var(--warning);
}

.fix-section p {
    margin: 0 0 1rem 0;
    font-size: 0.9rem;
    opacity: 0.9;
}

.fix-controls {
    display: flex;
    gap: 0.5rem;
}

.select-input {
    background: var(--bg-dark);
    border: 1px solid var(--border);
    color: var(--text-main);
    padding: 0.4rem 0.8rem;
    border-radius: var(--radius-sm);
    flex: 1;
}

/* Table */
.preview-container {
    margin-bottom: 2rem;
}

.preview-container h3 {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 0.8rem;
}

.table-wrapper {
    max-height: 250px;
    overflow-y: auto;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

th,
td {
    padding: 0.75rem 1rem;
    text-align: left;
}

th {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-muted);
    font-weight: 500;
    position: sticky;
    top: 0;
    backdrop-filter: blur(5px);
}

tr {
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

tr:last-child {
    border-bottom: none;
}

.status-icon {
    font-size: 1.1rem;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
}

.delay-1 {
    animation-delay: 0.2s;
}

.delay-2 {
    animation-delay: 0.4s;
}

/* Footer */
.footer {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 2rem;
    opacity: 0.6;
}

.footer a {
    color: var(--text-main);
    text-decoration: none;
    border-bottom: 1px dotted var(--text-muted);
}

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

    .card {
        padding: 1.5rem;
    }

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

/* Trust Badge */
.trust-badge {
    display: inline-block;
    margin-top: 0.5rem;
    padding: 0.25rem 0.75rem;
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.2);
    border-radius: 100px;
    font-size: 0.8rem;
    color: var(--success);
    font-weight: 500;
}

/* Upload Hint */
.upload-hint {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-top: 1rem;
    opacity: 0.7;
}

/* Features Section */
.features {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 1.5rem;
    margin-top: 3rem;
    margin-bottom: 2rem;
}

.feature-item {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    text-align: center;
    transition: transform 0.2s;
}

.feature-item:hover {
    transform: translateY(-2px);
    background: rgba(255, 255, 255, 0.04);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    display: block;
}

.feature-item h3 {
    font-size: 1rem;
    margin: 0 0 0.5rem 0;
    font-weight: 600;
}

.feature-item p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin: 0;
    line-height: 1.5;
}