:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --error-color: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --radius: 12px;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 2rem;
}

.container {
    width: 100%;
    max-width: 1000px;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.app-header {
    text-align: center;
}

.app-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -0.025em;
    background: linear-gradient(to right, #2563eb, #1e40af);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.app-header p {
    color: var(--text-secondary);
}

/* Upload Section */
.upload-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.upload-card {
    background: var(--card-bg);
    border: 2px dashed var(--border-color);
    border-radius: var(--radius);
    padding: 2.5rem;
    text-align: center;
    transition: all 0.2s ease;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 250px;
}

.upload-card:hover {
    border-color: var(--primary-color);
    background-color: #f0f9ff;
}

.upload-card.active {
    border-color: var(--success-color);
    background-color: #f0fdf4;
}

.icon-wrapper {
    width: 64px;
    height: 64px;
    background-color: #eff6ff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.icon-wrapper svg {
    width: 32px;
    height: 32px;
}

.upload-card h3 {
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.file-name {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    word-break: break-all;
    max-width: 100%;
}

/* Actions */
.actions {
    display: flex;
    justify-content: center;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius);
    cursor: pointer;
    transition: background-color 0.2s;
    -webkit-box-shadow: var(--shadow-md);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-hover);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-secondary {
    background-color: white;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
}

.btn-secondary:hover {
    background-color: #f8fafc;
    border-color: #cbd5e1;
}

/* Loading */
.hidden {
    display: none !important;
}

#loading {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    color: var(--text-secondary);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

    100% {
        transform: rotate(360deg);
    }
}

/* Results */
.status-card {
    padding: 1.5rem;
    border-radius: var(--radius);
    margin-bottom: 2rem;
    text-align: center;
    font-weight: 500;
}

.status-card.success {
    background-color: #dcfce7;
    color: #166534;
    border: 1px solid #bbf7d0;
}

.status-card.diff {
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.diff-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.diff-stats {
    font-size: 0.875rem;
    color: var(--text-secondary);
    background: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    border: 1px solid var(--border-color);
}

.table-container {
    background: white;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    overflow-x: auto;
    border: 1px solid var(--border-color);
}

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

th,
td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: #f8fafc;
    font-weight: 600;
    color: var(--text-secondary);
}

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

td.bg-red {
    background-color: #fef2f2;
    color: #ef4444;
}

td.bg-green {
    background-color: #f0fdf4;
    color: #16a34a;
}

/* Responsive */
@media (max-width: 768px) {
    .upload-section {
        grid-template-columns: 1fr;
    }
}

/* Footer Branding */
.app-footer {
    margin-top: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    padding-top: 3rem;
    padding-bottom: 2rem;
    border-top: 1px solid var(--border-color);
    width: 100%;
}

.brand-container {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.footer-logo {
    height: 64px;
    width: auto;
    object-fit: contain;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.1));
}

.brand-name {
    font-family: 'Playfair Display', serif;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.02em;
    background: linear-gradient(135deg, #1e293b 0%, #475569 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.credits-text {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 400;
    margin-top: 0.5rem;
}

.highlight {
    font-weight: 700;
    color: var(--primary-color);
}
/* Key Selection */
.key-selection {
    margin-bottom: 1.5rem;
    text-align: left;
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
}

.key-selection label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-color);
}

.key-select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    background-color: white;
    font-size: 1rem;
    cursor: pointer;
    transition: border-color 0.2s;
}

.key-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.hint {
    margin-top: 0.5rem;
    font-size: 0.875rem;
    color: #64748b;
}

.actions {
    text-align: center;
    margin: 2rem 0;
}