:root {
    --bg-app: #121212;
    --bg-panel: #1e1e1e;
    --bg-input: #2c2c2c;
    --border-color: #333;
    --primary: #3b82f6; /* Blue */
    --primary-hover: #2563eb;
    --text-main: #e5e7eb;
    --text-muted: #9ca3af;
    --danger: #ef4444;
    --success: #10b981;
    --radius: 8px;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background-color: var(--bg-app);
    color: var(--text-main);
    margin: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.app-header {
    background-color: var(--bg-panel);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.app-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-main);
    margin: 0;
}

.main-content {
    flex: 1;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

@media (max-width: 768px) {
    .main-content {
        grid-template-columns: 1fr;
    }
}

.card {
    background-color: var(--bg-panel);
    border-radius: var(--radius);
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 500;
    margin-top: 0;
    margin-bottom: 1.5rem;
    color: var(--text-main);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
}

/* Upload Zone */
.upload-zone {
    flex: 1;
    border: 2px dashed var(--border-color);
    border-radius: var(--radius);
    background-color: rgba(255, 255, 255, 0.02);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: 250px;
    position: relative;
    text-align: center;
    padding: 2rem;
}

.upload-zone:hover, .upload-zone.drag-over {
    border-color: var(--primary);
    background-color: rgba(59, 130, 246, 0.05);
}

.upload-icon {
    font-size: 3rem;
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.upload-text {
    font-size: 1rem;
    color: var(--text-main);
    font-weight: 500;
}

.upload-subtext {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: 0.5rem;
}

#fileInput {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.file-info {
    margin-top: 1rem;
    padding: 0.75rem;
    background-color: var(--bg-input);
    border-radius: var(--radius);
    display: none; /* Hidden by default */
    align-items: center;
    gap: 0.5rem;
    width: 100%;
}
.file-info.active {
    display: flex;
}

.file-name {
    font-size: 0.9rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Form Controls */
.form-group {
    margin-bottom: 1.25rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-muted);
}

input[type="number"] {
    width: 100%;
    padding: 0.75rem;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    background-color: var(--bg-input);
    color: var(--text-main);
    font-size: 0.95rem;
    transition: border-color 0.2s;
}

input[type="number"]:focus {
    outline: none;
    border-color: var(--primary);
}

.row {
    display: flex;
    gap: 1rem;
}

.col {
    flex: 1;
}

.helper-text {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
    display: block;
}

/* Button */
.btn-primary {
    width: 100%;
    padding: 0.875rem;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
    margin-top: auto;
}

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

.btn-primary:disabled {
    background-color: var(--border-color);
    color: var(--text-muted);
    cursor: not-allowed;
}

/* Status */
#status {
    margin-top: 1rem;
    padding: 0.75rem;
    border-radius: var(--radius);
    font-size: 0.875rem;
    text-align: center;
    display: none;
}

#status.visible {
    display: block;
}

#status.error {
    background-color: rgba(239, 68, 68, 0.1);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

#status.success {
    background-color: rgba(16, 185, 129, 0.1);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.2);
}