/* Distance Metric Selector Pane */
.metric-selector-pane {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #f8f9fa;
    border-radius: 20px;
    padding: 40px;
    animation: fadeIn 0.3s ease;
}

.selector-card {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    text-align: center;
    max-width: 800px;
    width: 100%;
}

.selector-card h2 {
    color: #1f2937;
    margin-bottom: 10px;
    font-size: 2rem;
}

.selector-card p {
    color: #6b7280;
    margin-bottom: 30px;
    font-size: 1.1rem;
}

.metric-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.metric-option {
    border: 2px solid #e5e7eb;
    border-radius: 16px;
    padding: 30px;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: left;
}

.metric-option:hover {
    border-color: #5FA8E4;
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(95, 168, 228, 0.15);
}

.metric-option h3 {
    margin: 0 0 10px 0;
    color: #1f2937;
    font-size: 1.4rem;
}

.metric-option p {
    margin: 0;
    color: #6b7280;
    font-size: 1rem;
}

/* K-Value Selector Pane */
.k-selector-pane {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #f8f9fa;
    border-radius: 20px;
    padding: 40px;
    animation: fadeIn 0.3s ease;
}

.k-options {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 15px;
}

.k-option {
    border: 2px solid #e5e7eb;
    border-radius: 16px;
    padding: 25px 20px;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: center;
}

.k-option:hover {
    border-color: #5FA8E4;
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(95, 168, 228, 0.15);
}

.k-option h3 {
    margin: 0 0 5px 0;
    color: #1f2937;
    font-size: 1.3rem;
}

.k-option p {
    margin: 0;
    color: #6b7280;
    font-size: 0.85rem;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}