#hc-ortalama-atomik-kutle-hesaplayici {
    background: #ffffff;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    font-family: 'Segoe UI', sans-serif;
    max-width: 500px;
    margin: 20px auto;
    border: 1px solid #e2e8f0;
}

#hc-ortalama-atomik-kutle-hesaplayici h3 {
    margin: 0 0 10px;
    color: #1e293b;
    font-size: 1.4rem;
}

#hc-ortalama-atomik-kutle-hesaplayici p {
    margin-bottom: 25px;
    color: #64748b;
    font-size: 0.9rem;
}

#hc-ortalama-atomik-kutle-hesaplayici .hc-isotope-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 25px;
}

#hc-ortalama-atomik-kutle-hesaplayici .hc-isotope-item label {
    display: block;
    font-size: 0.8rem;
    font-weight: 700;
    color: #475569;
    margin-bottom: 5px;
}

#hc-ortalama-atomik-kutle-hesaplayici .hc-input-group {
    display: flex;
    gap: 10px;
}

#hc-ortalama-atomik-kutle-hesaplayici input {
    flex: 1;
    padding: 10px;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    background: #f8fafc;
    font-size: 0.9rem;
}

#hc-ortalama-atomik-kutle-hesaplayici .hc-btn {
    width: 100%;
    background: #2563eb;
    color: white;
    padding: 14px;
    border: none;
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
}

#hc-ortalama-atomik-kutle-hesaplayici .hc-result {
    margin-top: 30px;
    padding: 20px;
    background: #f0f9ff;
    border-radius: 12px;
    border: 1px solid #bae6fd;
    text-align: center;
    display: none;
}

#hc-ortalama-atomik-kutle-hesaplayici .hc-result.visible {
    display: block;
}

#hc-ortalama-atomik-kutle-hesaplayici #hc-res-avg-mass {
    font-size: 2rem;
    font-weight: 800;
    color: #0c4a6e;
    display: block;
}

#hc-ortalama-atomik-kutle-hesaplayici .hc-warn-note {
    margin-top: 15px;
    font-size: 0.8rem;
    color: #b91c1c;
    background: #fef2f2;
    padding: 8px;
    border-radius: 6px;
}