.oa-container {
    max-width: 720px;
    margin: 30px auto;
    padding: 30px;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    font-family: 'Segoe UI', sans-serif;
}
.oa-title {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 20px;
}
.oa-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}
.oa-inputs label, .oa-target label {
    display: block;
    margin-bottom: 15px;
    font-weight: 500;
}
.oa-inputs input, .oa-target input {
    width: 100%;
    padding: 8px 10px;
    border: 1px solid #ccc;
    border-radius: 8px;
    font-size: 15px;
}
.oa-outputs div {
    display: flex;
    justify-content: space-between;
    padding: 10px 12px;
    margin-bottom: 10px;
    background: #f0f6fb;
    border-radius: 10px;
    font-weight: 500;
}
.oa-target {
    margin-top: 30px;
    display: flex;
    gap: 20px;
    align-items: flex-end;
}
.oa-target button {
    padding: 10px 16px;
    background: #0099e6;
    color: #fff;
    font-weight: 600;
    font-size: 14px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
}