.nxd-subnet-tool {
    display: flex;
    flex-wrap: wrap;
    gap: 25px;
    max-width: 1100px;
    margin: 40px auto;
    font-family: "Segoe UI", sans-serif;
}
.nxd-subnet-card {
    flex: 1 1 400px;
    background: #fff;
    border-radius: 12px;
    padding: 24px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.05);
    border: 1px solid #eaeaea;
}
.nxd-subnet-card h3 {
    font-size: 20px;
    margin-bottom: 20px;
    color: #222;
}
.nxd-subnet-card label {
    font-weight: 600;
    display: block;
    margin-top: 10px;
    margin-bottom: 4px;
}
.nxd-subnet-card input  {
    width: 100%;
    padding: 10px 4px;
    font-size: 16px;
    border: 1px solid #ccc;
    border-radius: 6px;
    margin-bottom: 10px;
    background-color: #fefefe;
    appearance: none;
    text-overflow: ellipsis;
    white-space: nowrap;
    overflow: hidden;
}

.nxd-subnet-card select {
    width: 100%;
    padding: 0px 0px 0px 0px;
    font-size: 16px;
    border: 1px solid #ccc;
    border-radius: 6px;
    margin-bottom: 10px;
    background-color: #fefefe;
    appearance: none;
    text-overflow: ellipsis;
    white-space: nowrap;
    overflow: hidden;
}

#nxd-calc-btn {
    background-color: #f16123;
    border: none;
    color: white;
    padding: 10px 18px;
    font-size: 16px;
    border-radius: 6px;
    cursor: pointer;
    margin-top: 10px;
    width: 100%;
    transition: background 0.2s ease;
}
#nxd-calc-btn:hover {
    background-color: #d85015;
}
.nxd-output-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 15px;
    font-size: 15px;
    margin-top: 10px;
}
.nxd-output-grid div {
    padding: 10px;
    background: #f9f9f9;
    border-radius: 6px;
    border: 1px solid #eee;
}