.rpc-wrap {
    max-width: 700px;
    margin: 20px auto;
    padding: 20px;
    font-family: Arial, sans-serif;
    background: #ffffff82;
    border-radius: 16px;
    box-shadow: 0 12px 40px rgba(0,0,0,0.1);
}

.rpc-header {
    text-align: center;
}

/* TOP CONTROLS */
#rpc-mode {
    display: flex;
    gap: 10px;
    margin-top: 10px;
}

#rpc-mode button {
    flex: 1;
    padding: 8px;
    border: none;
    cursor: pointer;
    background: #eee;
    border-radius: 6px;
}

#rpc-mode .active {
    background: #0073aa;
    color: white;
}

/* INPUT */
#rpc-input {
    display: flex;
    gap: 10px;
    margin: 10px 0;
}

#rpc-input input,
#rpc-input select {
    padding: 6px;
}

/* SVG RESISTOR */
.rpc-svg-wrap {
    display: flex;
    justify-content: center;
    margin: 20px 0;
}

.rpc-svg {
    width: 100%;
    max-width: 650px;
}

.wire {
    stroke: #444;
    stroke-width: 6;
}

.body {
    fill: #f3d9b1;
    stroke: #caa76a;
}

.band {
    transition: fill 0.25s ease, opacity 0.25s ease;
}

/* CONTROLS */
#rpc-controls {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    margin-top: 10px;
}

#rpc-controls select {
    padding: 6px;
    border-radius: 6px;
    border: 1px solid #ddd;
    font-weight: bold;
}

/* RESULT */
.rpc-result {
    margin-top: 15px;
    font-size: 16px;
    line-height: 1.6;
}