/* Layout */
* {
    box-sizing: border-box;
}
body {
    font-family: sans-serif;
    margin: 0;
}
.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 15px;
}

/* Range slider */
#slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: #ddd;
    outline: none;
    margin: 15px 0;
    cursor: pointer;
}
#slider::-webkit-slider-runnable-track {
    background: linear-gradient(to right, #337ab7 0%, #337ab7 var(--pct, 0%), #ddd var(--pct, 0%), #ddd 100%);
    height: 6px;
    border-radius: 3px;
}
#slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #337ab7;
    cursor: pointer;
    margin-top: -7px;
}
#slider::-moz-range-track {
    background: #ddd;
    height: 6px;
    border-radius: 3px;
}
#slider::-moz-range-progress {
    background: #337ab7;
    height: 6px;
    border-radius: 3px;
}
#slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #337ab7;
    cursor: pointer;
    border: none;
}

#box {
    padding: 30px 0;
}

/* Controls row */
#controls {
    display: flex;
    gap: 16px;
    align-items: center;
    margin: 10px 0 5px;
    flex-wrap: wrap;
}
#currency-switcher,
#mode-switcher {
    display: flex;
    gap: 6px;
}
.currency-btn {
    padding: 5px 14px;
    border: 1px solid #337ab7;
    border-radius: 4px;
    background: #fff;
    color: #337ab7;
    cursor: pointer;
    font-size: 14px;
    font-weight: bold;
    transition: background 0.15s, color 0.15s;
}
.currency-btn:hover {
    background: #e8f0f8;
}
.currency-btn.active {
    background: #337ab7;
    color: #fff;
}