* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;

    background:
        radial-gradient(circle at top, #252536, #08080d 60%);

    color: white;
    font-family: Arial, sans-serif;
}

.app {
    width: min(700px, 92%);
    margin: auto;
    padding: 40px 0;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;

    margin-bottom: 30px;
}

.small {
    margin: 0;
    letter-spacing: 5px;
    opacity: .55;
    font-size: 12px;
}

h1 {
    margin: 5px 0 0;
    font-size: 38px;
}

h2 {
    margin-top: 0;
}

.panel {
    background: rgba(25, 25, 35, .92);

    border: 1px solid #363644;
    border-radius: 18px;

    padding: 25px;
    margin-bottom: 20px;

    box-shadow: 0 15px 50px rgba(0,0,0,.3);
}

.control {
    margin: 25px 0;
}

.control label {
    display: flex;
    justify-content: space-between;

    margin-bottom: 10px;

    font-weight: bold;
}

.control span {
    opacity: .6;
}

input[type="range"] {
    width: 100%;
    cursor: pointer;
}

.buttons,
.presets {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
}

button {
    border: 0;
    border-radius: 10px;

    padding: 15px;

    background: #292936;
    color: white;

    font-weight: bold;
    cursor: pointer;
}

button:hover {
    filter: brightness(1.25);
}

.primary {
    background: #2878ff;
}

.danger {
    background: #b82d3d;
}

#connection {
    padding: 10px 15px;
    border-radius: 999px;

    font-size: 12px;
    font-weight: bold;
}

.offline {
    background: #32151a;
    color: #ff6475;
}

.online {
    background: #153522;
    color: #64ff91;
}

footer {
    text-align: center;
    opacity: .35;
    font-size: 11px;
    letter-spacing: 2px;
}

@media (max-width: 550px) {

    header {
        display: block;
    }

    #connection {
        display: inline-block;
        margin-top: 15px;
    }

    h1 {
        font-size: 30px;
    }

    .buttons,
    .presets {
        grid-template-columns: 1fr;
    }
}