* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
    width: 100%;
    min-height: 100%;
}

body {
    min-height: 100vh;
    overflow-x: hidden;

    font-family:
        Arial,
        Helvetica,
        sans-serif;

    color: white;

    background: #050505;
}

/* Background */
.background {
    position: fixed;

    inset: 0;

    width: 100vw;
    height: 100vh;

    background:
        radial-gradient(
            circle at center,
            #202020 0%,
            #090909 55%,
            #020202 100%
        );

    z-index: 0;
}

/* Main */
.container {
    position: relative;

    z-index: 2;

    min-height: 100vh;

    display: flex;

    flex-direction: column;

    align-items: center;

    justify-content: center;

    padding: 25px 15px;
}

/* Card */
.speed-card {
    width: min(500px, 94vw);

    padding: 38px 30px 30px;

    border-radius: 30px;

    background:
        rgba(20, 20, 20, 0.78);

    border:
        1px solid rgba(255, 255, 255, 0.1);

    box-shadow:
        0 30px 100px rgba(0, 0, 0, 0.65);

    backdrop-filter: blur(18px);

    -webkit-backdrop-filter: blur(18px);

    text-align: center;
}

/* Logo */
.logo {
    font-size: 15px;

    letter-spacing: 6px;

    font-weight: bold;

    opacity: 0.8;

    margin-bottom: 25px;
}

/* Gauge */
.gauge {
    display: flex;

    align-items: center;

    justify-content: center;

    margin-bottom: 20px;
}

.gauge-ring {
    width: 245px;
    height: 245px;

    border-radius: 50%;

    display: flex;

    flex-direction: column;

    align-items: center;

    justify-content: center;

    background:
        radial-gradient(
            circle,
            #171717 58%,
            #111 59%,
            #111 63%,
            #292929 64%,
            #111 67%,
            #111 100%
        );

    border:
        7px solid #292929;

    box-shadow:
        0 0 0 4px rgba(255,255,255,.03),
        0 20px 60px rgba(0,0,0,.5);
}

.speed-number {
    font-size: 55px;

    line-height: 1;

    font-weight: 300;

    letter-spacing: -2px;
}

.speed-unit {
    margin-top: 7px;

    font-size: 14px;

    opacity: 0.5;

    letter-spacing: 2px;
}

/* Status */
.status {
    min-height: 22px;

    margin-bottom: 18px;

    font-size: 14px;

    opacity: 0.65;
}

/* Start */
.start-button {
    width: 105px;
    height: 105px;

    border-radius: 50%;

    border: 0;

    background: white;

    color: #111;

    font-size: 28px;

    font-weight: bold;

    cursor: pointer;

    box-shadow:
        0 12px 40px rgba(0,0,0,.4);

    transition:
        transform .2s ease,
        opacity .2s ease;
}

.start-button:hover {
    transform: scale(1.06);
}

.start-button:disabled {
    opacity: .5;

    cursor: wait;
}

/* Stats */
.stats {
    display: grid;

    grid-template-columns:
        repeat(3, 1fr);

    gap: 10px;

    margin-top: 32px;
}

.stat {
    padding: 15px 8px;

    border-radius: 15px;

    background:
        rgba(255,255,255,.055);

    border:
        1px solid rgba(255,255,255,.06);
}

.stat-title {
    font-size: 10px;

    letter-spacing: 2px;

    opacity: .45;

    margin-bottom: 7px;
}

.stat-value {
    font-size: 20px;

    font-weight: bold;
}

.stat-value small {
    font-size: 9px;

    opacity: .45;

    font-weight: normal;
}

/* Progress */
.progress-box {
    margin-top: 25px;
}

.progress-text {
    display: flex;

    justify-content: space-between;

    margin-bottom: 7px;

    font-size: 10px;

    opacity: .45;
}

.progress {
    width: 100%;

    height: 5px;

    border-radius: 10px;

    overflow: hidden;

    background:
        rgba(255,255,255,.1);
}

#progressBar {
    width: 0%;

    height: 100%;

    background: white;

    transition:
        width .15s linear;
}

footer {
    margin-top: 20px;

    font-size: 11px;

    opacity: .3;
}

/* Mobile */
@media (max-width: 480px) {

    .speed-card {
        padding:
            30px 20px 25px;

        border-radius: 25px;
    }

    .gauge-ring {
        width: 210px;
        height: 210px;
    }

    .speed-number {
        font-size: 48px;
    }

    .start-button {
        width: 95px;
        height: 95px;
    }

}