Körből nyíló gomb

.we-btn-bar {
    position: relative;

    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 16px;

    min-width: 175px;
    height: 54px;

    padding: 0 26px;

    border: 1px solid rgba(255,255,255,.16);
    border-radius: 12px;

    background: #111518;
    color: #f3f0e8;

    font-family: Arial, sans-serif;
    font-size: 14px;
    font-weight: 500;
    letter-spacing: .4px;

    cursor: pointer;
    overflow: hidden;

    transition:
        transform .75s cubic-bezier(.22,1,.36,1),
        border-radius .75s cubic-bezier(.22,1,.36,1),
        border-color .6s ease,
        box-shadow .75s ease;
}

.we-btn-bar-text,
.we-btn-bar-arrow {
    position: relative;
    z-index: 2;

    transition:
        transform .8s cubic-bezier(.22,1,.36,1),
        color .6s ease;
}

.we-btn-bar-arrow {
    font-size: 20px;
    line-height: 1;
}

.we-btn-bar-line {
    position: absolute;

    left: 50%;
    bottom: 0;

    width: 18px;
    height: 3px;

    border-radius: 3px 3px 0 0;

    background: #c9a86a;

    transform:
        translateX(-50%)
        scaleX(1);

    transform-origin: center;

    transition:
        width 1s cubic-bezier(.22,1,.36,1),
        height .7s cubic-bezier(.22,1,.36,1),
        border-radius .7s ease;
}

.we-btn-bar:hover {
    transform:
        translateY(-4px);

    border-radius: 18px;
    border-color: rgba(201,168,106,.55);

    box-shadow:
        0 20px 42px rgba(0,0,0,.42);
}

.we-btn-bar:hover .we-btn-bar-line {
    width: 100%;
    height: 100%;

    border-radius: 0;
}

.we-btn-bar:hover .we-btn-bar-text {
    color: #17130d;

    transform:
        translateY(-1px)
        translateX(-3px);
}

.we-btn-bar:hover .we-btn-bar-arrow {
    color: #17130d;

    transform:
        translateX(7px)
        scale(1.12);
}

.we-btn-bar:active {
    transform:
        translateY(-1px)
        scale(.97);
}

Ehhez az animációhoz nincs külön JavaScript.