body {
    width: 100%;
    height: 100%;
}

/* 设置拍摄按钮 */
:root {
    --text-color: hsla(210, 50%, 85%, 1);
    --shadow-color: hsla(210, 40%, 52%, .4);
    --btn-color: hsl(210, 80%, 42%);
    --bg-color: #141218;
}
#photo_body{
    position: absolute;
    top: 40%;
    left: 50%;
    transform: translate(-50%, -50%);
}
#start_button {
    /* position: relative; */
    position: absolute;
    padding: 10px 20px;
    border: none;
    background: none;
    cursor: pointer;
    font-family: "Source Code Pro";
    font-weight: 900;
    text-transform: uppercase;
    font-size: 30px;
    color: var(--text-color);
    background-color: var(--btn-color);
    box-shadow: var(--shadow-color) 2px 2px 22px;
    border-radius: 7px;
    z-index: 0;
    overflow: hidden;
    top: 45%;
    left: 50%;
    transform: translate(-50%, -50%);
    /* 使用css3的transform来实现 */
}

#start_button:focus {
    outline-color: transparent;
    box-shadow: var(--btn-color) 2px 2px 22px;
}

.right::after,
#start_button::after {
    content: var(--content);
    display: block;
    position: absolute;
    white-space: nowrap;
    padding: 40px 40px;
    pointer-events: none;
}

#start_button::after {
    font-weight: 200;
    top: -30px;
    left: -20px;
}

.right,
.left {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
}

.right {
    left: 66%;
}

.left {
    right: 66%;
}

.right::after {
    top: -30px;
    left: calc(-66% - 20px);
    background-color: var(--bg-color);
    color: transparent;
    transition: transform .4s ease-out;
    transform: translate(0, -90%) rotate(0deg)
}

#start_button:hover .right::after {
    transform: translate(0, -47%) rotate(0deg)
}

#start_button .right:hover::after {
    transform: translate(0, -50%) rotate(-7deg)
}

#start_button .left:hover~.right::after {
    transform: translate(0, -50%) rotate(7deg)
}

/* bubbles */

#start_button::before {
    content: '';
    pointer-events: none;
    opacity: .6;
    background: radial-gradient(circle at 20% 35%, transparent 0, transparent 2px, var(--text-color) 3px, var(--text-color) 4px, transparent 4px), radial-gradient(circle at 75% 44%, transparent 0, transparent 2px, var(--text-color) 3px, var(--text-color) 4px, transparent 4px), radial-gradient(circle at 46% 52%, transparent 0, transparent 4px, var(--text-color) 5px, var(--text-color) 6px, transparent 6px);
    width: 100%;
    height: 300%;
    top: 0;
    left: 0;
    position: absolute;
    animation: bubbles 5s linear infinite both;
}

@keyframes bubbles {
    from {
        transform: translate();
    }

    to {
        transform: translate(0, -66.666%);
    }
}

.photo-parameter {
    display: none;
}