style.css

body {
    font-size: 15pt;
    background-color: slategray;
    /*background-image: linear-gradient(#e04343, #255ba1);*/
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

p {
    user-select: none;
}

.bottom {
    position: absolute;
    bottom: 70px;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    background-color: rgba(0, 0, 0, 0.65);
    width: 100%;
    padding-top: 10px;

   /*min-width: 635px;
    max-width: 2024px;
    min-height: 220px;*/
}

.bottom #camera-modes {
    user-select: none;
    -webkit-tap-highlight-color: rgba(0,0,0, 0.65);
    position: relative;
    text-align: center;
    margin-left: -24px;
}

.bottom #camera-modes p {
    display: inline;
    padding: 0 12px;
    background-color: white;
    cursor: pointer;
}

.bottom #camera-modes .cam-p {
    color: black;
}

.bottom #camera-modes .cam-p.active {
    color: yellow;
    background-color: #fff;
} 

.record-btn {
    position: relative;
    margin-top: 15px;
    width: 60px;
    height: 60px;
    border-radius: 100%;
    background-color: transparent;
    cursor: pointer;
    border: 3px solid #fff;
    -webkit-tap-highlight-color: rgba(0,0,0, 0.65);
    transition: 0.7s;
}

.record {
    position: absolute;
    width: 25px;
    height: 25px;
    border-radius: 5px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: rgb(255, 59, 59);
    transition: 0.2s;
}

.record-btn.active .record {
    width: 48px;
    height: 48px;
    border-radius: 100%;
}

.rec-timer {
    background-color: #fff;
    border: 2px solid red;
    display: flex;
    align-items: center;
}

.rec-timer .dot {
    position: absolute;
    background-color: transparent;
    width: 20px;
    height: 20px;
    margin-left: -25px;
    border-radius: 100%;
    transition: 0.3s ease-in-out;
}

.rec-timer .dot.active {
    background-color: rgb(255, 59, 59);
}

.cam-p {background-color: #fff;}
.cam-p.active {background-color: yellow;}