JS Stopwatch

HTML

<div class="timer">
     <h3>3 Minutes Stop Watch</h3>

    <p> <span id="min">0</span>min <span id="sec">0</span>sec</p>
    <p>
        <button id="start">Start</button>
        <button id="stop" disabled>Stop</button>
        <button id="reset">Reset</button>
    </p>
</div>

CSS

.timer {
    width: 360px;
    height: 680px: margin: 0 auto;
    padding: 20px;
    border: 1px solid transparent;
    background: rgba(26, 188, 156,1.0);
    color: rgba(52, 73, 94, 0.9);
    text-align: center;
}

button {
    padding: 10px;
    width: 50px;
    height: 50px;
    border-radius: 100%;
    margin: 0 10px;
    border: 1px solid rgba(52, 73, 94,0.67);
    color: rgba(52, 73, 94,1.0);
    background: rgba(26, 188, 156,1.0);
    cursor: pointer;
}
button:disabled {
    color: rgba(52, 73, 94,0.5);
}
button:focus, button:hover {
    background: rgba(26, 188, 156,0.7);
    outline: transparent;
}

JavaScript

var counter,
    time = 360,
        sec = document.getElementById("sec"),
        min = document.getElementById("min"),
        start = document.getElementById("start"),
        reset = document.getElementById("reset"),
        stop = document.getElementById("stop");

    start.addEventListener("click", function () {
        toggle();
        counter = setInterval(count, 1000);
    });

    stop.addEventListener("click", function () {
        toggle();
        clearInterval(counter);
    });

    reset.addEventListener("click", function () {
        time = 180;
        sec.innerHTML = time % 60;
        min.innerHTML = Math.floor(time / 60);
    });

    function count() {
        if (time === 0) {
            sec.innerHTML = 0;
            min.innerHTML = 0;
            toggle();
            clearInterval(counter);
        } else {
            time--;
            sec.innerHTML = time % 60;
            min.innerHTML = Math.floor(time / 60);
        }
    }

    function toggle() {
        if (start.disabled) {
            start.disabled = false;
            stop.disabled = true;
        } else {
            start.disabled = true;
            stop.disabled = false
        }
    };