style.css

body,html {
    margin: 0;
    padding: 0;
    background-color:black;
}
* {
    box-sizing: border-box;
}

.container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

#clock {
    font-family: 'Orbitron', sans-serif;
    font-size: 15vw;
    background-image: linear-gradient(180deg,
        rgba(99,253,136,1) 0%,
        rgba(51,197,142,1) 50%,
        rgba(39,97,116,1) 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -moz-background-clip: text;
    -webkit-text-fill-color: transparent; 
    -moz-text-fill-color: transparent;
}

.controls {
    margin-top: 16px;
}

.button {
    font-weight: bold;
    border-radius: 5px;
    border: none;
    color: white;
    padding: 4px 8px;
    margin-left: 4px;
    cursor: pointer;
}

.set-alarm {
    background-color: #498AFB;
}

.clear-alarm {
    background-color: #FF3860;
}