style.css

* {
    box-sizing: border-box;
}

body {
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #f0f0ff;
    font-family: "Arial", sans-serif;
}

button,
button:focus,
button:focus-visible {
    outline: 0;
    border: none;
}

#container {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    width: 500px;
    background-color: #fafafa;
    padding: 0px;
    box-shadow: 0 20px 30px 0 rgba(1, 1, 1, 0.07);
    margin: 96px 0;
    border-radius: 20px;
}

#taskForm {
    --h: 50px;
    display: flex;
    gap: 20px;
    justify-content: center;
    width: 100%;
    padding: 24px;
}

#taskForm #taskAdd {
    cursor: pointer;
    transition: all 0.3s ease-in-out;
    width: var(--h);
    height: var(--h);
    background: #3b44fb;
    color: #fff;
    text-align: center;
    font-size: 32px;
    font-weight: 300;
    border-radius: 12px;
    border: 0;
    outline: 0;
    will-change: transform;
}

#taskForm #taskAdd:hover {
    background: #050fe5;
    transform: scale(0.95);
}

#taskForm #taskAdd:active {
    transform: scale(0.9);
}

#taskForm input#taskInput {
    font-family: inherit;
    font-size: 16px;
    font-weight: 600;
    border: 3px solid #eee;
    background-color: #fff;
    color: #0d0d0d;
    width: calc(100% - var(--h));
    padding: 0 18px;
    line-height: 1;
    border-radius: 12px;
    transition: .25s;
}

#taskForm input#taskInput::placeholder {
    color: #aaa;
}

#taskForm input#taskInput:focus-visible,
#taskForm input#taskInput:focus {
    outline: none;
    border-color: #dfdfdf;
}

#tasksList {
    padding: 0;
    list-style-type: none;
    margin: 0 28px;
}

#tasksList li {
    --h: 58px;
    --bdrs: 12px;
    transition: all 0.3s ease-in-out;
    box-shadow: 0 20px 30px 0 rgba(1, 1, 1, 0.07);
    border-radius: var(--bdrs);
    color: #0d0d0d;
    padding: 20px;
    font-weight: 600;
    background-color: #fff;
    position: relative;
    will-change: transform;
    margin-bottom: 24px;
    height: var(--h);
}

#tasksList li .delete {
    cursor: pointer;
    transition: all 0.3s ease-in-out;
    position: absolute;
    top: 0;
    right: 0;
    width: var(--h);
    height: var(--h);
    opacity: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #fa4b4b;
    border-radius: var(--bdrs);
    color: #fff;
}

#tasksList li:hover {
    transition: all 0.3s ease-in-out;
    transform: scale(1.05);
    box-shadow: 0 20px 30px 0 rgba(1, 1, 1, 0.2);
}

#tasksList li:hover .delete {
    opacity: 1;
}

#tasksList li .delete:hover {
    opacity: 0.75;
}

#tasksList li .edit {
    transition: 0.3s;
    border: 3px solid transparent;
    padding: 7px 10px;
    border-radius: 10px;
}

#tasksList li .edit[contenteditable="true"] {
    border-color: #3b44fb;
}