* {
    margin: 0;
    padding: 0;
    font-family: "poppins", sans-serif;
    box-sizing: border-box;
}

.container {
    width: 100%;
    min-height: 100vh;
    background: #333;
    padding: 10px;
}

.todo-app {
    width: 100%;
    max-width: 540px;
    background: #fff;
    padding: 40px 30px 70px;
    margin: 50px auto 20px;
    border-radius: 15px;
}

.todo-app > h2 {
    color: #333;
    display: flex;
    align-items: center;
    margin-bottom: 20px;
}

.row {
    display: flex;
    align-items: center;
    justify-content: space-around;
    background: #d2d2d2;
    border-radius: 30px;
    padding-left: 20px;
    margin-bottom: 25px;
    flex-wrap: wrap;
    gap: 10px;
}

input {
    flex: 1;
    border: 0;
    outline: 0;
    background: transparent;
    padding: 10px;
    font-size: 14px;
    min-width: 0;
}

button {
    border: 0;
    outline: 0;
    padding: 16px 50px;
    background: #333;
    color: #fff;
    font-size: 16px;
    cursor: pointer;
    border-radius: 50px;
    white-space: nowrap;
}

ul li {
    list-style: none;
    font-size: 17px;
    padding: 12px 8px 12px 50px;
    user-select: none;
    position: relative;
    cursor: pointer;
    word-wrap: break-word;
}

ul li::before {
    content: '';
    position: absolute;
    height: 20px;
    width: 20px;
    border-radius: 50%;
    background-image: url(assets/unchecklist.png);
    background-size: cover;
    background-position: center;
    top: 13px;
    left: 20px;
}

ul li.checked {
    color: #555;
    text-decoration: line-through;
}

ul li.checked::before {
    background-image: url(assets/checklist.png);
}

ul li span {
    position: absolute;
    right: 0;
    width: 40px;
    height: 40px;
    font-size: 22px;
    color: #555;
    line-height: 40px;
    text-align: center;
    border-radius: 50%;
}

ul li span:hover {
    background: #edeef0;
}

@media (max-width: 600px) {
    .todo-app {
        padding: 25px 15px 50px;
        margin: 30px 10px;
    }

    .row {
        flex-direction: column;
        align-items: stretch;
        padding: 15px;
    }

    input {
        width: 100%;
        margin-bottom: 10px;
    }

    button {
        width: 100%;
        padding: 14px;
        font-size: 16px;
    }

    ul li {
        font-size: 16px;
        padding-left: 40px;
    }

    ul li::before {
        left: 10px;
    }

    ul li span {
        right: 5px;
    }
}