* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: "Lemonada", cursive;
}

.container {
    width: 100%;
    min-height: 100vh;
    padding: 10px;
    background: linear-gradient(135deg, #1c8686, #10c2bc);
}

.todo-app {
    width: 100%;
    max-width: 550px;
    margin: 100px auto;
    padding: 20px;
    align-items: center;
    background: #fffffff7;
    border-radius: 10px;
}

.todo-app h2 {
    color: #1c8686;
    text-align: center;
    font-size: 25px;
    position: relative;
}
.todo-app h2::before {
    content: '';
    position: absolute;
    width: 120px;
    height: 90%;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    border-bottom: 1px solid #1c8686;
}

.todo-app .row {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 15px;
}

.todo-app .row #write-task{ 
    flex: 1;
    margin-right: 10px;
    padding: 5px 10px;
    font-size: 14px;
    border: 1px solid #ccc;
    background-color: transparent;
    outline: none;
    border-radius: 5px;
}

.todo-app .row #write-task:focus { 
    outline: none;
}

.todo-app .row button {
    padding: 5px 20px;
    background-color: #10c2bc;
    border: 1px solid #ccc;
    border-radius: 5px;
    color: #fff;
    font-weight: bold;
    font-size: 14px;
    cursor: pointer;
}

.todo-app ul { 
    list-style: none;
    padding: 5px 15px;
}

.todo-app ul li {
    margin-bottom: 10px;
    padding: 5px 10px;
    border-radius: 10px;
    user-select: none;
    cursor: pointer;
    position: relative;
    border: 1px solid #10c2bc70;
}

.todo-app ul li:hover {
    background-color: #10c2bc39;
    color: #1c8686;
}

.todo-app ul li.done {
    background-color: #10c2bc39;
    color: #1c868699;
    text-decoration: line-through;
}

.todo-app ul li span {
    position: absolute;
    right: 5px;
    top: 50%;
    transform: translateY(-50%);
    background-color: #10c2bc;
    color: #fff;
    width: 25px;
    height: 25px;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 50%;
    font-size: 12px;
}

.todo-app ul li span:hover { 
    color: #fc0000;
    font-weight: bold;
    background-color: #fff;
}