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

body {
    background: linear-gradient(135deg, #0f172a, #1e293b);
    color: white;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

body > div:first-child {
    width: 100%;
    max-width: 500px;

    display: flex;
    gap: 10px;

    margin-top: 30px;
    justify-content: center;
}

#todoInput {
    flex: 1;
    padding: 12px;
    border-radius: 10px;
    border: none;
    outline: none;
    background: #1e293b;
    color: white;
}

button {
    padding: 10px 14px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
}

#child2 {

    width: 100%;
    max-width: 500px;

    display: flex;
    margin-top: 20px;
    flex-direction: column;
    justify-content: center;   
    align-items: center;       

    gap: 12px;
}

.box {
    width: 100%;
    background: #1e293b;
    padding: 10px;
    border-radius: 12px;

    display: flex;
    justify-content: space-between;
    align-items: center;

    box-shadow: 0 8px 20px rgba(0,0,0,0.3);
}
.done {
    background-color: rgb(23, 252, 76);
    /* text-decoration: line-through; */
}
@media (max-width: 600px) {

    body > div:first-child {
        flex-direction: column;
        padding: 0 15px;
    }

    #todoInput {
        width: 100%;
    }

    button {
        width: 100%;
    }

    #child2 {
        padding: 0 15px;
    }

    .box {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
}