* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    min-height: 100vh;
    background-color: #0f0f0f;
    display: flex;
    justify-content: center;
    align-items: center;
    color: #ffffff;
}

.container {
    width: 100%;
    max-width: 420px;
    background: #1a1a1a;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8);
}

h1 {
    text-align: center;
    margin-bottom: 20px;
    font-size: 26px;
}

form {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

form input {
    flex: 1;
    padding: 10px;
    font-size: 16px;
    border-radius: 8px;
    border: none;
    outline: none;
}

form button {
    padding: 10px 16px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    background-color: #4caf50;
    color: #fff;
    cursor: pointer;
    transition: background 0.3s;
}

form button:hover {
    background-color: #43a047;
}

#alltask div {
    background: #262626;
    padding: 12px;
    margin-bottom: 10px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

#alltask span {
    flex: 1;
    font-size: 16px;
}

#alltask button {
    margin-left: 8px;
    padding: 6px 10px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}

#alltask button:first-of-type {
    background-color: #2196f3;
    color: white;
}

#alltask button:first-of-type:hover {
    background-color: #1e88e5;
}

#alltask button:last-of-type {
    background-color: #f44336;
    color: white;
}

#alltask button:last-of-type:hover {
    background-color: #e53935;
}

.completed {
    text-decoration: line-through;
    color: #9e9e9e;
}