* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', sans-serif;
    background-color: #f0f2f5;
    display: flex;
    justify-content: center;
    padding-top: 40px;
}

.container {
    background: white;
    width: 90%;
    max-width: 450px;
    padding: 2rem;
    border-radius: 20px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
}

header h1 {
    margin-bottom: 20px;
    text-align: center;
    color: #1a1a1a;
}


#todo-list {
    list-style: none;
    margin-bottom: 25px;
    max-height: 400px;
    overflow-y: auto;
}

.todo-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    border-radius: 10px;
    transition: background 0.2s;
}

.todo-item:hover {
    background: #f8f9fa;
}


.todo-text {
    flex: 1;
    font-size: 1rem;
    transition: color 0.3s, text-decoration 0.3s;
}


.completed .todo-text {
    text-decoration: line-through;
    color: #a0aec0;
}


.todo-checkbox {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: #6c5ce7;
}


#todo-form {
    display: flex;
    gap: 10px;
    border-top: 1px solid #eee;
    padding-top: 20px;
}

#todo-input {
    flex: 1;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 10px;
    outline: none;
}

#add-btn {
    background: #6c5ce7;
    color: white;
    border: none;
    padding: 0 20px;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1.5rem;
}

.delete-btn {
    background: none;
    border: none;
    color: #ff7675;
    cursor: pointer;
    font-weight: bold;
    font-size: 0.8rem;
}