style.css

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

body {
    font-family: system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f5f5f5;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    color: #2c3e50;
    font-size: 2.5rem;
}

header small {
    font-size: 0.8rem;
}

header a {
    color: #666;
    text-decoration: none;
}

header a:hover {
    color: #2c3e50;
}

.container {
    max-width: 500px;
    margin: 0 auto;
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

#todo-form {
    display: flex;
    gap: 10px;
    margin-bottom: 2rem;
}

#todo-input {
    flex: 1;
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 5px;
    font-size: 16px;
}

#todo-input:focus {
    outline: none;
    border-color: #3498db;
}

button {
    padding: 12px 24px;
    background: #3498db;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
}

button:hover {
    background: #2980b9;
}

#todo-list {
    list-style: none;
    margin-bottom: 2rem;
}

.todo-item {
    display: flex;
    align-items: center;
    padding: 12px;
    background: #f8f9fa;
    margin-bottom: 8px;
    border-radius: 5px;
    border-left: 4px solid #3498db;
}

.todo-item.completed {
    opacity: 0.7;
    border-left-color: #27ae60;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
}

.todo-text {
    flex: 1;
    margin: 0 12px;
}

.delete-btn {
    background: #e74c3c;
    padding: 6px 12px;
    font-size: 12px;
}

.delete-btn:hover {
    background: #c0392b;
}

.stats {
    display: flex;
    justify-content: space-between;
    font-size: 14px;
    color: #666;
    border-top: 1px solid #eee;
    padding-top: 1rem;
}

@media (max-width: 600px) {
    body {
        padding: 10px;
    }
    
    .container {
        padding: 1rem;
    }
    
    header h1 {
        font-size: 2rem;
    }
}