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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #6e8efb, #a777e3);
    color: white;
    padding: 30px 20px;
    text-align: center;
}

header h1 {
    margin-bottom: 10px;
}

main {
    padding: 20px;
}

.card {
    background-color: white;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.card h2 {
    margin-bottom: 15px;
    color: #6e8efb;
}

button {
    background-color: #6e8efb;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #5d7ce0;
}

.color-box {
    height: 100px;
    background-color: #f0f0f0;
    margin-top: 15px;
    border-radius: 4px;
    transition: background-color 0.5s;
}

.counter-container {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 15px;
}

#counterValue {
    font-size: 24px;
    margin: 0 20px;
    min-width: 40px;
    text-align: center;
}

/* Todo List Styles */
.todo-container {
    margin-top: 15px;
}

.todo-input-container {
    display: flex;
    margin-bottom: 15px;
}

#todoInput {
    flex: 1;
    padding: 8px 12px;
    border: 1px solid #ddd;
    border-radius: 4px 0 0 4px;
    font-size: 16px;
}

#addTodoBtn {
    border-radius: 0 4px 4px 0;
}

.todo-list {
    list-style-type: none;
    padding: 0;
}

.todo-item {
    display: flex;
    align-items: center;
    padding: 10px;
    border-bottom: 1px solid #eee;
    animation: fadeIn 0.3s ease-in;
}

.todo-item:last-child {
    border-bottom: none;
}

.todo-text {
    flex: 1;
    margin-left: 10px;
}

.todo-item.completed .todo-text {
    text-decoration: line-through;
    color: #888;
}

.delete-btn {
    background-color: #ff6b6b;
    margin-left: 10px;
    padding: 4px 8px;
    font-size: 14px;
}

.delete-btn:hover {
    background-color: #ff5252;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

footer {
    text-align: center;
    padding: 20px;
    background-color: #f9f9f9;
    color: #777;
    font-size: 14px;
}

@media (max-width: 600px) {
    .container {
        border-radius: 0;
    }
    
    header {
        padding: 20px 15px;
    }
    
    .card {
        padding: 15px;
    }
}