* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    font-family: Arial, sans-serif;
    background-color: #f5f5f5;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}
.container {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 500px;
    padding: 30px;
}
h1 {
    color: #333;
    margin-bottom: 25px;
    text-align: center;
    font-size: 24px;
}
.input-section {
    display: flex;
    gap: 10px;
    margin-bottom: 25px;
}
#todoInput {
    flex: 1;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 14px;
}
#todoInput:focus {
    outline: none;
    border-color: #999;
}
#addBtn {
    padding: 12px 20px;
    background: #333;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
}
#addBtn:hover {
    background: #555;
}
.filters {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    justify-content: center;
}
.filter-btn {
    padding: 8px 16px;
    border: 1px solid #ddd;
    background: white;
    color: #333;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
}
.filter-btn.active {
    background: #333;
    color: white;
    border-color: #333;
}
.filter-btn:hover {
    background: #f0f0f0;
}
.filter-btn.active:hover {
    background: #555;
}
#todoList {
    list-style: none;
}
.todo-item {
    background: #fafafa;
    padding: 15px;
    margin-bottom: 10px;
    border-radius: 4px;
    display: flex;
    align-items: center;
    gap: 12px;
    border: 1px solid #eee;
}
.todo-item:hover {
    background: #f0f0f0;
}
.todo-item.completed {
    opacity: 0.6;
}
.todo-item.completed .todo-text {
    text-decoration: line-through;
    color: #999;
}
.todo-checkbox {
    width: 18px;
    height: 18px;
    cursor: pointer;
}
.todo-text {
    flex: 1;
    font-size: 14px;
    color: #333;
}
.delete-btn {
    padding: 6px 12px;
    background: #666;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 13px;
}
.delete-btn:hover {
    background: #888;
}
.stats {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #eee;
    text-align: center;
    color: #666;
    font-size: 14px;
}
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: #999;
}
.empty-state svg {
    width: 80px;
    height: 80px;
    margin-bottom: 15px;
    opacity: 0.3;
}
.empty-state p {
    font-size: 14px;
}