body {
    font-family: system-ui, -apple-system, sans-serif;
    background-color: #f4f4f5;
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
}

#app-container {
    background: white;
    width: 100%;
    max-width: 500px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    padding: 20px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #e4e4e7;
    padding-bottom: 10px;
    margin-bottom: 20px;
}

.hidden {
    display: none !important;
}

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

input[type="text"] {
    flex: 1;
    padding: 10px;
    border: 1px solid #d4d4d8;
    border-radius: 4px;
}

button {
    padding: 10px 15px;
    background-color: #000;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

button:hover {
    background-color: #333;
}

ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px;
    border-bottom: 1px solid #f4f4f5;
}

li.completed span {
    text-decoration: line-through;
    color: #a1a1aa;
}

.task-actions button {
    margin-left: 5px;
    font-size: 12px;
    padding: 5px 10px;
}

.delete-btn {
    background-color: #ef4444;
}

.delete-btn:hover {
    background-color: #dc2626;
}