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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f7fc;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    padding: 20px;
}

.app-container {
    width: 100%;
    max-width: 600px;
    background-color: #ffffff;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    padding: 30px;
}

.header h1 {
    color: #2c3e50;
    text-align: center;
    margin-bottom: 20px;
}

.task-form {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
}

.task-input {
    flex-grow: 1; 
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    font-size: 16px;
}

.task-input:focus {
    outline: none;
    border-color: #e74c3c;
}

.add-button {
    padding: 0 20px;
    background-color: #e74c3c;
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.add-button:hover {
    background-color: #c0392b;
}

.task-list {
    list-style: none;
}

.task-item {
    display: flex;
    align-items: center;
    padding: 15px 10px;
    border-bottom: 1px solid #eee;
    transition: background-color 0.2s;
}

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

.footer {
    margin-top: 30px;
    text-align: center;
}

.filters .filter-btn {
    background: none;
    border: 1px solid transparent;
    color: #777;
    margin: 0 5px;
    padding: 5px 10px;
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.3s ease;
}

.filters .filter-btn:hover {
    color: #333;
    background-color: #f0f0f0;
}

.filters .filter-btn.active {
    border-color: #e74c3c;
    color: #e74c3c;
}

.task-item .task-text {
    flex-grow: 1;
    margin-right: 15px;
}

.task-item.completed .task-text {
    text-decoration: line-through;
    color: #aaa;
}

.task-actions {
    display: flex;
    align-items: center;
    gap: 15px;
}

.delete-button {
    background: none;
    border: none;
    color: #aaa;
    cursor: pointer;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 0.3s ease;
}

.delete-button:hover {
    color: #e74c3c;
}

.task-checkbox {
    -webkit-appearance: none;
    appearance: none;
    background-color: transparent;
    margin: 0;
    font: inherit;
    color: currentColor;
    width: 22px;
    height: 22px;
    border: 2px solid #ccc;
    border-radius: 4px;
    transform: translateY(-0.075em);
    display: grid;
    place-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
}

.task-checkbox::before {
    content: "";
    width: 12px;
    height: 12px;
    transform: scale(0);
    transition: 120ms transform ease-in-out;
    box-shadow: inset 1em 1em #4a90e2;
    clip-path: polygon(14% 44%, 0 65%, 50% 100%, 100% 16%, 80% 0%, 43% 62%);
}

.task-checkbox:checked {
    border-color: #e74c3c;
}

.task-checkbox:checked::before {
    transform: scale(1);
    box-shadow: inset 1em 1em #e74c3c;
}