/* Base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

:root {
    --primary-color: #4e54c8;
    --primary-light: #8f94fb;
    --accent-color: #ff6b6b;
    --text-color: #333;
    --text-light: #777;
    --bg-color: #f9f9f9;
    --card-bg: #ffffff;
    --border-color: #eaeaea;
    --success-color: #4caf50;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    --transition: all 0.3s ease;
}

body {
    background: linear-gradient(135deg, var(--primary-light), var(--primary-color));
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    color: var(--text-color);
}

.container {
    background-color: var(--card-bg);
    border-radius: 12px;
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 550px;
    padding: 30px;
    margin-bottom: 20px;
}

header {
    text-align: center;
    margin-bottom: 25px;
}

h1 {
    color: var(--primary-color);
    margin-bottom: 5px;
    font-size: 32px;
    font-weight: 600;
}

.subtitle {
    color: var(--text-light);
    font-size: 14px;
}

/* Input styles */
.todo-input {
    display: flex;
    margin-bottom: 25px;
}

#task-input {
    flex: 1;
    padding: 14px 18px;
    border: 1px solid var(--border-color);
    border-radius: 8px 0 0 8px;
    font-size: 16px;
    outline: none;
    transition: var(--transition);
}

#task-input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(78, 84, 200, 0.1);
}

#add-task-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0 20px;
    border-radius: 0 8px 8px 0;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
}

#add-task-btn:hover {
    background-color: var(--primary-light);
}

#add-task-btn i {
    font-size: 14px;
}

/* Filter buttons */
.filters {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
    gap: 10px;
}

.filter-btn {
    background-color: transparent;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 8px 16px;
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
}

.filter-btn:hover {
    background-color: rgba(78, 84, 200, 0.05);
}

.filter-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* Task list container */
.todo-list-container {
    min-height: 200px;
    position: relative;
}

/* Empty state */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 0;
    color: var(--text-light);
    text-align: center;
}

.empty-state i {
    font-size: 48px;
    margin-bottom: 15px;
    color: var(--border-color);
}

.empty-state p {
    font-size: 16px;
}

/* Task list styles */
#task-list {
    list-style-type: none;
    margin-bottom: 20px;
}

.task-item {
    display: flex;
    align-items: center;
    padding: 14px 0;
    border-bottom: 1px solid var(--border-color);
    animation: fadeIn 0.4s ease;
    transition: var(--transition);
}

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

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

.task-checkbox-container {
    margin-right: 15px;
    position: relative;
}

.task-checkbox {
    appearance: none;
    -webkit-appearance: none;
    width: 22px;
    height: 22px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.task-checkbox:checked {
    border-color: var(--success-color);
    background-color: var(--success-color);
}

.task-checkbox:checked::after {
    content: '\f00c';
    font-family: 'Font Awesome 5 Free';
    font-weight: 900;
    color: white;
    font-size: 12px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.task-text {
    flex: 1;
    font-size: 16px;
    color: var(--text-color);
    transition: var(--transition);
    word-break: break-word;
}

.completed .task-text {
    text-decoration: line-through;
    color: var(--text-light);
}

.task-actions {
    display: flex;
    gap: 10px;
}

.delete-btn {
    background-color: transparent;
    color: var(--accent-color);
    border: none;
    cursor: pointer;
    font-size: 18px;
    opacity: 0.7;
    transition: var(--transition);
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.delete-btn:hover {
    opacity: 1;
    background-color: rgba(255, 107, 107, 0.1);
}

/* Stats and clear button */
.todo-stats {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 15px;
    border-top: 1px solid var(--border-color);
    font-size: 14px;
    color: var(--text-light);
}

#clear-completed {
    background-color: transparent;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
}

#clear-completed:hover {
    color: var(--accent-color);
}

/* Footer */
footer {
    color: rgba(255, 255, 255, 0.8);
    text-align: center;
    font-size: 14px;
    margin-top: 10px;
}

/* Responsive adjustments */
@media (max-width: 600px) {
    .container {
        padding: 20px;
        border-radius: 8px;
    }
    
    h1 {
        font-size: 26px;
    }
    
    #task-input, #add-task-btn {
        padding: 12px;
        font-size: 14px;
    }
    
    .task-text {
        font-size: 14px;
    }
    
    .empty-state i {
        font-size: 36px;
    }
    
    .empty-state p {
        font-size: 14px;
    }
}

/* Animations */
@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.task-item.deleting {
    opacity: 0;
    transform: translateX(30px);
}

.task-item.completing .task-checkbox {
    animation: pulse 0.3s;
}