style.css

/* Reset default browser styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Body Styling */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #f0f2f5, #c3cfe2);
    color: #333;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    animation: backgroundFade 10s infinite alternate;
}

/* Header Styling with Animation */
.header {
    background-color: #4CAF50;
    width: 100%;
    padding: 20px 0;
    text-align: center;
    color: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    animation: slideDown 1s ease-out;
}

.header h1 {
    font-size: 2.5rem;
    animation: fadeIn 2s ease-in-out;
}

/* Container Styling */
.container {
    width: 90%;
    max-width: 800px;
    margin-top: 30px;
    background: white;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
    animation: popIn 0.5s ease-out;
}

/* Input Section Styling with Animation */
.input-section {
    display: flex;
    flex-direction: column;
    gap: 15px;
    margin-bottom: 25px;
    animation: fadeInUp 1s ease-out;
}

.input-section input {
    padding: 12px 15px;
    font-size: 16px;
    border: 2px solid #ddd;
    border-radius: 8px;
    transition: border-color 0.3s, transform 0.3s;
}

.input-section input:focus {
    border-color: #4CAF50;
    outline: none;
    transform: scale(1.02);
}

/* Buttons Styling with Hover Animations */
.buttons {
    display: flex;
    gap: 15px;
}

.buttons button {
    flex: 1;
    padding: 12px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background 0.3s, transform 0.2s, box-shadow 0.3s;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

#add-todo-btn {
    background-color: #4CAF50;
    color: white;
}

#add-todo-btn:hover {
    background-color: #45a049;
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0,0,0,0.15);
}

#clear-task-list-btn {
    background-color: #f44336;
    color: white;
}

#clear-task-list-btn:hover {
    background-color: #e53935;
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0,0,0,0.15);
}

/* Lists Section Styling with Animation */
.lists-section {
    display: flex;
    flex-direction: column;
    gap: 25px;
    animation: fadeInUp 1s ease-out;
}

.list-container {
    background: #fafafa;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    position: relative;
    overflow: hidden;
    animation: fadeIn 1.5s ease-in;
}

.list-container h2 {
    margin-bottom: 15px;
    color: #555;
    animation: slideInLeft 1s ease-out;
}

ul {
    list-style-type: none;
}

li {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 15px;
    border-bottom: 1px solid #eee;
    background: #fff;
    transition: background 0.3s, transform 0.3s;
    animation: fadeInUp 0.5s ease-out;
}

li:hover {
    background: #f9f9f9;
    transform: translateX(5px);
}

li:last-child {
    border-bottom: none;
}

li.completed {
    text-decoration: line-through;
    color: #888;
    background: #e0ffe0;
    transition: background 0.3s, color 0.3s;
}

/* Todo Text Styling */
li .todo-text {
    flex: 1;
    margin-left: 15px;
    animation: fadeIn 1s ease-in;
}

/* Actions Buttons Styling with Animation */
li .actions button {
    margin-left: 10px;
    background: none;
    border: none;
    cursor: pointer;
    color: #4CAF50;
    font-size: 18px;
    transition: color 0.3s, transform 0.2s;
    animation: fadeIn 1s ease-in;
}

li .actions button:hover {
    color: #388E3C;
    transform: scale(1.2);
}

/* Responsive Design */
@media (min-width: 600px) {
    .lists-section {
        flex-direction: row;
        gap: 30px;
    }

    .list-container {
        width: 50%;
    }
}

/* Keyframe Animations */

/* Background Gradient Animation */
@keyframes backgroundFade {
    0% { background: linear-gradient(135deg, #f0f2f5, #c3cfe2); }
    100% { background: linear-gradient(135deg, #c3cfe2, #f0f2f5); }
}

/* Slide Down Animation for Header */
@keyframes slideDown {
    from { transform: translateY(-100%); }
    to { transform: translateY(0); }
}

/* Fade In Animation */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* Fade In Up Animation */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Slide In Left Animation for Headers */
@keyframes slideInLeft {
    from { opacity: 0; transform: translateX(-20px); }
    to { opacity: 1; transform: translateX(0); }
}

/* Pop In Animation for Container */
@keyframes popIn {
    0% { transform: scale(0.8); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}