body {
    font-family: 'Roboto', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    padding: 20px;
    box-sizing: border-box;
    transition: background-color 0.3s, color 0.3s;
}

body.light-mode {
    background-color: #f4f4f4;
    color: #333;
}

body.dark-mode {
    background-color: #121212;
    color: #e0e0e0;
}

.container {
    background: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    text-align: center;
    width: 100%;
    max-width: 500px;
    transition: box-shadow 0.3s, background-color 0.3s;
}

.container.light-mode {
    background: #fff;
}

.container.dark-mode {
    background: #1e1e1e;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
}

.container:hover {
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
}

.timer {
    margin: 20px 0;
    font-size: 48px;
    color: #333;
    transition: color 0.3s;
}

.timer.light-mode {
    color: #333;
}

.timer.dark-mode {
    color: #e0e0e0;
}

.controls button {
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    background-color: #007bff;
    color: #fff;
    transition: background-color 0.3s;
}

.controls button:hover {
    background-color: #0056b3;
}

.controls button.light-mode {
    background-color: #007bff;
}

.controls button.light-mode:hover {
    background-color: #0056b3;
}

.controls button.dark-mode {
    background-color: #1976d2;
}

.controls button.dark-mode:hover {
    background-color: #1565c0;
}

.task-manager {
    margin-top: 20px;
}

#task-input {
    padding: 10px;
    width: 80%;
    margin-right: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 16px;
    transition: border-color 0.3s, background-color 0.3s;
}

#task-input.light-mode {
    border-color: #ccc;
    background-color: #fff;
    color: #333;
}

#task-input.dark-mode {
    border-color: #616161;
    background-color: #212121;
    color: #e0e0e0;
}

#add-task {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    background-color: #28a745;
    color: #fff;
    transition: background-color 0.3s;
}

#add-task:hover {
    background-color: #218838;
}

#add-task.light-mode {
    background-color: #28a745;
}

#add-task.light-mode:hover {
    background-color: #218838;
}

#add-task.dark-mode {
    background-color: #388e3c;
}

#add-task.dark-mode:hover {
    background-color: #2e7d32;
}

#task-list {
    list-style: none;
    padding: 0;
    margin: 10px 0;
}

#task-list li {
    background: #f9f9f9;
    padding: 10px;
    margin: 5px 0;
    border: 1px solid #ddd;
    border-radius: 5px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.3s, border-color 0.3s;
}

#task-list li.light-mode {
    background: #f9f9f9;
    border-color: #ddd;
}

#task-list li.light-mode:hover {
    background: #e9e9e9;
}

#task-list li.dark-mode {
    background: #303030;
    border-color: #424242;
}

#task-list li.dark-mode:hover {
    background: #424242;
}

#task-list li button {
    background: none;
    border: none;
    cursor: pointer;
    color: #007bff;
    font-size: 14px;
    transition: color 0.3s;
}

#task-list li button:hover {
    color: #0056b3;
}

#task-list li button.light-mode {
    color: #007bff;
}

#task-list li.button.light-mode:hover {
    color: #0056b3;
}

#task-list li button.dark-mode {
    color: #2196f3;
}

#task-list li button.dark-mode:hover {
    color: #1976d2;
}

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

.container, .controls button, #add-task, #task-list li {
    animation: fadeIn 0.5s ease-in-out;
}

/* Theme Toggle Button */
.theme-toggle {
    margin-bottom: 20px;
    text-align: right;
}

#theme-toggle {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    background-color: #007bff;
    color: #fff;
    transition: background-color 0.3s;
}

#theme-toggle:hover {
    background-color: #0056b3;
}

#theme-toggle.light-mode {
    background-color: #007bff;
}

#theme-toggle.light-mode:hover {
    background-color: #0056b3;
}

#theme-toggle.dark-mode {
    background-color: #28a745;
}

#theme-toggle.dark-mode:hover {
    background-color: #218838;
}