theme.css

/* Theme Container Styles */
.theme-container {
    position: absolute;
    top: 10px;
    right: 10px;
    display: flex;
    align-items: center; 
    background-color: #fff;
    padding: 10px;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.theme-title {
    margin: 0;
    font-size: 17px;
    color: #333;
    margin-right: 10px; 
}

/* Light Theme */
body.light-mode {
    background-color: #f4f4f4;
    color: #000;
}

#timer.light-mode {
    color: #000;
}

#buttons.light-mode button {
    background-color: #3498db;
    color: #fff;
}

#buttons.light-mode button:disabled {
    background-color: #bdc3c7;
    cursor: not-allowed;
}

ul.light-mode {
    color: #1d3b4f;
}

/* Dark Theme */
body.dark-mode {
    background-color: #1a1b3f;
    color: #fff;
}

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

#buttons.dark-mode button {
    background-color: #3498db;
    color: #fff;
}

#buttons.dark-mode button:disabled {
    background-color: #bdc3c7;
    cursor: not-allowed;
}

ul.clickable.dark-mode {
    color: #fff;
}

/* Toggle Switch Styles */
.switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    -webkit-transition: .4s;
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    -webkit-transition: .4s;
    transition: .4s;
}

input:checked + .slider {
    background-color: #2196F3;
}

input:checked + .slider:before {
    -webkit-transform: translateX(26px);
    -ms-transform: translateX(26px);
    transform: translateX(26px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}