body {
    font-family: Arial, sans-serif;
    background-color: white;
    background-image: url(Assets/os.png);
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-size: cover;
}
.navbar {
    position: fixed;
    bottom: 0;
    width: 100%;
    background: lightgrey;
    padding: 10px;
    display: flex;
    align-items: left;
}
.start-menu {
    position: fixed;
    bottom: -200px;
    left: 10px;
    width: 250px;
    background: rgba(201, 201, 201, 0.95);
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.5);
    display: none;
    text-align: center;
    transition: bottom 0.3s ease-in-out;
}
.popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 300px;
    background: white;
    padding: 15px;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
    display: none;
    text-align: center;
}
.button {
    display: block;
    margin: 10px auto;
    padding: 10px;
    background: #007BFF;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    text-align: centre;
    font-weight: bold;
    width: 90%;
}
.btn {
    display: block;
    margin: 1px;
    padding: 10px;
    background: #007BFF;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    text-align: centre;
    font-weight: bold;
    width: 7%;
    margin-right: 95%;
}
.button:hover, .btn:hover {
    background: #0056b3;
}
.dark-theme {
    background-color: rgb(77, 77, 77);
    color: white;
}
.dark-theme .popup {
    background-color: gray;
    color: white;
}
.dark-theme .navbar, .dark-theme .start-menu{
    background-color: rgb(37, 37, 37);
    color: white;
}
.close {
    margin-left: 90%;
    border-radius: 50%;
    background-color: red;
    border: 1px solid black;
    transition: 0.3s;
}
.close:hover{
    background-color: rgb(202, 0, 0);
    cursor: pointer;
}
a {color: rgb(0, 173, 173);}
#num1 {margin-bottom: 5px;}
.ico {width: 200px;}

@media screen and (max-width: 800px){
    .btn {
        display: block;
        margin: 1px;
        padding: 10px;
        background: #007BFF;
        color: white;
        border: none;
        border-radius: 5px;
        cursor: pointer;
        text-align: centre;
        font-weight: bold;
        width: 24%;
        margin-right: 76%;
    }
}
body {
    background-color: black;
    background-repeat: round;
}