body{
    margin: 0;
    font-family: Arial, sans-serif;

    background-image: url(13.png);
    background-size: cover;       /* أهم سطر */
    background-position: center;   /* يخليها في النص */
    background-repeat: no-repeat;  /* يمنع التكرار */
    background-attachment: fixed;  /* شكل شيك */

    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
}

/* SLIDER */
.slider{
    width: 90%;
    max-width: 900px;
    aspect-ratio: 16 / 9;
    position: relative;
    overflow: hidden;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.slider img{
    width: 100%;
    height: 100%;
    object-fit: cover;
    position: absolute;
    opacity: 0;
    transition: 0.6s ease;
}

.slider img.active{
    opacity: 1;
}

/* number */
.slide-num{
    position: absolute;
    top: 10px;
    left: 10px;
    background: rgba(0,0,0,0.5);
    color: #fff;
    padding: 5px 10px;
    border-radius: 6px;
    font-size: 14px;
    z-index: 2;
}

/* controls */
.slider-controls{
    width: 90%;
    max-width: 900px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 15px;
    gap: 10px;
}

.prev, .next{
    background: #13c2c2;
    color: #fff;
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    flex: 1;
    text-align: center;
    font-weight: bold;
}

.number{
    flex: 2;
    text-align: center;
}

.number ul{
    list-style: none;
    padding: 0;
    margin: 0;
}

.number ul li{
    display: inline-block;
    width: 26px;
    height: 26px;
    line-height: 26px;
    margin: 0 2px;
    background: #ddd;
    border-radius: 4px;
    cursor: pointer;
}

.number ul li.active{
    background: #13c2c2;
}

/* buttons */
button{
    margin-top: 15px;
    padding: 8px 15px;
    width: 200px;
    border: none;
    border-radius: 6px;
    background: #13c2c2;
    color: white;
    cursor: pointer;
    font-weight: bold;
    text-transform: uppercase;
}

/* MOBILE */
@media(max-width: 600px){
    .slider-controls{
        flex-direction: column;
    }

    .prev, .next, .number{
        width: 86%;
    }
}