html, body {
  min-height: 100vh;              /* کل ارتفاع صفحه */
  margin: 0;                 /* حذف فاصله‌های پیش‌فرض */
  padding: 0;                /* حذف فاصله‌های پیش‌فرض */
  overflow: hidden;
}
body {
    font-family: 'vazir', Lalezar;
    color: white;
    background: 
    linear-gradient(rgba(0,0,0,0.3), rgba(0,0,0,0.3)), 
    url('../assets/images/background.jpg');
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center;
}
h1, h2, h5 {
    text-align: center;  
}
.center-container {
    display: flex;
    flex-direction: column;   /* عناصر زیر هم قرار بگیرند */
    justify-content: center;
    align-items: center;
    height: 100vh;
    text-align: center;
}

.download-text {
    color: white;
    font-family: 'vazir', Lalezar;
    font-size: 20px;
    margin-bottom: 20px;      /* فاصله از دکمه */
}

.download-btn {
    display: inline-block;
    padding: 15px 30px;
    background: linear-gradient(45deg, #ff9800, #ff5722);
    color: white;
    font-size: 18px;
    font-family: 'vazir', Lalezar;
    text-decoration: none;
    border-radius: 40px;
    box-shadow: 0 6px 15px rgba(0,0,0,0.4);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.download-btn:hover {
    transform: scale(1.08);
    box-shadow: 0 8px 20px rgba(0,0,0,0.6);
    background: linear-gradient(45deg, #ff5722, #e64a19);
}

@media (max-width: 768px) {
    body {
        background: 
            linear-gradient(rgba(0,0,0,0.3), rgba(0,0,0,0.3)), 
            url('../assets/images/background-mobile.jpg');
        background-repeat: no-repeat;
        background-size: cover;
        background-position: center;
    }
}