body {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background-color: #f8f9fa;
    font-family: 'IRANSans', sans-serif;
}
.form-signin {
    width: 100%;
    max-width: 340px;
    padding: 15px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05);
}
.form-signin img {
    width: 70px;
    margin-bottom: 20px;
}
.form-signin button {
    font-weight: bold;
}
body {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100vh;
    font-family: 'IRANSans', sans-serif;
    overflow: hidden;
}
body::before {
    content: "";
    position: absolute;
    inset: 0;
    background: inherit; /* از همان تصویر body استفاده می‌کند */
    filter: blur(6px) brightness(0.9);
    transform: scale(1.1);
    z-index: 0;
}
.form-signin {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 340px;
    padding: 20px;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(4px);
    border-radius: 12px;
    box-shadow: 0 0 25px rgba(0, 0, 0, 0.15);
}