/* ---------- BODY AUTH + BACKGROUND IMAGE ---------- */
body.auth-body {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

    body.auth-body::before {
        content: "";
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: url('/Content/images/nen_dnk.jpg') no-repeat center center;
        background-size: cover;
        filter: blur(8px) brightness(0.7);
        z-index: -1;
    }

/* ---------- FORM CONTAINER ---------- */
.auth-form-container {
    width: 95%;
    max-width: 800px; /* tăng rộng tối đa */
    background: rgba(255, 255, 255, 0.95);
    padding: 50px ; /* tăng padding cho cảm giác rộng hơn */
    border-radius: 14px;
    box-shadow: 0 12px 30px rgba(0,0,0,0.25);
    animation: fadeInUp 0.8s ease forwards;
    opacity: 0;
}

/* ---------- CONTAINER FORM ---------- */
.auth-container {
    max-width: 1000px;
    margin: 60px auto;
    padding: 40px 50px;
    background-color: rgba(248, 249, 250, 0.95); /* nhẹ, trong suốt */
    border-radius: 14px;
    box-shadow: 0 12px 30px rgba(0,0,0,0.2);
    animation: fadeInUp 0.8s ease forwards;
    opacity: 0;
}

    .auth-container:hover {
        box-shadow: 0 15px 40px rgba(0, 0, 0, 0.3);
    }

    .auth-container h2 {
        color: #ffc107;
        font-weight: 700;
        margin-bottom: 35px;
        text-align: center;
    }

/* ---------- FORM INPUT ---------- */
.input-group .form-control {
    border-radius: 0.6rem;
    transition: all 0.3s ease;
    border: 1px solid #ddd;
    box-shadow: inset 0 0 0 rgba(0,0,0,0);
    padding: 12px 14px;
}

    .input-group .form-control:focus {
        border-color: #ffc107;
        box-shadow: 0 0 10px rgba(255, 193, 7, 0.6);
        outline: none;
    }

/* ---------- INPUT ICON ---------- */
.input-group-text {
    background-color: #ffc107;
    border: none;
    color: #fff;
    transition: all 0.3s ease;
}

    .input-group-text i {
        transition: transform 0.3s ease;
    }

.input-group .form-control:focus + .input-group-text i,
.input-group .form-control:focus ~ .input-group-text i {
    transform: rotate(20deg) scale(1.2);
}

/* ---------- BUTTON ---------- */
.btn-warning {
    transition: all 0.3s ease;
}

    .btn-warning:hover {
        background-color: #e0a800;
        transform: translateY(-3px) scale(1.02);
        box-shadow: 0 6px 18px rgba(0,0,0,0.25);
    }

.btn-secondary {
    transition: all 0.3s ease;
}

    .btn-secondary:hover {
        background-color: #6c757d;
        transform: translateY(-2px);
        box-shadow: 0 5px 15px rgba(0,0,0,0.2);
    }

/* ---------- POPUP THÔNG BÁO ---------- */
#popup-message {
    min-width: 300px;
    border-radius: 10px;
    padding: 14px 20px;
    font-weight: 500;
    box-shadow: 0 6px 18px rgba(0,0,0,0.25);
}

/* ---------- ANIMATION ---------- */
section.auth-container {
    animation: fadeInUp 0.8s ease forwards;
    opacity: 0;
}

@keyframes fadeInUp {
    0% {
        opacity: 0;
        transform: translateY(25px);
    }

    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ---------- RESPONSIVE ---------- */
@media (max-width: 768px) {
    .auth-container {
        padding: 35px 30px;
        margin: 40px 20px;
    }
}

@media (max-width: 576px) {
    .auth-container {
        padding: 25px 20px;
        margin: 20px 15px;
    }
}
.back-btn-top-left {
    position: fixed;
    top: 20px; /* cách mép trên 20px */
    left: 20px; /* cách mép trái 20px */
    font-size: 1.8rem;
    color: #ffc107;
    z-index: 9999;
    text-decoration: none;
    background: rgba(0,0,0,0.3);
    padding: 8px 12px;
    border-radius: 8px;
    transition: all 0.3s ease;
}

    .back-btn-top-left:hover {
        color: #fff;
        background: rgba(0,0,0,0.5);
        transform: scale(1.1);
    }