/* Open Button */
.open-btn {
    padding: 16px 30px;
    font-size: 18px;
    border: none;
    border-radius: 12px;
    background: #22c55e;
    color: #fff;
    cursor: pointer;
}

/* Overlay */
#overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.75);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 999;
}

/* Popup */
.popup {
    width: 660px;
    background: #ffffff;
    border-radius: 22px;
    padding: 45px;
    text-align: center;
    position: relative;
    box-shadow: 0 40px 80px rgba(0,0,0,0.35);
}

.popup h1 {
    font-size: 32px;
    margin-bottom: 10px;
}

.popup p {
    color: #475569;
    font-size: 17px;
}

/* Countdown */
.countdown {
    display: flex;
    gap: 20px;
    margin: 35px 0;
}

.time-box {
    flex: 1;
    background: linear-gradient(135deg, #2563eb, #1e40af);
    color: #fff;
    padding: 24px 10px;
    border-radius: 18px;
}

.time-box span {
    display: block;
    font-size: 46px;
    font-weight: 700;
}

.time-box small {
    font-size: 14px;
    letter-spacing: 1px;
}

/* Buttons */
.btn-group {
    display: flex;
    gap: 24px;
    margin-top: 30px;
}

.btn {
    flex: 1;
    padding: 18px;
    font-size: 17px;
    border-radius: 14px;
    border: none;
    cursor: pointer;
    color: #fff;
}

.student {
    background: #0ea5e9;
}

.teacher {
    background: #22c55e;
}

/* Close Button */
.close {
    position: absolute;
    top: 18px;
    right: 22px;
    font-size: 22px;
    cursor: pointer;
    color: #475569;
}
.close:hover {
    color: #dc2626;
}
/* =========================
   MOBILE RESPONSIVE POPUP
========================= */

/* Tablets */
@media (max-width: 768px) {

    .popup {
        width: 92%;
        padding: 30px 22px;
        border-radius: 18px;
    }

    .popup h1 {
        font-size: 26px;
    }

    .popup p {
        font-size: 15px;
    }

    .countdown {
        gap: 12px;
        margin: 25px 0;
    }

    .time-box {
        padding: 18px 8px;
        border-radius: 14px;
    }

    .time-box span {
        font-size: 34px;
    }

    .btn-group {
        gap: 16px;
    }

    .btn {
        padding: 16px;
        font-size: 16px;
    }
}

/* Mobile Phones */
@media (max-width: 480px) {

    .popup {
        width: 95%;
        padding: 24px 18px;
        border-radius: 16px;
    }

    .popup h1 {
        font-size: 22px;
        line-height: 1.3;
    }

    .popup p {
        font-size: 14px;
    }

    /* Stack countdown vertically */
    .countdown {
        flex-direction: column;
        gap: 14px;
    }

    .time-box span {
        font-size: 30px;
    }

    /* Stack buttons */
    .btn-group {
        flex-direction: column;
        gap: 14px;
    }

    .btn {
        width: 100%;
        padding: 16px;
        font-size: 15px;
        border-radius: 12px;
    }

    /* Close button larger for touch */
    .close {
        font-size: 26px;
        top: 14px;
        right: 16px;
    }
}