.modal-box {
    background: white;
    border-radius: 12px;
    width: 90%;
    max-width: 400px;
    overflow: hidden;   /* keeps header's rounded corners clean */
}

.modal-header {
    display: flex;
    justify-content: space-between;   /* title left, close button right */
    align-items: center;
    padding: 16px;
    border-bottom: 1px solid #eee;
    background-color: rgb(182, 182, 182);
}

.modal-title {
    margin: 0;
    font-size: 18px;
}

.modal-close-btn {
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
}

.modal-body {
    padding: 16px;
}

.modal-footer {
    padding: 12px 16px;
    border-top: 1px solid #eee;
    display: flex;
    justify-content: center;
}

.modal-overlay {
    display: flex;             /* becomes flex only when JS sets display, but flex here is the "on" state */
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    align-items: center;
    justify-content: center;
    z-index: 1000;
}