#formSubmitOverlay {
    position: fixed;
    inset: 0;
    z-index: 99999;
    display: none;
    align-items: center;
    justify-content: center;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
}

#formSubmitOverlay.is-visible {
    display: flex;
}

.form-submit-loading-box {
    background: #fff;
    border-radius: 16px;
    padding: 2rem 2.5rem;
    text-align: center;
    max-width: 320px;
    width: calc(100% - 2rem);
    box-shadow: 0 20px 50px rgba(15, 23, 42, 0.2);
    border: 1px solid #e2e8f0;
}

.form-submit-spinner {
    width: 52px;
    height: 52px;
    margin: 0 auto 1.15rem;
    border: 4px solid #e2e8f0;
    border-top-color: #00D084;
    border-radius: 50%;
    animation: formSubmitSpin 0.75s linear infinite;
}

.form-submit-loading-text {
    margin: 0;
    font-size: 0.95rem;
    font-weight: 600;
    color: #0f172a;
    line-height: 1.45;
}

.form-submit-loading-hint {
    margin: 0.5rem 0 0;
    font-size: 0.8rem;
    color: #64748b;
}

@keyframes formSubmitSpin {
    to { transform: rotate(360deg); }
}