#signupOverlay.auth-overlay {
    position: fixed;
    inset: 0;
    display: none;
    z-index: 2000;
}
#signupOverlay.auth-overlay.show {
    display: block;
}
#signupOverlay .auth-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(10, 10, 10, 0.75);
    backdrop-filter: blur(6px);
}
#signupOverlay .auth-popup {
    position: relative;
    max-width: 480px;
    margin: 8% auto;
    background: rgba(0, 0, 0, 0.9);
    border: 1px solid rgba(0, 255, 255, 0.4);
    box-shadow: 0 0 24px rgba(0, 255, 255, 0.35);
    border-radius: 16px;
    padding: 24px;
    color: #fff;
}
#signupOverlay .auth-close {
    position: absolute;
    top: 10px;
    right: 12px;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: 1px solid rgba(0, 255, 255, 0.5);
    background: rgba(0, 0, 0, 0.6);
    color: #00ffff;
}
#signupOverlay .auth-header {
    margin-bottom: 16px;
}
#signupOverlay .auth-title {
    font-size: 1.6rem;
    margin: 0 0 6px 0;
}
#signupOverlay .auth-subtitle {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.8);
}
#signupOverlay .auth-field {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 14px;
}
#signupOverlay .auth-field input {
    padding: 10px 12px;
    background: rgba(0, 0, 0, 0.7);
    border: 1px solid rgba(0, 255, 255, 0.4);
    border-radius: 10px;
    color: #fff;
}
#signupOverlay .auth-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 8px;
}