/* 登录 / 注册页 — 主按钮动效 */

.portal-auth {
    --motion-ease: cubic-bezier(0.22, 1, 0.36, 1);
}

.portal-auth .btn {
    position: relative;
    overflow: hidden;
    transition:
        transform 0.22s var(--motion-ease),
        box-shadow 0.22s var(--motion-ease),
        filter 0.2s ease,
        opacity 0.15s ease;
}

.portal-auth .btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(
        105deg,
        transparent 38%,
        rgba(255, 255, 255, 0.22) 50%,
        transparent 62%
    );
    transform: translateX(-130%);
    transition: transform 0.55s var(--motion-ease);
    pointer-events: none;
}

.portal-auth .btn:hover {
    transform: translateY(-2px);
    box-shadow:
        0 10px 28px rgba(0, 176, 240, 0.35),
        0 4px 12px rgba(240, 96, 0, 0.2);
    filter: brightness(1.06);
}

.portal-auth .btn:hover::before {
    transform: translateX(130%);
}

.portal-auth .btn:active {
    transform: translateY(0) scale(0.98);
    box-shadow: 0 4px 14px rgba(0, 176, 240, 0.25);
    filter: brightness(0.98);
}

.portal-auth .btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
}

.portal-captcha-row {
    display: flex;
    align-items: stretch;
    gap: 10px;
    margin-top: 0;
}

.portal-captcha-row input {
    flex: 1;
    min-width: 0;
    margin-top: 0;
}

.portal-captcha-img-btn {
    flex-shrink: 0;
    padding: 0;
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    background: rgba(0, 0, 0, 0.12);
    cursor: pointer;
    overflow: hidden;
    line-height: 0;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.portal-captcha-img-btn:hover {
    border-color: rgba(0, 176, 240, 0.55);
    box-shadow: 0 4px 14px rgba(0, 176, 240, 0.2);
}

.portal-captcha-img-btn:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.portal-captcha-img {
    display: block;
    width: 128px;
    height: 44px;
    border-radius: 11px;
}

@media (prefers-reduced-motion: reduce) {
    .portal-auth .btn,
    .portal-auth .btn::before,
    .portal-invite-promo {
        transition: none;
        animation: none;
    }

    .portal-auth .btn:hover {
        transform: none;
    }
}