.captcha-img { border-radius: 6px; background: #6EC4F0; max-width: 100%; height: auto; user-select: none; }
.captcha-refresh {
    width: 44px; height: 44px; flex: 0 0 44px; border-radius: 50%; border: none;
    background: linear-gradient(180deg, #5BC0F8, #1E88E5); color: #fff; font-size: 1.4rem;
    display: inline-flex; align-items: center; justify-content: center;
    box-shadow: 0 2px 6px rgba(30, 136, 229, 0.45); transition: transform .3s;
}
.captcha-refresh:hover { transform: rotate(180deg); }
.captcha-input { max-width: 280px; letter-spacing: 4px; font-weight: 600; text-transform: uppercase; }
.captcha-input::placeholder { letter-spacing: normal; font-weight: normal; text-transform: none; }