.modal .captcha-wrapper {
    text-align: center;
}
.modal .captcha-box {
    position: relative;
    width: 500px;
    height: 330px;  /* 与图片高度一致 */
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    cursor: crosshair;
    background: #fff;
}
.modal .captcha-box img, .captcha-box canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    user-select: none;
    touch-action: none;
}
.modal .btn-panel {
    margin-top: 15px;
}

.modal button:active { background: #1976D2; }
.modal button:disabled { background: #aaa; cursor: not-allowed; }
.modal .message {
    margin-top: 10px;
    color: #333;
    font-weight: bold;
    min-height: 20px;
}
/* 备用提示文字（若图片未绘制时显示） */
.modal .hint-text {
    font-size: 13px;
    color: #555;
    margin-top: 5px;
}

.modal .btn{
    min-width: 100px; /* 保证倒计时显示时不跳动 */
}