/* ========== 手写签名面板 ========== */
.signature-canvas-wrapper {
    position: relative;
    background: #f0fdf4;
    border: 2px dashed #a7f3d0;
    border-radius: var(--radius);
    overflow: hidden;
    touch-action: none;
    user-select: none;
    -webkit-user-select: none;
}
.signature-canvas-wrapper canvas {
    display: block;
    width: 100%;
    height: 160px;
    cursor: crosshair;
}
.signature-canvas-wrapper .sig-tip {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%,-50%);
    color: var(--gray-300);
    font-size: 18px;
    pointer-events: none;
    transition: opacity .2s;
}
.signature-canvas-wrapper.drawing .sig-tip { opacity: 0; }
.signature-canvas-actions {
    display: flex;
    gap: 10px;
    margin-top: 8px;
}
.signature-canvas-actions .btn { font-size: 13px; padding: 4px 14px; }
.signature-display {
    display: inline-block;
    max-width: 160px;
    max-height: 60px;
    vertical-align: middle;
}