GlassIslands

// 回归目标：一个节点同时挂 ext.glass(backdrop_blur) 与 overflow_hidden +
// corner_radius（effect 链 backdrop_blur -> rounded_clip，两个 requires_offscreen）
// 时，同帧存在两个这样的节点 -> 后画节点的内容整体不可见（内容命令没落进
// 自己的 layer 作用域，玻璃背板合成盖在其上）。下游应用 Sidebar+Inspector 实拍。
pub fn buildGlassIslands(scope: *ui.Scope, cx: *ui.Cx) anyerror!*ui.Node {
    _ = scope;
    const a = cx.allocator;
    const c = try col(cx, 12);
    try c.appendChild(a, try label(cx, "Two blur+rounded-clip islands: BOTH must show their content"));

    const bd = try glassBackdrop(cx, 420);
    // 高频黑白条纹靶压在 first 岛左边缘正下方（islands_row padding 24 -> 岛左缘
    // x=24）：gi=0 承诺"仅 blur"，blur(24) 把 8px 周期条纹平均成灰；rim 区若仍
    // sharp 回退（glass.metal rim_sharp 漏 gi 门控的回归），岛左缘 8px 带会清晰
    // 透出近黑条纹，e2e 按 rim/参照带 darkest pixel 差分断言。单条宽黑条不行：
    // 黑条自身 blur 后也偏暗，sharp/blur 只差 ~25 灰阶，抓不住变异。
    const rim_probe = try ui.box(cx, .{
        .position = .absolute,
        .width = .{ .px = 32 },
        .height = .{ .grow = .{} },
        .direction = .row,
        .background = ui.Color.rgba(250, 250, 252, 255),
        .gap = 4,
    }, .{});
    (try rim_probe.style.ensureExtFallible(a)).inset = .{ .left = .{ .px = 10 }, .top = .{ .px = 0 } };
    for (0..4) |_| {
        try rim_probe.appendChild(a, try ui.box(cx, .{
            .width = .{ .px = 4 },
            .height = .{ .grow = .{} },
            .background = ui.Color.rgba(4, 4, 6, 255),
        }, .{}));
    }
    try bd.appendChild(a, rim_probe);
    const islands_row = try ui.box(cx, .{
        .position = .absolute,
        .width = .{ .grow = .{} },
        .height = .{ .grow = .{} },
        .direction = .row,
        .justify = .space_between,
        .padding = ui.Padding.all(24),
    }, .{});
    inline for (.{ "first", "second" }) |name| {
        const island = try ui.box(cx, .{
            .width = .{ .px = 220 },
            .height = .{ .px = 320 },
            .direction = .column,
            .gap = 10,
            .padding = ui.Padding.all(16),
            // alpha 40：底色再低一档，rim-band 像素断言需要黑条 sharp/blur 的
            // 对比窗口（96 时 37% 白把 sharp 黑抬到 ~160、blur ~190，抓不住回归）
            .background = ui.Color.rgba(255, 255, 255, 40),
            .border = .{ .width = 1, .color = ui.Color.rgba(255, 255, 255, 140), .radius = 12 },
            .overflow_hidden = true,
        }, .{});
        const ext = try island.style.ensureExtFallible(a);
        ext.corner_radius = ui.CornerRadius.uniform(12);
        ext.glass = .{ .backdrop_blur = 24, .glass_intensity = 0 };
        island.meta.ownership.meta.test_id = "story.glassislands." ++ name;

        try island.appendChild(a, try ui.text(cx, "Island " ++ name, .{
            .font_size = 15,
            .font_weight = 700,
            .color = ui.Color.rgba(20, 20, 28, 255),
        }));
        // 深色内容块：e2e 像素断言的靶（内容丢失 bug 下这里只剩白玻璃底）
        const slab = try ui.box(cx, .{
            .width = .{ .grow = .{} },
            .height = .{ .px = 120 },
            .background = ui.Color.rgba(24, 28, 40, 255),
        }, .{});
        (try slab.style.ensureExtFallible(a)).corner_radius = ui.CornerRadius.uniform(8);
        slab.meta.ownership.meta.test_id = "story.glassislands." ++ name ++ ".slab";
        try island.appendChild(a, slab);
        try island.appendChild(a, try ui.text(cx, "content below the slab", .{
            .font_size = 12,
            .color = ui.Color.rgba(40, 44, 56, 255),
        }));
        try islands_row.appendChild(a, island);
    }
    try bd.appendChild(a, islands_row);
    try c.appendChild(a, bd);
    return c;
}