From 2ae6bef083f6a922a6c25db3465d93832159706a Mon Sep 17 00:00:00 2001
From: Kuba Orlik <kontakt@kuba-orlik.name>
Date: Fri, 14 Aug 2026 14:01:34 +0200
Subject: [PATCH] Add crossover component

---
 .../jdd-components/crossover/crossover.css    |  5 ++
 .../crossover/crossover.jdd.tsx               | 65 +++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 src/back/jdd-components/crossover/crossover.css
 create mode 100644 src/back/jdd-components/crossover/crossover.jdd.tsx

diff --git a/src/back/jdd-components/crossover/crossover.css b/src/back/jdd-components/crossover/crossover.css
new file mode 100644
index 0000000..4f1c28c
--- /dev/null
+++ b/src/back/jdd-components/crossover/crossover.css
@@ -0,0 +1,5 @@
+.crossover {
+	display: grid;
+	grid-template-columns: subgrid;
+	grid-column: screen !important;
+}
diff --git a/src/back/jdd-components/crossover/crossover.jdd.tsx b/src/back/jdd-components/crossover/crossover.jdd.tsx
new file mode 100644
index 0000000..c1d45aa
--- /dev/null
+++ b/src/back/jdd-components/crossover/crossover.jdd.tsx
@@ -0,0 +1,65 @@
+import { TempstreamJSX } from "tempstream";
+import type {
+	ComponentToHTMLArgs,
+	ExtractStructuredComponentArgumentsParsed,
+	JDDContext,
+} from "@sealcode/jdd";
+import { Component, ComponentArguments } from "@sealcode/jdd";
+
+const component_arguments = {
+	breakpoints_ascending: new ComponentArguments.List(
+		new ComponentArguments.Structured({
+			display_up_to_px: new ComponentArguments.Number(),
+			content: new ComponentArguments.NestedComponent(),
+		})
+	),
+} as const;
+
+export class Crossover extends Component<typeof component_arguments> {
+	getArguments() {
+		return component_arguments;
+	}
+
+	getCSSClumps(
+		jdd_context: JDDContext,
+		args: ExtractStructuredComponentArgumentsParsed<typeof component_arguments>
+	) {
+		const result = (args.breakpoints_ascending || [])
+			.map((breakpoint) => breakpoint.content.getCSSClumps(jdd_context))
+			.flat();
+		return result;
+	}
+
+	async toHTML({
+		args: { breakpoints_ascending },
+		classes,
+		jdd_context,
+	}: ComponentToHTMLArgs<typeof component_arguments>): Promise<string> {
+		const uid = crypto.randomUUID();
+		const id = "id-" + uid;
+		return (
+			<div class={["crossover", `crossover--id-${uid}`, ...classes]} id={id}>
+				{breakpoints_ascending.map((breakpoint) =>
+					breakpoint.content.render(jdd_context)
+				)}
+				{
+					/* HTML */ `<style>
+						${breakpoints_ascending
+								.map(
+									(breakpoint, index) =>
+										`@container (min-width: ${breakpoints_ascending[index - 1]?.display_up_to_px || 0}px) and (max-width: ${breakpoint.display_up_to_px}px){#${id} > *:not(:nth-child(${index + 1})){display: none;}}`
+								)
+								.join("")}
+							@container
+							(min-width: ${breakpoints_ascending.at(-1)
+								?.display_up_to_px}px) {
+							#${id} > * {
+								display: none;
+							}
+						}
+					</style>`
+				}
+			</div>
+		);
+	}
+}