Improve web-ui message and tool UX

- Add collapsible thinking blocks with shimmer animation during streaming
- Update user messages to use orange gradient pill styling (matching sitegeist)
- Fix cost display to only show for completed messages, not while streaming
- Update tool renderers to use ChevronsUpDown/ChevronUp icons instead of rotating ChevronRight
- Export ThinkingBlock component from public API

packages/web-ui/src/app.css

@@ -42,3 +42,26 @@ body {
 .fixed.inset-0 button[type="button"] {
 	cursor: pointer;
 }
+
+/* Shimmer animation for thinking text */
+@keyframes shimmer {
+	0% {
+		background-position: -200% 0;
+	}
+	100% {
+		background-position: 200% 0;
+	}
+}
+
+.animate-shimmer {
+	animation: shimmer 2s ease-in-out infinite;
+}
+
+/* User message with fancy pill styling */
+.user-message-container {
+	transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
+	position: relative;
+	background: linear-gradient(135deg, rgba(217, 79, 0, 0.12), rgba(255, 107, 0, 0.12), rgba(212, 165, 0, 0.12));
+	border: 1px solid rgba(255, 107, 0, 0.25);
+	backdrop-filter: blur(10px);
+}

packages/web-ui/src/components/MessageList.ts

@@ -65,7 +65,7 @@ export class MessageList extends LitElement {
 					template: html`<assistant-message
 						.message=${amsg}
 						.tools=${this.tools}
-						.isStreaming=${this.isStreaming}
+						.isStreaming=${false}
 						.pendingToolCalls=${this.pendingToolCalls}
 						.toolResultsById=${resultByCallId}
 						.hideToolCalls=${false}

packages/web-ui/src/components/Messages.ts

@@ -12,6 +12,7 @@ import { renderTool } from "../tools/index.js";
 import type { Attachment } from "../utils/attachment-utils.js";
 import { formatUsage } from "../utils/format.js";
 import { i18n } from "../utils/i18n.js";
+import "./ThinkingBlock.js";
 
 export type UserMessageWithAttachments = UserMessageType & { attachments?: Attachment[] };
 
@@ -62,19 +63,21 @@ export class UserMessage extends LitElement {
 				: this.message.content.find((c) => c.type === "text")?.text || "";
 
 		return html`
-			<div class="py-2 px-4 border-l-4 border-accent-foreground/60 text-primary-foreground">
+			<div class="flex justify-start ml-4">
-				<markdown-block .content=${content}></markdown-block>
+				<div class="user-message-container py-2 px-4 rounded-xl">
-				${
+					<markdown-block .content=${content}></markdown-block>
-					this.message.attachments && this.message.attachments.length > 0
+					${
-						? html`
+						this.message.attachments && this.message.attachments.length > 0
-							<div class="mt-3 flex flex-wrap gap-2">
+							? html`
-								${this.message.attachments.map(
+								<div class="mt-3 flex flex-wrap gap-2">
-									(attachment) => html` <attachment-tile .attachment=${attachment}></attachment-tile> `,
+									${this.message.attachments.map(
-								)}
+										(attachment) => html` <attachment-tile .attachment=${attachment}></attachment-tile> `,
-							</div>
+									)}
-						`
+								</div>
-						: ""
+							`
-				}
+							: ""
+					}
+				</div>
 			</div>
 		`;
 	}
@@ -107,7 +110,9 @@ export class AssistantMessage extends LitElement {
 			if (chunk.type === "text" && chunk.text.trim() !== "") {
 				orderedParts.push(html`<markdown-block .content=${chunk.text}></markdown-block>`);
 			} else if (chunk.type === "thinking" && chunk.thinking.trim() !== "") {
-				orderedParts.push(html` <markdown-block .content=${chunk.thinking} .isThinking=${true}></markdown-block> `);
+				orderedParts.push(
+					html`<thinking-block .content=${chunk.thinking} .isStreaming=${this.isStreaming}></thinking-block>`,
+				);
 			} else if (chunk.type === "toolCall") {
 				if (!this.hideToolCalls) {
 					const tool = this.tools?.find((t) => t.name === chunk.name);
@@ -133,7 +138,7 @@ export class AssistantMessage extends LitElement {
 			<div>
 				${orderedParts.length ? html` <div class="px-4 flex flex-col gap-3">${orderedParts}</div> ` : ""}
 				${
-					this.message.usage
+					this.message.usage && !this.isStreaming
 						? this.onCostClick
 							? html` <div class="px-4 mt-2 text-xs text-muted-foreground cursor-pointer hover:text-foreground transition-colors" @click=${this.onCostClick}>${formatUsage(this.message.usage)}</div> `
 							: html` <div class="px-4 mt-2 text-xs text-muted-foreground">${formatUsage(this.message.usage)}</div> `

packages/web-ui/src/components/ThinkingBlock.ts

@@ -0,0 +1,43 @@
+import { icon } from "@mariozechner/mini-lit";
+import { html, LitElement } from "lit";
+import { customElement, property, state } from "lit/decorators.js";
+import { ChevronRight } from "lucide";
+
+@customElement("thinking-block")
+export class ThinkingBlock extends LitElement {
+	@property() content!: string;
+	@property({ type: Boolean }) isStreaming = false;
+	@state() private isExpanded = false;
+
+	protected override createRenderRoot(): HTMLElement | DocumentFragment {
+		return this;
+	}
+
+	override connectedCallback(): void {
+		super.connectedCallback();
+		this.style.display = "block";
+	}
+
+	private toggleExpanded() {
+		this.isExpanded = !this.isExpanded;
+	}
+
+	override render() {
+		const shimmerClasses = this.isStreaming
+			? "animate-shimmer bg-gradient-to-r from-muted-foreground via-foreground to-muted-foreground bg-[length:200%_100%] bg-clip-text text-transparent"
+			: "";
+
+		return html`
+			<div class="thinking-block">
+				<div
+					class="thinking-header cursor-pointer select-none flex items-center gap-2 py-1 text-sm text-muted-foreground hover:text-foreground transition-colors"
+					@click=${this.toggleExpanded}
+				>
+					<span class="transition-transform inline-block ${this.isExpanded ? "rotate-90" : ""}">${icon(ChevronRight, "sm")}</span>
+					<span class="${shimmerClasses}">Thinking...</span>
+				</div>
+				${this.isExpanded ? html`<markdown-block .content=${this.content} .isThinking=${true}></markdown-block>` : ""}
+			</div>
+		`;
+	}
+}

packages/web-ui/src/index.ts

@@ -46,6 +46,7 @@ export {
 export { RuntimeMessageBridge } from "./components/sandbox/RuntimeMessageBridge.js";
 export { RUNTIME_MESSAGE_ROUTER } from "./components/sandbox/RuntimeMessageRouter.js";
 export type { SandboxRuntimeProvider } from "./components/sandbox/SandboxRuntimeProvider.js";
+export { ThinkingBlock } from "./components/ThinkingBlock.js";
 export { ApiKeyPromptDialog } from "./dialogs/ApiKeyPromptDialog.js";
 export { AttachmentOverlay } from "./dialogs/AttachmentOverlay.js";
 // Dialogs

packages/web-ui/src/tools/renderer-registry.ts

@@ -1,7 +1,7 @@
 import { html, icon, type TemplateResult } from "@mariozechner/mini-lit";
 import type { Ref } from "lit/directives/ref.js";
 import { ref } from "lit/directives/ref.js";
-import { ChevronRight, Loader } from "lucide";
+import { ChevronsUpDown, ChevronUp, Loader } from "lucide";
 import type { ToolRenderer } from "./types.js";
 
 // Registry of tool renderers
@@ -85,11 +85,23 @@ export function renderCollapsibleHeader(
 			if (isCollapsed) {
 				content.classList.remove("max-h-0");
 				content.classList.add("max-h-[2000px]", "mt-3");
-				chevron.classList.add("rotate-90");
+				// Show ChevronUp, hide ChevronsUpDown
+				const upIcon = chevron.querySelector(".chevron-up");
+				const downIcon = chevron.querySelector(".chevrons-up-down");
+				if (upIcon && downIcon) {
+					upIcon.classList.remove("hidden");
+					downIcon.classList.add("hidden");
+				}
 			} else {
 				content.classList.remove("max-h-[2000px]", "mt-3");
 				content.classList.add("max-h-0");
-				chevron.classList.remove("rotate-90");
+				// Show ChevronsUpDown, hide ChevronUp
+				const upIcon = chevron.querySelector(".chevron-up");
+				const downIcon = chevron.querySelector(".chevrons-up-down");
+				if (upIcon && downIcon) {
+					upIcon.classList.add("hidden");
+					downIcon.classList.remove("hidden");
+				}
 			}
 		}
 	};
@@ -108,8 +120,9 @@ export function renderCollapsibleHeader(
 				${statusIcon(toolIcon, toolIconColor)}
 				${text}
 			</div>
-			<span class="inline-block text-muted-foreground transition-transform duration-300 ${defaultExpanded ? "rotate-90" : ""}" ${ref(chevronRef)}>
+			<span class="inline-block text-muted-foreground" ${ref(chevronRef)}>
-				${icon(ChevronRight, "sm")}
+				<span class="chevron-up ${defaultExpanded ? "" : "hidden"}">${icon(ChevronUp, "sm")}</span>
+				<span class="chevrons-up-down ${defaultExpanded ? "hidden" : ""}">${icon(ChevronsUpDown, "sm")}</span>
 			</span>
 		</button>
 	`;