feat(web): add interactive CLI modes section

apps/web/app/page.tsx

@@ -6,6 +6,7 @@ export default function Page() {
       <Navbar />
       <Hero />
       <Features />
+      <Modes />
     </main>
   )
 }

apps/web/components/modes.tsx

@@ -0,0 +1,171 @@
+"use client"
+
+import { useState } from "react"
+import { cn } from "@/lib/utils"
+
+const modes = [
+  {
+    flag: "default",
+    label: "Default",
+    command: "explainthisrepo facebook/react",
+    description: "Full repository explanation written to EXPLAIN.md",
+    output: [
+      "Fetching repository data...",
+      "Analyzing file tree and structure...",
+      "Reading high-signal files...",
+      "",
+      "React is a JavaScript library for building user",
+      "interfaces using a component-based architecture...",
+      "",
+      "EXPLAIN.md created successfully.",
+    ],
+  },
+  {
+    flag: "--quick",
+    label: "Quick",
+    command: "explainthisrepo facebook/react --quick",
+    description: "One-sentence summary printed to terminal",
+    output: [
+      "Fetching repository data...",
+      "",
+      "React is a declarative JavaScript library for",
+      "building composable user interfaces.",
+    ],
+  },
+  {
+    flag: "--detailed",
+    label: "Detailed",
+    command: "explainthisrepo facebook/react --detailed",
+    description: "Deeper explanation including architecture and structure",
+    output: [
+      "Fetching repository data...",
+      "Analyzing file tree and structure...",
+      "Reading high-signal files...",
+      "Building architecture map...",
+      "",
+      "React is a UI library using a fiber-based reconciler.",
+      "Core packages: react, react-dom, react-reconciler.",
+      "Architecture: virtual DOM with concurrent rendering.",
+      "",
+      "EXPLAIN.md created successfully.",
+    ],
+  },
+  {
+    flag: "--simple",
+    label: "Simple",
+    command: "explainthisrepo facebook/react --simple",
+    description: "Short, easy explanation printed to terminal",
+    output: [
+      "Fetching repository data...",
+      "",
+      "React helps you build websites by breaking the UI",
+      "into reusable pieces called components.",
+    ],
+  },
+  {
+    flag: "--stack",
+    label: "Stack",
+    command: "explainthisrepo facebook/react --stack",
+    description: "Tech stack breakdown from repo signals. No AI.",
+    output: [
+      "Detecting stack from repo signals...",
+      "",
+      "Languages:  JavaScript, TypeScript, C++",
+      "Build:      Rollup, Gradle",
+      "Testing:    Jest",
+      "CI/CD:      GitHub Actions, CircleCI",
+      "Package:    Yarn workspaces (monorepo)",
+    ],
+  },
+]
+
+export function Modes() {
+  const [activeMode, setActiveMode] = useState(0)
+  const mode = modes[activeMode]
+
+  return (
+    <section id="modes" className="border-y border-border bg-card/50 py-24 md:py-32">
+      <div className="mx-auto max-w-6xl px-6">
+        <div className="mb-16 text-center">
+          <p className="mb-3 text-sm font-medium uppercase tracking-widest text-primary">
+            Modes
+          </p>
+          <h2 className="text-balance text-3xl font-bold tracking-tight text-foreground md:text-4xl">
+            Multiple ways to understand a repo
+          </h2>
+          <p className="mx-auto mt-4 max-w-2xl text-pretty text-muted-foreground leading-relaxed">
+            Choose the right level of detail. From a one-liner to a full
+            architectural breakdown.
+          </p>
+        </div>
+
+        <div className="grid gap-8 lg:grid-cols-5">
+          {/* Mode selector */}
+          <div className="flex flex-row gap-2 overflow-x-auto lg:col-span-2 lg:flex-col lg:gap-1.5 lg:overflow-x-visible">
+            {modes.map((m, index) => (
+              <button
+                key={m.flag}
+                type="button"
+                onClick={() => setActiveMode(index)}
+                className={cn(
+                  "flex-shrink-0 rounded-lg px-4 py-3 text-left transition-all",
+                  index === activeMode
+                    ? "bg-secondary border border-primary/30 text-foreground"
+                    : "text-muted-foreground hover:text-foreground hover:bg-secondary/50"
+                )}
+              >
+                <div className="flex items-center gap-3">
+                  <code className="font-mono text-xs text-primary">
+                    {m.flag}
+                  </code>
+                </div>
+                <p className="mt-1 text-sm hidden lg:block">{m.description}</p>
+              </button>
+            ))}
+          </div>
+
+          {/* Terminal preview */}
+          <div className="lg:col-span-3">
+            <div className="overflow-hidden rounded-xl border border-border bg-background shadow-xl">
+              <div className="flex items-center gap-2 border-b border-border px-4 py-3">
+                <div className="h-3 w-3 rounded-full bg-[#ff5f57]" />
+                <div className="h-3 w-3 rounded-full bg-[#febc2e]" />
+                <div className="h-3 w-3 rounded-full bg-[#28c840]" />
+                <span className="ml-3 text-xs text-muted-foreground font-mono">
+                  {mode.label.toLowerCase()}
+                </span>
+              </div>
+              <div className="p-5 font-mono text-sm leading-relaxed min-h-[280px]">
+                <div className="text-foreground font-semibold">
+                  $ {mode.command}
+                </div>
+                <div className="mt-2">
+                  {mode.output.map((line, i) => (
+                    <div
+                      key={i}
+                      className={cn(
+                        line === ""
+                          ? "h-4"
+                          : line.startsWith("EXPLAIN.md")
+                            ? "text-primary font-medium"
+                            : line.startsWith("Fetching") ||
+                                line.startsWith("Analyzing") ||
+                                line.startsWith("Reading") ||
+                                line.startsWith("Building") ||
+                                line.startsWith("Detecting")
+                              ? "text-muted-foreground"
+                              : "text-foreground/90"
+                      )}
+                    >
+                      {line || "\u00A0"}
+                    </div>
+                  ))}
+                </div>
+              </div>
+            </div>
+          </div>
+        </div>
+      </div>
+    </section>
+  )
+}