diff --git a/src/app/layout.tsx b/src/app/layout.tsx
index e5b3f64..ea80f4a 100644
--- a/src/app/layout.tsx
+++ b/src/app/layout.tsx
@@ -6,6 +6,7 @@ import "./globals.css";
 import "../styles/type.css";
 import "../styles/buttons.css";
 import "../styles/avatar.css";
+import "../styles/signin.css";
 import "../styles/legacy.css";
 
 const manrope = Manrope({
diff --git a/src/components/SignInForm.tsx b/src/components/SignInForm.tsx
index bd5db95..d98d9d8 100644
--- a/src/components/SignInForm.tsx
+++ b/src/components/SignInForm.tsx
@@ -3,6 +3,7 @@
 import { useState, type FormEvent } from "react";
 import { signIn, type Person } from "@/lib/auth-client";
 import { Logo } from "./Logo";
+import { SparkleButton } from "./Buttons";
 
 export function SignInForm({ onSignedIn }: { onSignedIn: (p: Person) => void }) {
   const [email, setEmail] = useState("");
@@ -27,39 +28,72 @@ export function SignInForm({ onSignedIn }: { onSignedIn: (p: Person) => void })
   }
 
   return (
-    <main className="center">
-      <form className="card" onSubmit={submit} noValidate>
-        <Logo />
-        <h1>Sign in to Minnect</h1>
-        {error && (
-          <p role="alert" className="error">
-            {error}
-          </p>
-        )}
-        <label htmlFor="email">Email</label>
-        <input
-          id="email"
-          name="email"
-          type="email"
-          autoComplete="username"
-          required
-          value={email}
-          onChange={(e) => setEmail(e.target.value)}
-        />
-        <label htmlFor="password">Password</label>
-        <input
-          id="password"
-          name="password"
-          type="password"
-          autoComplete="current-password"
-          required
-          value={password}
-          onChange={(e) => setPassword(e.target.value)}
-        />
-        <button type="submit" disabled={busy || !email || !password}>
-          {busy ? "Signing in..." : "Sign in"}
-        </button>
-      </form>
+    <main className="signin">
+      <div className="signin-glow" aria-hidden="true" />
+      <div className="signin-col">
+        <div className="signin-brand">
+          <Logo size={30} />
+          <span className="type-wordmark">MINNECT</span>
+        </div>
+        <div className="signin-head">
+          <span className="type-eyebrow">Members</span>
+          <h1 className="signin-title">
+            Human answers for <em>human decisions</em>
+          </h1>
+          <div className="signin-rule" aria-hidden="true" />
+        </div>
+        <form className="signin-form" onSubmit={submit} noValidate>
+          {error && (
+            <p role="alert" className="error signin-error">
+              {error}
+            </p>
+          )}
+          <label className="signin-label" htmlFor="email">
+            Email
+          </label>
+          <div className="signin-field">
+            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.6" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
+              <rect x="3" y="5" width="18" height="14" rx="3" />
+              <path d="m4 7 8 6 8-6" />
+            </svg>
+            <input
+              id="email"
+              name="email"
+              type="email"
+              autoComplete="username"
+              placeholder="you@company.com"
+              required
+              value={email}
+              onChange={(e) => setEmail(e.target.value)}
+            />
+          </div>
+          <label className="signin-label signin-label-next" htmlFor="password">
+            Password
+          </label>
+          <div className="signin-field">
+            <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="1.6" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true">
+              <rect x="4.5" y="10.5" width="15" height="10" rx="2.5" />
+              <path d="M8 10.5V8a4 4 0 0 1 8 0v2.5" />
+            </svg>
+            <input
+              id="password"
+              name="password"
+              type="password"
+              autoComplete="current-password"
+              placeholder="Your password"
+              required
+              value={password}
+              onChange={(e) => setPassword(e.target.value)}
+            />
+          </div>
+          <SparkleButton
+            type="submit"
+            className="signin-submit"
+            label={busy ? "Signing in..." : "Sign in"}
+            disabled={busy || !email || !password}
+          />
+        </form>
+      </div>
     </main>
   );
 }
diff --git a/src/styles/legacy.css b/src/styles/legacy.css
index 7172ec0..0eafaa8 100644
--- a/src/styles/legacy.css
+++ b/src/styles/legacy.css
@@ -4,8 +4,6 @@
    here; the file goes when it is empty. Do not add new rules here.
    Literal white and black are only text on crimson and video letterboxing. */
 .center { min-height: 100vh; display: grid; place-items: center; padding: 16px; }
-.card { width: 100%; max-width: 400px; background: var(--tile); border: 1px solid var(--line); border-radius: 8px; padding: 32px 24px; display: flex; flex-direction: column; gap: 8px; }
-.card h1 { font-size: 22px; margin: 12px 0 8px; }
 label { font-size: 14px; font-weight: 500; margin-top: 8px; }
 input { font: inherit; padding: 12px; border: 1px solid var(--line-2); border-radius: 8px; background: var(--tile-2); color: var(--ink); }
 input:focus-visible, button:focus-visible { outline: 2px solid var(--ink); outline-offset: 2px; }
diff --git a/src/styles/signin.css b/src/styles/signin.css
new file mode 100644
index 0000000..5beac15
--- /dev/null
+++ b/src/styles/signin.css
@@ -0,0 +1,104 @@
+/* Sign-in page (spec "Sign in", ADR 0001). Outside .app: one centered column, no breakpoints.
+   Tokens only, so it follows the active theme (dark by default). */
+.signin {
+  position: relative;
+  min-height: 100vh;
+  overflow: hidden;
+  display: flex;
+  justify-content: center;
+  padding: 28px 24px;
+  background: var(--bg);
+  color: var(--ink);
+}
+.signin-glow {
+  position: absolute;
+  left: 50%;
+  top: -220px;
+  width: 560px;
+  height: 420px;
+  transform: translateX(-50%);
+  border-radius: 50%;
+  background: radial-gradient(ellipse, color-mix(in srgb, var(--accent), transparent 84%), transparent 65%);
+  pointer-events: none;
+}
+.signin-col {
+  position: relative;
+  width: 100%;
+  max-width: 342px;
+  display: flex;
+  flex-direction: column;
+}
+.signin-brand {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 10px;
+  padding-top: 40px;
+  font-size: 15px;
+}
+.signin-head {
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  gap: 14px;
+  text-align: center;
+  margin: 72px 0 40px;
+}
+.signin-title {
+  margin: 0;
+  font-family: var(--font-serif), Georgia, serif;
+  font-size: 40px;
+  font-weight: 600;
+  line-height: 1.05;
+  color: var(--ink);
+}
+.signin-title em { font-style: italic; font-weight: 500; }
+.signin-rule {
+  width: 48px;
+  height: 1px;
+  background: linear-gradient(90deg, transparent, color-mix(in srgb, var(--ink), transparent 40%), transparent);
+}
+.signin-form { display: flex; flex-direction: column; gap: 12px; }
+.signin-label {
+  margin: 0;
+  font-size: 11px;
+  font-weight: 700;
+  text-transform: uppercase;
+  letter-spacing: 0.16em;
+  color: var(--ink-3);
+}
+.signin-label-next { margin-top: 6px; }
+.signin-field {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  height: 52px;
+  padding: 0 16px;
+  border-radius: var(--r-ctl);
+  background: var(--tile-2);
+  color: var(--ink-3);
+  box-shadow: inset 0 0 0 1px var(--line-2);
+  transition: box-shadow .25s;
+}
+.signin-field:focus-within {
+  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--ink), transparent 45%), 0 0 0 4px color-mix(in srgb, var(--ink), transparent 94%);
+}
+.signin-field svg { width: 18px; height: 18px; flex: none; }
+.signin-field input {
+  flex: 1;
+  min-width: 0;
+  height: 100%;
+  margin: 0;
+  padding: 0;
+  border: 0;
+  border-radius: 0;
+  outline: 0;
+  background: transparent;
+  font: inherit;
+  font-size: 15px;
+  color: var(--ink);
+}
+.signin-field input::placeholder { color: var(--ink-3); }
+.signin-form .signin-submit { margin-top: 18px; width: 100%; height: 54px; }
+.signin-form .signin-submit:disabled { opacity: .5; cursor: not-allowed; }
+.signin-error { margin: 0; }