Add cookie disclaimer

src/main/resources/static/css/styles.css

@@ -2063,3 +2063,90 @@ button:disabled:hover {
   background: #60a5fa;
   box-shadow: 0 0 0 4px rgba(96, 165, 250, 0.2);
 }
+
+.cookie-consent {
+  position: fixed;
+  bottom: 16px;
+  left: 16px;
+  right: 16px;
+  max-width: 520px;
+  margin-left: auto;
+  padding: 16px 52px 14px 18px;
+  display: grid;
+  grid-template-columns: 1fr auto;
+  gap: 12px;
+  background: linear-gradient(135deg, rgba(124, 58, 237, 0.25), rgba(59, 130, 246, 0.18));
+  border: 1px solid rgba(148, 163, 184, 0.35);
+  border-radius: 14px;
+  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.45);
+  color: #e2e8f0;
+  z-index: 11000;
+  backdrop-filter: blur(4px);
+  transition:
+    opacity 150ms ease,
+    transform 150ms ease;
+}
+
+.cookie-consent-exit {
+  opacity: 0;
+  transform: translateY(6px);
+}
+
+.cookie-consent-body {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+  padding-right: 18px;
+}
+
+.cookie-consent-copy {
+  margin: 0;
+  line-height: 1.45;
+  color: #cbd5e1;
+}
+
+.cookie-consent-copy a {
+  color: #a5b4fc;
+  text-decoration: underline;
+}
+
+.cookie-consent-actions {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  flex-wrap: wrap;
+  justify-content: flex-end;
+}
+
+.cookie-consent-close {
+  position: absolute;
+  top: 10px;
+  right: 10px;
+  background: transparent;
+  border: 1px solid rgba(226, 232, 240, 0.3);
+  color: #e2e8f0;
+  border-radius: 50%;
+  width: 32px;
+  height: 32px;
+  font-size: 18px;
+  font-weight: 700;
+  line-height: 1;
+  cursor: pointer;
+  transition: all 120ms ease;
+}
+
+.cookie-consent-close:hover {
+  background: rgba(255, 255, 255, 0.08);
+  border-color: rgba(226, 232, 240, 0.45);
+}
+
+@media (max-width: 640px) {
+  .cookie-consent {
+    grid-template-columns: 1fr;
+    padding: 16px;
+  }
+
+  .cookie-consent-actions {
+    justify-content: flex-start;
+  }
+}

src/main/resources/static/js/cookie-consent.js

@@ -0,0 +1,86 @@
+(() => {
+    const CONSENT_STORAGE_KEY = "imgfloat.cookie-consent.dismissed";
+    const COOKIE_MAX_AGE_SECONDS = 60 * 60 * 24 * 365; // 1 year
+
+    const readConsentCookie = () => {
+        return document.cookie
+            .split("; ")
+            .find((entry) => entry.startsWith(`${CONSENT_STORAGE_KEY}=`))
+            ?.split("=")[1];
+    };
+
+    const persistDismissal = () => {
+        try {
+            window.localStorage.setItem(CONSENT_STORAGE_KEY, "true");
+        } catch { }
+        document.cookie = `${CONSENT_STORAGE_KEY}=true; max-age=${COOKIE_MAX_AGE_SECONDS}; path=/; SameSite=Lax`;
+    };
+
+    const hasDismissed = () => {
+        try {
+            if (window.localStorage.getItem(CONSENT_STORAGE_KEY) === "true") {
+                return true;
+            }
+        } catch { }
+        return readConsentCookie() === "true";
+    };
+
+    const shouldShowBanner = () => {
+        if (!document.body) {
+            return false;
+        }
+        if (document.body.classList.contains("broadcast-body")) {
+            return false;
+        }
+        return !hasDismissed();
+    };
+
+    const dismissBanner = (banner) => {
+        if (!banner) {
+            return;
+        }
+        persistDismissal();
+        banner.classList.add("cookie-consent-exit");
+        window.setTimeout(() => banner.remove(), 180);
+    };
+
+    const renderBanner = () => {
+        if (!shouldShowBanner()) {
+            return;
+        }
+
+        const banner = document.createElement("section");
+        banner.className = "cookie-consent";
+        banner.setAttribute("role", "dialog");
+        banner.setAttribute("aria-live", "polite");
+        banner.setAttribute("aria-label", "Cookie usage notice");
+
+        banner.innerHTML = `
+      <div class="cookie-consent-body">
+        <p class="eyebrow subtle">Cookies & privacy</p>
+        <p class="cookie-consent-copy">
+          Imgfloat uses essential cookies to keep you signed in. By continuing to use the site, you agree to this use.
+        </p>
+      </div>
+      <div class="cookie-consent-actions">
+        <button type="button" class="button" data-consent-action="accept">Accept</button>
+        <button type="button" class="button ghost" data-consent-action="dismiss">Dismiss</button>
+      </div>
+      <button type="button" class="cookie-consent-close" aria-label="Close cookie notice" data-consent-action="dismiss">
+        &times;
+      </button>
+    `;
+
+        banner.querySelectorAll("[data-consent-action]").forEach((element) => {
+            element.addEventListener("click", () => dismissBanner(banner));
+        });
+
+        document.body.appendChild(banner);
+    };
+
+    if (document.readyState === "loading") {
+        document.addEventListener("DOMContentLoaded", renderBanner);
+    } else {
+        renderBanner();
+    }
+})();