diff --git a/cmd/check-ip/web/app.js b/cmd/check-ip/web/app.js
index 37e7620..1f40d69 100644
--- a/cmd/check-ip/web/app.js
+++ b/cmd/check-ip/web/app.js
@@ -1,221 +1,192 @@
-(function () {
-  "use strict";
+const App = {
+  myIpMode: false,
 
-  function $(sel, $parent) {
-    return ($parent || document).querySelector(sel);
-  }
+  submit(event) {
+    event.preventDefault();
+    const input = event.target.querySelector('[data-input]');
+    const host = input.value.trim();
+    this.check(host);
+  },
 
-  function $$(sel, $parent) {
-    return Array.from(($parent || document).querySelectorAll(sel));
-  }
-
-  const form      = $(".search-form");
-  const input     = $("input[type=\"text\"]", form);
-  const btn       = $("button", form);
-  const myIpLink  = $("#my-ip-link");
-  const loading   = $(".loading");
-  const errorEl   = $(".error-msg");
-  const resultEl  = $(".result");
-  let myIpVisible = false;
-
-  function show(el) { el.classList.add("visible"); }
-  function hide(el) { el.classList.remove("visible"); }
-
-  function render(result, isMyIp) {
-    hide(errorEl);
-    hide(resultEl);
-    if (isMyIp) myIpVisible = true;
-
-    const host = result.ip;
-    const resolvedFrom = result.resolved_from || "";
-    const blocked = result.blocked;
-    const blockedIn = result.blocked_inbound;
-    const blockedOut = result.blocked_outbound;
-    const whitelisted = result.allowlisted;
-    const geo = result.geo || {};
-
-    // Verdict
-    let verdictClass = "unknown";
-    let verdictText = "UNKNOWN";
-    if (whitelisted) {
-      verdictClass = "whitelist";
-      verdictText = "ALLOWED (whitelist)";
-    } else if (blocked) {
-      verdictClass = "blocked";
-      verdictText = "BLOCKED";
-    } else {
-      verdictClass = "allowed";
-      verdictText = "ALLOWED";
-    }
-
-    // Geo info
-    let geoParts = [];
-    if (geo.city) geoParts.push(geo.city);
-    if (geo.region) {
-      geoParts.push(geo.region + (geo.region_iso ? " (" + geo.region_iso + ")" : ""));
-    } else if (geo.region_iso) {
-      geoParts.push(geo.region_iso);
-    }
-    if (geo.country) {
-      geoParts.push(geo.country + (geo.country_iso ? " (" + geo.country_iso + ")" : ""));
-    }
-    if (geo.continent) {
-      geoParts.push(geo.continent + (geo.continent_code ? " (" + geo.continent_code + ")" : ""));
-    }
-    let geoStr = geoParts.length ? geoParts.join(", ") : "—";
-    let latLonStr = "";
-    if (geo.latitude || geo.longitude) {
-      latLonStr = geo.latitude.toFixed(4) + ", " + geo.longitude.toFixed(4);
-    }
-    let asnStr = geo.asn ? "AS" + geo.asn + " " + (geo.asn_org || "") : "—";
-    let postalStr = geo.postal_code || "";
-    let tzStr = geo.timezone || "";
-    let metroStr = geo.metro_code ? String(geo.metro_code) : "";
-    let accuracyStr = geo.accuracy_radius ? String(geo.accuracy_radius) : "";
-    let registeredStr = geo.registered_country ? (geo.registered_country + (geo.registered_country_iso ? " (" + geo.registered_country_iso + ")" : "")) : "";
-
-    // Trait badges
-    let traitBadges = "";
-    if (geo.anycast) {
-      traitBadges += '<span class="trait-badge anycast">anycast</span>';
-    }
-    if (geo.anonymous_proxy) {
-      traitBadges += '<span class="trait-badge anonymous">anonymous proxy</span>';
-    }
-    if (geo.satellite) {
-      traitBadges += '<span class="trait-badge satellite">satellite</span>';
-    }
-    if (geo.country_in_eu) {
-      traitBadges += '<span class="trait-badge eu">EU</span>';
-    }
-
-    // Block details
-    let blockHtml = "";
-    if (blockedIn || blockedOut) {
-      const parts = [];
-      if (blockedIn) parts.push("inbound");
-      if (blockedOut) parts.push("outbound");
-      blockHtml = '<span class="block-badge">BLOCKED: ' + parts.join(" + ") + '</span>';
-    } else {
-      blockHtml = '<span class="block-badge clean">clean</span>';
-    }
-
-    resultEl.innerHTML =
-      '<div class="result-header">' +
-        '<span class="verdict ' + verdictClass + '">' + verdictText + '</span>' +
-        '<span class="host">' + escapeHtml(host) + '</span>' +
-        (resolvedFrom ? '<span class="resolved">→ ' + escapeHtml(resolvedFrom) + '</span>' : '') +
-      '</div>' +
-      '<div class="result-body">' +
-        (geoStr !== "—" ?
-          '<div class="result-section">' +
-            '<h3>Location</h3>' +
-            '<p class="mono">' + escapeHtml(geoStr) + '</p>' +
-          '</div>' : '') +
-        (latLonStr ?
-          '<div class="result-section">' +
-            '<h3>Coordinates</h3>' +
-            '<p class="mono">' + escapeHtml(latLonStr) + '</p>' +
-          '</div>' : '') +
-        (postalStr || tzStr || metroStr || accuracyStr ?
-          '<div class="result-section">' +
-            '<h3>Details</h3>' +
-            '<p class="mono">' +
-              (postalStr ? escapeHtml(postalStr) + " " : "") +
-              (tzStr ? escapeHtml(tzStr) + " " : "") +
-              (metroStr ? "Metro " + escapeHtml(metroStr) + " " : "") +
-              (accuracyStr ? "±" + escapeHtml(accuracyStr) + "km" : "") +
-            '</p>' +
-          '</div>' : '') +
-        (traitBadges ?
-          '<div class="result-section">' +
-            '<h3>Traits</h3>' +
-            '<div class="block-list">' + traitBadges + '</div>' +
-          '</div>' : '') +
-        (registeredStr ?
-          '<div class="result-section">' +
-            '<h3>Registered Country</h3>' +
-            '<p class="mono">' + escapeHtml(registeredStr) + '</p>' +
-          '</div>' : '') +
-        '<div class="result-section">' +
-          '<h3>ASN</h3>' +
-          '<p class="mono">' + escapeHtml(asnStr) + '</p>' +
-        '</div>' +
-        '<div class="result-section">' +
-          '<h3>Blocklist</h3>' +
-          '<div class="block-list">' + blockHtml + '</div>' +
-        '</div>' +
-      '</div>';
-
-    show(resultEl);
-  }
-
-  function escapeHtml(s) {
-    const d = document.createElement("div");
-    d.textContent = s;
-    return d.innerHTML;
-  }
-
-  function submitHost(host) {
-    hide(errorEl);
-    hide(resultEl);
-    show(loading);
+  check(host) {
+    const btn = document.querySelector('[data-submit-btn]');
     btn.disabled = true;
-    var isMyIp = host === "";
+    this.clearState();
+    document.querySelector('[data-state="loading"]').hidden = false;
+    this.myIpMode = host === '';
 
-    fetch("/check?host=" + encodeURIComponent(host) + "&format=json")
-      .then(function (r) {
-        if (!r.ok) throw new Error("HTTP " + r.status);
+    fetch('/check?host=' + encodeURIComponent(host) + '&format=json')
+      .then(function(r) {
+        if (!r.ok) throw new Error('HTTP ' + r.status);
         return r.json();
       })
-      .then(function (data) {
-        hide(loading);
-        render(data, isMyIp);
+      .then(function(data) {
+        document.querySelector('[data-state="loading"]').hidden = true;
+        document.querySelector('[data-state="result"]').hidden = false;
+        App.render(data);
       })
-      .catch(function (err) {
-        hide(loading);
-        errorEl.textContent = "Error: " + err.message;
-        show(errorEl);
+      .catch(function(err) {
+        document.querySelector('[data-state="loading"]').hidden = true;
+        document.querySelector('[data-state="error"]').hidden = false;
+        document.querySelector('[data-error-text]').textContent = err.message;
       })
-      .finally(function () {
+      .finally(function() {
         btn.disabled = false;
       });
-  }
+  },
 
-  form.addEventListener("submit", function (e) {
-    e.preventDefault();
-    submitHost(input.value.trim());
-  });
+  clearState() {
+    document.querySelector('[data-state="result"]').hidden = true;
+    document.querySelector('[data-state="error"]').hidden = true;
+    document.querySelectorAll('[data-verdict]').forEach(function(el) { el.hidden = true; });
+    document.querySelectorAll('[data-section]').forEach(function(el) { el.hidden = true; });
+    document.querySelectorAll('[data-trait]').forEach(function(el) { el.hidden = true; });
+    document.querySelectorAll('[data-block]').forEach(function(el) { el.hidden = true; });
+    document.querySelector('[data-resolved-from]').hidden = true;
+  },
 
-  myIpLink.addEventListener("click", function (e) {
-    e.preventDefault();
-    if (myIpVisible) {
-      hide(resultEl);
-      myIpLink.textContent = "Show my IP Info";
-      myIpVisible = false;
-    } else {
-      myIpLink.textContent = "Hide my IP Info";
-      submitHost("");
+  render(data) {
+    /* ── Verdict ──────────────────────────────────────────── */
+    document.querySelectorAll('[data-verdict]').forEach(function(el) { el.hidden = true; });
+    var verdictKey = 'allowed';
+    if (data.allowlisted) {
+      verdictKey = 'whitelist';
+    } else if (data.blocked_inbound && data.blocked_outbound) {
+      verdictKey = 'blocked-inbound-outbound';
+    } else if (data.blocked_inbound) {
+      verdictKey = 'blocked-inbound';
+    } else if (data.blocked_outbound) {
+      verdictKey = 'blocked-outbound';
     }
-  });
+    document.querySelector('[data-verdict="' + verdictKey + '"]').hidden = false;
 
-  // Pre-fill from URL query param or hash fragment and auto-submit
-  (function init() {
-    let host = new URLSearchParams(window.location.search).get("host");
-    // Also check hash fragment (e.g. /#/?host=google.com)
+    /* ── IP address ───────────────────────────────────────── */
+    document.querySelector('[data-value="ip"]').textContent = data.ip;
+
+    /* ── Resolved from ────────────────────────────────────── */
+    if (data.resolved_from) {
+      document.querySelector('[data-value="resolved-from"]').textContent = data.resolved_from;
+      document.querySelector('[data-resolved-from]').hidden = false;
+    }
+
+    /* ── Geo ──────────────────────────────────────────────── */
+    var geo = data.geo || {};
+
+    /* Location */
+    var locParts = [];
+    if (geo.city) locParts.push(geo.city);
+    if (geo.region) {
+      locParts.push(geo.region + (geo.region_iso ? ' (' + geo.region_iso + ')' : ''));
+    } else if (geo.region_iso) {
+      locParts.push(geo.region_iso);
+    }
+    if (geo.country) {
+      locParts.push(geo.country + (geo.country_iso ? ' (' + geo.country_iso + ')' : ''));
+    }
+    if (geo.continent) {
+      locParts.push(geo.continent + (geo.continent_code ? ' (' + geo.continent_code + ')' : ''));
+    }
+    if (locParts.length) {
+      document.querySelector('[data-value="location"]').textContent = locParts.join(', ');
+      document.querySelector('[data-section="location"]').hidden = false;
+    }
+
+    /* Coordinates */
+    if (geo.latitude || geo.longitude) {
+      document.querySelector('[data-value="coordinates"]').textContent =
+        geo.latitude.toFixed(4) + ', ' + geo.longitude.toFixed(4);
+      document.querySelector('[data-section="coordinates"]').hidden = false;
+    }
+
+    /* Details */
+    var detailParts = [];
+    if (geo.postal_code) detailParts.push(geo.postal_code);
+    if (geo.timezone) detailParts.push(geo.timezone);
+    if (geo.metro_code) detailParts.push('Metro ' + String(geo.metro_code));
+    if (geo.accuracy_radius) detailParts.push('±' + String(geo.accuracy_radius) + 'km');
+    if (detailParts.length) {
+      document.querySelector('[data-value="details"]').textContent = detailParts.join(' ');
+      document.querySelector('[data-section="details"]').hidden = false;
+    }
+
+    /* Traits */
+    var traitMap = {
+      anycast: 'anycast',
+      anonymous: 'anonymous_proxy',
+      satellite: 'satellite',
+      eu: 'country_in_eu'
+    };
+    var hasTraits = false;
+    var traitKeys = Object.keys(traitMap);
+    for (var i = 0; i < traitKeys.length; i++) {
+      if (geo[traitMap[traitKeys[i]]]) {
+        document.querySelector('[data-trait="' + traitKeys[i] + '"]').hidden = false;
+        hasTraits = true;
+      }
+    }
+    if (hasTraits) {
+      document.querySelector('[data-section="traits"]').hidden = false;
+    }
+
+    /* Registered country */
+    if (geo.registered_country) {
+      var rcParts = geo.registered_country +
+        (geo.registered_country_iso ? ' (' + geo.registered_country_iso + ')' : '');
+      document.querySelector('[data-value="registered-country"]').textContent = rcParts;
+      document.querySelector('[data-section="registered-country"]').hidden = false;
+    }
+
+    /* ASN */
+    if (geo.asn) {
+      document.querySelector('[data-value="asn"]').textContent =
+        'AS' + geo.asn + ' ' + (geo.asn_org || '');
+    } else {
+      document.querySelector('[data-value="asn"]').textContent = '—';
+    }
+
+    /* Blocklist */
+    var hasBlock = false;
+    if (data.blocked_inbound) {
+      document.querySelector('[data-block="inbound"]').hidden = false;
+      hasBlock = true;
+    }
+    if (data.blocked_outbound) {
+      document.querySelector('[data-block="outbound"]').hidden = false;
+      hasBlock = true;
+    }
+    if (!hasBlock) {
+      document.querySelector('[data-block="clean"]').hidden = false;
+    }
+  },
+
+  toggleIpInfo(event) {
+    event.preventDefault();
+    var link = document.querySelector('[data-my-ip-link]');
+    if (this.myIpMode) {
+      document.querySelector('[data-state="result"]').hidden = true;
+      link.textContent = 'Show my IP Info';
+      this.myIpMode = false;
+    } else {
+      link.textContent = 'Hide my IP Info';
+      this.check('');
+    }
+  },
+
+  init() {
+    var host = new URLSearchParams(window.location.search).get('host');
     if (!host) {
-      const hashQuery = window.location.hash.split("?")[1];
+      var hashQuery = window.location.hash.split('?')[1];
       if (hashQuery) {
-        host = new URLSearchParams(hashQuery).get("host");
+        host = new URLSearchParams(hashQuery).get('host');
       }
     }
     if (host) {
-      input.value = host;
-      submitHost(host);
+      document.querySelector('[data-input]').value = host;
+      this.check(host);
+    } else {
+      document.querySelector('[data-input]').focus();
     }
-    // Focus input on load (only if no auto-submit triggered)
-    if (!host) {
-      input.focus();
-    }
-  })();
-})();
+  }
+};
+
+App.init();
diff --git a/cmd/check-ip/web/index.html b/cmd/check-ip/web/index.html
index 167ed8d..6492a62 100644
--- a/cmd/check-ip/web/index.html
+++ b/cmd/check-ip/web/index.html
@@ -3,33 +3,88 @@
 <head>
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <title>IP Location & Status</title>
+  <title>IP Location &amp; Status</title>
   <link rel="stylesheet" href="/style.css">
 </head>
 <body>
-  <div class="container">
-    <h1>IP Location & Status</h1>
+  <main class="container" data-app>
+    <h1>IP Location &amp; Status</h1>
     <p class="subtitle">Look up an IP address, domain, or your own IP against blocklists and GeoIP databases.</p>
 
-    <form class="search-form" autocomplete="off">
-      <input type="text" name="host" placeholder="Enter IP or domain…">
-      <button type="submit">Check</button>
+    <form class="search-form" data-form autocomplete="off" onsubmit="App.submit(window.event)">
+      <input type="text" name="host" placeholder="Enter IP or domain…" data-input>
+      <button type="submit" data-submit-btn>Check</button>
     </form>
 
-    <a href="#" class="my-ip-link" id="my-ip-link">Show my IP Info</a>
+    <a href="#" class="my-ip-link" data-my-ip-link onclick="App.toggleIpInfo(window.event)">Show my IP Info</a>
 
-    <div class="loading">
-      <span class="spinner"></span> Resolving and checking…
+    <div class="loading" data-state="loading" hidden>
+      <span class="spinner"></span>
+      Resolving and checking…
     </div>
 
-    <div class="error-msg"></div>
+    <div class="error-msg" data-state="error" hidden>
+      <span>Error: </span>
+      <span data-error-text></span>
+    </div>
 
-    <div class="result"></div>
+    <div class="result" data-state="result" hidden>
+      <div class="result-header">
+        <span data-verdict-badge>
+          <span data-verdict="whitelist" hidden class="verdict verdict-whitelist">ALLOWED (whitelist)</span>
+          <span data-verdict="blocked-inbound-outbound" hidden class="verdict verdict-blocked">BLOCKED (inbound + outbound)</span>
+          <span data-verdict="blocked-inbound" hidden class="verdict verdict-blocked">BLOCKED (inbound)</span>
+          <span data-verdict="blocked-outbound" hidden class="verdict verdict-blocked">BLOCKED (outbound)</span>
+          <span data-verdict="allowed" hidden class="verdict verdict-allowed">ALLOWED</span>
+        </span>
+        <span class="host" data-value="ip"></span>
+        <span data-resolved-from hidden class="resolved">→ <span data-value="resolved-from"></span></span>
+      </div>
+      <div class="result-body">
+        <div class="result-section" data-section="location" hidden>
+          <h3>Location</h3>
+          <p class="mono" data-value="location"></p>
+        </div>
+        <div class="result-section" data-section="coordinates" hidden>
+          <h3>Coordinates</h3>
+          <p class="mono" data-value="coordinates"></p>
+        </div>
+        <div class="result-section" data-section="details" hidden>
+          <h3>Details</h3>
+          <p class="mono" data-value="details"></p>
+        </div>
+        <div class="result-section" data-section="traits" hidden>
+          <h3>Traits</h3>
+          <div class="block-list">
+            <span data-trait="anycast" hidden class="trait-badge anycast">anycast</span>
+            <span data-trait="anonymous" hidden class="trait-badge anonymous">anonymous proxy</span>
+            <span data-trait="satellite" hidden class="trait-badge satellite">satellite</span>
+            <span data-trait="eu" hidden class="trait-badge eu">EU</span>
+          </div>
+        </div>
+        <div class="result-section" data-section="registered-country" hidden>
+          <h3>Registered Country</h3>
+          <p class="mono" data-value="registered-country"></p>
+        </div>
+        <div class="result-section" data-section="asn">
+          <h3>ASN</h3>
+          <p class="mono" data-value="asn">—</p>
+        </div>
+        <div class="result-section" data-section="blocklist">
+          <h3>Blocklist</h3>
+          <div class="block-list">
+            <span data-block="inbound" hidden class="block-badge">inbound</span>
+            <span data-block="outbound" hidden class="block-badge">outbound</span>
+            <span data-block="clean" hidden class="block-badge clean">clean</span>
+          </div>
+        </div>
+      </div>
+    </div>
 
     <footer>
       <a href="/healthz">/healthz</a>
     </footer>
-  </div>
+  </main>
 
   <script src="/app.js"></script>
 </body>
diff --git a/cmd/check-ip/web/style.css b/cmd/check-ip/web/style.css
index 3e8b3a8..ea095dd 100644
--- a/cmd/check-ip/web/style.css
+++ b/cmd/check-ip/web/style.css
@@ -1,5 +1,6 @@
 /* ── Reset & base ─────────────────────────────────────────── */
 *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
+[hidden] { display: none !important; }
 
 :root {
   --bg:        #fafafa;
@@ -60,7 +61,7 @@ html {
 }
 
 body {
-  min-height: 100dvh;
+  min-height: 100vh;
   display: flex;
   flex-direction: column;
   align-items: center;
@@ -126,6 +127,7 @@ button {
 
 button:hover { background: var(--primary-hover); }
 button:active { transform: scale(.98); }
+button:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }
 button:disabled {
   opacity: .6;
   cursor: not-allowed;
@@ -133,7 +135,6 @@ button:disabled {
 
 /* ── Result card ──────────────────────────────────────────── */
 .result {
-  display: none;
   background: var(--surface);
   border: 1px solid var(--border);
   border-radius: var(--radius);
@@ -141,8 +142,6 @@ button:disabled {
   overflow: hidden;
 }
 
-.result.visible { display: block; }
-
 .result-header {
   padding: 1rem 1.25rem;
   border-bottom: 1px solid var(--border);
@@ -165,6 +164,7 @@ button:disabled {
   word-break: break-all;
 }
 
+/* ── Verdict badge ────────────────────────────────────────── */
 .verdict {
   display: inline-flex;
   align-items: center;
@@ -178,30 +178,25 @@ button:disabled {
   white-space: nowrap;
 }
 
-.verdict.allowed {
+.verdict.verdict-allowed {
   background: var(--ok-bg);
   color: var(--ok);
   border: 1px solid var(--ok-border);
 }
 
-.verdict.blocked {
+.verdict.verdict-blocked {
   background: var(--bad-bg);
   color: var(--bad);
   border: 1px solid var(--bad-border);
 }
 
-.verdict.whitelist {
+.verdict.verdict-whitelist {
   background: var(--warn-bg);
   color: var(--warn);
   border: 1px solid var(--warn-border);
 }
 
-.verdict.unknown {
-  background: var(--bg);
-  color: var(--muted);
-  border: 1px solid var(--border);
-}
-
+/* ── Result body ──────────────────────────────────────────── */
 .result-body {
   padding: 1.25rem;
 }
@@ -237,6 +232,7 @@ button:disabled {
   gap: .375rem;
 }
 
+/* ── Block badge ──────────────────────────────────────────── */
 .block-badge {
   font-size: .75rem;
   font-weight: 600;
@@ -313,15 +309,12 @@ button:disabled {
 
 /* ── Loading spinner ──────────────────────────────────────── */
 .loading {
-  display: none;
   text-align: center;
   padding: 2rem;
   color: var(--muted);
   font-size: .875rem;
 }
 
-.loading.visible { display: block; }
-
 .spinner {
   display: inline-block;
   width: 1.25rem;
@@ -338,7 +331,6 @@ button:disabled {
 
 /* ── Error ────────────────────────────────────────────────── */
 .error-msg {
-  display: none;
   background: var(--bad-bg);
   color: var(--bad);
   border: 1px solid var(--bad-border);
@@ -348,8 +340,6 @@ button:disabled {
   font-size: .875rem;
 }
 
-.error-msg.visible { display: block; }
-
 /* ── My IP link ───────────────────────────────────────────── */
 .my-ip-link {
   display: inline-block;
@@ -364,6 +354,7 @@ button:disabled {
 }
 
 .my-ip-link:hover { text-decoration-color: var(--primary); }
+.my-ip-link:focus-visible { outline: 2px solid var(--primary); outline-offset: 2px; }
 
 /* ── Footer ───────────────────────────────────────────────── */
 footer {