Form — Top error summary + jump-to-field

:root {
  --brand: #5b5bf0;
  --brand-d: #4646d6;
  --brand-700: #3a3ab8;
  --brand-50: #eef0ff;
  --accent: #00b4a6;
  --accent-soft: #d8f5f2;
  --ink: #101322;
  --ink-2: #3a4060;
  --muted: #6c7393;
  --bg: #f6f7fb;
  --white: #ffffff;
  --surface: #ffffff;
  --line: rgba(16, 19, 34, 0.1);
  --line-2: rgba(16, 19, 34, 0.16);
  --ok: #2f9e6f;
  --warn: #d98a2b;
  --danger: #d4503e;
  --danger-soft: #fbeeec;
  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 20px;
  --sh-1: 0 1px 2px rgba(16, 19, 34, 0.08);
  --sh-2: 0 8px 24px rgba(16, 19, 34, 0.08);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 48px 20px 64px;
  background:
    radial-gradient(1200px 460px at 14% -8%, var(--brand-50), transparent 60%),
    radial-gradient(900px 420px at 100% 0%, var(--accent-soft), transparent 55%),
    var(--bg);
  color: var(--ink);
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.page {
  width: 100%;
  max-width: 600px;
}

/* ── Card ───────────────────────────────────────────── */
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  box-shadow: var(--sh-2);
  padding: 32px;
}

.card__head {
  margin-bottom: 22px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 11px;
  border-radius: 999px;
  background: var(--brand-50);
  color: var(--brand-700);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.card__title {
  margin: 14px 0 8px;
  font-size: 27px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.18;
}

.card__lede {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  max-width: 50ch;
}

/* ── Error summary ──────────────────────────────────── */
.summary {
  margin-bottom: 24px;
  padding: 18px 20px 8px;
  border: 1px solid var(--danger);
  border-left-width: 5px;
  border-radius: var(--r-md);
  background: var(--danger-soft);
  animation: summaryIn 0.28s ease;
}

.summary:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--danger) 45%, transparent);
  outline-offset: 2px;
}

.summary__title {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 6px;
  color: var(--danger);
  font-size: 17px;
  font-weight: 700;
}

.summary__list {
  margin: 0;
  padding: 0 0 6px 30px;
  display: grid;
  gap: 4px;
}

.summary__list li {
  list-style: disc;
}

.summary__list a {
  color: var(--danger);
  font-weight: 600;
  font-size: 14.5px;
  text-decoration: underline;
  text-underline-offset: 3px;
  border-radius: 4px;
  cursor: pointer;
}

.summary__list a:hover {
  color: #a93b2c;
}

.summary__list a:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--danger) 45%, transparent);
  outline-offset: 2px;
}

@keyframes summaryIn {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ── Form grid ──────────────────────────────────────── */
.form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.field {
  grid-column: 1 / -1;
  min-width: 0;
  border: 0;
  margin: 0;
  padding: 0;
}

.field--half {
  grid-column: span 1;
}

.field--group {
  padding: 0;
}

.field__label {
  display: block;
  margin-bottom: 4px;
  padding: 0;
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
}

legend.field__label {
  float: left;
}

.req {
  color: var(--danger);
  font-weight: 700;
}

.field__hint {
  margin: 0 0 8px;
  font-size: 13px;
  color: var(--muted);
}

.field__error {
  margin: 0 0 8px;
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--danger);
}

.field__error::before {
  content: "";
  flex: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--danger);
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='white' d='M12 2a10 10 0 100 20 10 10 0 000-20zm0 5a1 1 0 011 1v5a1 1 0 11-2 0V8a1 1 0 011-1zm0 9.5a1.2 1.2 0 110 2.4 1.2 1.2 0 010-2.4z'/%3E%3C/svg%3E")
    center / contain no-repeat;
  mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='white' d='M12 2a10 10 0 100 20 10 10 0 000-20zm0 5a1 1 0 011 1v5a1 1 0 11-2 0V8a1 1 0 011-1zm0 9.5a1.2 1.2 0 110 2.4 1.2 1.2 0 010-2.4z'/%3E%3C/svg%3E")
    center / contain no-repeat;
}

.field__error--check::before {
  margin-top: 0;
}

/* ── Inputs ─────────────────────────────────────────── */
.input {
  width: 100%;
  padding: 11px 13px;
  font: inherit;
  font-size: 15px;
  color: var(--ink);
  background: var(--white);
  border: 1.5px solid var(--line-2);
  border-radius: var(--r-sm);
  box-shadow: var(--sh-1);
  transition:
    border-color 0.15s ease,
    box-shadow 0.15s ease,
    background 0.15s ease;
}

.input::placeholder {
  color: #9aa0bd;
}

.input:hover:not(:disabled) {
  border-color: var(--ink-2);
}

.input:focus-visible {
  outline: none;
  border-color: var(--brand);
  box-shadow: 0 0 0 4px var(--brand-50);
}

.input:disabled {
  background: #f1f2f7;
  color: var(--muted);
  cursor: not-allowed;
  box-shadow: none;
}

/* Error / success states on the wrapping .field */
.field.is-error .input {
  border-color: var(--danger);
  background: #fffafa;
}

.field.is-error .input:focus-visible {
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--danger) 20%, transparent);
}

.field.is-valid .input {
  border-color: var(--ok);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='%232f9e6f' stroke-width='2.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 12.5l4.5 4.5L19 7'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 40px;
}

.field.is-valid .input:focus-visible {
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--ok) 18%, transparent);
}

/* ── Radio group ────────────────────────────────────── */
.radios {
  clear: both;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}

.radio {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 13px 13px 13px 38px;
  border: 1.5px solid var(--line-2);
  border-radius: var(--r-sm);
  background: var(--white);
  cursor: pointer;
  transition:
    border-color 0.15s ease,
    background 0.15s ease,
    box-shadow 0.15s ease;
}

.radio input {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
}

.radio__box {
  position: absolute;
  top: 14px;
  left: 13px;
  width: 16px;
  height: 16px;
  border: 2px solid var(--line-2);
  border-radius: 50%;
  transition:
    border-color 0.15s ease,
    box-shadow 0.15s ease;
}

.radio__box::after {
  content: "";
  position: absolute;
  inset: 3px;
  border-radius: 50%;
  background: var(--brand);
  transform: scale(0);
  transition: transform 0.15s ease;
}

.radio:hover {
  border-color: var(--ink-2);
}

.radio input:checked ~ .radio__box {
  border-color: var(--brand);
}

.radio input:checked ~ .radio__box::after {
  transform: scale(1);
}

.radio:has(input:checked) {
  border-color: var(--brand);
  background: var(--brand-50);
}

.radio input:focus-visible ~ .radio__box {
  box-shadow: 0 0 0 4px var(--brand-50);
}

.radio__text strong {
  display: block;
  font-size: 14px;
  color: var(--ink);
}

.radio__text small {
  display: block;
  margin-top: 2px;
  font-size: 12px;
  color: var(--muted);
}

.field.is-error .radio {
  border-color: var(--danger);
}

/* ── Checkbox ───────────────────────────────────────── */
.field--check {
  margin-top: 2px;
}

.check {
  display: flex;
  align-items: flex-start;
  gap: 11px;
  cursor: pointer;
  font-size: 14.5px;
  color: var(--ink-2);
}

.check input {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
}

.check__box {
  flex: none;
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  margin-top: 1px;
  border: 1.5px solid var(--line-2);
  border-radius: 6px;
  background: var(--white);
  color: var(--white);
  transition:
    background 0.15s ease,
    border-color 0.15s ease,
    box-shadow 0.15s ease;
}

.check__box svg {
  opacity: 0;
  transform: scale(0.6);
  transition:
    opacity 0.12s ease,
    transform 0.12s ease;
}

.check input:checked ~ .check__box {
  background: var(--brand);
  border-color: var(--brand);
}

.check input:checked ~ .check__box svg {
  opacity: 1;
  transform: scale(1);
}

.check input:focus-visible ~ .check__box {
  box-shadow: 0 0 0 4px var(--brand-50);
}

.field--check.is-error .check__box {
  border-color: var(--danger);
}

/* ── Actions ────────────────────────────────────────── */
.form__actions {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: 6px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  font: inherit;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--r-sm);
  border: 1.5px solid transparent;
  cursor: pointer;
  transition:
    transform 0.12s ease,
    box-shadow 0.15s ease,
    background 0.15s ease,
    border-color 0.15s ease;
}

.btn:active {
  transform: translateY(1px);
}

.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 4px var(--brand-50);
}

.btn--primary {
  background: var(--brand);
  color: var(--white);
  box-shadow: var(--sh-1);
}

.btn--primary:hover {
  background: var(--brand-d);
}

.btn--ghost {
  background: var(--white);
  color: var(--ink-2);
  border-color: var(--line-2);
}

.btn--ghost:hover {
  border-color: var(--ink-2);
  background: #fafbff;
}

.form__status {
  margin: 0;
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
}

.form__status.is-error {
  color: var(--danger);
}

.form__status.is-ok {
  color: var(--ok);
}

/* ── Success panel ──────────────────────────────────── */
.success {
  text-align: center;
  padding: 18px 12px 6px;
  animation: summaryIn 0.3s ease;
}

.success:focus-visible {
  outline: none;
}

.success__badge {
  display: inline-grid;
  place-items: center;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--ok);
  margin-bottom: 14px;
}

.success__title {
  margin: 0 0 8px;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.success__text {
  margin: 0 auto 20px;
  max-width: 42ch;
  color: var(--muted);
  font-size: 15px;
}

/* ── Toast ──────────────────────────────────────────── */
.toast {
  position: fixed;
  left: 50%;
  bottom: 26px;
  transform: translateX(-50%) translateY(16px);
  max-width: calc(100vw - 40px);
  padding: 12px 18px;
  background: var(--ink);
  color: var(--white);
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--r-md);
  box-shadow: var(--sh-2);
  opacity: 0;
  pointer-events: none;
  transition:
    opacity 0.22s ease,
    transform 0.22s ease;
  z-index: 60;
}

.toast.is-visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ── Responsive ─────────────────────────────────────── */
@media (max-width: 520px) {
  body {
    padding: 24px 14px 48px;
  }

  .card {
    padding: 22px 18px;
    border-radius: var(--r-md);
  }

  .card__title {
    font-size: 23px;
  }

  .form {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .field--half {
    grid-column: 1 / -1;
  }

  .radios {
    grid-template-columns: 1fr;
  }

  .form__actions {
    flex-direction: column;
    align-items: stretch;
  }

  .form__actions .btn {
    width: 100%;
  }

  .form__status {
    text-align: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}

/* Form — Top error summary + jump-to-field
 * GOV.UK style accessible error-summary pattern.
 * - On invalid submit, an error summary (role=alert) lists every invalid field
 *   as links. The summary receives focus; activating a link focuses the field.
 * - Each field shows its own inline error with aria-invalid + aria-describedby.
 * - Fixing a field removes it from the summary live (on blur / input).
 * - A valid submit shows a success confirmation panel.
 */
(function () {
  "use strict";

  var form = document.getElementById("signup-form");
  if (!form) return;

  var summary = document.getElementById("error-summary");
  var summaryList = document.getElementById("summary-list");
  var summaryHeading = document.getElementById("summary-heading");
  var statusEl = document.getElementById("form-status");
  var successPanel = document.getElementById("success-panel");
  var successText = document.getElementById("success-text");
  var restartBtn = document.getElementById("restart");
  var toastEl = document.getElementById("toast");

  /* Field order matters: summary links follow document/visual order. */
  var ORDER = ["fullName", "email", "memberId", "age", "plan", "password", "terms"];

  var LABELS = {
    fullName: "Full name",
    email: "Email address",
    memberId: "Member ID",
    age: "Age",
    plan: "Membership plan",
    password: "Password",
    terms: "Terms acceptance",
  };

  /* Whether the form has been submitted once. Before that we don't nag
     on every keystroke — classic "validate on submit, then live-correct". */
  var submitted = false;

  /* ── Toast helper ─────────────────────────────────── */
  var toastTimer;
  function toast(msg) {
    if (!toastEl) return;
    toastEl.textContent = msg;
    toastEl.hidden = false;
    /* force reflow so the transition runs from hidden */
    void toastEl.offsetWidth;
    toastEl.classList.add("is-visible");
    clearTimeout(toastTimer);
    toastTimer = setTimeout(function () {
      toastEl.classList.remove("is-visible");
      setTimeout(function () {
        toastEl.hidden = true;
      }, 240);
    }, 2600);
  }

  /* ── Validators ───────────────────────────────────── */
  var EMAIL_RE = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;

  var validators = {
    fullName: function () {
      var v = form.elements.fullName.value.trim();
      if (!v) return "Enter your full name.";
      if (v.length < 2) return "Your name looks too short.";
      if (!/\s/.test(v)) return "Enter your first and last name.";
      return "";
    },
    email: function () {
      var v = form.elements.email.value.trim();
      if (!v) return "Enter your email address.";
      if (!EMAIL_RE.test(v)) return "Enter a valid email, like [email protected].";
      return "";
    },
    memberId: function () {
      var v = form.elements.memberId.value.trim();
      if (!v) return "Enter your 6-digit member ID.";
      if (!/^\d{6}$/.test(v)) return "Member ID must be exactly 6 digits.";
      return "";
    },
    age: function () {
      var raw = form.elements.age.value.trim();
      if (!raw) return "Enter your age.";
      if (!/^\d{1,3}$/.test(raw)) return "Age must be a whole number.";
      var n = parseInt(raw, 10);
      if (n < 18) return "You must be 18 or older to apply.";
      if (n > 120) return "Enter a realistic age.";
      return "";
    },
    plan: function () {
      var checked = form.querySelector('input[name="plan"]:checked');
      if (!checked) return "Choose a membership plan.";
      return "";
    },
    password: function () {
      var v = form.elements.password.value;
      if (!v) return "Create a password.";
      if (v.length < 8) return "Use at least 8 characters.";
      if (!/\d/.test(v)) return "Include at least one number.";
      return "";
    },
    terms: function () {
      if (!form.elements.terms.checked) return "You must accept the terms to continue.";
      return "";
    },
  };

  /* The control that should receive focus when jumping to a field. */
  function focusTargetFor(name) {
    if (name === "plan") {
      var checked = form.querySelector('input[name="plan"]:checked');
      return checked || form.querySelector('input[name="plan"]');
    }
    return form.elements[name];
  }

  function wrapperFor(name) {
    return form.querySelector('[data-field="' + name + '"]');
  }

  /* ── Per-field UI ─────────────────────────────────── */
  function showFieldError(name, message) {
    var wrap = wrapperFor(name);
    var errEl = document.getElementById(name + "-error");
    var control = focusTargetFor(name);
    if (!wrap || !errEl) return;

    wrap.classList.add("is-error");
    wrap.classList.remove("is-valid");
    errEl.textContent = message;
    errEl.hidden = false;

    if (control) {
      control.setAttribute("aria-invalid", "true");
      linkDescribedBy(name, control, true);
    }
  }

  function clearFieldError(name, opts) {
    var wrap = wrapperFor(name);
    var errEl = document.getElementById(name + "-error");
    var control = focusTargetFor(name);
    if (!wrap || !errEl) return;

    wrap.classList.remove("is-error");
    errEl.hidden = true;
    errEl.textContent = "";

    if (control) {
      control.removeAttribute("aria-invalid");
      linkDescribedBy(name, control, false);
    }
    /* Mark valid (green tick) only for text-like inputs that have content. */
    if (opts && opts.markValid && control && "value" in control && control.value) {
      wrap.classList.add("is-valid");
    } else {
      wrap.classList.remove("is-valid");
    }
  }

  /* Keep aria-describedby pointing at hint (+ error when present). */
  function linkDescribedBy(name, control, hasError) {
    var hintId = name + "-hint";
    var errId = name + "-error";
    var ids = [];
    if (document.getElementById(hintId)) ids.push(hintId);
    if (hasError) ids.push(errId);
    if (ids.length) control.setAttribute("aria-describedby", ids.join(" "));
    else if (document.getElementById(hintId)) control.setAttribute("aria-describedby", hintId);
    else control.removeAttribute("aria-describedby");
  }

  /* ── Summary ──────────────────────────────────────── */
  function buildSummary(errors) {
    summaryList.innerHTML = "";
    ORDER.forEach(function (name) {
      if (!errors[name]) return;
      var li = document.createElement("li");
      var a = document.createElement("a");
      a.href = "#" + name;
      a.textContent = errors[name];
      a.dataset.target = name;
      li.appendChild(a);
      summaryList.appendChild(li);
    });

    var count = summaryList.children.length;
    summaryHeading.textContent =
      count === 1
        ? "There is a problem with 1 field"
        : "There are problems with " + count + " fields";
  }

  function hideSummary() {
    summary.hidden = true;
    summaryList.innerHTML = "";
  }

  /* Update the summary in place (after a fix), without stealing focus. */
  function refreshSummary() {
    if (summary.hidden) return;
    var errors = collectErrors();
    if (Object.keys(errors).length === 0) {
      hideSummary();
      setStatus("All fields look good. Ready to submit.", "ok");
      return;
    }
    buildSummary(errors);
    setStatus("", "");
  }

  function collectErrors() {
    var errors = {};
    ORDER.forEach(function (name) {
      var msg = validators[name]();
      if (msg) errors[name] = msg;
    });
    return errors;
  }

  function setStatus(msg, kind) {
    statusEl.textContent = msg;
    statusEl.classList.remove("is-error", "is-ok");
    if (kind === "error") statusEl.classList.add("is-error");
    if (kind === "ok") statusEl.classList.add("is-ok");
  }

  /* ── Summary link clicks → jump to field ──────────── */
  summaryList.addEventListener("click", function (e) {
    var link = e.target.closest("a[data-target]");
    if (!link) return;
    e.preventDefault();
    var name = link.dataset.target;
    var control = focusTargetFor(name);
    var wrap = wrapperFor(name);
    if (wrap) wrap.scrollIntoView({ behavior: "smooth", block: "center" });
    if (control) {
      /* slight delay lets the scroll start before focus */
      setTimeout(function () {
        control.focus({ preventScroll: true });
      }, 60);
    }
  });

  /* ── Live correction after first submit ───────────── */
  function validateSingle(name, markValid) {
    var msg = validators[name]();
    if (msg) {
      showFieldError(name, msg);
    } else {
      clearFieldError(name, { markValid: markValid });
    }
    return !msg;
  }

  ORDER.forEach(function (name) {
    var wrap = wrapperFor(name);
    if (!wrap) return;
    var controls = wrap.querySelectorAll("input");

    controls.forEach(function (control) {
      /* Re-validate on blur once the form has been submitted once. */
      control.addEventListener("blur", function () {
        if (!submitted) return;
        validateSingle(name, true);
        refreshSummary();
      });

      /* If a field is already in error, clear it as soon as it becomes valid. */
      var ev = control.type === "radio" || control.type === "checkbox" ? "change" : "input";
      control.addEventListener(ev, function () {
        if (!submitted) return;
        var wasError = wrap.classList.contains("is-error");
        if (wasError && !validators[name]()) {
          clearFieldError(name, { markValid: control.type === "text" || control.type === "email" || control.type === "password" });
          refreshSummary();
        } else if (wrap.classList.contains("is-error")) {
          /* still invalid — keep summary text fresh */
          var m = validators[name]();
          if (m) showFieldError(name, m);
        }
      });
    });
  });

  /* Keep member ID / age numeric-only for a tidier UX. */
  ["memberId", "age"].forEach(function (name) {
    form.elements[name].addEventListener("input", function () {
      this.value = this.value.replace(/\D/g, "");
    });
  });

  /* ── Submit ───────────────────────────────────────── */
  form.addEventListener("submit", function (e) {
    e.preventDefault();
    submitted = true;

    var errors = collectErrors();

    /* Apply every field's state (errors + valid ticks). */
    ORDER.forEach(function (name) {
      if (errors[name]) showFieldError(name, errors[name]);
      else clearFieldError(name, { markValid: true });
    });

    var keys = Object.keys(errors);
    if (keys.length > 0) {
      buildSummary(errors);
      summary.hidden = false;
      /* Move focus to the summary so screen-reader users hear it first. */
      summary.focus();
      summary.scrollIntoView({ behavior: "smooth", block: "start" });
      setStatus(
        keys.length === 1
          ? "1 field needs your attention."
          : keys.length + " fields need your attention.",
        "error"
      );
      toast("Check the highlighted fields.");
      return;
    }

    /* Valid — show success state. */
    hideSummary();
    var name = form.elements.fullName.value.trim().split(/\s+/)[0];
    var email = form.elements.email.value.trim();
    successText.textContent =
      "Thanks, " + name + ". We have emailed your confirmation to " + email +
      " and your membership is being set up.";

    form.hidden = true;
    successPanel.hidden = false;
    successPanel.focus();
    toast("Application submitted successfully.");
  });

  /* ── Reset ────────────────────────────────────────── */
  form.addEventListener("reset", function () {
    submitted = false;
    hideSummary();
    setStatus("", "");
    ORDER.forEach(function (name) {
      var wrap = wrapperFor(name);
      if (wrap) wrap.classList.remove("is-error", "is-valid");
      var errEl = document.getElementById(name + "-error");
      if (errEl) {
        errEl.hidden = true;
        errEl.textContent = "";
      }
      var control = focusTargetFor(name);
      if (control) control.removeAttribute("aria-invalid");
    });
    toast("Form cleared.");
  });

  /* ── Restart from success panel ───────────────────── */
  if (restartBtn) {
    restartBtn.addEventListener("click", function () {
      successPanel.hidden = true;
      form.hidden = false;
      form.reset();
      submitted = false;
      form.elements.fullName.focus();
    });
  }
})();

<!doctype html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <title>Form — Top error summary + jump-to-field</title>
    <link rel="preconnect" href="https://fonts.googleapis.com" />
    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
    <link
      href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap"
      rel="stylesheet"
    />
    <link rel="stylesheet" href="style.css" />
  </head>
  <body>
    <main class="page">
      <section class="card" aria-labelledby="form-title">
        <header class="card__head">
          <span class="eyebrow">
            <svg viewBox="0 0 24 24" width="14" height="14" aria-hidden="true">
              <path
                fill="none"
                stroke="currentColor"
                stroke-width="2"
                stroke-linecap="round"
                stroke-linejoin="round"
                d="M9 12.5l2 2 4-4M12 3l8 4v5c0 5-3.5 8-8 9-4.5-1-8-4-8-9V7l8-4z"
              />
            </svg>
            Membership application
          </span>
          <h1 id="form-title" class="card__title">Open your Northwind account</h1>
          <p class="card__lede">
            Submit the form with mistakes and an error summary appears at the top.
            Each entry links straight to the field that needs fixing, GOV.UK style.
          </p>
        </header>

        <!-- Error summary: injected/toggled by JS, gets focus on submit-fail -->
        <div
          id="error-summary"
          class="summary"
          role="alert"
          tabindex="-1"
          hidden
        >
          <h2 class="summary__title">
            <svg viewBox="0 0 24 24" width="20" height="20" aria-hidden="true">
              <circle cx="12" cy="12" r="9" fill="none" stroke="currentColor" stroke-width="2" />
              <path
                fill="none"
                stroke="currentColor"
                stroke-width="2"
                stroke-linecap="round"
                d="M12 7.5v5.5M12 16.2v.2"
              />
            </svg>
            <span id="summary-heading">There is a problem</span>
          </h2>
          <ul class="summary__list" id="summary-list"></ul>
        </div>

        <form id="signup-form" class="form" novalidate>
          <div class="field" data-field="fullName">
            <label class="field__label" for="fullName">
              Full name <span class="req" aria-hidden="true">*</span>
            </label>
            <p class="field__hint" id="fullName-hint">As it appears on your ID, e.g. Marisol Quintero.</p>
            <p class="field__error" id="fullName-error" hidden></p>
            <input
              class="input"
              id="fullName"
              name="fullName"
              type="text"
              autocomplete="name"
              placeholder="Marisol Quintero"
              aria-describedby="fullName-hint"
              required
            />
          </div>

          <div class="field" data-field="email">
            <label class="field__label" for="email">
              Email address <span class="req" aria-hidden="true">*</span>
            </label>
            <p class="field__hint" id="email-hint">We send your confirmation here. No spam, ever.</p>
            <p class="field__error" id="email-error" hidden></p>
            <input
              class="input"
              id="email"
              name="email"
              type="email"
              autocomplete="email"
              inputmode="email"
              placeholder="[email protected]"
              aria-describedby="email-hint"
              required
            />
          </div>

          <div class="field field--half" data-field="memberId">
            <label class="field__label" for="memberId">
              Member ID <span class="req" aria-hidden="true">*</span>
            </label>
            <p class="field__hint" id="memberId-hint">Six digits from your welcome letter, e.g. 480293.</p>
            <p class="field__error" id="memberId-error" hidden></p>
            <input
              class="input"
              id="memberId"
              name="memberId"
              type="text"
              inputmode="numeric"
              autocomplete="off"
              placeholder="480293"
              maxlength="6"
              aria-describedby="memberId-hint"
              required
            />
          </div>

          <div class="field field--half" data-field="age">
            <label class="field__label" for="age">
              Age <span class="req" aria-hidden="true">*</span>
            </label>
            <p class="field__hint" id="age-hint">You must be 18 or older to apply.</p>
            <p class="field__error" id="age-error" hidden></p>
            <input
              class="input"
              id="age"
              name="age"
              type="text"
              inputmode="numeric"
              autocomplete="off"
              placeholder="29"
              maxlength="3"
              aria-describedby="age-hint"
              required
            />
          </div>

          <fieldset class="field field--group" data-field="plan">
            <legend class="field__label">
              Membership plan <span class="req" aria-hidden="true">*</span>
            </legend>
            <p class="field__hint" id="plan-hint">Pick the tier that fits — you can change later.</p>
            <p class="field__error" id="plan-error" hidden></p>
            <div class="radios" role="radiogroup" aria-describedby="plan-hint">
              <label class="radio">
                <input type="radio" name="plan" value="basic" aria-describedby="plan-hint" />
                <span class="radio__box" aria-hidden="true"></span>
                <span class="radio__text">
                  <strong>Basic</strong>
                  <small>Core access, monthly billing</small>
                </span>
              </label>
              <label class="radio">
                <input type="radio" name="plan" value="plus" aria-describedby="plan-hint" />
                <span class="radio__box" aria-hidden="true"></span>
                <span class="radio__text">
                  <strong>Plus</strong>
                  <small>Priority support + perks</small>
                </span>
              </label>
              <label class="radio">
                <input type="radio" name="plan" value="founder" aria-describedby="plan-hint" />
                <span class="radio__box" aria-hidden="true"></span>
                <span class="radio__text">
                  <strong>Founder</strong>
                  <small>Everything, billed yearly</small>
                </span>
              </label>
            </div>
          </fieldset>

          <div class="field" data-field="password">
            <label class="field__label" for="password">
              Create a password <span class="req" aria-hidden="true">*</span>
            </label>
            <p class="field__hint" id="password-hint">At least 8 characters with a number.</p>
            <p class="field__error" id="password-error" hidden></p>
            <input
              class="input"
              id="password"
              name="password"
              type="password"
              autocomplete="new-password"
              placeholder="••••••••"
              aria-describedby="password-hint"
              required
            />
          </div>

          <div class="field field--check" data-field="terms">
            <label class="check">
              <input type="checkbox" id="terms" name="terms" aria-describedby="terms-error" />
              <span class="check__box" aria-hidden="true">
                <svg viewBox="0 0 24 24" width="14" height="14" aria-hidden="true">
                  <path
                    fill="none"
                    stroke="currentColor"
                    stroke-width="3"
                    stroke-linecap="round"
                    stroke-linejoin="round"
                    d="M5 12.5l4.5 4.5L19 7"
                  />
                </svg>
              </span>
              <span class="check__text">
                I accept the membership terms and privacy policy
                <span class="req" aria-hidden="true">*</span>
              </span>
            </label>
            <p class="field__error field__error--check" id="terms-error" hidden></p>
          </div>

          <div class="form__actions">
            <button type="submit" class="btn btn--primary">
              Create account
              <svg viewBox="0 0 24 24" width="18" height="18" aria-hidden="true">
                <path
                  fill="none"
                  stroke="currentColor"
                  stroke-width="2"
                  stroke-linecap="round"
                  stroke-linejoin="round"
                  d="M5 12h14M13 6l6 6-6 6"
                />
              </svg>
            </button>
            <button type="reset" class="btn btn--ghost">Reset</button>
            <p class="form__status" id="form-status" role="status" aria-live="polite"></p>
          </div>
        </form>

        <!-- Success confirmation, swapped in after a valid submit -->
        <div class="success" id="success-panel" hidden tabindex="-1">
          <span class="success__badge" aria-hidden="true">
            <svg viewBox="0 0 24 24" width="30" height="30">
              <circle cx="12" cy="12" r="11" fill="none" stroke="currentColor" stroke-width="2" />
              <path
                fill="none"
                stroke="currentColor"
                stroke-width="2"
                stroke-linecap="round"
                stroke-linejoin="round"
                d="M7 12.5l3.2 3.2L17 9"
              />
            </svg>
          </span>
          <h2 class="success__title">Application received</h2>
          <p class="success__text" id="success-text">
            Thanks. We have emailed your confirmation and your account is being set up.
          </p>
          <button type="button" class="btn btn--ghost" id="restart">Start another application</button>
        </div>
      </section>
    </main>

    <!-- Toast region -->
    <div class="toast" id="toast" role="status" aria-live="polite" hidden></div>

    <script src="script.js"></script>
  </body>
</html>