:root {
  --bg: #f3f4f6;
  --card: #ffffff;
  --ink: #1f2937;
  --muted: #6b7280;
  --line: #d1d5db;
  --accent: #2563eb;
  --accent-dark: #1d4ed8;
  --error: #dc2626;
  --ok: #047857;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", "Hiragino Kaku Gothic ProN",
    Meiryo, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
}

.test-banner {
  background: #fef3c7;
  color: #92400e;
  text-align: center;
  padding: 10px 16px;
  font-size: 14px;
  border-bottom: 1px solid #fde68a;
}

.card {
  max-width: 760px;
  margin: 32px auto;
  background: var(--card);
  padding: 32px;
  border-radius: 12px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 8px 24px rgba(0, 0, 0, 0.06);
}

h1 {
  margin: 0 0 4px;
  font-size: 24px;
}

.lead {
  margin: 0 0 24px;
  color: var(--muted);
  font-size: 14px;
}

.field { margin-bottom: 18px; }

.row {
  display: flex;
  gap: 12px;
}
.row .field { flex: 1; }
@media (max-width: 420px) {
  .row { flex-direction: column; gap: 0; }
}

/* Checkbox column sits beside 名前; the hidden spacer keeps the checkbox aligned
   with the inputs (not the labels). */
.check-col {
  flex: 0 0 auto;
}
.check-col .spacer {
  display: block;
  font-size: 14px;
  margin-bottom: 6px;
  visibility: hidden;
}
.check-col .check {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 400;
  white-space: nowrap;
  padding: 10px 0;
}
.check-col .check input {
  width: auto;
  margin: 0;
}

label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 6px;
}

.req,
.opt {
  font-size: 11px;
  font-weight: 600;
  padding: 1px 6px;
  border-radius: 4px;
  vertical-align: middle;
}
.req { background: #fee2e2; color: var(--error); }
.opt { background: #e5e7eb; color: var(--muted); }

input[type="text"],
input[type="email"],
input[type="password"] {
  width: 100%;
  padding: 10px 12px;
  font-size: 15px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

input[aria-invalid="true"] {
  border-color: var(--error);
}

.check label {
  font-weight: 400;
  display: flex;
  align-items: center;
  gap: 8px;
}
.check input { width: auto; }

.hint {
  margin: 6px 0 0;
  font-size: 12px;
  color: var(--muted);
}

.error {
  margin: 6px 0 0;
  font-size: 13px;
  color: var(--error);
  min-height: 0;
}
.error:empty { display: none; }

.submit {
  width: 100%;
  margin-top: 8px;
  padding: 12px;
  font-size: 16px;
  font-weight: 700;
  color: #fff;
  background: var(--accent);
  border: none;
  border-radius: 8px;
  cursor: pointer;
}
.submit:hover { background: var(--accent-dark); }

.success {
  text-align: center;
}
.success h2 {
  color: var(--ok);
  margin: 0 0 8px;
}
.success dl {
  text-align: left;
  background: #f9fafb;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px 16px;
  margin: 16px 0;
}
.success dt {
  font-size: 12px;
  color: var(--muted);
  margin-top: 8px;
}
.success dt:first-child { margin-top: 0; }
.success dd {
  margin: 0;
  font-size: 15px;
}

.link {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  font-size: 14px;
  text-decoration: underline;
}

/* Rules table */
.rules { max-width: 760px; }
.rules h2 {
  margin: 0 0 4px;
  font-size: 18px;
}
.rules h3 {
  margin: 20px 0 8px;
  font-size: 15px;
  color: var(--ink);
}
.common-rules {
  margin: 0 0 8px;
  padding-left: 20px;
  font-size: 13px;
}
.common-rules li { margin-bottom: 4px; }
.rules code {
  background: #f3f4f6;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 0 4px;
  font-size: 12px;
}
.rules .ok { color: var(--ok); font-weight: 700; }
.rules .ng { color: var(--error); font-weight: 700; }
.glossary {
  margin: 0;
  font-size: 13px;
}
.glossary dt {
  font-weight: 700;
  margin-top: 12px;
}
.glossary dt:first-child { margin-top: 0; }
.glossary dd {
  margin: 4px 0 0;
  padding-left: 14px;
  border-left: 3px solid var(--line);
  color: var(--ink);
}
.rules table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}
.rules th,
.rules td {
  border: 1px solid var(--line);
  padding: 8px 10px;
  text-align: left;
  vertical-align: top;
}
.rules thead th {
  background: #f3f4f6;
}
.rules tbody th {
  background: #f9fafb;
  white-space: nowrap;
  font-weight: 600;
}
.rules td { color: var(--ink); }
@media (max-width: 520px) {
  .rules tbody th { white-space: normal; }
}

.foot {
  text-align: center;
  color: var(--muted);
  font-size: 12px;
  padding: 16px;
}