:root {
  --bg: #f6f4ef;
  --surface: #ffffff;
  --surface-2: #efece4;
  --ink: #1c2230;
  --ink-2: #4c5466;
  --ink-3: #7c8496;
  --line: #e2ded4;
  --accent: #1f6f63;
  --accent-ink: #ffffff;
  --accent-soft: #e2f0ec;
  --warn: #9a5b00;
  --warn-soft: #fdf1dc;
  --danger: #b4232c;
  --danger-soft: #fde8e8;
  --shadow: 0 1px 2px rgb(28 34 48 / .04), 0 8px 24px rgb(28 34 48 / .06);
  --radius: 18px;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #12151b;
    --surface: #1a1e26;
    --surface-2: #232834;
    --ink: #eceef2;
    --ink-2: #b4bac6;
    --ink-3: #868d9b;
    --line: #2c3240;
    --accent: #5cc3ae;
    --accent-ink: #0b1714;
    --accent-soft: #173a33;
    --warn: #f0b24b;
    --warn-soft: #3a2c12;
    --danger: #ff7b82;
    --danger-soft: #3d1a1d;
    --shadow: 0 1px 2px rgb(0 0 0 / .3), 0 8px 24px rgb(0 0 0 / .25);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Zen Kaku Gothic New", "Hiragino Sans", "Noto Sans JP", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); }
button, input, select, textarea { font: inherit; color: inherit; }

.wrap { width: min(960px, 100%); margin: 0 auto; padding: 0 16px; }

/* ---------- header ---------- */
.hero { padding-top: 56px; padding-bottom: 28px; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12px; letter-spacing: .18em; font-weight: 700; color: var(--accent);
  text-transform: uppercase;
}
.eyebrow svg { width: 18px; height: 18px; }
.hero h1 {
  margin: 10px 0 12px;
  font-size: clamp(30px, 6vw, 44px);
  line-height: 1.25; letter-spacing: .02em; font-weight: 900;
}
.hero p { margin: 0; color: var(--ink-2); max-width: 40em; }
.updated { margin-top: 14px; font-size: 13px; color: var(--ink-3); }

.nav {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: saturate(1.4) blur(12px);
  -webkit-backdrop-filter: saturate(1.4) blur(12px);
  border-bottom: 1px solid var(--line);
}
.nav ul {
  display: flex; gap: 6px; margin: 0 auto; padding: 10px 16px; list-style: none;
  overflow-x: auto; scrollbar-width: none;
}
.nav ul::-webkit-scrollbar { display: none; }
.nav a {
  display: block; white-space: nowrap; padding: 6px 14px; border-radius: 999px;
  font-size: 14px; font-weight: 700; color: var(--ink-2); text-decoration: none;
}
.nav a:hover { background: var(--surface-2); color: var(--ink); }

/* ---------- sections ---------- */
section { padding: 36px 0 8px; }
.section-head { display: flex; align-items: baseline; gap: 12px; margin-bottom: 16px; }
.section-head h2 { margin: 0; font-size: 22px; font-weight: 900; letter-spacing: .02em; }
.section-head .sub { color: var(--ink-3); font-size: 13px; }

.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.pad { padding: 20px; }

.banner {
  margin-top: 20px; padding: 14px 18px; border-radius: 14px;
  background: var(--warn-soft); color: var(--warn); font-weight: 700;
  display: flex; gap: 10px; align-items: flex-start;
}
.banner[hidden] { display: none; }

/* ---------- network cards ---------- */
.areas { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 420px), 1fr)); }
.area-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 16px 20px 0; }
.area-head h3 { margin: 0; font-size: 18px; font-weight: 900; }
.seg {
  display: inline-flex; padding: 3px; border-radius: 999px; background: var(--surface-2);
}
.seg button {
  border: 0; background: transparent; cursor: pointer;
  padding: 4px 12px; border-radius: 999px; font-size: 13px; font-weight: 700; color: var(--ink-2);
}
.seg button[aria-pressed="true"] { background: var(--surface); color: var(--ink); box-shadow: 0 1px 3px rgb(0 0 0 / .12); }

.net { display: grid; grid-template-columns: 148px 1fr; gap: 20px; padding: 18px 20px 20px; align-items: center; }
.net[hidden] { display: none; }
.qr {
  background: #fff; border-radius: 12px; padding: 6px; border: 1px solid var(--line);
  aspect-ratio: 1; width: 100%;
}
.qr svg { width: 100%; height: 100%; display: block; }
.band-tag {
  display: inline-block; font-size: 11px; font-weight: 700; letter-spacing: .06em;
  padding: 1px 8px; border-radius: 6px; background: var(--accent-soft); color: var(--accent);
}
.band-hint { font-size: 12px; color: var(--ink-3); margin-left: 6px; }
.kv { margin: 10px 0 0; }
.kv dt { font-size: 12px; color: var(--ink-3); font-weight: 700; letter-spacing: .06em; }
.kv dd { margin: 0 0 8px; display: flex; align-items: center; gap: 8px; min-width: 0; }
.kv .val { font-family: var(--mono); font-size: 16px; font-weight: 600; word-break: break-all; min-width: 0; }
.copy {
  flex: none; border: 1px solid var(--line); background: var(--surface); cursor: pointer;
  border-radius: 8px; padding: 2px 10px; font-size: 12px; font-weight: 700; color: var(--ink-2);
}
.copy:hover { border-color: var(--accent); color: var(--accent); }
.copy.done { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }

@media (max-width: 480px) {
  .net { grid-template-columns: 1fr; justify-items: start; }
  .net .qr { width: 180px; justify-self: center; }
  .net .info { width: 100%; }
}

.howto { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 260px), 1fr)); margin-top: 16px; }
.howto .card { padding: 16px 18px; }
.howto h4 { margin: 0 0 4px; font-size: 15px; }
.howto ol { margin: 0; padding-left: 1.3em; color: var(--ink-2); font-size: 14px; }

/* ---------- lists ---------- */
.list { margin: 0; padding: 0; list-style: none; }
.list li { display: flex; gap: 12px; padding: 14px 20px; border-top: 1px solid var(--line); }
.list li:first-child { border-top: 0; }
.num {
  flex: none; width: 26px; height: 26px; border-radius: 50%;
  display: grid; place-items: center; font-size: 13px; font-weight: 900;
  background: var(--accent-soft); color: var(--accent); margin-top: 2px;
}
.num.ng { background: var(--danger-soft); color: var(--danger); }
.list strong { display: block; }
.list small { color: var(--ink-3); font-size: 13px; }

/* ---------- wired ---------- */
.notice { padding: 16px 20px; border-radius: 14px; background: var(--surface-2); color: var(--ink-2); font-size: 14px; margin-bottom: 16px; }
.wired h3 { margin: 0 0 6px; font-size: 18px; }
.wired p { margin: 0; color: var(--ink-2); }
.gallery { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 220px), 1fr)); align-items: start; margin-top: 16px; }
.gallery figure { margin: 0; }
.gallery a { display: block; border-radius: 12px; overflow: hidden; background: var(--surface-2); }
.gallery img { width: 100%; height: auto; max-height: 560px; object-fit: contain; }
.gallery figcaption { font-size: 13px; color: var(--ink-3); margin-top: 6px; }

/* ---------- form ---------- */
.form { display: grid; gap: 16px; }
.row { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(min(100%, 200px), 1fr)); }
.field label { display: block; font-size: 13px; font-weight: 700; margin-bottom: 6px; }
.field .req { color: var(--danger); margin-left: 4px; font-size: 11px; }
.field .hint { font-size: 12px; color: var(--ink-3); margin-top: 4px; }
input[type="text"], input[type="email"], input[type="password"], input[type="datetime-local"], select, textarea {
  width: 100%; padding: 11px 13px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--bg);
  font-size: 16px; /* iOS のズーム防止 */
}
textarea { min-height: 140px; resize: vertical; line-height: 1.7; }
input:focus-visible, select:focus-visible, textarea:focus-visible, button:focus-visible, a:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 2px;
}
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chips label {
  margin: 0; cursor: pointer; padding: 7px 14px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--bg); font-size: 14px; font-weight: 700;
}
.chips input { position: absolute; opacity: 0; pointer-events: none; }
.chips input:checked + span { color: var(--accent); }
.chips label:has(input:checked) { border-color: var(--accent); background: var(--accent-soft); }
.chips label:has(input:focus-visible) { outline: 2px solid var(--accent); outline-offset: 2px; }
.check { display: flex; gap: 8px; align-items: flex-start; font-size: 13px; color: var(--ink-2); }
.check input { margin-top: 5px; }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: 0; cursor: pointer; border-radius: 12px; padding: 12px 22px; text-decoration: none;
  background: var(--accent); color: var(--accent-ink); font-weight: 900; font-size: 15px;
}
.btn:disabled { opacity: .55; cursor: progress; }
.btn.ghost { background: transparent; color: var(--ink); border: 1px solid var(--line); }
.btn.small { padding: 6px 12px; font-size: 13px; border-radius: 9px; }
.btn.danger { background: var(--danger); color: #fff; }
.msg { font-size: 14px; font-weight: 700; }
.msg.ok { color: var(--accent); }
.msg.ng { color: var(--danger); }
.done-box { text-align: center; padding: 36px 20px; }
.done-box h3 { margin: 8px 0; }

footer { padding-top: 48px; padding-bottom: 40px; color: var(--ink-3); font-size: 13px; text-align: center; }

.skeleton { background: linear-gradient(90deg, var(--surface-2), var(--line), var(--surface-2)); background-size: 200% 100%; animation: sk 1.4s infinite; border-radius: 12px; }
@keyframes sk { to { background-position: -200% 0; } }
@media (prefers-reduced-motion: reduce) { .skeleton { animation: none; } html { scroll-behavior: auto; } }