:root {
  --bg: #f6f1ff;
  --bg-glow: #f3dcff;
  --grid: rgba(124, 58, 237, .06);
  --surface: rgba(255, 255, 255, .78);
  --solid: #ffffff;
  --text: #13203a;
  --muted: #56637a;
  --border: rgba(124, 58, 237, .18);
  --accent: #7c3aed;
  --accent-weak: #efe6ff;
  --cyan: #e0459b;
  --brand-from: #7c3aed;
  --brand-to: #e0459b;
  --good: #1a7f37;
  --field: rgba(251, 248, 255, .9);
  --radius: 18px;
  --shadow: 0 0 0 1px rgba(0, 180, 224, .08), 0 8px 28px rgba(31, 111, 235, .12);
  --glow: 0 0 18px rgba(224, 69, 155, .4);
  --ring: rgba(124, 58, 237, .12);
  --sweep: rgba(224, 69, 155, .16);
  --blip: #00c389;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a1020;
    --bg-glow: #0f2a4a;
    --grid: rgba(61, 214, 255, .06);
    --surface: rgba(20, 30, 52, .78);
    --solid: #141e34;
    --text: #e6eefc;
    --muted: #93a2bd;
    --border: rgba(61, 214, 255, .2);
    --accent: #5ea8ff;
    --accent-weak: #13284a;
    --cyan: #3dd6ff;
    --brand-from: #1c4fd6;
    --brand-to: #0896c0;
    --good: #4ac26b;
    --field: rgba(10, 18, 34, .85);
    --shadow: 0 0 0 1px rgba(61, 214, 255, .08), 0 8px 28px rgba(0, 0, 0, .35);
    --glow: 0 0 18px rgba(61, 214, 255, .5);
    --ring: rgba(61, 214, 255, .1);
    --sweep: rgba(61, 214, 255, .13);
    --blip: #3dffb0;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  /* うっすら光る背景と方眼（未来的な計器盤のイメージ） */
  background:
    radial-gradient(900px 500px at 85% -10%, var(--bg-glow), transparent 70%),
    radial-gradient(700px 400px at -10% 30%, var(--bg-glow), transparent 70%),
    linear-gradient(var(--grid) 1px, transparent 1px) 0 0 / 28px 28px,
    linear-gradient(90deg, var(--grid) 1px, transparent 1px) 0 0 / 28px 28px,
    var(--bg);
  background-attachment: fixed;
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", "Hiragino Sans", "Yu Gothic UI", "Meiryo", sans-serif;
  line-height: 1.75;
  -webkit-text-size-adjust: 100%;
}

/* ---- 背景のレーダー（画面に固定。中身の後ろに描く） ---- */
/* 同心円の目盛りと十字の線 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    linear-gradient(90deg, transparent calc(50% - 1px), var(--ring) calc(50% - 1px) calc(50% + 1px), transparent calc(50% + 1px)),
    linear-gradient(transparent calc(38% - 1px), var(--ring) calc(38% - 1px) calc(38% + 1px), transparent calc(38% + 1px)),
    repeating-radial-gradient(circle at 50% 38%, transparent 0 118px, var(--ring) 118px 120px);
  -webkit-mask-image: radial-gradient(circle at 50% 38%, #000 0 55%, transparent 85%);
  mask-image: radial-gradient(circle at 50% 38%, #000 0 55%, transparent 85%);
}
/* ゆっくり回る光の帯 */
body::after {
  content: "";
  position: fixed;
  left: 50%;
  top: 38%;
  width: 170vmax;
  height: 170vmax;
  z-index: -1;
  pointer-events: none;
  border-radius: 50%;
  background: conic-gradient(from 0deg, var(--sweep), transparent 55deg, transparent);
  -webkit-mask-image: radial-gradient(circle, #000 0 30%, transparent 62%);
  mask-image: radial-gradient(circle, #000 0 30%, transparent 62%);
  transform: translate(-50%, -50%) rotate(0deg);
  animation: bg-sweep 9s linear infinite;
  will-change: transform;
}
/* ときどき光る点 */
html::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(circle at 68% 24%, var(--blip) 0 4px, transparent 9px),
    radial-gradient(circle at 27% 52%, var(--blip) 0 3px, transparent 8px),
    radial-gradient(circle at 80% 63%, var(--blip) 0 3px, transparent 8px);
  filter: drop-shadow(0 0 6px var(--blip));
  opacity: 0;
  animation: bg-blip 9s ease-out infinite;
}
@keyframes bg-sweep { to { transform: translate(-50%, -50%) rotate(360deg); } }
@keyframes bg-blip { 0%, 8% { opacity: 0; } 12% { opacity: .55; } 40%, 100% { opacity: 0; } }

a { color: var(--accent); }

.site-header {
  background: linear-gradient(110deg, var(--brand-from), var(--brand-to));
  box-shadow: 0 2px 16px rgba(0, 120, 200, .3);
  border-bottom: 1px solid rgba(255, 255, 255, .35);
}
.site-header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
}
.logo {
  font-weight: 800;
  font-size: 1.2rem;
  color: #fff;
  text-decoration: none;
  letter-spacing: .04em;
  text-shadow: 0 0 12px rgba(255, 255, 255, .55);
}
.logo span { color: #fff36b; text-shadow: 0 0 12px rgba(255, 243, 107, .8); }
.site-header nav a {
  color: rgba(255, 255, 255, .88);
  text-decoration: none;
  font-size: .9rem;
  font-weight: 600;
  margin-left: 14px;
}
.site-header nav a:hover { color: #fff; text-decoration: underline; }

.inner {
  max-width: 880px;
  margin: 0 auto;
  padding: 14px 16px;
}

main.inner { padding-top: 24px; padding-bottom: 40px; }

h1 { font-size: 1.6rem; line-height: 1.4; margin: 0 0 8px; }
h2 { position: relative; font-size: 1.2rem; margin: 36px 0 12px; padding-left: 16px; line-height: 1.4; letter-spacing: .03em; }
h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: .15em;
  bottom: .15em;
  width: 5px;
  border-radius: 3px;
  background: linear-gradient(var(--accent), var(--cyan));
  box-shadow: var(--glow);
}
h3 { font-size: 1rem; margin: 20px 0 6px; }
.lead { color: var(--muted); margin: 0 0 20px; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  padding: 20px;
}

/* ---- トップページのツール一覧 ---- */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 14px;
}
.tool-card {
  display: block;
  color: var(--text);
  text-decoration: none;
  transition: border-color .15s, transform .15s;
}
.tool-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.tool-card .icon { font-size: 1.8rem; line-height: 1; }
.tool-card h2, .tool-card h3 { border: 0; margin: 10px 0 4px; padding: 0; font-size: 1.05rem; }
.tool-card h2::before { display: none; }
.tool-card p { margin: 0; color: var(--muted); font-size: .9rem; }

/* ---- フォーム ---- */
label { font-weight: 600; font-size: .92rem; }
input[type="text"], input[type="number"], select, textarea {
  width: 100%;
  font: inherit;
  color: var(--text);
  background: var(--field);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
}
input[type="text"], input[type="number"], select { height: 46px; }
input:focus, select:focus, textarea:focus {
  outline: 2px solid var(--cyan);
  outline-offset: 1px;
  box-shadow: var(--glow);
}
textarea { min-height: 220px; resize: vertical; }

.row { display: flex; gap: 12px; flex-wrap: wrap; align-items: flex-end; }
.row > .field { flex: 1 1 160px; }
.field { display: flex; flex-direction: column; gap: 4px; margin-bottom: 12px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font: inherit;
  font-weight: 700;
  border: 0;
  background: linear-gradient(110deg, var(--brand-from), var(--brand-to));
  color: #fff;
  border-radius: 999px;
  padding: 11px 22px;
  cursor: pointer;
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(0, 150, 220, .35), inset 0 1px 0 rgba(255, 255, 255, .35);
  transition: box-shadow .2s, filter .2s;
}
.btn:hover { filter: brightness(1.08); box-shadow: var(--glow), inset 0 1px 0 rgba(255, 255, 255, .35); }
.btn.secondary { background: transparent; color: var(--accent); border: 1px solid var(--accent); box-shadow: none; }
.btn:disabled { opacity: .5; cursor: not-allowed; }

/* ---- 結果表示 ---- */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 10px;
  margin-top: 14px;
}
.stat {
  background: var(--accent-weak);
  border-radius: 10px;
  padding: 12px 14px;
}
.stat .label { font-size: .8rem; color: var(--muted); }
.stat .value { font-size: 1.5rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.stat .value small { font-size: .85rem; font-weight: 600; margin-left: 2px; }

.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-variant-numeric: tabular-nums; }
th, td { padding: 8px 10px; border-bottom: 1px solid var(--border); text-align: left; white-space: nowrap; }
th { font-size: .85rem; color: var(--muted); font-weight: 600; }
tr.highlight td { background: var(--accent-weak); font-weight: 700; }

.note { font-size: .88rem; color: var(--muted); }

/* ---- 広告枠（AdSense のコードをここに貼る） ---- */
.ad-slot {
  margin: 28px 0;
  min-height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.ad-slot:empty::before {
  content: "広告";
  color: var(--muted);
  font-size: .75rem;
  border: 1px dashed var(--border);
  border-radius: 8px;
  width: 100%;
  text-align: center;
  padding: 36px 0;
}

/* ---- FAQ ---- */
details {
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  padding: 10px 14px;
  margin-bottom: 8px;
}
summary { cursor: pointer; font-weight: 600; }
details p { margin: 8px 0 2px; }

.related { display: flex; flex-wrap: wrap; gap: 8px; padding: 0; list-style: none; }
.related a {
  display: inline-block;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  text-decoration: none;
  font-size: .9rem;
}

.site-footer {
  border-top: 1px solid var(--border);
  background: var(--solid);
  color: var(--muted);
  font-size: .85rem;
}
.site-footer a { color: var(--muted); margin-right: 14px; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

@media (max-width: 480px) {
  h1 { font-size: 1.35rem; }
  .card { padding: 16px; }
  .site-header nav a { margin-left: 0; margin-right: 12px; }
}