/* Usefull 公式サイト */
:root {
  --blue: #2b5fe0;
  --blue-deep: #1d3fb3;
  --blue-soft: #e8efff;
  --marker: #ffd84d;
  --fg: #15171a;
  --sub: #5a616b;
  --bg: #ffffff;
  --band: #f5f7fb;
  --card: #ffffff;
  --line: #e1e5ec;
  --s: #2b6be6;
  --v: #d93a3a;
  --o: #1e8e5a;
  --m: #8a5cf5;
  --radius: 18px;
  --shadow: 0 10px 30px rgba(20, 40, 90, 0.1);
}
@media (prefers-color-scheme: dark) {
  :root {
    --blue: #6f9cff;
    --blue-deep: #4a78f0;
    --blue-soft: #1b2740;
    --marker: #8a6d14;
    --fg: #eef1f5;
    --sub: #a9b0ba;
    --bg: #0e1013;
    --band: #15181d;
    --card: #1a1e24;
    --line: #2c3139;
    --s: #6f9cff;
    --v: #ff7b7b;
    --o: #4cc38a;
    --m: #b79cff;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } * { animation: none !important; transition: none !important; } }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.8 -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic UI", sans-serif;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "palt";
}
img { max-width: 100%; }
a { color: var(--blue); }
h1, h2, h3 { line-height: 1.4; letter-spacing: 0.01em; word-break: auto-phrase; }
h2 { font-size: clamp(24px, 3.4vw, 34px); margin: 0 0 16px; }
h3 { font-size: 19px; margin: 0 0 8px; }
.wrap { width: 100%; max-width: 1120px; margin: 0 auto; padding: 0 20px; }
.wrap.narrow { max-width: 760px; }
.center { text-align: center; }
.sub { color: var(--sub); max-width: 640px; margin: 0 auto 32px; }
.eyebrow { color: var(--blue); font-weight: 700; font-size: 13px; letter-spacing: 0.14em; margin: 0 0 8px; }
.section { padding: 96px 0; }
.band { background: var(--band); padding: 96px 0; }
.sp { display: none; }
@media (max-width: 600px) { .sp { display: inline; } .section, .band { padding: 72px 0; } }

.skip { position: absolute; left: -999px; }
.skip:focus { left: 12px; top: 12px; z-index: 100; background: var(--card); padding: 8px 12px; border-radius: 8px; }
:focus-visible { outline: 3px solid var(--blue); outline-offset: 3px; border-radius: 6px; }

/* ボタン */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  background: var(--blue); color: #fff; font-weight: 700; text-decoration: none;
  border-radius: 999px; padding: 12px 24px; transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 6px 16px rgba(43, 95, 224, 0.3);
}
@media (prefers-color-scheme: dark) { .btn { color: #0e1013; } }
.btn:hover { transform: translateY(-1px); box-shadow: 0 10px 22px rgba(43, 95, 224, 0.38); }
.btn-sm { padding: 8px 16px; font-size: 14px; box-shadow: none; }
.btn-lg { padding: 16px 32px; font-size: 17px; }
.btn-block { display: flex; width: 100%; }
.btn-light { background: #fff; color: var(--blue-deep); box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2); }

/* ナビ */
.nav { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--bg) 85%, transparent); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.nav-inner { display: flex; align-items: center; gap: 24px; height: 64px; }
.logo { display: flex; align-items: center; gap: 8px; font-weight: 800; font-size: 19px; color: var(--fg); text-decoration: none; }
.logo img { border-radius: 7px; }
.nav nav { display: flex; gap: 22px; margin-left: auto; }
.nav nav a { color: var(--sub); text-decoration: none; font-size: 14px; font-weight: 600; }
.nav nav a:hover { color: var(--fg); }
@media (max-width: 760px) { .nav nav { display: none; } .nav .btn { margin-left: auto; } }

/* ヒーロー */
.hero { padding: 72px 0 96px; background:
  radial-gradient(900px 400px at 85% 10%, var(--blue-soft), transparent 70%),
  radial-gradient(600px 300px at 0% 100%, color-mix(in srgb, var(--marker) 25%, transparent), transparent 70%); }
.hero-grid { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 56px; align-items: center; }
@media (max-width: 900px) { .hero-grid { grid-template-columns: 1fr; } .hero { padding-top: 40px; } }
h1 { font-size: clamp(32px, 5.2vw, 54px); margin: 0 0 20px; line-height: 1.3; }
.marker { background: linear-gradient(transparent 62%, var(--marker) 62%, var(--marker) 92%, transparent 92%); padding: 0 2px; }
.lead { font-size: 17px; color: var(--sub); max-width: 560px; }
.lead strong { color: var(--fg); }
.cta-row { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; margin: 28px 0 20px; }
.soon { font-size: 14px; color: var(--sub); }
.hero-points { display: flex; flex-wrap: wrap; gap: 8px 20px; padding: 0; margin: 0; list-style: none; font-size: 14px; color: var(--sub); }
.hero-points li::before { content: "✓ "; color: var(--o); font-weight: 700; }

/* スマホのモック */
.phone { justify-self: center; width: 330px; max-width: 100%; border-radius: 40px; padding: 12px; background: #11141a; box-shadow: 0 30px 60px rgba(20, 40, 90, 0.28); transform: rotate(2deg); }
.phone-screen { background: var(--band); border-radius: 30px; padding: 18px 14px 20px; min-height: 560px; font-size: 13px; line-height: 1.6; position: relative; overflow: hidden; }
.ph-tabs { display: flex; background: var(--line); border-radius: 10px; padding: 3px; margin-bottom: 12px; }
.ph-tabs span { flex: 1; text-align: center; padding: 5px 0; border-radius: 8px; color: var(--sub); font-weight: 600; font-size: 12px; }
.ph-tabs .on { background: var(--card); color: var(--fg); }
.ph-card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 12px; }
.ph-en { margin: 0 0 8px; font-weight: 700; }
.svoc { display: flex; flex-wrap: wrap; gap: 5px; margin-bottom: 8px; }
.svoc span { border: 1.5px solid; border-radius: 7px; padding: 2px 6px; font-size: 12px; }
.svoc i { font-style: normal; font-weight: 800; margin-right: 4px; }
.c-s { color: var(--s); } .c-v { color: var(--v); } .c-o { color: var(--o); } .c-m { color: var(--m); }
.ph-ja { margin: 0; color: var(--sub); font-size: 12px; }
.ph-toast { margin: 12px 0; background: color-mix(in srgb, var(--o) 15%, var(--card)); color: var(--fg); font-weight: 700; border-radius: 12px; padding: 10px 12px; display: flex; align-items: center; gap: 8px; animation: pop 0.6s 0.8s both; }
.dot { width: 8px; height: 8px; border-radius: 50%; background: var(--o); }
.ph-word { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 12px; display: grid; gap: 2px; animation: slide 0.6s 1.3s both; }
.ph-word b { font-size: 16px; }
.ph-word em { font-style: normal; font-size: 11px; font-weight: 700; color: var(--blue); background: var(--blue-soft); padding: 1px 6px; border-radius: 6px; margin-left: 6px; }
.ph-word small { color: var(--sub); }
.ph-word .ex { color: var(--fg); }
mark { background: var(--marker); color: inherit; padding: 0 2px; border-radius: 3px; font-weight: 700; text-decoration: underline; text-decoration-thickness: 2px; }
@keyframes pop { from { opacity: 0; transform: translateY(8px) scale(0.96); } to { opacity: 1; transform: none; } }
@keyframes slide { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: none; } }

/* 課題 */
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; margin-top: 40px; }
@media (max-width: 860px) { .grid3 { grid-template-columns: 1fr; } }
.pain { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.pain-q { font-weight: 700; font-size: 17px; margin: 0 0 8px; }
.pain p:last-child { color: var(--sub); margin: 0; font-size: 15px; }

/* ステップ */
.steps { list-style: none; padding: 0; margin: 48px 0 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; counter-reset: s; }
@media (max-width: 860px) { .steps { grid-template-columns: 1fr; } }
.steps li { position: relative; padding: 28px 24px; border-radius: var(--radius); background: var(--band); }
.step-no { display: inline-grid; place-items: center; width: 40px; height: 40px; border-radius: 50%; background: var(--blue); color: #fff; font-weight: 800; margin-bottom: 12px; }
@media (prefers-color-scheme: dark) { .step-no { color: #0e1013; } }
.steps p { color: var(--sub); margin: 0; }

/* デモ */
.demo { background: var(--card); border: 1px solid var(--line); border-radius: 24px; padding: 24px; box-shadow: var(--shadow); }
.demo-levels { display: flex; gap: 8px; justify-content: center; flex-wrap: wrap; margin-bottom: 20px; }
.demo-levels button { font: inherit; font-weight: 700; border: 1.5px solid var(--line); background: var(--band); color: var(--fg); padding: 8px 20px; border-radius: 999px; cursor: pointer; }
.demo-levels button.on { background: var(--blue); border-color: var(--blue); color: #fff; }
@media (prefers-color-scheme: dark) { .demo-levels button.on { color: #0e1013; } }
.demo-body { display: grid; grid-template-columns: 1.2fr 1fr; gap: 24px; }
@media (max-width: 860px) { .demo-body { grid-template-columns: 1fr; } }
.demo-text { font-size: 18px; line-height: 2; padding: 20px; background: var(--band); border-radius: 16px; }
.demo-text .hit { background: var(--marker); border-radius: 4px; padding: 0 2px; font-weight: 700; transition: background 0.3s; }
.demo-text .miss { color: var(--sub); text-decoration: underline dotted; text-underline-offset: 5px; }
.demo-count { font-weight: 800; font-size: 18px; margin: 0 0 12px; }
.demo-words ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.demo-words li { border: 1px solid var(--line); border-radius: 12px; padding: 10px 14px; display: flex; gap: 10px; align-items: baseline; flex-wrap: wrap; animation: pop 0.35s both; }
.demo-words li b { font-size: 16px; }
.demo-words .tag { font-size: 11px; font-weight: 700; padding: 1px 7px; border-radius: 6px; background: var(--band); color: var(--sub); }
.demo-words .tag.lv { background: var(--blue-soft); color: var(--blue); }
.demo-words .ja { color: var(--sub); font-size: 14px; width: 100%; }
.demo-note { color: var(--sub); font-size: 13px; margin: 16px 0 0; text-align: center; }

/* 機能 */
.feature { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; margin-top: 72px; }
.feature.reverse .feature-text { order: 2; }
@media (max-width: 860px) { .feature { grid-template-columns: 1fr; gap: 24px; margin-top: 56px; } .feature.reverse .feature-text { order: 0; } }
.feature-text p { color: var(--sub); }
.checks { list-style: none; padding: 0; margin: 12px 0 0; display: grid; gap: 6px; }
.checks li::before { content: "✓"; color: var(--o); font-weight: 800; margin-right: 8px; }
.feature-visual { background: linear-gradient(135deg, var(--blue-soft), var(--band)); border-radius: 24px; padding: 32px; }
.mini-card { background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 18px; box-shadow: var(--shadow); }
.center-card { text-align: center; }
.mini-title { font-size: 13px; font-weight: 700; color: var(--sub); margin: 0 0 8px; }
.slash { margin: 0 0 6px; font-weight: 600; }
.slash.ja { color: var(--sub); font-weight: 400; font-size: 15px; }
.word-row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.word-row b { font-size: 18px; }
.tag { font-size: 11px; font-weight: 700; padding: 1px 7px; border-radius: 6px; background: var(--band); color: var(--sub); }
.tag.lv { background: var(--blue-soft); color: var(--blue); }
.mini-ja { margin: 6px 0; font-weight: 700; }
.mini-ex { margin: 0 0 6px; }
.mini-meta { margin: 0; color: var(--sub); font-size: 13px; }
.chat { display: grid; gap: 10px; }
.bubble { margin: 0; padding: 12px 16px; border-radius: 16px; max-width: 90%; }
.bubble.me { justify-self: end; background: var(--blue); color: #fff; border-bottom-right-radius: 4px; }
@media (prefers-color-scheme: dark) { .bubble.me { color: #0e1013; } }
.bubble.ai { background: var(--card); border: 1px solid var(--line); border-bottom-left-radius: 4px; }
.big { font-size: 56px; font-weight: 800; margin: 0; line-height: 1.1; }
.big span { font-size: 20px; margin-left: 4px; }
.rates { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; margin-top: 16px; }
.rates span { background: var(--band); border-radius: 10px; padding: 8px 4px; font-size: 13px; font-weight: 700; display: grid; }
.rates span.on { background: var(--blue); color: #fff; }
@media (prefers-color-scheme: dark) { .rates span.on { color: #0e1013; } }
.rates small { font-weight: 400; font-size: 11px; opacity: 0.9; }

/* 比較 */
.table-wrap { overflow-x: auto; margin-top: 32px; }
.compare { width: 100%; min-width: 620px; border-collapse: separate; border-spacing: 0; background: var(--card); border: 1px solid var(--line); border-radius: 18px; overflow: hidden; }
.compare th, .compare td { padding: 14px 16px; border-bottom: 1px solid var(--line); text-align: center; }
.compare tbody tr:last-child th, .compare tbody tr:last-child td { border-bottom: 0; }
.compare th[scope="row"] { text-align: left; font-weight: 600; }
.compare td { color: var(--sub); }
.compare .us { background: var(--blue-soft); color: var(--fg); font-weight: 700; }

/* こんな人に */
.personas > div { padding: 24px; border-radius: var(--radius); border: 1px solid var(--line); }
.personas p { color: var(--sub); margin: 0; }

/* 料金 */
.price { display: grid; justify-items: center; gap: 16px; margin-top: 32px; }
.price-card { background: var(--card); border: 2px solid var(--blue); border-radius: 24px; padding: 32px; width: 100%; max-width: 420px; box-shadow: var(--shadow); }
.plan { font-weight: 700; color: var(--blue); margin: 0; }
.yen { font-size: 44px; font-weight: 800; margin: 0 0 12px; }
.price-card .btn { margin-top: 24px; }
.price-note { color: var(--sub); font-size: 14px; margin: 0; }

/* FAQ */
details { border-bottom: 1px solid var(--line); padding: 18px 4px; }
summary { font-weight: 700; cursor: pointer; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; color: var(--blue); font-size: 22px; line-height: 1; }
details[open] summary::after { content: "−"; }
details p { color: var(--sub); margin: 12px 0 0; }

/* 最後のCTA */
.final { padding: 96px 0; background: linear-gradient(135deg, #3b7bff, #1d3fb3); color: #fff; }
.final h2 { color: #fff; }
.final p { opacity: 0.9; margin: 0 0 28px; }

/* フッター */
.footer { padding: 40px 0; border-top: 1px solid var(--line); }
.footer-inner { display: flex; flex-wrap: wrap; align-items: center; gap: 16px 32px; }
.footer nav { display: flex; flex-wrap: wrap; gap: 8px 20px; }
.footer nav a { color: var(--sub); font-size: 14px; text-decoration: none; }
.footer nav a:hover { color: var(--fg); }
.copy { color: var(--sub); font-size: 13px; margin: 0 0 0 auto; }
@media (max-width: 760px) { .copy { margin: 0; } }

/* スマホ幅の調整 */
@media (max-width: 600px) {
  .demo { padding: 16px; }
  .demo-levels { gap: 6px; }
  .demo-levels button { padding: 7px 14px; font-size: 14px; }
  .demo-text { font-size: 16px; padding: 16px; }
  .compare { min-width: 0; font-size: 13px; }
  .compare th, .compare td { padding: 10px 6px; }
  .compare th[scope="row"] { width: 34%; }
}
.demo-text { align-self: start; }