/* 紹介ページ（castback の LP と同じデザイン） */
    :root {
      --paper: #f6f2ea; --paper-2: #efe9dc; --card: #fffdf8;
      --ink: #23201b; --ink-2: #5d574c; --ink-3: #8d8676;
      --line: #ddd4c3; --line-2: #c9bea8;
      --red: #a23a2a; --red-d: #86301f; --marker: #f3df8f;
      --mincho: "Shippori Mincho B1", "Yu Mincho", "Hiragino Mincho ProN", serif;
      --gothic: "Zen Kaku Gothic New", "Hiragino Sans", "Yu Gothic", sans-serif;
      --hand: "Klee One", var(--gothic);
    }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: var(--gothic); color: var(--ink); background: var(--paper); line-height: 1.95; font-size: 16px; -webkit-font-smoothing: antialiased; }
    a { color: inherit; }
    img { max-width: 100%; height: auto; display: block; }
    .wrap { max-width: 1040px; margin: 0 auto; padding: 0 28px; }
    .narrow { max-width: 680px; }
    section { padding: 88px 0; border-top: 1px solid var(--line); scroll-margin-top: 56px; }
    h1, h2, h3 { font-family: var(--mincho); font-weight: 800; letter-spacing: .02em; line-height: 1.5; }
    h2 { font-size: 30px; margin-bottom: 20px; }
    h2 small { display: block; font-family: var(--gothic); font-size: 13px; font-weight: 700; color: var(--red); letter-spacing: .1em; margin-bottom: 6px; }
    p + p { margin-top: 1em; }
    br.sp { display: none; }
    .mk { background: linear-gradient(transparent 58%, var(--marker) 58%); }
    .lead { color: var(--ink-2); }

    header { position: sticky; top: 0; z-index: 10; background: rgba(246,242,234,.94); backdrop-filter: blur(6px); border-bottom: 1px solid var(--line); }
    .nav { display: flex; align-items: center; height: 56px; gap: 22px; }
    .brand { display: flex; align-items: center; gap: 9px; font-weight: 700; font-size: 15px; text-decoration: none; white-space: nowrap; }
    .nav-links { display: flex; gap: 20px; margin-left: auto; font-size: 14px; color: var(--ink-2); }
    .nav-links a, .nav-login { text-decoration: none; }
    .nav-links a:hover, .nav-login:hover { color: var(--red); }
    .nav-login { font-size: 14px; color: var(--ink-2); }

    .btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 50px; padding: 0 26px; border-radius: 4px; font-weight: 700; font-size: 15px; text-decoration: none; border: 1.5px solid var(--ink); transition: background .15s, color .15s; white-space: nowrap; }
    .btn-main { background: var(--red); border-color: var(--red); color: #fff; }
    .btn-main:hover { background: var(--red-d); border-color: var(--red-d); }
    .btn-line { background: transparent; color: var(--ink); }
    .btn-line:hover { background: var(--ink); color: var(--paper); }
    .btn-sm { min-height: 36px; padding: 0 14px; font-size: 13px; }

    /* ── 最初の画面 ── */
    .hero { padding: 72px 0 88px; }
    .hero-text { max-width: 640px; }
    .hero-tag { font-size: 13px; color: var(--ink-2); border-left: 3px solid var(--red); padding-left: 10px; }
    .hero h1 { font-size: 44px; margin: 18px 0 22px; line-height: 1.45; }
    .hero .lead { font-size: 16.5px; }
    .hero-cta { display: flex; gap: 12px; margin-top: 30px; flex-wrap: wrap; align-items: center; }
    .hero-cta .note { font-size: 13px; color: var(--ink-3); }
    .hero-cta .note a { color: var(--red); }
    .hero-shot { position: relative; margin-top: 76px; }
    .hand { font-family: var(--hand); color: var(--red); font-size: 17px; line-height: 1.5; }
    .hero-shot .hand { position: absolute; right: 4%; top: -48px; transform: rotate(-3deg); }

    figure { background: var(--card); border: 1px solid var(--line-2); border-radius: 6px; padding: 8px; box-shadow: 0 1px 0 var(--line), 0 18px 40px -24px rgba(60,45,20,.35); }
    figure img { border-radius: 3px; border: 1px solid var(--line); }
    figcaption { font-size: 13px; color: var(--ink-3); padding: 10px 6px 2px; }

    .login-error { background: #f8e3dd; color: var(--red-d); padding: 12px 16px; border-radius: 4px; font-size: 14px; margin-bottom: 18px; }

    /* ── こんな月末 ── */
    .memo { background: var(--card); border: 1px solid var(--line-2); padding: 30px 34px; margin-top: 30px; position: relative;
      background-image: repeating-linear-gradient(transparent 0 35px, #ece4d3 35px 36px); background-position: 0 22px; }
    .memo::before { content: ''; position: absolute; top: -10px; left: 50%; width: 110px; height: 22px; margin-left: -55px; background: rgba(214,196,150,.55); transform: rotate(-2deg); }
    .memo ul { list-style: none; }
    .memo li { line-height: 36px; padding-left: 1.4em; text-indent: -1.4em; }
    .memo li::before { content: '□ '; color: var(--ink-3); }
    .after { margin-top: 26px; }

    /* ── 仕組み ── */
    .steps { list-style: none; margin-top: 34px; display: grid; grid-template-columns: repeat(3, 1fr); border-top: 2px solid var(--ink); }
    .steps li { padding: 22px 24px 4px 0; }
    .steps li + li { padding-left: 24px; border-left: 1px solid var(--line); }
    .steps .no { font-family: var(--mincho); font-size: 34px; font-weight: 800; color: var(--red); line-height: 1; }
    .steps h3 { font-size: 19px; margin: 10px 0 8px; }
    .steps p { font-size: 15px; color: var(--ink-2); }
    .steps .hand { font-size: 15px; margin-top: 10px; color: var(--red); }

    /* ── 画面 ── */
    .row { display: grid; grid-template-columns: 5fr 7fr; gap: 48px; align-items: start; margin-top: 64px; }
    .row.flip { grid-template-columns: 7fr 5fr; }
    .row.flip .txt { order: 2; }
    .row h3 { font-size: 22px; margin-bottom: 12px; }
    .row p { color: var(--ink-2); font-size: 15.5px; }
    .row ul { margin-top: 14px; padding-left: 1.2em; font-size: 15px; color: var(--ink-2); }
    .row li { margin-bottom: 4px; }
    .row li::marker { color: var(--red); }

    /* ── 計算例 ── */
    .calc { margin-top: 30px; background: var(--card); border: 1px solid var(--line-2); padding: 8px 28px 20px; }
    .calc table { width: 100%; border-collapse: collapse; font-size: 15.5px; }
    .calc td, .calc th { padding: 12px 4px; border-bottom: 1px dashed var(--line-2); text-align: left; }
    .calc th { font-size: 13px; color: var(--ink-3); font-weight: 500; }
    .calc .n { text-align: right; font-variant-numeric: tabular-nums; }
    .calc tfoot td { border-bottom: 3px double var(--ink); border-top: 1.5px solid var(--ink); font-weight: 700; font-size: 18px; }
    .calc .hand { margin-top: 14px; text-align: right; }
    .small { font-size: 13px; color: var(--ink-3); margin-top: 14px; }

    /* ── できること ── */
    .dl { margin-top: 30px; display: grid; grid-template-columns: 1fr 1fr; column-gap: 48px; }
    .dl div { padding: 18px 0; border-bottom: 1px solid var(--line); }
    .dl dt { font-weight: 700; font-size: 16px; }
    .dl dd { color: var(--ink-2); font-size: 15px; margin-top: 4px; }

    /* ── データの扱い ── */
    .plain { margin-top: 24px; padding-left: 1.2em; }
    .plain li { margin-bottom: 10px; color: var(--ink-2); }
    .plain li b { color: var(--ink); }
    .plain li::marker { color: var(--red); }

    /* ── 料金（レシート） ── */
    .price-wrap { display: grid; grid-template-columns: 1fr 340px; gap: 56px; align-items: center; }
    .receipt { background: #fff; padding: 30px 28px 38px; font-family: ui-monospace, "Cascadia Mono", Consolas, monospace; font-size: 14px; line-height: 1.9; color: #2b2b2b;
      box-shadow: 0 16px 34px -20px rgba(60,45,20,.45); transform: rotate(1.2deg);
      -webkit-mask: radial-gradient(circle 7px at 50% 100%, transparent 98%, #000) 0 0 / 18px 100% repeat-x; mask: radial-gradient(circle 7px at 50% 100%, transparent 98%, #000) 0 0 / 18px 100% repeat-x; }
    .receipt .c { text-align: center; }
    .receipt .sub { font-size: 12px; color: #777; }
    .receipt hr { border: 0; border-top: 1px dashed #aaa; margin: 10px 0; }
    .receipt .l { display: flex; justify-content: space-between; gap: 10px; }
    .receipt .big { font-size: 20px; font-weight: 700; }

    /* ── 始め方 ── */
    .start { counter-reset: s; list-style: none; margin-top: 28px; }
    .start li { counter-increment: s; position: relative; padding: 0 0 26px 58px; }
    .start li::before { content: counter(s); position: absolute; left: 0; top: 0; width: 38px; height: 38px; border: 1.5px solid var(--ink); border-radius: 50%; display: grid; place-items: center; font-family: var(--mincho); font-weight: 800; }
    .start li:not(:last-child)::after { content: ''; position: absolute; left: 19px; top: 44px; bottom: 6px; border-left: 1px dashed var(--line-2); }
    .start h3 { font-family: var(--gothic); font-size: 17px; font-weight: 700; }
    .start p { color: var(--ink-2); font-size: 15px; }
    .small a, .faq details p a { color: var(--red); }

    /* ── FAQ ── */
    .faq { margin-top: 24px; border-top: 1px solid var(--ink); }
    .faq details { border-bottom: 1px solid var(--line); padding: 18px 0; }
    .faq summary { font-weight: 700; cursor: pointer; list-style: none; display: flex; gap: 12px; }
    .faq summary::-webkit-details-marker { display: none; }
    .faq summary::before { content: 'Q.'; font-family: var(--mincho); color: var(--red); }
    .faq details p { color: var(--ink-2); font-size: 15px; margin-top: 8px; padding-left: 30px; }

    /* ── おわりに ── */
    .end { text-align: center; background: var(--paper-2); }
    .end h2 { font-size: 32px; }
    .end .hero-cta { justify-content: center; }

    footer { padding: 36px 0 44px; color: var(--ink-3); font-size: 13px; border-top: 1px solid var(--line); }
    footer .wrap { display: flex; justify-content: space-between; gap: 14px 24px; flex-wrap: wrap; }
    footer nav { display: flex; gap: 18px; flex-wrap: wrap; }
    footer a { text-decoration: none; }
    footer a:hover { color: var(--ink); }

    @media (max-width: 860px) {
      body { font-size: 15.5px; }
      .wrap { padding: 0 18px; }
      section { padding: 60px 0; }
      .nav-links { display: none; }
      .nav-login { margin-left: auto; }
      .hero { padding: 44px 0 60px; }
      .hero h1 { font-size: clamp(24px, 7vw, 32px); }
      br.sp { display: inline; }
      .hero-shot { margin-top: 64px; }
      .hero-shot .hand { font-size: 15px; }
      h2, .end h2 { font-size: 24px; }
      .steps { grid-template-columns: 1fr; }
      .steps li, .steps li + li { padding: 20px 0 16px; border-left: 0; border-bottom: 1px solid var(--line); }
      .row, .row.flip, .price-wrap, .dl { grid-template-columns: 1fr; gap: 20px; }
      .row.flip .txt { order: 0; }
      .row { margin-top: 48px; }
      .dl { gap: 0; }
      .memo { padding: 24px 20px; }
      .calc { padding: 4px 14px 16px; }
      .calc td, .calc th { font-size: 14px; }
      .receipt { width: 100%; max-width: 340px; margin: 10px auto 0; }
    }
    @media (max-width: 480px) {
      .brand span { display: none; }
      .hero-cta .btn { width: 100%; }
    }