:root {
    color-scheme: light;
    --paper: #faf8f4; --card: #ffffff; --ink: #17223b; --ink-2: #4b5670; --mute: #858da0; --line: #e9e4da;
    --navy: #14284b; --brand: #2457c5; --accent: #e8743b; --tint: #eef3fb; --warm: #fff3ea;
    --shadow: 0 1px 2px rgba(20,40,75,.05), 0 10px 30px rgba(20,40,75,.07);
    --shadow-h: 0 2px 4px rgba(20,40,75,.06), 0 18px 40px rgba(20,40,75,.12);
    --serif: "Shippori Mincho", "Hiragino Mincho ProN", "Yu Mincho", serif;
    --sans: "Zen Kaku Gothic New", "Hiragino Sans", "Yu Gothic", sans-serif;
  }
  @media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
      color-scheme: dark;
      --paper: #0f1522; --card: #171f31; --ink: #f2f4f9; --ink-2: #b9c0d1; --mute: #8790a3; --line: #283148;
      --navy: #0b1220; --brand: #7ea3ff; --accent: #f08a55; --tint: #16213a; --warm: #2a2018;
    }
  }
  * { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  html, body { margin: 0; padding: 0; }
  body { background: var(--paper); color: var(--ink); font-family: var(--sans); font-size: 16px; line-height: 1.8; -webkit-font-smoothing: antialiased; }
  a { color: var(--brand); text-underline-offset: 3px; }
  .wrap { max-width: 1040px; margin: 0 auto; padding: 0 28px; }
  @media (max-width: 560px) { .wrap { padding: 0 18px; } }
  .card { background: var(--card); border-radius: 20px; box-shadow: var(--shadow); }

  /* page head */
  .ch { text-align: center; padding: 46px 0 8px; }
  .ch h1 { font-family: var(--serif); font-weight: 800; font-size: clamp(30px, 5vw, 42px); margin: 0; letter-spacing: .08em; }
  .ch .line { display: inline-block; width: 78px; height: 5px; margin: 10px 0 12px; border-radius: 3px; background: linear-gradient(90deg, var(--brand) 50%, var(--accent) 50%); }
  .ch p { margin: 0; color: var(--ink-2); font-size: 14.5px; }

  /* filter tabs */
  .tabs { display: flex; flex-wrap: wrap; justify-content: center; gap: 8px; margin: 22px 0 26px; }
  .tab { font: inherit; font-size: 14px; font-weight: 700; color: var(--ink-2); background: var(--card); border: 1.5px solid var(--line); border-radius: 999px; padding: 8px 18px; cursor: pointer; }
  .tab:hover { border-color: var(--navy); color: var(--ink); }
  .tab[aria-pressed="true"] { background: var(--navy); border-color: var(--navy); color: #fff; }
  .tab small { font-weight: 500; opacity: .7; margin-left: 4px; }

  /* list / related cards */
  .grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
  @media (max-width: 860px) { .grid { grid-template-columns: 1fr 1fr; } }
  @media (max-width: 560px) { .grid { grid-template-columns: 1fr; } }
  .cx { display: flex; flex-direction: column; text-decoration: none; color: inherit; background: var(--card); border-radius: 18px; overflow: hidden; box-shadow: 0 2px 4px rgba(20,40,75,.05), 0 12px 28px rgba(20,40,75,.10); transition: transform .18s; }
  .cx:hover { transform: translateY(-3px); }
  .th { display: grid; place-items: center; aspect-ratio: 16 / 10; padding: 16px; }
  .tt { background: rgba(255,255,255,.72); border-radius: 6px; padding: 16px 20px; font-family: var(--serif); font-weight: 800; font-size: clamp(15px, 2vw, 19px); line-height: 1.6; text-align: center; color: var(--navy); }
  .th.t1 { background: linear-gradient(135deg, #cddcf7, #eaf0fb 60%, #dfe8f8); }
  .th.t2 { background: linear-gradient(135deg, #fbdcc9, #fdefe6 60%, #f8e3d4); }
  .th.t3 { background: linear-gradient(135deg, #d9d3f3, #efecfa 60%, #e3def5); }
  .th.t4 { background: linear-gradient(135deg, #cdeede, #eaf8f1 60%, #d8f1e4); }
  .cm { display: flex; align-items: center; gap: 8px; padding: 14px 20px 0; font-size: 13px; font-weight: 700; color: var(--ink-2); }
  .dot { width: 14px; height: 14px; border-radius: 50%; flex: none; display: inline-block; }
  .dot.d1 { background: #2a8bd8; } .dot.d2 { background: #e8743b; } .dot.d3 { background: #6a58d6; } .dot.d4 { background: #1baf7a; }
  .ct { font-family: var(--serif); font-size: 17px; line-height: 1.55; padding: 8px 20px 0; font-weight: 800; }
  .cl { font-size: 13.5px; color: var(--ink-2); line-height: 1.75; padding: 6px 20px 20px; }

  /* article */
  .back { display: inline-block; margin: 28px 0 14px; font-size: 14px; font-weight: 700; text-decoration: none; }
  .back:hover { text-decoration: underline; }
  .art { padding: 32px 36px 28px; max-width: 820px; margin: 0 auto; }
  @media (max-width: 600px) { .art { padding: 22px 18px; } }
  .cr-meta { display: flex; align-items: center; justify-content: space-between; gap: 10px; font-size: 13px; font-weight: 700; color: var(--ink-2); }
  .cr-meta > span:first-child { display: inline-flex; align-items: center; gap: 8px; }
  .cr-count { font-variant-numeric: tabular-nums; color: var(--mute); }
  .cr-title { font-family: var(--serif); font-size: clamp(22px, 3.4vw, 30px); line-height: 1.5; margin: 10px 0 16px; }
  .cr-body { font-size: 15.5px; line-height: 1.95; }
  .cr-body p { margin: 10px 0; }
  .cr-body ul { margin: 6px 0 10px; padding-left: 1.3em; }
  .cr-body li { margin: 4px 0; }
  .cr-note { font-size: 13.5px; color: var(--ink-2); background: var(--tint); border-radius: 12px; padding: 12px 16px; }
  .cr-stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 14px; margin: 8px 0 12px; }
  .cr-stat { background: var(--tint); border-radius: 14px; padding: 14px 18px; }
  .cr-stat b { font-family: var(--serif); font-size: 36px; color: var(--navy); }
  .cr-stat span { font-weight: 800; margin-left: 4px; }
  .cr-stat p { margin: 4px 0 0; font-size: 13px; color: var(--ink-2); line-height: 1.6; }
  .cr-bars { list-style: none; margin: 8px 0 12px; padding: 0; display: grid; gap: 8px; }
  .cr-bars li { display: grid; grid-template-columns: 170px 1fr 56px; gap: 10px; align-items: center; font-size: 13.5px; margin: 0; }
  @media (max-width: 600px) { .cr-bars li { grid-template-columns: 1fr 48px; } .cr-bars .b { grid-column: 1 / -1; grid-row: 2; } }
  .cr-bars .b { height: 12px; background: #e9edf5; border-radius: 999px; overflow: hidden; }
  .cr-bars .b i { display: block; height: 100%; background: var(--brand); border-radius: 999px; }
  .cr-bars .v { text-align: right; font-weight: 800; font-variant-numeric: tabular-nums; }
  .cr-steps { margin: 6px 0 10px; padding-left: 1.4em; }
  .cr-steps li { margin: 8px 0; }
  .cr-steps b { display: block; }
  .cr-src { font-size: 12.5px; color: var(--mute); margin: 8px 0 0; }
  .cr-src a { color: inherit; }
  .cr-more { margin-top: 18px; }
  .btn { display: inline-flex; align-items: center; gap: 8px; text-decoration: none; font-weight: 700; font-size: 15px; padding: 13px 24px; border-radius: 999px; }
  .btn-primary { background: var(--accent); color: #fff; box-shadow: 0 8px 20px rgba(232,116,59,.35); }
  .btn-navy { background: var(--navy); color: #fff; }
  .cr-nav { display: flex; justify-content: space-between; gap: 10px; margin-top: 24px; padding-top: 16px; border-top: 1px solid var(--line); }
  .cr-nav a { font-size: 14px; font-weight: 700; color: var(--ink-2); text-decoration: none; max-width: 48%; }
  .cr-nav a:hover { color: var(--brand); text-decoration: underline; }
  .cr-nav a small { display: block; font-size: 11.5px; font-weight: 500; color: var(--mute); }
  .cr-nav .nx { text-align: right; margin-left: auto; }
  .rel { max-width: 1040px; margin: 40px auto 0; }
  .rel h2 { font-family: var(--serif); font-size: 21px; margin: 0 0 16px; }
  .cta-bar { margin: 40px auto 0; max-width: 820px; padding: 26px 30px; border-radius: 22px; background: var(--navy); color: #fff; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 14px 24px; }
  .cta-bar b { font-family: var(--serif); font-size: 19px; display: block; }
  .cta-bar span { font-size: 13.5px; opacity: .85; }

  footer.site-footer { margin-top: 80px; background: var(--navy); color: rgba(255,255,255,.7); font-size: 13px; }
  footer.site-footer .wrap { padding-top: 34px; padding-bottom: 34px; display: flex; flex-wrap: wrap; gap: 12px 28px; justify-content: space-between; align-items: center; }
  footer.site-footer a { color: inherit; }
  footer.site-footer .fl { display: flex; gap: 22px; flex-wrap: wrap; }
  .cr-body h3 { font-family: var(--serif); font-size: 20px; line-height: 1.5; margin: 34px 0 10px; padding-left: 12px; border-left: 5px solid var(--accent); }
  .cr-body h3:first-child { margin-top: 8px; }
  .cr-tw { overflow-x: auto; margin: 10px 0 14px; border: 1px solid var(--line); border-radius: 14px; }
  .cr-table { border-collapse: collapse; width: 100%; min-width: 620px; font-size: 13.5px; line-height: 1.65; }
  .cr-table th, .cr-table td { padding: 10px 12px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
  .cr-table thead th { background: var(--navy); color: #fff; font-size: 12.5px; }
  .cr-table tbody th { background: var(--tint); white-space: nowrap; width: 1%; }
  .cr-table tbody tr:last-child th, .cr-table tbody tr:last-child td { border-bottom: 0; }
  .cr-steps.qs { list-style: none; padding-left: 0; counter-reset: q; }
  .cr-steps.qs li { counter-increment: q; padding-left: 40px; position: relative; }
  .cr-steps.qs li::before { content: "Q" counter(q); position: absolute; left: 0; top: 2px; font-family: var(--serif); font-weight: 800; color: var(--accent); }
  .art { max-width: 860px; }
  [hidden] { display: none !important; }

/* article pages */
.crumb { margin: 26px 0 14px; font-size: 13px; color: var(--mute); }
.crumb a { color: var(--ink-2); text-decoration: none; }
.crumb a:hover { text-decoration: underline; }
.crumb span { margin: 0 6px; }
.note-box { margin-top: 20px; padding: 16px 20px; border-radius: 14px; background: var(--warm); border: 1px solid var(--line); display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px 18px; }
.note-box b { font-family: var(--serif); }
.note-box p { margin: 2px 0 0; font-size: 13px; color: var(--ink-2); }

  /* ---- illustrated backgrounds ---- */
  body::before { content: ""; position: fixed; inset: 0; z-index: -1; pointer-events: none;
    background:
      url("./column-doodle.svg") 0 0 / 360px 360px repeat,
      radial-gradient(520px 380px at 8% 6%, rgba(36,87,197,.10), transparent 70%),
      radial-gradient(520px 380px at 96% 28%, rgba(232,116,59,.10), transparent 70%),
      radial-gradient(560px 420px at 30% 100%, rgba(143,131,232,.12), transparent 70%); }
  @media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) body::before { opacity: .55; } }

  /* list page head: a scene behind the title */
  #colIndex .ch { position: relative; isolation: isolate; margin-top: 22px; padding: 64px 20px 54px; border-radius: 28px; overflow: hidden; box-shadow: var(--shadow); }
  #colIndex .ch::before { content: ""; position: absolute; inset: 0; z-index: -2; background: url("./column-hero.svg") center / cover no-repeat; }
  #colIndex .ch::after { content: ""; position: absolute; inset: 0; z-index: -1; background: radial-gradient(ellipse 62% 78% at 50% 52%, rgba(255,255,255,.92) 30%, rgba(255,255,255,0) 100%); }
  #colIndex .ch p { color: #33405c; font-weight: 500; font-size: 15px; }
  @media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) #colIndex .ch::before { filter: brightness(.5) saturate(.9); } :root:not([data-theme="light"]) #colIndex .ch::after { background: radial-gradient(ellipse 52% 70% at 50% 50%, rgba(15,21,34,.7), rgba(15,21,34,0) 100%); } :root:not([data-theme="light"]) #colIndex .ch h1 { color: #fff; } :root:not([data-theme="light"]) #colIndex .ch p { color: #d5dbea; } }

  /* article: a scene band across the top of the card */
  .art { position: relative; overflow: hidden; padding-top: 150px; }
  .art::before { content: ""; position: absolute; left: 0; right: 0; top: 0; height: 118px; background: url("./column-hero.svg") center 74% / cover no-repeat; border-bottom: 1px solid var(--line); }
  @media (max-width: 600px) { .art { padding-top: 128px; } .art::before { height: 96px; background-position: center 80%; } }
  @media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .art::before { filter: brightness(.5) saturate(.9); } }

  /* thumbnails: doodles + a big soft circle per theme */
  .th { position: relative; overflow: hidden; }
  .th::before { content: ""; position: absolute; right: -34px; bottom: -44px; width: 150px; height: 150px; border-radius: 50%; background: rgba(255,255,255,.45); }
  .th::after { content: ""; position: absolute; left: -26px; top: -30px; width: 90px; height: 90px; border-radius: 50%; background: rgba(255,255,255,.35); }
  .th .tt { position: relative; z-index: 1; }
  .th.t1 { background: url("./column-doodle.svg") 60% 40% / 240px repeat, linear-gradient(135deg, #cddcf7, #eaf0fb 60%, #dfe8f8); }
  .th.t2 { background: url("./column-doodle.svg") 20% 70% / 240px repeat, linear-gradient(135deg, #fbdcc9, #fdefe6 60%, #f8e3d4); }
  .th.t3 { background: url("./column-doodle.svg") 80% 20% / 240px repeat, linear-gradient(135deg, #d9d3f3, #efecfa 60%, #e3def5); }
  .th.t4 { background: url("./column-doodle.svg") 40% 90% / 240px repeat, linear-gradient(135deg, #cdeede, #eaf8f1 60%, #d8f1e4); }

  /* break lines at phrase boundaries */
  h1, h2, h3, h4, p, li { word-break: auto-phrase; line-break: strict; text-wrap: pretty; }
  h1, h2, h3 { text-wrap: balance; }

  /* ---- refined column cards (list, related, home carousel share this look) ---- */
  .cx { border: 1px solid var(--line); border-radius: 20px; box-shadow: 0 1px 2px rgba(20,40,75,.04), 0 10px 26px rgba(20,40,75,.07); transition: transform .2s, box-shadow .2s; }
  .cx:hover { transform: translateY(-4px); box-shadow: 0 2px 4px rgba(20,40,75,.05), 0 18px 38px rgba(20,40,75,.13); }
  .th { aspect-ratio: 16 / 9; place-items: end start; padding: 20px 22px; --tc: #2a8bd8; }
  .th.t2 { --tc: #e8743b; } .th.t3 { --tc: #6a58d6; } .th.t4 { --tc: #1baf7a; }
  .th .tt { background: none; padding: 0; text-align: left; font-size: clamp(18px, 2vw, 22px); line-height: 1.5; letter-spacing: .01em; }
  .th .tt::before { content: ""; display: block; width: 30px; height: 4px; border-radius: 2px; background: var(--tc); margin-bottom: 10px; }
  .cx .cm { align-self: flex-start; margin: 16px 20px 0; padding: 3px 12px 3px 10px; border-radius: 999px; background: var(--tint); font-size: 12px; gap: 6px; color: var(--ink-2); }
  .cx .cm .dot { width: 8px; height: 8px; }
  .cx .ct { padding-top: 10px; text-wrap: balance; display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 3; overflow: hidden; }
  .cx .cl { flex: 1; color: var(--ink-2); font-weight: 500; padding-bottom: 8px; display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 3; overflow: hidden; }
  .cx::after { content: "読む →"; display: block; padding: 0 20px 18px; font-size: 13px; font-weight: 800; color: var(--brand); }
  .th .tt { text-shadow: 0 0 14px rgba(255,255,255,.95), 0 0 5px rgba(255,255,255,.9); }