/* =========================================================
   GBLBOX 公式サイト
   紙色の地に墨。見出しは OS 同梱の明朝（外部フォントは CSP で
   読めないため自前配信も外部読み込みもしない）。
   色は装飾ではなく意味に使う：アクセントは1色、強調は決定的な
   数字だけに与える。
   ========================================================= */

:root{
  --paper:#F2EFE8;
  --paper-2:#EAE5DA;
  --ink:#14171C;
  --ink-2:#3A3E45;
  --muted:#6E6A62;
  --rule:#D8D3C8;
  --rule-2:#E4DFD4;
  --line:#C9C3B6;
  --accent:#0A5FD0;
  --dark:#14171C;
  --dark-fg:#F2EFE8;
  --dark-muted:#AAB2BD;
  --mincho:"Hiragino Mincho ProN","Yu Mincho",YuMincho,"Noto Serif JP","Songti SC",serif;
  --sans:-apple-system,BlinkMacSystemFont,"Hiragino Sans","Noto Sans JP",Segoe UI,Roboto,sans-serif;
}

*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;background:var(--paper);font-size:100%}
body{
  margin:0;background:var(--paper);color:var(--ink);
  font-family:var(--sans);font-size:1rem;line-height:1.95;letter-spacing:0;
  -webkit-font-smoothing:antialiased;font-feature-settings:"palt" 1;
  font-optical-sizing:auto;text-spacing-trim:trim-start;
}
p,li{text-wrap:pretty}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
a:focus-visible,.btn:focus-visible,summary:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
::selection{background:rgba(10,95,208,.16)}

.wrap{max-width:880px;margin:0 auto;padding:0 24px}
.wrap-body{padding-bottom:64px}
.wrap-note{padding-top:44px}
.wrap-foot{padding-bottom:64px}

/* --- ヘッダー --- */
header.site{display:flex;align-items:center;flex-wrap:wrap;gap:10px;padding:22px 0 18px}
.brand{font-family:var(--mincho);font-weight:700;font-size:1.25rem;letter-spacing:.02em}
nav.site{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:8px 16px;margin-left:auto}
nav.site a{color:var(--muted);font-size:13px}
nav.site a:hover{color:var(--ink)}

.langbar{display:flex;align-items:center;gap:8px;padding:14px 0 0;border-top:1px solid var(--rule)}
.lang-label{color:var(--muted);font-size:13px}
.langbar a{font-size:13px;color:var(--muted);border:1px solid var(--line);border-radius:999px;padding:3px 13px}
.langbar a[aria-current="page"]{color:var(--ink);border-color:var(--ink)}

/* --- 見出し --- */
h1{font-family:var(--mincho);font-size:clamp(1.875rem,5.2vw,3.125rem);line-height:1.32;font-weight:700;letter-spacing:-.012em;margin:0}
h2{font-family:var(--mincho);font-size:clamp(1.4375rem,3.4vw,2.125rem);line-height:1.45;font-weight:700;letter-spacing:-.006em;margin:0}
h3{font-size:1.0625rem;font-weight:700;letter-spacing:0;margin:0}
.eyebrow{display:flex;align-items:center;gap:12px;margin:0;font-size:13px;letter-spacing:.16em;color:var(--muted)}
.eyebrow::before{content:"";width:34px;height:1px;background:var(--ink);display:block;flex:0 0 auto}
.lead{font-size:1.0625rem;line-height:2.05;letter-spacing:.002em;color:var(--ink-2);margin:0;max-width:32em}
.section-intro{font-size:.9375rem;line-height:1.98;letter-spacing:.004em;color:var(--ink-2);margin:0;max-width:46em}
.muted{color:var(--muted)}
.small{font-size:.8125rem;letter-spacing:.012em}
.note{font-size:.8125rem;line-height:1.95;letter-spacing:.012em;color:var(--muted);margin:0}

section{padding:52px 0 0}
.rule{height:1px;background:var(--rule);border:0;margin:56px 0 0}
.hr{height:1px;background:var(--rule);border:0;margin:56px 0 20px}

/* --- ボタン --- */
.btns{display:flex;flex-wrap:wrap;align-items:center;gap:14px 22px;margin:0}
.btn{display:inline-block;background:var(--ink);color:var(--paper);font-size:16px;font-weight:500;padding:15px 30px}
.btn:hover{text-decoration:none;background:#000}
.btn.alt{background:transparent;color:var(--ink);border:1px solid var(--line)}
.btn.alt:hover{background:var(--paper-2)}

/* --- ヒーロー --- */
.hero{display:flex;gap:56px;align-items:flex-start;padding:44px 0 0}
.hero-main{flex:1 1 auto;min-width:0;display:flex;flex-direction:column;gap:26px}
.hero-shot{flex:0 0 auto;background:var(--dark);padding:18px 18px 22px;display:flex;flex-direction:column;gap:12px}
.hero-shot img{display:block;width:250px;height:452px;object-fit:cover;object-position:top}
.hero-shot span{font-size:12px;color:var(--dark-muted)}
.trust-list{display:flex;flex-wrap:wrap;gap:10px;font-size:13px;color:var(--muted);margin:0;padding:0;list-style:none}
.trust{border:1px solid var(--line);border-radius:999px;padding:5px 13px}

/* --- 比較表 --- */
.compare{display:grid;grid-template-columns:230px 1fr 1fr;border-top:1px solid var(--ink);margin-top:26px}
.cmp-h,.cmp-a,.cmp-b{border-bottom:1px solid var(--rule-2);padding:17px 0}
.cmp-a,.cmp-b{padding-left:20px;padding-right:20px;display:flex;align-items:baseline;gap:9px}
.cmp-b{background:var(--paper-2)}
.cmp-h{display:flex;flex-direction:column;gap:3px}
.cmp-h span{font-size:15px;color:var(--ink-2)}
.cmp-h small{font-size:12px;color:var(--muted)}
.cmp-val{font-family:var(--mincho);font-size:19px;font-weight:500}
.cmp-unit{font-size:14px;color:var(--muted)}
.cmp-tag{font-size:12px;font-weight:700;color:var(--accent);margin-left:auto}
/* 見出し行 */
.cmp-head{flex-direction:column;align-items:flex-start;gap:5px;padding-top:20px;border-bottom-color:var(--rule)}
.cmp-head small{font-size:12px;color:var(--muted);letter-spacing:.08em}
.cmp-head b{font-family:var(--mincho);font-size:24px;font-weight:700}
.cmp-blank{border-bottom-color:var(--rule)}
/* 決定的な行 */
.cmp-h.key span{font-weight:700;color:var(--ink)}
.cmp-h.key:empty,.cmp-h.key:has(> small:only-child){padding-top:8px}
.key .cmp-val{font-size:30px;font-weight:700}
.cmp-b.key .cmp-val{color:var(--accent)}

/* --- 4つの数字 --- */
.points{display:grid;grid-template-columns:1fr 1fr;gap:34px 52px;margin-top:30px}
.point{display:flex;flex-direction:column;gap:11px;padding-top:17px;border-top:3px solid var(--ink)}
.point p{margin:0;font-size:15px;line-height:1.95;color:var(--ink-2)}

/* --- 画面紹介 --- */
.screen-grid{display:grid;grid-template-columns:1fr 1fr;gap:56px 26px;margin-top:26px}
.screen-card{margin:0}
.screen-frame{background:var(--dark);padding:16px 16px 0;display:flex;justify-content:center;overflow:hidden}
.screen-frame img{display:block;width:100%;max-width:270px;height:300px;object-fit:cover;object-position:top}
.screen-card figcaption{padding:10px 2px 0}
.screen-card figcaption b{display:block;font-size:16px}
.screen-card figcaption span{display:block;font-size:14px;line-height:1.85;color:var(--ink-2);margin-top:4px}

/* --- 手順 --- */
.steps-block{display:flex;gap:52px;align-items:flex-start;margin-top:8px}
.steps-block h2{flex:0 0 300px}
.steps-body{flex:1 1 auto;min-width:0;display:flex;flex-direction:column;gap:20px}
.chips{display:flex;flex-wrap:wrap;gap:11px;margin:0;padding:0;list-style:none}
.chips li{font-size:14px;padding:9px 16px;border:1px solid var(--line)}

/* --- FAQ --- */
.faq{display:flex;flex-direction:column;gap:0;margin-top:22px;border-top:1px solid var(--rule)}
.faq details{border-bottom:1px solid var(--rule);padding:16px 0}
.faq summary{list-style:none;cursor:pointer;font-size:16px;font-weight:700;display:flex;align-items:center;justify-content:space-between;gap:14px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"";flex:0 0 auto;width:8px;height:8px;border-right:1.5px solid var(--muted);border-bottom:1.5px solid var(--muted);transform:rotate(45deg);margin-right:3px}
.faq details[open] summary::after{transform:rotate(-135deg);border-color:var(--ink)}
.faq p{margin:10px 0 0;font-size:15px;line-height:1.95;color:var(--ink-2)}

/* --- 最終CTA --- */
.final-cta{background:var(--dark);color:var(--dark-fg)}
.final-cta-inner{max-width:880px;margin:0 auto;padding:46px 24px 50px;display:flex;align-items:center;gap:40px;flex-wrap:wrap}
.final-cta h2{color:var(--dark-fg)}
.final-cta p{margin:8px 0 0;font-size:15px;color:var(--dark-muted)}
.final-cta-copy{flex:1 1 320px;min-width:0}
.final-cta .btn{background:var(--paper);color:var(--ink);margin-left:auto;white-space:nowrap}
.final-cta .btn:hover{background:#fff}

footer.site{padding-top:20px;border-top:1px solid var(--rule);color:var(--muted);font-size:13px}
footer.site a{color:var(--muted)}

/* --- 狭い画面 --- */
@media (max-width:760px){
  .hero{flex-direction:column;gap:32px}
  .hero-shot{align-self:flex-start}
  .points{grid-template-columns:1fr;gap:26px}
  .steps-block{flex-direction:column;gap:20px}
  .steps-block h2{flex:0 0 auto}
  .screen-grid{grid-template-columns:1fr}
  .final-cta .btn{margin-left:0}
}
@media (max-width:640px){
  .compare{grid-template-columns:1fr 1fr}
  .cmp-h{grid-column:1 / -1;border-bottom:0;padding:18px 0 6px}
  .cmp-a,.cmp-b{padding-left:14px;padding-right:14px}
  .compare > .cmp-h:first-child{display:none}
  .key .cmp-val{font-size:26px}
}

/* =========================================================
   動き（CSS のみ。script-src が無いので JS は使えない）
   reduced motion では完成形を静止して見せる。
   ========================================================= */
@keyframes gb-rise{from{opacity:0;translate:0 10px}to{opacity:1;translate:none}}
@keyframes gb-draw{from{scale:0 1}to{scale:1 1}}

@media (prefers-reduced-motion: no-preference){
  .hero .eyebrow,.hero h1,.hero .lead,.hero .btns,.hero .trust-list,.hero-shot{
    animation:gb-rise .62s cubic-bezier(.22,.68,.32,1) backwards;
  }
  .hero h1{animation-delay:.06s}
  .hero .lead{animation-delay:.14s}
  .hero .btns{animation-delay:.22s}
  .hero .trust-list{animation-delay:.30s}
  .hero-shot{animation-delay:.16s}

  .btn,.faq summary::after,.screen-frame img{transition:background .2s ease,transform .3s ease,color .2s ease}
  .screen-card:hover .screen-frame img{transform:scale(1.03)}

  /* §7 開くときは減速、閉じるときは加速。往路と復路のカーブを鏡にする */
  @supports selector(details::details-content){
    :root{interpolate-size:allow-keywords}
    .faq details::details-content{
      block-size:0;overflow:clip;
      transition:block-size .28s cubic-bezier(.4,0,1,1),content-visibility .28s allow-discrete;
    }
    .faq details[open]::details-content{
      block-size:auto;
      transition-timing-function:cubic-bezier(0,0,.2,1);
    }
  }

  /* 押した瞬間に返す。離すまで待たない */
  .btn:active{transform:scale(.975);transition-duration:.1s;transition-timing-function:ease-out}
  .guide-list a{transition:background .18s ease}
  .guide-list a:active{background:var(--paper-2)}
  .faq summary:active{opacity:.6;transition:opacity .1s ease-out}

  @supports (animation-timeline: view()){
    main h2,.section-intro,.compare,.point,.screen-card,.steps-body,.faq details,.note{
      animation-name:gb-rise;animation-fill-mode:both;animation-timing-function:linear;
      animation-timeline:view();animation-range:entry 4% entry 60%;
    }
    .points .point:nth-child(2n){animation-range:entry 10% entry 66%}
    .screen-grid .screen-card:nth-child(2n){animation-range:entry 10% entry 66%}
    /* 決定的な2行は、下線が引かれてから数字が立つ */
    .compare .cmp-h.key{view-timeline-name:--gb-key}
    .compare .cmp-h.key::after{
      content:"";display:block;height:2px;background:var(--accent);margin-top:6px;transform-origin:left;
      animation-name:gb-draw;animation-fill-mode:both;animation-timing-function:linear;
      animation-timeline:--gb-key;animation-range:entry 25% entry 85%;
    }
  }
}

/* =========================================================
   解説記事（/guide/）
   ========================================================= */
.article{max-width:720px;margin:0 auto;padding:6px 0 0}
.article h1{font-size:clamp(1.625rem,4.2vw,2.375rem);line-height:1.4;letter-spacing:-.01em;margin:0 0 1.375rem}
.article h2{font-size:clamp(1.25rem,2.6vw,1.625rem);line-height:1.5;letter-spacing:-.004em;margin:3.375rem 0 .875rem}
.article h3{font-size:17px;font-weight:700;margin:32px 0 8px}
.article p{margin:0 0 1.125rem;font-size:1rem;line-height:2.05;color:var(--ink-2)}
.article p.lead{font-size:1.0625rem;letter-spacing:.002em;color:var(--ink-2);max-width:none;margin-bottom:1.625rem}
.article ul{margin:0 0 18px;padding-left:1.35em}
.article li{margin:7px 0;line-height:1.95;color:var(--ink-2)}
.article strong{color:var(--ink);font-weight:700}
.crumb{font-size:13px;color:var(--muted);margin:0 0 24px}
.crumb a{color:var(--muted)}
.formula{
  font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:14px;line-height:1.9;
  background:var(--paper-2);border:1px solid var(--rule);padding:15px 17px;margin:0 0 20px;overflow-x:auto;
  white-space:pre-wrap;
}
table.data{width:100%;border-collapse:collapse;margin:0 0 10px;font-size:15px}
table.data th,table.data td{text-align:left;padding:12px;border-bottom:1px solid var(--rule-2)}
table.data thead th{border-bottom:1px solid var(--ink);font-size:13px;color:var(--muted);font-weight:500}
table.data td.num{font-family:var(--mincho);font-size:19px;white-space:nowrap}
table.data tr.hi td{background:var(--paper-2)}
table.data tr.hi td.num{color:var(--accent);font-weight:700}
.article .note{margin:0 0 18px}
.cta-inline{border-top:1px solid var(--rule);margin-top:56px;padding-top:28px;display:flex;align-items:center;gap:18px 22px;flex-wrap:wrap}
.guide-list{display:grid;border-top:1px solid var(--ink);margin-top:24px}
.guide-list a{display:block;padding:22px 2px;border-bottom:1px solid var(--rule-2);color:var(--ink)}
.guide-list a:hover{background:var(--paper-2);text-decoration:none}
.guide-list b{display:block;font-family:var(--mincho);font-size:21px;font-weight:700;margin-bottom:6px}
.guide-list span{display:block;font-size:14px;color:var(--ink-2);line-height:1.85}

/* =========================================================
   §14 コントラストを上げる設定への対応。
   透過は使っていないので prefers-reduced-transparency は対象外。
   ========================================================= */
@media (prefers-contrast: more){
  :root{
    --ink-2:#1A1D22;
    --muted:#46423B;
    --rule:#B4AE9F;
    --rule-2:#C4BEB0;
    --line:#8C8676;
    --accent:#0847A0;
  }
  .btn.alt,.chips li,.trust,.langbar a{border-width:2px}
  a:hover{text-decoration-thickness:2px}
}

/* 図。記事内の表と対になる視覚化で、hover は SVG の title（JS不要） */
.chart{margin:8px 0 26px}
.chart svg{display:block}
.chart figcaption{margin-top:10px;font-size:.8125rem;line-height:1.85;letter-spacing:.012em;color:var(--muted)}