/* ---------- コラム共通スタイル（トップページのトーンに合わせた白・黒・グレー） ---------- */
:root{
  --ink:#111111;
  --white:#ffffff;
  --grey-bg:#f5f5f5;
  --grey-text:#707072;
  --line:#e5e5e5;
  --red:#e4002b;
  --display:'Anton','Noto Sans JP',Impact,sans-serif;
  --sans:'Noto Sans JP','Helvetica Neue',Helvetica,Arial,sans-serif;
  --gutter:clamp(16px,4vw,48px);
  --radius-pill:999px;
}
*,*::before,*::after{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(--white);color:var(--ink);font-family:var(--sans);font-size:16px;line-height:1.9;-webkit-font-smoothing:antialiased;overflow-x:hidden}
img{max-width:100%;display:block;height:auto}
a{color:inherit;text-decoration:none}
h1,h2,h3,h4{margin:0;text-wrap:balance}
p{margin:0}
ul,ol{margin:0;padding:0;list-style:none}
:focus-visible{outline:3px solid var(--ink);outline-offset:3px}
main [id]{scroll-margin-top:80px}

.wrap{width:100%;max-width:1440px;margin-inline:auto;padding-inline:var(--gutter)}
.wrap--narrow{max-width:820px}

/* ---------- Buttons ---------- */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5em;min-height:48px;padding:0 28px;border-radius:var(--radius-pill);font-weight:700;font-size:15px;letter-spacing:.02em;border:1.5px solid var(--ink);background:var(--ink);color:var(--white);cursor:pointer;transition:background .2s,color .2s,transform .2s;white-space:nowrap}
.btn:hover{background:#3a3a3a;border-color:#3a3a3a}
.btn:active{transform:scale(.98)}
.btn--ghost{background:transparent;color:var(--ink)}
.btn--ghost:hover{background:var(--ink);color:var(--white)}
.btn--white{background:var(--white);color:var(--ink);border-color:var(--white)}
.btn--white:hover{background:var(--grey-bg);border-color:var(--grey-bg)}
.btn--line{background:#06c755;border-color:#06c755;color:var(--white)}
.btn--line:hover{background:#05b04c;border-color:#05b04c}
.btn--line svg{width:22px;height:22px;fill:currentColor;flex:none}

/* ---------- Top bar / Header ---------- */
.topbar{background:var(--grey-bg);font-size:12px;color:var(--ink)}
.topbar .wrap{display:flex;justify-content:flex-end;gap:24px;min-height:36px;align-items:center}
.topbar a:hover{color:var(--grey-text)}
.header{position:sticky;top:0;z-index:50;background:var(--white);border-bottom:1px solid var(--line)}
.header .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px;min-height:64px}
.brand{display:flex;flex-direction:column;line-height:1.1}
.brand__en{font-family:var(--display);font-size:22px;letter-spacing:.02em;text-transform:uppercase}
.brand__ja{font-size:12px;font-weight:400;color:var(--grey-text);letter-spacing:.06em;margin-top:3px}
.header__nav{display:flex;align-items:center;gap:24px}
.header__nav a.link{font-weight:700;font-size:15px;position:relative;padding:4px 0}
.header__nav a.link::after{content:"";position:absolute;left:0;bottom:0;width:100%;height:2px;background:var(--ink);transform:scaleX(0);transform-origin:left;transition:transform .25s}
.header__nav a.link:hover::after,.header__nav a.link[aria-current="page"]::after{transform:scaleX(1)}
@media (max-width:640px){
  .header__nav{gap:14px}
  .header__nav a.link{display:none}
  .header__nav a.link--keep{display:inline-block;font-size:14px}
  .header__nav .btn{min-height:40px;padding:0 16px;font-size:13px}
  .brand__en{font-size:19px}
}

/* ---------- Breadcrumb ---------- */
.crumbs{display:flex;flex-wrap:wrap;gap:6px;padding-block:14px;font-size:13px;color:var(--grey-text)}
.crumbs li+li::before{content:"/";margin-right:6px;color:#bdbdbd}
.crumbs a:hover{text-decoration:underline;text-underline-offset:3px}
.crumbs [aria-current]{color:var(--ink)}

/* ---------- Section scaffolding ---------- */
.section{padding-block:clamp(48px,7vw,96px)}
.section--grey{background:var(--grey-bg)}
.eyebrow{font-size:13px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;color:var(--grey-text);margin-bottom:14px}
.title{font-family:var(--display);font-size:clamp(40px,6.5vw,88px);line-height:.95;text-transform:uppercase;letter-spacing:-.005em}
.title__ja{display:block;font-family:var(--sans);font-weight:900;font-size:clamp(18px,2.2vw,26px);letter-spacing:.02em;margin-top:14px;text-transform:none}
.lead{margin-top:22px;font-size:16px;line-height:1.9;max-width:36em;color:var(--grey-text)}

/* ---------- Article cards (一覧・関連記事・トップページ共通) ---------- */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:clamp(20px,3vw,40px);margin-top:40px}
.card{display:flex;flex-direction:column;position:relative}
.card__img{aspect-ratio:3/2;overflow:hidden;background:#e9e9e9}
.card__img img{width:100%;height:100%;object-fit:cover;transition:transform .6s ease}
.card:hover .card__img img{transform:scale(1.04)}
.card__meta{display:flex;align-items:center;gap:12px;margin-top:16px;font-size:12px;color:var(--grey-text);letter-spacing:.06em;font-variant-numeric:tabular-nums}
.tag{display:inline-flex;align-items:center;min-height:24px;padding:0 10px;border:1px solid var(--ink);border-radius:var(--radius-pill);font-size:11px;font-weight:700;letter-spacing:.1em;color:var(--ink);white-space:nowrap}
.card__title{margin-top:8px;font-size:18px;font-weight:900;line-height:1.5}
.card__title a::after{content:"";position:absolute;inset:0}
.card:hover .card__title{text-decoration:underline;text-underline-offset:4px}
.card__desc{margin-top:8px;font-size:14px;color:var(--grey-text);line-height:1.7}
@media (max-width:900px){.cards{grid-template-columns:1fr 1fr}}
@media (max-width:560px){.cards{grid-template-columns:1fr;gap:28px}}

/* ---------- Article ---------- */
.article{padding-block:0 clamp(64px,9vw,120px)}
.article__head{max-width:820px;margin-inline:auto;padding-block:clamp(28px,4vw,56px) 32px}
.article__meta{display:flex;flex-wrap:wrap;align-items:center;gap:12px;font-size:13px;color:var(--grey-text);margin-bottom:18px;font-variant-numeric:tabular-nums}
.article__title{font-size:clamp(25px,4vw,40px);font-weight:900;line-height:1.45;letter-spacing:.01em}
.article__lead{margin-top:20px;font-size:16px;color:var(--grey-text)}
.article__hero{max-width:1040px;margin:8px auto 0;aspect-ratio:2/1;overflow:hidden;background:#e9e9e9}
.article__hero img{width:100%;height:100%;object-fit:cover}
.article__body{max-width:820px;margin-inline:auto;margin-top:clamp(32px,5vw,56px)}
.article__body h2{font-size:clamp(21px,2.6vw,26px);font-weight:900;line-height:1.5;margin-top:56px;padding-top:20px;border-top:2px solid var(--ink)}
.article__body h3{font-size:18px;font-weight:900;margin-top:36px;padding-left:14px;border-left:4px solid var(--ink);line-height:1.5}
.article__body h4{font-size:16px;font-weight:900;margin-top:24px}
.article__body p{margin-top:16px}
.article__body ul,.article__body ol{margin-top:16px;padding-left:1.5em}
.article__body ul{list-style:disc}
.article__body ol{list-style:decimal}
.article__body li{margin-top:6px}
.article__body li::marker{font-weight:700}
.article__body strong{font-weight:900}
.article__body p a,.article__body li a{text-decoration:underline;text-underline-offset:3px}
.article__body p a:hover,.article__body li a:hover{color:var(--grey-text)}

.toc{margin-top:32px;padding:24px 28px;background:var(--grey-bg)}
.toc__h{font-size:12px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;color:var(--grey-text)}
.toc ol{margin-top:10px;padding-left:1.5em;list-style:decimal}
.toc li{margin-top:4px;font-size:15px;font-weight:700}
.toc a:hover{text-decoration:underline;text-underline-offset:3px}

.drill{margin-top:28px;padding:24px 28px;border:1px solid var(--line);border-radius:12px}
.drill h3{margin-top:0;padding-left:0;border-left:0}
.drill__spec{display:flex;flex-wrap:wrap;gap:6px 20px;margin-top:10px;font-size:13px;color:var(--grey-text)}
.drill__spec b{color:var(--ink);font-weight:700}
.drill ol,.drill ul{margin-top:12px}
.drill p{margin-top:12px}

.note{margin-top:24px;padding:20px 24px;background:var(--grey-bg);border-left:4px solid var(--ink);font-size:15px}
.note--warn{border-left-color:var(--red)}
.note__h{font-weight:900;font-size:13px;letter-spacing:.1em;margin-bottom:6px}
.note p{margin-top:0}
.note ul{margin-top:8px}

.plan{margin-top:16px;border-top:1px solid var(--ink)}
.plan li{display:grid;grid-template-columns:7em 1fr;gap:12px;padding-block:12px;border-bottom:1px solid var(--line);margin:0;list-style:none}
.plan b{font-weight:900}
@media (max-width:480px){.plan li{grid-template-columns:1fr;gap:2px}}

.faq{margin-top:12px}
.faq details{border-bottom:1px solid var(--line);padding:16px 0}
.faq summary{font-weight:700;cursor:pointer;list-style:none;display:flex;gap:12px;align-items:flex-start}
.faq summary::-webkit-details-marker{display:none}
.faq summary::before{content:"Q";font-family:var(--display);font-size:20px;line-height:1.4;flex:none}
.faq details p{padding-left:32px;font-size:15px;color:var(--grey-text);margin-top:10px}

.author{margin-top:48px;padding:22px 26px;border:1px solid var(--line);font-size:14px;line-height:1.7;color:var(--grey-text)}
.author__name{font-weight:900;font-size:15px;color:var(--ink)}

.cta{margin-top:56px;background:var(--ink);color:var(--white);padding:clamp(32px,5vw,56px) clamp(20px,4vw,48px);text-align:center}
.cta__title{font-family:var(--display);font-size:clamp(36px,6vw,64px);line-height:.95;text-transform:uppercase}
.cta__ja{display:block;font-family:var(--sans);font-weight:900;font-size:clamp(17px,2vw,22px);margin-top:14px;text-transform:none}
.cta p{margin-top:14px;font-size:15px;color:#d6d6d6}
.cta__btns{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin-top:28px}
.cta .btn--line{border-color:#06c755}

.related{margin-top:clamp(56px,8vw,96px)}
.related__h{font-family:var(--display);font-size:clamp(28px,4vw,44px);text-transform:uppercase;line-height:1}
.related__h span{display:block;font-family:var(--sans);font-weight:900;font-size:16px;margin-top:8px;text-transform:none}
.related .cards{margin-top:28px}
.related__more{margin-top:32px}

/* ---------- Footer ---------- */
.footer{background:var(--ink);color:var(--white);padding-block:clamp(40px,6vw,64px) 28px}
.footer__grid{display:grid;grid-template-columns:1.4fr 1fr;gap:32px;align-items:start}
.footer__brand{font-family:var(--display);font-size:clamp(30px,4vw,48px);line-height:.95;text-transform:uppercase}
.footer__brand small{display:block;font-family:var(--sans);font-size:13px;font-weight:400;letter-spacing:.08em;margin-top:12px;color:#a5a5a5;text-transform:none}
.footer__h{font-size:12px;font-weight:700;letter-spacing:.16em;text-transform:uppercase;color:#a5a5a5;margin-bottom:12px}
.footer p{font-size:15px;line-height:1.9}
.footer__links{display:flex;flex-wrap:wrap;gap:8px 20px;margin-top:12px;font-size:14px}
.footer__links a{text-decoration:underline;text-underline-offset:3px}
.footer__links a:hover{color:#a5a5a5}
.copy{margin-top:36px;padding-top:18px;border-top:1px solid #333;font-size:12px;color:#a5a5a5;letter-spacing:.06em}
@media (max-width:720px){.footer__grid{grid-template-columns:1fr}}