/* アートパーク コラム共通（LPと同じ色・書体） */
:root{
  --blue:#1873E8; --blue-d:#0B3D91; --navy:#072A4A; --orange:#F5821F; --orange-d:#D96A0B; --yellow:#FFE566;
  --ink:#1B2A3A; --muted:#5C6B7A; --line:#DCE3EA; --sky:#EAF4FF; --paper:#F6F9FC;
  --font:"Noto Sans JP","Hiragino Kaku Gothic ProN","Yu Gothic",sans-serif;
}
*{margin:0;padding:0;box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{background:#fff;color:var(--ink);font-family:var(--font);font-size:16px;line-height:1.95;font-feature-settings:"palt"}
img{max-width:100%;height:auto;display:block}
a{color:var(--blue)}
:focus-visible{outline:3px solid var(--yellow);outline-offset:3px}

.top{position:sticky;top:0;z-index:10;background:#fff;border-bottom:1px solid var(--line)}
.top .in{max-width:1080px;margin:0 auto;padding:10px 16px;display:flex;align-items:center;justify-content:space-between;gap:12px}
.logo{display:flex;align-items:center;gap:8px;font-weight:900;font-size:18px;color:var(--navy);text-decoration:none}
.logo img{width:28px;height:28px;border-radius:7px}
.logo small{font-size:11px;font-weight:500;color:var(--muted)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border-radius:999px;font-weight:700;text-decoration:none;color:#fff;background:var(--orange);padding:10px 20px;font-size:14px;box-shadow:0 3px 0 var(--orange-d);white-space:nowrap}
.btn:hover{filter:brightness(1.05)}
.btn.blue{background:var(--blue);box-shadow:0 3px 0 var(--blue-d)}
.btn .free{background:#fff;color:var(--orange-d);border-radius:999px;font-size:11px;padding:1px 8px}
.btn.blue .free{color:var(--blue-d)}

.crumb{max-width:760px;margin:0 auto;padding:16px 16px 0;font-size:12px;color:var(--muted)}
.crumb a{color:var(--muted)}
.crumb ol{list-style:none;display:flex;flex-wrap:wrap;gap:4px}
.crumb li+li::before{content:"›";margin-right:4px}

article{max-width:760px;margin:0 auto;padding:16px 16px 48px}
.kicker{display:inline-block;background:var(--sky);color:var(--blue-d);font-size:12px;font-weight:700;border-radius:4px;padding:2px 10px;margin-bottom:10px}
article h1{font-size:28px;line-height:1.45;font-weight:900;color:var(--navy);letter-spacing:.01em}
.meta{font-size:12px;color:var(--muted);margin:12px 0 20px}
.hero-img{border-radius:12px;margin:0 0 8px;aspect-ratio:3/2;object-fit:cover;width:100%}
.cap{font-size:12px;color:var(--muted);margin-bottom:24px}
.lead{font-size:16px;background:var(--paper);border-left:4px solid var(--blue);padding:16px 18px;border-radius:0 8px 8px 0;margin:8px 0 28px}

.toc{border:1px solid var(--line);border-radius:10px;padding:16px 20px;margin:0 0 36px;background:#fff}
.toc b{display:block;font-size:14px;color:var(--navy);margin-bottom:6px}
.toc ol{padding-left:1.4em;font-size:14px;line-height:1.9}
.toc a{color:var(--ink);text-decoration:none}
.toc a:hover{color:var(--blue);text-decoration:underline}

article h2{font-size:22px;line-height:1.5;font-weight:900;color:var(--navy);margin:48px 0 16px;padding:10px 0 10px 14px;border-left:6px solid var(--blue);background:linear-gradient(90deg,var(--sky),transparent 80%);scroll-margin-top:72px}
article h3{font-size:18px;line-height:1.5;font-weight:700;color:var(--navy);margin:28px 0 10px;padding-bottom:6px;border-bottom:2px solid var(--line)}
article p{margin:0 0 18px}
article ul,article ol{margin:0 0 18px;padding-left:1.4em}
article li{margin:4px 0}
article strong{background:linear-gradient(transparent 62%,var(--yellow) 62%);font-weight:700}
article figure{margin:24px 0}
article figure img{border-radius:10px;border:1px solid var(--line)}
article figcaption{font-size:12px;color:var(--muted);margin-top:6px}

.tbl{width:100%;overflow-x:auto;margin:0 0 20px}
.tbl table{border-collapse:collapse;width:100%;min-width:520px;font-size:14px;line-height:1.7}
.tbl th,.tbl td{border:1px solid var(--line);padding:10px 12px;vertical-align:top;text-align:left}
.tbl thead th{background:var(--navy);color:#fff;font-weight:700}
.tbl tbody th{background:var(--paper);font-weight:700;white-space:nowrap}

.box{border-radius:10px;padding:16px 18px;margin:0 0 20px;font-size:15px}
.box.point{background:var(--sky);border:1px solid #BFDAFB}
.box.warn{background:#FFF6EC;border:1px solid #F8D3AE}
.box.check{background:#fff;border:2px solid var(--line)}
.box>b:first-child{display:block;color:var(--navy);margin-bottom:6px}
.box ul{margin-bottom:0}
.box.check ul{list-style:none;padding-left:0}
.box.check li{padding-left:1.6em;position:relative}
.box.check li::before{content:"";position:absolute;left:0;top:.45em;width:1em;height:1em;border:2px solid var(--blue);border-radius:3px}

.summary{background:var(--paper);border-radius:12px;padding:20px 22px;margin:36px 0 0}
.summary h2{margin-top:0;background:none;border:0;padding:0;font-size:20px}

.cta{margin:44px 0 0;border-radius:16px;background:linear-gradient(135deg,var(--blue),var(--blue-d));color:#fff;padding:28px 22px;display:grid;grid-template-columns:1fr;gap:16px}
.cta .t{font-size:13px;opacity:.9}
.cta h2{margin:0;background:none;border:0;padding:0;color:#fff;font-size:21px}
.cta p{margin:0;font-size:14px;opacity:.95}
.cta .row{display:flex;flex-wrap:wrap;gap:10px}
.cta img{border-radius:10px}
@media (min-width:720px){.cta{grid-template-columns:1.2fr 1fr;align-items:center}}

.author{display:flex;gap:12px;align-items:flex-start;border-top:1px solid var(--line);margin-top:40px;padding-top:20px;font-size:13px;color:var(--muted)}
.author img{width:44px;height:44px;border-radius:10px;flex:none}
.author b{color:var(--ink);font-size:14px}

.related{max-width:760px;margin:0 auto;padding:0 16px 56px}
.related h2{font-size:18px;color:var(--navy);margin-bottom:12px}
.cards{display:grid;grid-template-columns:1fr;gap:12px}
@media (min-width:640px){.cards{grid-template-columns:1fr 1fr}}
.card{display:block;border:1px solid var(--line);border-radius:12px;padding:16px;text-decoration:none;color:var(--ink);background:#fff;transition:border-color .15s}
.card:hover{border-color:var(--blue)}
.card small{color:var(--blue-d);font-weight:700;font-size:12px}
.card b{display:block;font-size:15px;line-height:1.6;margin-top:4px}
.card span{display:block;font-size:13px;color:var(--muted);margin-top:6px;line-height:1.7}

.list-head{background:linear-gradient(135deg,var(--sky),#fff);border-bottom:1px solid var(--line)}
.list-head .in{max-width:1080px;margin:0 auto;padding:36px 16px}
.list-head h1{font-size:28px;font-weight:900;color:var(--navy)}
.list-head p{color:var(--muted);margin-top:8px}
.list{max-width:1080px;margin:0 auto;padding:28px 16px 56px}
.list .cards{gap:16px}
@media (min-width:900px){.list .cards{grid-template-columns:1fr 1fr 1fr}}

footer.site{background:var(--navy);color:#cfd8e3;font-size:12px;padding:24px 16px;text-align:center;line-height:2}
footer.site a{color:#fff;margin:0 8px}
@media (max-width:480px){article h1{font-size:23px} article h2{font-size:19px} .top .btn{padding:8px 14px;font-size:13px}}