/* =====================================================
   コラム共通スタイル（column/ 内の全ページで使用）
   色・ヘッダー・フッターはトップページと同じ
===================================================== */
:root{
  --navy:#4F46E5;--green:#4F46E5;--green-hover:#4338CA;--violet:#9333EA;--coral:#E55B5B;--mint:#10B981;
  --bg-blue:#F5F5FF;
  --slate-100:#f1f5f9;--slate-200:#e2e8f0;--slate-300:#cbd5e1;--slate-400:#94a3b8;
  --slate-500:#64748b;--slate-600:#475569;--slate-700:#334155;--slate-800:#1e293b;
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html,body{width:1440px;}
body{
  font-family:'Noto Sans JP','Noto Sans JP Fallback',sans-serif;
  color:var(--slate-800);font-size:16px;line-height:1.8;background:#fff;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none;}
ul,ol{list-style:none;}
img{display:block;max-width:none;}
.container{width:1440px;margin:0 auto;padding:0 96px;}

/* ---------- Header ---------- */
#main-header{
  position:fixed;top:0;left:0;width:100%;z-index:50;
  height:84px;background:#fff;border-bottom:1px solid var(--slate-200);
  display:flex;align-items:center;transition:box-shadow .3s ease, background-color .3s ease;
}
#main-header.scrolled{box-shadow:0 10px 30px rgba(7,85,141,.08);background:rgba(255,255,255,.94);backdrop-filter:blur(10px);}
.header-inner{display:flex;align-items:center;justify-content:space-between;width:100%;}
.logo-link{display:flex;align-items:center;}
.site-logo{height:56px;width:auto;object-fit:contain;}
.desktop-nav{display:flex;align-items:center;gap:28px;font-size:16px;font-weight:500;color:var(--slate-700);}
.desktop-nav a{transition:color .2s ease;}
.desktop-nav a:hover,.desktop-nav a.is-current{color:var(--navy);}
.btn-header-cta{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  background:var(--green);color:#fff;font-weight:700;font-size:16px;
  padding:14px 28px;border-radius:9999px;transition:background-color .2s ease;
}
.btn-header-cta:hover{background:var(--green-hover);}
.menu-toggle{display:none;background:none;border:none;font-size:24px;color:var(--navy);cursor:pointer;padding:8px;line-height:1;}
.mobile-nav{display:none;position:absolute;top:100%;left:0;width:100%;flex-direction:column;background:#fff;border-top:1px solid var(--slate-200);box-shadow:0 16px 28px rgba(30,20,80,.1);padding:8px 24px 24px;}
.mobile-nav a{padding:16px 4px;font-size:17px;font-weight:500;color:var(--slate-700);border-bottom:1px solid var(--slate-100);}
.mobile-nav a.mobile-nav-cta{
  display:block;text-align:center;margin-top:16px;color:#fff;border-bottom:none;
  background:linear-gradient(135deg,var(--navy),var(--violet));border-radius:9999px;font-weight:700;
}
#main-header.menu-open .mobile-nav{display:flex;}

/* ---------- ページタイトル帯 ---------- */
.page-hero{
  padding:140px 0 56px;
  background:
    radial-gradient(900px 500px at 85% -20%, rgba(147,51,234,.14), transparent 60%),
    radial-gradient(700px 400px at 10% 10%, rgba(79,70,229,.10), transparent 55%),
    linear-gradient(to bottom,#ffffff,#F5F5FF);
}
.page-hero.is-center{text-align:center;padding:164px 0 64px;}
.page-hero-en{font-size:14px;font-weight:700;letter-spacing:.2em;color:var(--violet);margin-bottom:8px;}
.page-hero h1{
  font-size:40px;font-weight:900;line-height:1.4;
  background:linear-gradient(120deg,var(--navy),var(--violet));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;
}
.page-hero-desc{font-size:17px;color:var(--slate-700);margin-top:14px;}

/* パンくず */
.breadcrumb{width:960px;margin:0 auto 28px;display:flex;flex-wrap:wrap;gap:8px;font-size:13px;color:var(--slate-500);}
.breadcrumb a{text-decoration:underline;text-underline-offset:3px;}
.breadcrumb a:hover{color:var(--navy);}
.breadcrumb li + li::before{content:"›";margin-right:8px;color:var(--slate-400);}

/* 記事タイトル */
.article-head{width:960px;margin:0 auto;}
.article-cat{
  display:inline-block;font-size:13px;font-weight:700;color:#fff;padding:4px 14px;border-radius:9999px;
  background:linear-gradient(135deg,var(--navy),var(--violet));margin-bottom:16px;
}
.article-head h1{font-size:36px;font-weight:900;color:#1e1b3a;line-height:1.5;background:none;-webkit-text-fill-color:currentColor;}
.article-date{font-size:14px;color:var(--slate-500);margin-top:14px;}

/* ---------- 記事本文 ---------- */
.article-section{background:linear-gradient(180deg,#F5F5FF,#F1F1FF);padding:0 0 112px;}
.article-card{
  width:960px;margin:0 auto;background:#fff;border-radius:32px;
  padding:64px 80px 72px;box-shadow:0 8px 30px -12px rgba(30,20,80,.12);
}
.article-lead{font-size:17px;color:var(--slate-700);line-height:2;}
.article-toc{margin-top:36px;background:var(--bg-blue);border:1px solid #e4e1fb;border-radius:16px;padding:26px 32px;}
.article-toc-title{font-size:15px;font-weight:800;color:var(--navy);margin-bottom:10px;}
.article-toc ol{counter-reset:toc;}
.article-toc li{counter-increment:toc;font-size:15px;line-height:1.9;}
.article-toc li::before{content:counter(toc) ".";color:var(--violet);font-weight:700;margin-right:8px;}
.article-toc a{text-decoration:underline;text-underline-offset:3px;color:var(--slate-700);}
.article-toc a:hover{color:var(--navy);}

.article-body h2{
  font-size:24px;font-weight:800;color:#1e1b3a;line-height:1.5;
  margin:56px 0 18px;padding:14px 20px;border-radius:12px;
  background:var(--bg-blue);border-left:6px solid var(--navy);
  scroll-margin-top:110px;
}
.article-body h3{font-size:18px;font-weight:800;color:var(--navy);margin:32px 0 10px;line-height:1.6;}
.article-body p{font-size:16px;color:var(--slate-600);line-height:2;}
.article-body p + p{margin-top:14px;}
.article-body strong{color:var(--slate-800);font-weight:700;}
.article-body .list{margin:14px 0;}
.article-body .list li{position:relative;padding-left:22px;font-size:16px;color:var(--slate-600);line-height:1.9;}
.article-body .list li + li{margin-top:8px;}
.article-body .list li::before{content:"";position:absolute;left:5px;top:.82em;width:7px;height:7px;border-radius:9999px;background:var(--violet);}
.article-body .steps{margin:14px 0;counter-reset:step;}
.article-body .steps li{position:relative;padding-left:44px;font-size:16px;color:var(--slate-600);line-height:1.9;counter-increment:step;}
.article-body .steps li + li{margin-top:12px;}
.article-body .steps li::before{
  content:counter(step);position:absolute;left:0;top:2px;width:28px;height:28px;border-radius:9999px;
  background:linear-gradient(135deg,var(--navy),var(--violet));color:#fff;font-size:14px;font-weight:800;
  display:flex;align-items:center;justify-content:center;
}
.note-box{margin:22px 0;border-radius:16px;padding:22px 26px;font-size:15px;line-height:1.9;}
.note-box .note-title{display:flex;align-items:center;gap:8px;font-weight:800;margin-bottom:6px;font-size:15px;}
.note-box.point{background:#F0FDF7;border:1px solid #c5efdc;color:var(--slate-700);}
.note-box.point .note-title{color:#0b8f63;}
.note-box.caution{background:#FEF5F5;border:1px solid #f6d1d1;color:var(--slate-700);}
.note-box.caution .note-title{color:var(--coral);}
.note-box .list li{font-size:15px;}
.article-disclaimer{margin-top:48px;padding-top:24px;border-top:1px solid var(--slate-200);font-size:13px;color:var(--slate-500);line-height:1.9;}

/* 記事下の相談ボックス */
.article-cta{
  width:960px;margin:40px auto 0;border-radius:32px;padding:48px 40px;text-align:center;color:#fff;
  background:linear-gradient(135deg,var(--navy),var(--violet));box-shadow:0 24px 48px -16px rgba(79,70,229,.45);
}
.article-cta h2{font-size:26px;font-weight:800;line-height:1.5;}
.article-cta p{font-size:16px;color:#e7e5ff;margin-top:10px;}
.btn-pill{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;width:320px;
  border-radius:9999px;font-weight:700;font-size:17px;padding:18px 32px;
  transition:transform .2s ease, background-color .2s ease;
}
.btn-pill:hover{transform:translateY(-2px);}
.btn-white{background:#fff;color:var(--navy);margin-top:24px;}
.btn-outline{background:#fff;color:var(--navy);border:1.5px solid rgba(79,70,229,.3);}
.btn-outline:hover{background:var(--bg-blue);}
.article-cta .cta-note{font-size:14px;color:#d9d6ff;margin-top:14px;}

/* 関連コラム・一覧カード */
.related{width:960px;margin:72px auto 0;}
.related-title{font-size:22px;font-weight:800;color:#1e1b3a;margin-bottom:20px;text-align:center;}
.column-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px;}
.related .column-grid{grid-template-columns:repeat(2,1fr);}
.column-list{width:1248px;margin:0 auto;}
.column-card{
  display:flex;flex-direction:column;background:#fff;border-radius:24px;overflow:hidden;
  border:1px solid var(--slate-100);box-shadow:0 8px 30px -12px rgba(30,20,80,.12);
  transition:transform .3s cubic-bezier(.16,1,.3,1), box-shadow .3s ease;
}
.column-card:hover{transform:translateY(-6px);box-shadow:0 22px 40px -14px rgba(79,70,229,.3);}
.column-thumb{
  height:150px;display:flex;align-items:center;justify-content:center;color:#fff;font-size:52px;
  background:linear-gradient(135deg,var(--navy),var(--violet));
}
.column-thumb.t2{background:linear-gradient(135deg,#6366F1,#3B82F6);}
.column-thumb.t3{background:linear-gradient(135deg,#9333EA,#DB2777);}
.column-card-body{padding:24px 26px 28px;display:flex;flex-direction:column;flex:1;}
.column-card-cat{font-size:12px;font-weight:700;color:var(--violet);letter-spacing:.04em;margin-bottom:8px;}
.column-card h3,.column-card h2{font-size:18px;font-weight:800;color:#1e1b3a;line-height:1.6;}
.column-card p{font-size:14px;color:var(--slate-600);line-height:1.8;margin-top:10px;}
.column-card-more{margin-top:auto;padding-top:16px;font-size:14px;font-weight:700;color:var(--navy);display:flex;align-items:center;gap:6px;}
.back-row{text-align:center;margin-top:56px;}

/* ---------- Footer ---------- */
footer{background:#1a1533;color:#a5a0c9;padding:96px 0 0;}
.footer-inner{display:flex;justify-content:space-between;align-items:flex-start;padding-bottom:64px;}
.footer-logo{height:58px;width:auto;margin-bottom:20px;}
.footer-note{font-size:14px;color:var(--slate-400);max-width:420px;}
.footer-links{display:flex;flex-wrap:wrap;gap:8px 24px;margin-top:14px;}
.footer-link{font-size:14px;color:var(--slate-300);text-decoration:underline;text-underline-offset:3px;transition:color .2s ease;}
.footer-link:hover{color:#fff;}
.footer-company-info{text-align:right;}
.footer-company-info .company-title{font-size:14px;color:var(--slate-200);margin-bottom:14px;}
.footer-company-info .company-name{font-size:17px;color:var(--slate-300);font-weight:700;margin-bottom:12px;}
.footer-company-info p{font-size:14px;color:var(--slate-400);line-height:1.7;}
.footer-copyright{border-top:2px solid var(--slate-800);padding:32px 0;text-align:center;}
.footer-copyright p{font-size:13px;color:var(--slate-500);}

/* ---------- タブレット（〜1024px） ---------- */
@media (max-width:1024px){
  html,body{width:100%;}
  img{max-width:100%;}
  .container{width:100%;padding:0 32px;}
  .desktop-nav,.btn-header-cta{display:none;}
  .menu-toggle{display:block;}
  .page-hero{padding:116px 0 44px;}
  .page-hero.is-center{padding:130px 0 52px;}
  .breadcrumb,.article-head,.article-card,.article-cta,.related,.column-list{width:100%;}
  .article-card{padding:48px 44px 56px;}
  .article-head h1{font-size:30px;}
  .column-grid,.related .column-grid{grid-template-columns:repeat(2,1fr);gap:20px;}
  .footer-inner{flex-direction:column;gap:36px;}
  .footer-company-info{text-align:left;}
}

/* ---------- スマホ（〜640px） ---------- */
@media (max-width:640px){
  .container{padding:0 20px;}
  body{font-size:15px;}
  #main-header{height:64px;}
  .site-logo{height:40px;}
  .page-hero{padding:92px 0 32px;}
  .page-hero.is-center{padding:104px 0 40px;}
  .page-hero h1{font-size:28px;}
  .page-hero-en{font-size:12px;}
  .page-hero-desc{font-size:14px;}
  .breadcrumb{font-size:12px;margin-bottom:20px;}
  .article-head h1{font-size:23px;line-height:1.55;}
  .article-section{padding-bottom:72px;}
  .article-card{padding:32px 22px 40px;border-radius:24px;}
  .article-lead{font-size:15px;line-height:1.95;}
  .article-toc{padding:20px 20px;margin-top:28px;}
  .article-toc li{font-size:14px;}
  .article-body h2{font-size:19px;margin:44px 0 14px;padding:12px 14px;scroll-margin-top:84px;}
  .article-body h3{font-size:16px;margin-top:26px;}
  .article-body p,.article-body .list li,.article-body .steps li{font-size:15px;line-height:1.95;}
  .note-box{padding:18px 18px;font-size:14px;}
  .note-box .list li{font-size:14px;}
  .article-cta{padding:36px 22px;border-radius:24px;}
  .article-cta h2{font-size:20px;}
  .article-cta p{font-size:14px;}
  .btn-pill{width:280px;max-width:100%;font-size:16px;}
  .related{margin-top:56px;}
  .related-title{font-size:19px;}
  .column-grid,.related .column-grid{grid-template-columns:1fr;}
  .column-thumb{height:120px;font-size:42px;}
  footer{padding:64px 0 0;}
}