@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+JP:wght@400;500;600;700;900&family=Zen+Kaku+Gothic+New:wght@500;700&display=swap');
*{margin:0;padding:0;box-sizing:border-box}
:root{
--c-deep:#0c4a6e;--c-ocean:#0369a1;--c-sky:#0ea5e9;--c-cyan:#06b6d4;--c-light:#e0f2fe;--c-pale:#f0f9ff;--c-ice:#ecfeff;
--c-amber:#f59e0b;--c-amber-light:#fef3c7;
--c-text:#0f172a;--c-text2:#475569;--c-text3:#94a3b8;
--c-bg:#f8fafc;--c-white:#ffffff;--c-border:#e2e8f0;--c-border2:#cbd5e1;
--shadow-sm:0 1px 2px rgba(0,0,0,.05);
--shadow:0 4px 6px -1px rgba(0,0,0,.07),0 2px 4px -2px rgba(0,0,0,.05);
--shadow-lg:0 10px 15px -3px rgba(0,0,0,.08),0 4px 6px -4px rgba(0,0,0,.05);
--shadow-xl:0 20px 25px -5px rgba(0,0,0,.1),0 8px 10px -6px rgba(0,0,0,.05);
--radius:12px;--radius-lg:16px;--radius-xl:24px;
--max-w:1160px;
--font-body:'Noto Sans JP','Hiragino Sans','Hiragino Kaku Gothic ProN',sans-serif;
--font-heading:'Zen Kaku Gothic New','Noto Sans JP',sans-serif;
}
html{scroll-behavior:smooth;font-size:16px;-webkit-text-size-adjust:100%}
body{font-family:var(--font-body);color:var(--c-text);background:var(--c-bg);line-height:1.85;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:var(--c-ocean);text-decoration:none;transition:color .25s}
a:hover{color:var(--c-deep)}
img{max-width:100%;height:auto;display:block}
.container{max-width:var(--max-w);margin:0 auto;padding:0 24px}

::selection{background:var(--c-sky);color:#fff}

header{position:sticky;top:0;z-index:1000;background:rgba(255,255,255,.72);backdrop-filter:blur(16px) saturate(180%);-webkit-backdrop-filter:blur(16px) saturate(180%);border-bottom:1px solid rgba(226,232,240,.6);transition:box-shadow .3s}
header.scrolled{box-shadow:0 4px 30px rgba(0,0,0,.08)}
.header-inner{display:flex;align-items:center;justify-content:space-between;padding:0 24px;max-width:var(--max-w);margin:0 auto;height:64px}
.logo{font-family:var(--font-heading);font-size:1.35rem;font-weight:700;color:var(--c-deep);display:flex;align-items:center;gap:10px;text-decoration:none;transition:opacity .25s}
.logo:hover{opacity:.8;color:var(--c-deep)}
.logo-icon{width:36px;height:36px;background:linear-gradient(135deg,var(--c-ocean),var(--c-cyan));border-radius:10px;display:flex;align-items:center;justify-content:center;color:#fff;font-size:1.1rem;font-weight:700;box-shadow:0 2px 8px rgba(6,182,212,.3)}
.hamburger{display:none;flex-direction:column;gap:5px;cursor:pointer;padding:8px;background:none;border:none;z-index:1001}
.hamburger span{display:block;width:22px;height:2px;background:var(--c-text);border-radius:2px;transition:all .3s}
.hamburger.active span:nth-child(1){transform:rotate(45deg) translate(5px,5px)}
.hamburger.active span:nth-child(2){opacity:0}
.hamburger.active span:nth-child(3){transform:rotate(-45deg) translate(5px,-5px)}
.nav-wrap{display:flex;align-items:center;gap:2px}
.nav-wrap>a{padding:8px 14px;border-radius:8px;font-size:.84rem;font-weight:500;color:var(--c-text2);transition:all .25s;white-space:nowrap}
.nav-wrap>a:hover{background:var(--c-pale);color:var(--c-ocean)}
.nav-more-btn{display:inline-flex;align-items:center;gap:4px;padding:8px 14px;border-radius:8px;font-size:.84rem;font-weight:500;color:var(--c-text3);cursor:pointer;background:none;border:none;transition:all .25s}
.nav-more-btn:hover{background:var(--c-pale);color:var(--c-ocean)}
.nav-more-btn svg{width:14px;height:14px;transition:transform .25s}
.nav-dropdown{position:absolute;top:100%;right:24px;background:#fff;border-radius:var(--radius);box-shadow:var(--shadow-xl);border:1px solid var(--c-border);padding:12px 8px;min-width:280px;display:none;z-index:999}
.nav-dropdown.open{display:block;animation:dropIn .25s ease}
@keyframes dropIn{from{opacity:0;transform:translateY(-8px)}to{opacity:1;transform:translateY(0)}}
.nav-dropdown a{display:block;padding:8px 14px;border-radius:8px;font-size:.84rem;color:var(--c-text2);transition:all .2s}
.nav-dropdown a:hover{background:var(--c-pale);color:var(--c-ocean)}

.progress-bar{position:fixed;top:0;left:0;height:3px;background:linear-gradient(90deg,var(--c-ocean),var(--c-cyan));z-index:9999;width:0;transition:width .1s linear}

.hero{position:relative;background:linear-gradient(135deg,#0c4a6e 0%,#0369a1 30%,#0ea5e9 70%,#06b6d4 100%);color:#fff;padding:80px 24px 100px;text-align:center;overflow:hidden}
.hero::before{content:'';position:absolute;inset:0;background:url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.04'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E")}
.hero::after{content:'';position:absolute;bottom:0;left:0;right:0;height:80px}
.hero h1{font-family:var(--font-heading);font-size:clamp(1.5rem,4vw,2.4rem);font-weight:700;margin-bottom:16px;letter-spacing:.02em;position:relative;z-index:1}
.hero p{font-size:clamp(.92rem,1.5vw,1.1rem);opacity:.9;max-width:600px;margin:0 auto 32px;line-height:1.8;position:relative;z-index:1}
.hero-cta{display:inline-flex;align-items:center;gap:8px;padding:14px 36px;background:var(--c-amber);color:#fff;font-weight:700;font-size:.95rem;border-radius:50px;border:none;cursor:pointer;transition:all .3s;box-shadow:0 4px 15px rgba(245,158,11,.4);position:relative;z-index:1;text-decoration:none}
.hero-cta:hover{transform:translateY(-2px);box-shadow:0 6px 20px rgba(245,158,11,.5);color:#fff}
.hero-stats{display:flex;justify-content:center;gap:40px;margin-top:40px;position:relative;z-index:1}
.hero-stat{text-align:center}
.hero-stat-num{font-family:var(--font-heading);font-size:1.8rem;font-weight:700}
.hero-stat-label{font-size:.78rem;opacity:.75}
.wave-divider{position:relative;margin-top:-1px}
.wave-divider svg{display:block;width:100%;height:auto}

.section{padding:56px 0}
.section-alt{background:var(--c-white)}
.section-title{font-family:var(--font-heading);font-size:clamp(1.15rem,2vw,1.5rem);font-weight:700;margin-bottom:8px;text-align:center;color:var(--c-text)}
.section-sub{font-size:.9rem;color:var(--c-text3);text-align:center;margin-bottom:36px}

.cat-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:16px}
.cat-card{background:var(--c-white);border-radius:var(--radius);padding:20px 16px;text-align:center;border:1px solid var(--c-border);transition:all .3s;cursor:pointer;text-decoration:none;color:var(--c-text);display:block;position:relative;overflow:hidden}
.cat-card::before{content:'';position:absolute;top:0;left:0;right:0;height:3px;background:var(--cat-color,var(--c-ocean));transform:scaleX(0);transition:transform .3s;transform-origin:left}
.cat-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);border-color:transparent}
.cat-card:hover::before{transform:scaleX(1)}
.cat-icon{width:44px;height:44px;border-radius:12px;margin:0 auto 12px;display:flex;align-items:center;justify-content:center;font-size:1.2rem;background:var(--cat-bg,var(--c-pale))}
.cat-card h3{font-family:var(--font-heading);font-size:.88rem;font-weight:600;margin-bottom:4px}
.cat-card p{font-size:.75rem;color:var(--c-text3)}

.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:20px}
.card{background:var(--c-white);border-radius:var(--radius);box-shadow:var(--shadow-sm);border:1px solid var(--c-border);overflow:hidden;transition:all .3s;display:flex;flex-direction:column}
.card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:var(--c-cyan)}
.card-body{padding:18px 20px;flex:1;display:flex;flex-direction:column}
.card-cat{display:inline-block;font-size:.72rem;font-weight:600;padding:3px 10px;border-radius:20px;margin-bottom:10px;width:fit-content}
.card-title{font-size:.92rem;font-weight:600;line-height:1.6;margin-bottom:10px;flex:1}
.card-title a{color:var(--c-text);transition:color .25s}
.card-title a:hover{color:var(--c-ocean)}
.card-meta{font-size:.78rem;color:var(--c-text3);display:flex;align-items:center;gap:12px}

.accordion-section{padding:56px 0}
.accordion-group{max-width:var(--max-w);margin:0 auto;padding:0 24px}
.accordion-item{border:1px solid var(--c-border);border-radius:var(--radius);margin-bottom:8px;overflow:hidden;background:var(--c-white);transition:box-shadow .3s}
.accordion-item:hover{box-shadow:var(--shadow)}
.accordion-header{display:flex;align-items:center;justify-content:space-between;padding:14px 20px;cursor:pointer;font-weight:600;font-size:.92rem;color:var(--c-text);transition:background .2s;gap:12px}
.accordion-header:hover{background:var(--c-pale)}
.accordion-header .acc-badge{font-size:.72rem;font-weight:500;padding:2px 8px;border-radius:10px;background:var(--c-pale);color:var(--c-ocean);white-space:nowrap}
.accordion-arrow{width:18px;height:18px;transition:transform .3s;flex-shrink:0;color:var(--c-text3)}
.accordion-item.open .accordion-arrow{transform:rotate(180deg)}
.accordion-body{max-height:0;overflow:hidden;transition:max-height .35s ease}
.accordion-body-inner{padding:0 20px 16px}
.accordion-body-inner a{display:block;padding:8px 0;font-size:.85rem;color:var(--c-text2);border-bottom:1px solid var(--c-border);transition:color .2s}
.accordion-body-inner a:last-child{border-bottom:none}
.accordion-body-inner a:hover{color:var(--c-ocean)}
.accordion-body-inner .acc-cat-label{font-size:.7rem;color:var(--c-text3);margin-left:8px}

.two-col{display:grid;grid-template-columns:1fr 280px;gap:36px;align-items:start}
.main-content{min-width:0}
.sidebar{position:sticky;top:80px}

.breadcrumb{padding:16px 0;font-size:.8rem;color:var(--c-text3);display:flex;flex-wrap:wrap;align-items:center;gap:2px}
.breadcrumb a{color:var(--c-text3);transition:color .2s}
.breadcrumb a:hover{color:var(--c-ocean)}
.breadcrumb .bc-sep{margin:0 4px}
.breadcrumb .bc-current{color:var(--c-text);font-weight:500}

.article-header{margin-bottom:36px}
.article-header .ah-cat{display:inline-block;font-size:.72rem;font-weight:600;padding:4px 14px;border-radius:20px;margin-bottom:14px}
.article-header h1{font-family:var(--font-heading);font-size:clamp(1.2rem,2.5vw,1.65rem);line-height:1.55;margin-bottom:14px;font-weight:700;letter-spacing:.01em}
.article-meta{display:flex;flex-wrap:wrap;gap:16px;font-size:.8rem;color:var(--c-text3);align-items:center}
.article-meta .am-badge{background:var(--c-pale);color:var(--c-ocean);padding:3px 12px;border-radius:20px;font-weight:600;font-size:.72rem}

.toc{background:var(--c-pale);border-radius:var(--radius);padding:20px 24px;margin-bottom:32px;border-left:4px solid var(--c-ocean)}
.toc-title{font-family:var(--font-heading);font-size:.88rem;font-weight:700;margin-bottom:10px;color:var(--c-ocean);display:flex;align-items:center;gap:6px}
.toc ul{list-style:none;padding-left:0}
.toc ul ul{padding-left:18px}
.toc li{margin-bottom:2px}
.toc a{font-size:.82rem;color:var(--c-text2);display:block;padding:3px 0;border-radius:4px;transition:all .2s}
.toc a:hover{color:var(--c-ocean);padding-left:4px}
.toc a.active{color:var(--c-ocean);font-weight:600;background:rgba(14,165,233,.08);padding-left:8px}

.article-body{font-size:.95rem;line-height:1.95;color:var(--c-text)}
.article-body h1{font-family:var(--font-heading);font-size:1.3rem;margin:40px 0 18px;padding-bottom:10px;border-bottom:2px solid var(--c-light);font-weight:700;color:var(--c-deep)}
.article-body h2{font-family:var(--font-heading);font-size:1.15rem;margin:32px 0 14px;padding-bottom:8px;border-bottom:1px solid var(--c-border);font-weight:700;color:var(--c-deep)}
.article-body h3{font-family:var(--font-heading);font-size:1.02rem;margin:24px 0 10px;font-weight:600;color:var(--c-text)}
.article-body p{margin-bottom:18px}
.article-body ul,.article-body ol{margin-bottom:18px;padding-left:24px}
.article-body li{margin-bottom:6px}
.article-body li::marker{color:var(--c-ocean)}
.article-body blockquote{border-left:4px solid var(--c-cyan);background:var(--c-pale);padding:16px 20px;margin:20px 0;border-radius:0 var(--radius) var(--radius) 0;font-size:.9rem;color:var(--c-text2)}
.article-body table{width:100%;border-collapse:separate;border-spacing:0;margin:20px 0;font-size:.88rem;border-radius:var(--radius);overflow:hidden;border:1px solid var(--c-border)}
.article-body th,.article-body td{padding:10px 14px;text-align:left}
.article-body th{background:var(--c-deep);color:#fff;font-weight:600;white-space:nowrap;font-size:.82rem}
.article-body td{border-bottom:1px solid var(--c-border)}
.article-body tr:nth-child(even) td{background:var(--c-pale)}
.article-body tr:last-child td{border-bottom:none}
.article-body hr{border:none;height:1px;background:linear-gradient(90deg,transparent,var(--c-border2),transparent);margin:32px 0}
.article-body a{color:var(--c-ocean);text-decoration:underline;text-underline-offset:3px;transition:color .2s}
.article-body a:hover{color:var(--c-deep)}
.article-body .headerlink{display:none}
.article-body img{border-radius:var(--radius)}
.article-body strong{color:var(--c-deep)}

.related{margin-top:48px;padding-top:32px;border-top:2px solid var(--c-light)}
.related h2{font-family:var(--font-heading);font-size:1.1rem;font-weight:700;margin-bottom:20px;color:var(--c-deep)}
.related-list{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px}
.related-item{padding:14px 18px;background:var(--c-white);border-radius:var(--radius);border:1px solid var(--c-border);font-size:.85rem;transition:all .25s}
.related-item:hover{border-color:var(--c-cyan);box-shadow:var(--shadow)}
.related-item a{color:var(--c-text)}
.related-item a:hover{color:var(--c-ocean)}

.sidebar-box{background:var(--c-white);border-radius:var(--radius);box-shadow:var(--shadow-sm);border:1px solid var(--c-border);padding:18px;margin-bottom:16px}
.sidebar-box h3{font-family:var(--font-heading);font-size:.88rem;font-weight:700;margin-bottom:12px;padding-bottom:8px;border-bottom:2px solid var(--c-ocean);color:var(--c-deep)}
.sidebar-box ul{list-style:none}
.sidebar-box li{margin-bottom:6px}
.sidebar-box a{font-size:.8rem;color:var(--c-text2);transition:color .2s}
.sidebar-box a:hover{color:var(--c-ocean)}
.sidebar-box .sb-current{font-weight:600;color:var(--c-ocean)}

.category-header{margin-bottom:32px;padding:32px;background:linear-gradient(135deg,var(--c-pale),var(--c-ice));border-radius:var(--radius-lg);text-align:center}
.category-header h1{font-family:var(--font-heading);font-size:1.4rem;font-weight:700;margin-bottom:8px;color:var(--c-deep)}
.category-header p{color:var(--c-text3);font-size:.9rem}

.footer-wave{margin-top:0}
.footer-wave svg{display:block;width:100%;height:auto}
footer{background:var(--c-deep);color:var(--c-text3);padding:48px 24px 0}
.footer-inner{max-width:var(--max-w);margin:0 auto;display:grid;grid-template-columns:1.2fr 1.5fr .8fr;gap:40px}
.footer-col h4{color:#e2e8f0;font-family:var(--font-heading);font-size:.92rem;margin-bottom:14px;font-weight:700}
.footer-col p{font-size:.82rem;line-height:1.7}
.footer-col a{display:block;font-size:.8rem;color:var(--c-text3);margin-bottom:6px;transition:color .25s}
.footer-col a:hover{color:var(--c-cyan)}
.footer-bottom{max-width:var(--max-w);margin:32px auto 0;padding-top:20px;border-top:1px solid rgba(255,255,255,.1);text-align:center;font-size:.78rem;color:rgba(148,163,184,.6);padding-bottom:20px}

.back-to-top{position:fixed;bottom:24px;right:24px;width:44px;height:44px;background:var(--c-ocean);color:#fff;border:none;border-radius:50%;cursor:pointer;display:flex;align-items:center;justify-content:center;box-shadow:var(--shadow-lg);opacity:0;transform:translateY(20px);transition:all .3s;z-index:900}
.back-to-top.visible{opacity:1;transform:translateY(0)}
.back-to-top:hover{background:var(--c-deep);transform:translateY(-2px)}

.fade-in{opacity:0;transform:translateY(20px);transition:opacity .6s ease,transform .6s ease}
.fade-in.visible{opacity:1;transform:translateY(0)}

@keyframes ripple{0%{transform:scale(1);opacity:.6}100%{transform:scale(2.5);opacity:0}}
.water-drops{position:absolute;inset:0;overflow:hidden;pointer-events:none;z-index:0}
.water-drop{position:absolute;border-radius:50%;background:rgba(255,255,255,.08);animation:ripple 4s ease-out infinite}
.water-drop:nth-child(1){width:20px;height:20px;top:20%;left:10%;animation-delay:0s}
.water-drop:nth-child(2){width:30px;height:30px;top:60%;left:80%;animation-delay:1.5s}
.water-drop:nth-child(3){width:15px;height:15px;top:40%;left:50%;animation-delay:3s}
.water-drop:nth-child(4){width:25px;height:25px;top:80%;left:25%;animation-delay:2s}
.water-drop:nth-child(5){width:18px;height:18px;top:10%;left:70%;animation-delay:.8s}

@media(max-width:768px){
.hamburger{display:flex}
.nav-wrap,.nav-dropdown{display:none}
.nav-wrap.mobile-open{display:flex;position:absolute;top:64px;left:0;right:0;background:rgba(255,255,255,.98);backdrop-filter:blur(16px);flex-direction:column;padding:12px 20px;border-bottom:1px solid var(--c-border);box-shadow:var(--shadow-lg);z-index:999}
.nav-wrap.mobile-open>a{padding:12px 14px;border-bottom:1px solid var(--c-border)}
.nav-dropdown.mobile-open{display:block;position:static;box-shadow:none;border:none;padding:0 14px}
.hero{padding:56px 20px 80px}
.hero-stats{gap:24px}
.hero-stat-num{font-size:1.3rem}
.two-col{grid-template-columns:1fr}
.sidebar{position:static;order:-1}
.card-grid{grid-template-columns:1fr}
.cat-grid{grid-template-columns:repeat(auto-fill,minmax(140px,1fr))}
.related-list{grid-template-columns:1fr}
.article-header h1{font-size:1.15rem}
.footer-inner{grid-template-columns:1fr;gap:28px}
.section{padding:40px 0}
.accordion-body-inner{padding:0 14px 14px}
}

@media(max-width:480px){
.hero{padding:40px 16px 64px}
.hero h1{font-size:1.25rem}
.cat-grid{grid-template-columns:repeat(2,1fr);gap:10px}
.cat-card{padding:14px 10px}
.card-grid{grid-template-columns:1fr}
}