:root{--ink:#17324d;--ink-deep:#092b4a;--mint:#58c3a5;--mint-dark:#16745f;--mint-soft:#e8f7f2;--blue:#245f8f;--blue-dark:#123f65;--blue-soft:#edf5fb;--paper:#fff;--wash:#eef5f6;--line:#c8d7de;--muted:#587080;--shadow:0 20px 60px #17324d1f;--radius:14px;--page:min(1280px, calc(100% - 48px));--reading:740px;--font-sans:"Hiragino Kaku Gothic ProN", "Yu Gothic", "YuGothic", "Noto Sans JP", system-ui, sans-serif}*,:before,:after{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{background:var(--paper);color:var(--ink);font-family:var(--font-sans);-webkit-font-smoothing:antialiased;margin:0;font-size:16px;line-height:1.8}body:before{z-index:-1;content:"";pointer-events:none;background-image:linear-gradient(#17324d05 1px,#0000 1px),linear-gradient(90deg,#17324d05 1px,#0000 1px);background-size:32px 32px;position:fixed;inset:0}img,svg{max-width:100%;display:block}a{color:inherit;text-underline-offset:.22em;text-decoration-thickness:1px}a:hover{color:var(--mint-dark)}button,input{font:inherit}:focus-visible{outline-offset:4px;outline:3px solid #245f8f8c}.visually-hidden{clip:rect(0 0 0 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.skip-link{z-index:1000;background:var(--ink);color:#fff;padding:10px 16px;position:fixed;top:12px;left:12px;transform:translateY(-150%)}.skip-link:focus{transform:translateY(0)}.page-shell{width:var(--page);margin-inline:auto}.site-header{z-index:100;backdrop-filter:blur(18px);background:#fffffff5;border-bottom:1px solid #17324d29;position:sticky;top:0}.header-inner{width:var(--page);justify-content:space-between;align-items:center;gap:30px;min-height:84px;margin-inline:auto;display:flex}.brand{color:var(--ink-deep);letter-spacing:.03em;white-space:nowrap;align-items:center;font-size:clamp(1.05rem,2vw,1.45rem);font-weight:800;line-height:1.25;text-decoration:none;display:inline-flex}.brand:hover{color:var(--ink-deep)}.brand-mark{flex:none;width:30px;height:30px;margin-right:10px}.site-nav{align-items:center;gap:clamp(18px,2.5vw,42px);display:flex}.site-nav>a{color:var(--ink);white-space:nowrap;font-size:.9rem;font-weight:700;text-decoration:none;position:relative}.site-nav>a:not(.search-link):after{background:var(--mint);content:"";height:2px;transition:transform .18s;position:absolute;bottom:-12px;left:0;right:0;transform:scaleX(0)}.site-nav>a:hover:after{transform:scaleX(1)}.search-link{border:1px solid var(--ink);border-radius:7px;align-items:center;gap:9px;min-height:44px;padding:0 18px;display:inline-flex}.search-link svg{fill:none;stroke:currentColor;stroke-linecap:round;stroke-width:2px;width:19px}.search-link:hover{background:var(--ink);color:#fff}.menu-button{border:1px solid var(--ink);background:#fff;border-radius:6px;width:46px;height:42px;padding:10px;display:none}.menu-button span[aria-hidden]{background:var(--ink);height:2px;margin:5px 0;transition:transform .18s;display:block}.hero{border-bottom:1px solid var(--line);grid-template-columns:minmax(0,.95fr) minmax(0,1.05fr);min-height:650px;display:grid}.hero-copy{flex-direction:column;justify-content:center;max-width:700px;padding:80px 42px 80px max(24px,50vw - 640px);display:flex}.hero h1{max-width:10.5em;color:var(--ink-deep);font-family:var(--font-sans);letter-spacing:.03em;margin:0 0 26px;font-size:clamp(3rem,4vw,4.8rem);font-weight:700;line-height:1.18}.hero h1 span{display:block}.hero-copy>p{max-width:33em;color:var(--ink);margin:0;font-size:clamp(1.05rem,1.5vw,1.25rem);line-height:1.95}.hero-actions{align-items:center;gap:28px;margin-top:34px;display:flex}.button{border:1px solid var(--ink);min-height:52px;color:var(--ink);text-align:center;border-radius:7px;justify-content:center;align-items:center;gap:14px;padding:10px 22px;font-size:.95rem;font-weight:800;text-decoration:none;transition:background .16s,color .16s,transform .16s;display:inline-flex}.button:hover{transform:translateY(-2px)}.button-primary{border-color:var(--blue);background:var(--blue);color:#fff}.button-primary:hover{border-color:var(--blue-dark);background:var(--blue-dark);color:#fff}.text-link{color:var(--mint-dark);text-underline-offset:.45em;font-weight:800}.hero-media{background:var(--wash);min-height:560px;position:relative;overflow:hidden}.hero-media picture,.hero-media img{width:100%;height:100%}.hero-media img{object-fit:cover;object-position:58% center}.home-section{padding:72px 0}.home-section>.affiliate-card{margin:34px 0 0}.section-heading{border-bottom:2px solid var(--ink);justify-content:space-between;align-items:flex-end;gap:30px;margin-bottom:34px;padding-bottom:20px;display:flex}.section-heading h2{letter-spacing:.02em;margin:0;font-size:clamp(2rem,4vw,3.4rem);line-height:1.25}.section-heading p{max-width:38em;color:var(--muted);margin:0}.section-heading-inline h2{font-size:clamp(1.8rem,3vw,2.5rem)}.section-heading-inline a{font-weight:800}.guide-index{border-top:1px solid var(--line)}.guide-link{border-bottom:1px solid var(--line);grid-template-columns:90px 1fr 42px;align-items:center;min-height:88px;text-decoration:none;transition:padding .16s,background .16s;display:grid}.guide-link:hover{background:var(--mint-soft);color:var(--ink);padding-left:12px}.guide-number,.article-index{color:var(--mint);letter-spacing:.02em;font-size:2.4rem;font-weight:800;line-height:1}.guide-link strong{font-size:clamp(1.05rem,2vw,1.45rem);line-height:1.35}.guide-link svg,.row-arrow svg{fill:none;stroke:currentColor;stroke-width:1.5px}.popular-block{margin-top:78px}.popular-block>h2{margin:0 0 16px;font-size:clamp(1.8rem,3vw,2.6rem)}.article-list{border-top:1px solid var(--line)}.article-row{border-bottom:1px solid var(--line);grid-template-columns:82px minmax(0,1fr) 44px;align-items:center;gap:24px;min-height:128px;padding:24px 12px;transition:background .16s;display:grid}.article-row:hover{background:var(--wash)}.article-category,.article-hero-category{color:var(--mint-dark);letter-spacing:.08em;font-size:.78rem;font-weight:800}.article-meta{color:var(--muted);flex-wrap:wrap;gap:8px 26px;margin-top:22px;font-size:.78rem;display:flex}.article-meta a{color:var(--ink);font-weight:700}.article-row h3{margin:3px 0;font-size:clamp(1rem,1.8vw,1.35rem);line-height:1.45}.article-row h3 a{text-decoration:none}.article-row p{max-width:58em;color:var(--muted);margin:4px 0 0;font-size:.9rem;line-height:1.65}.row-arrow{padding:12px 2px;text-decoration:none}.article-row-compact{grid-template-columns:70px minmax(0,1fr) 40px;min-height:92px}.site-footer{border-top:1px solid var(--line);background:#fff}.footer-main{grid-template-columns:1.5fr repeat(3,1fr);gap:50px;padding-top:72px;padding-bottom:64px;display:grid}.footer-brand>p{max-width:28em;color:var(--muted);margin:14px 0;font-size:.88rem}.footer-brand .amazon-associate{font-size:.72rem;line-height:1.65}.footer-column{flex-direction:column;gap:7px;display:flex}.footer-column h2{margin:0 0 10px;font-size:.9rem}.footer-column a{color:var(--muted);font-size:.82rem;text-decoration:none}.footer-bottom{background:var(--ink-deep);color:#fff;padding:16px 0}.footer-bottom .page-shell{justify-content:center;gap:28px;display:flex}.footer-bottom small{opacity:.8;font-size:.7rem}.page-intro{border-bottom:1px solid var(--line);padding:86px 0 54px}.page-intro h1{margin:0 0 16px;font-size:clamp(2.6rem,5vw,4.8rem);line-height:1.2}.page-intro p{max-width:48em;color:var(--muted);margin:0;font-size:1.08rem}.search-panel{background:var(--wash);padding:44px 0}.search-form{grid-template-columns:minmax(0,1fr) auto;gap:12px;display:grid}.search-form label{grid-column:1/-1;font-weight:800}.search-form input{border:1px solid var(--ink);min-height:56px;color:var(--ink);background:#fff;border-radius:6px;padding:0 18px}.search-status{min-height:1.8em;color:var(--muted);margin:10px 0 0;font-size:.82rem}.archive-section{padding:64px 0 110px}.article-page{background:#fff}.article-hero{padding-top:64px;padding-bottom:48px}.breadcrumbs{color:var(--muted);white-space:nowrap;align-items:center;gap:10px;margin-bottom:42px;font-size:.75rem;display:flex;overflow:hidden}.breadcrumbs span[aria-current]{text-overflow:ellipsis;overflow:hidden}.article-hero h1{max-width:1040px;color:var(--ink-deep);letter-spacing:.01em;margin:10px 0 20px;font-size:clamp(2.3rem,4.8vw,4.4rem);line-height:1.28}.article-lead{max-width:850px;color:var(--muted);margin:0;font-size:clamp(1rem,1.6vw,1.18rem)}.affiliate-disclosure{max-width:900px;color:var(--muted);margin-top:16px;font-size:.72rem;line-height:1.5}.article-layout{grid-template-columns:230px minmax(0, var(--reading)) 1fr;align-items:start;gap:54px;padding-top:34px;padding-bottom:90px;display:grid}.article-toc{border:1px solid var(--line);background:#fff;border-radius:8px;padding:22px;position:sticky;top:118px}.article-toc h2{border-bottom:1px solid var(--line);margin:0 0 10px;padding-bottom:10px;font-size:.85rem}.article-toc ol{margin:0;padding:0;list-style:none}.article-toc li+li{border-top:1px solid var(--line)}.article-toc a{color:var(--ink);grid-template-columns:28px 1fr;padding:11px 0;font-size:.75rem;font-weight:700;line-height:1.5;text-decoration:none;display:grid}.article-toc a span{color:var(--mint-dark)}.toc-affiliate{border-top:1px solid var(--line);margin-top:10px;padding-top:18px}.affiliate-card{background:#fff;border:1px solid #dce4e7;border-radius:10px;margin:48px 0;overflow:hidden;box-shadow:0 8px 24px #1331400f}.affiliate-card-link{grid-template-columns:minmax(150px,190px) 1fr;align-items:stretch;display:grid;position:relative;color:var(--ink)!important;text-align:left!important;text-decoration:none!important}.affiliate-card-image-wrap{background:#f7f8f6;place-items:center;min-height:180px;padding:14px;display:grid;position:relative}.affiliate-card-image{object-fit:contain;width:100%;height:100%;max-height:180px}.affiliate-card-link .affiliate-card-pr{z-index:1;color:#8a969f;letter-spacing:.08em;font-size:.62rem;position:absolute;bottom:8px;right:10px}.affiliate-card-copy{flex-direction:column;justify-content:center;gap:7px;padding:24px 26px;display:flex}.affiliate-card-copy strong{color:var(--ink-deep);font-size:1.1rem;line-height:1.45}.affiliate-card-copy>span{color:#385062;font-size:.9rem;line-height:1.7}.affiliate-card-copy small{color:var(--muted);font-size:.68rem;line-height:1.55}.affiliate-card-copy .affiliate-card-product-name{color:#596b77;margin-top:2px;font-weight:700}.affiliate-card-compact{box-shadow:none;border-radius:7px;margin:0}.affiliate-card-compact .affiliate-card-link{grid-template-columns:1fr}.affiliate-card-compact .affiliate-card-image-wrap{min-height:112px;padding:10px}.affiliate-card-compact .affiliate-card-image{max-height:112px}.affiliate-card-compact .affiliate-card-copy{gap:6px;padding:14px}.affiliate-card-compact .affiliate-card-copy strong{font-size:.84rem}.affiliate-card-compact .affiliate-card-copy>span{font-size:.72rem;line-height:1.55}.article-ad-pool{display:none}.article-content{min-width:0;font-size:1rem}.article-content>:first-child{margin-top:0}.article-content h2{border-bottom:2px solid var(--ink);color:var(--ink-deep);margin:0 0 24px;padding-top:52px;padding-bottom:12px;font-size:clamp(1.55rem,3vw,2.15rem);line-height:1.4}.article-content h3{color:var(--ink-deep);margin:42px 0 14px;font-size:1.3rem;line-height:1.5}.article-content p,.article-content li{color:#263f53}.article-content p{margin:1.3em 0}.article-content ul,.article-content ol{padding-left:1.35em}.article-content li+li{margin-top:.55em}.article-content a{color:#126e82;font-weight:700}.echo-history{margin-bottom:64px}.echo-history-intro{border-top:1px solid var(--line);padding:30px 0 24px}.echo-history-intro>span{color:var(--mint-dark);letter-spacing:.18em;margin-bottom:8px;font-size:.68rem;font-weight:800;display:block}.article-content .echo-history-intro h2{border-bottom:2px solid var(--ink);margin:0 0 18px;padding:0 0 14px}.echo-history-intro p{max-width:42em;margin:0}.echo-history-nav{border:1px solid var(--line);background:var(--wash);border-radius:8px;grid-template-columns:repeat(2,minmax(0,1fr));gap:1px 24px;margin:8px 0 54px;padding:16px;display:grid}.article-content .echo-history-nav a{min-height:44px;color:var(--ink-deep);border-bottom:1px solid #dce5e5;align-items:center;font-size:.82rem;text-decoration:none;display:flex}.article-content .echo-history-nav a:after{color:var(--mint-dark);content:"↓";margin-left:auto}.echo-history-group{margin-top:72px;scroll-margin-top:92px}.echo-history-group>header{border-bottom:1px solid var(--line);grid-template-columns:minmax(180px,.8fr) minmax(0,1.2fr);align-items:end;gap:28px;margin-bottom:22px;padding-bottom:18px;display:grid}.article-content .echo-history-group h3{color:var(--ink-deep);margin:0;font-size:1.55rem;line-height:1.35}.echo-history-group>header p{color:var(--muted);margin:0;font-size:.82rem;line-height:1.8}.echo-history-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;display:grid}.echo-model-card{min-width:0}.article-content .echo-model-card>a{background:#fff;border:1px solid #dce4e7;border-radius:9px;flex-direction:column;height:100%;text-decoration:none;transition:border-color .16s,box-shadow .16s,transform .16s;display:flex;position:relative;overflow:hidden;box-shadow:0 7px 22px #1331400b;color:var(--ink)!important}.article-content .echo-model-card>a:hover{border-color:#aebfc4;transform:translateY(-2px);box-shadow:0 13px 28px #13314017}.article-content .echo-model-card>a:focus-visible{outline-offset:3px;outline:3px solid #126e8259}.echo-model-image-wrap{background:#f8f9f7;border-bottom:1px solid #e7ebec;place-items:center;width:100%;min-height:210px;padding:16px;display:grid}.echo-model-image-wrap img{mix-blend-mode:multiply;object-fit:contain;width:100%;height:184px}.echo-model-copy{flex-direction:column;flex:1;padding:20px 20px 34px;display:flex}.echo-model-copy small{color:var(--mint-dark);letter-spacing:.04em;margin-bottom:7px;font-size:.66rem;font-weight:800}.echo-model-copy strong{color:var(--ink-deep);font-size:1.02rem;line-height:1.45}.echo-model-copy>span{color:#405667;margin-top:9px;font-size:.78rem;font-weight:400;line-height:1.72}.echo-model-pr{color:#8a969f;letter-spacing:.08em;font-size:.6rem;font-weight:400;position:absolute;bottom:9px;right:12px}.article-content table{border-collapse:collapse;width:100%;margin:28px 0;font-size:.84rem;display:block;overflow-x:auto}.article-content th,.article-content td{border:1px solid var(--line);vertical-align:top;min-width:130px;padding:13px 14px}.article-content th{background:var(--ink);color:#fff;text-align:left}.article-content blockquote{border-left:4px solid var(--mint);background:var(--mint-soft);margin:28px 0;padding:20px 24px}.article-content blockquote p{margin:0}.answer-box{border:2px solid var(--mint);background:#fbfffd;border-radius:10px;margin-bottom:22px;padding:28px}.answer-box>strong{color:var(--ink-deep);margin-bottom:12px;font-size:1.2rem;display:block}.answer-box ol,.answer-box ul{margin:0}.caution-box{border:1px solid var(--blue);background:var(--blue-soft);border-radius:8px;margin:26px 0;padding:22px 24px}.caution-box strong{color:var(--blue-dark)}.steps{counter-reset:steps;list-style:none;margin:30px 0!important;padding:0!important}.steps>li{border-bottom:1px solid var(--line);counter-increment:steps;min-height:64px;padding:14px 0 18px 68px;position:relative}.steps>li:before{background:var(--mint);color:#fff;content:counter(steps);border-radius:50%;place-items:center;width:46px;height:46px;font-size:1.15rem;font-weight:800;display:grid;position:absolute;top:10px;left:0}.decision-flow{border:1px solid var(--line);background:var(--wash);border-radius:8px;grid-template-columns:repeat(3,1fr);gap:28px;margin:30px 0;padding:20px;display:grid}.decision-flow>div{border:1px solid var(--ink);text-align:center;background:#fff;padding:15px;font-size:.82rem;font-weight:700;position:relative}.decision-flow>div:not(:last-child):after{color:var(--mint-dark);content:"→";position:absolute;top:50%;right:-22px}.source-list{border-top:2px solid var(--ink);background:var(--wash);margin-top:70px;padding:26px}.source-list h2{border:0;margin:0 0 14px;padding:0;font-size:1.35rem}.source-list ul{margin:0}.source-list p{color:var(--muted);margin-bottom:0;font-size:.75rem}.article-after{padding-bottom:112px}.related-section{margin-top:30px}.policy-page{max-width:820px;padding-top:72px;padding-bottom:110px}.policy-page h1{margin:0 0 14px;font-size:clamp(2.4rem,5vw,4rem);line-height:1.25}.policy-page .policy-lead{border-bottom:2px solid var(--ink);color:var(--muted);padding-bottom:30px;font-size:1.05rem}.policy-page h2{margin:50px 0 14px;font-size:1.65rem}.policy-page h3{margin:32px 0 10px;font-size:1.15rem}.policy-page li+li{margin-top:.5em}.not-found{text-align:center;min-height:62vh;padding:100px 0}.not-found strong{color:var(--mint);font-size:clamp(5rem,14vw,10rem);line-height:1;display:block}@media (width<=1080px){.header-inner{min-height:72px}.site-nav{gap:12px}.site-nav>a{font-size:.82rem}.search-link{padding-inline:12px}.hero{min-height:580px}.hero h1{font-size:clamp(2.7rem,4.4vw,3.6rem)}.article-layout{grid-template-columns:200px minmax(0,1fr);gap:38px}.article-content{max-width:var(--reading)}.footer-main{grid-template-columns:1.4fr repeat(3,1fr);gap:28px}}@media (width<=760px){:root{--page:min(100% - 32px, 1280px)}html{scroll-padding-top:84px}body{font-size:16px}.header-inner{min-height:66px}.brand-mark{width:24px;height:24px}.menu-button{display:block}.site-nav{border-bottom:1px solid var(--line);box-shadow:var(--shadow);background:#fff;flex-direction:column;align-items:stretch;gap:0;padding:18px 16px 22px;display:none;position:absolute;top:100%;left:0;right:0}.site-nav[data-open]{display:flex}.site-nav>a{font-size:1rem}.site-nav>a:not(.search-link){border-bottom:1px solid var(--line);padding:12px 4px;display:block}.search-link{justify-content:center;margin-top:14px}.hero{grid-template-columns:1fr;min-height:auto}.hero-copy{padding:56px 16px 48px}.hero h1{max-width:11em;font-size:clamp(2.35rem,10.5vw,3.2rem)}.button{font-size:1rem}.hero-actions{flex-direction:column;align-items:stretch;gap:18px}.hero-actions .button{width:100%}.hero-actions .text-link{text-align:center}.hero-media{min-height:280px}.hero-media img{object-position:62% center}.home-section{padding:56px 0}.section-heading{flex-direction:column;align-items:flex-start;gap:12px}.guide-link{grid-template-columns:64px 1fr 30px;min-height:76px}.guide-number{font-size:1.75rem}.popular-block{margin-top:54px}.article-row,.article-row-compact{grid-template-columns:50px minmax(0,1fr) 30px;gap:14px;padding:22px 4px}.article-index{font-size:1.55rem}.article-category,.article-hero-category{font-size:.85rem}.article-row h3{font-size:1.0625rem}.article-row p{display:none}.footer-main{grid-template-columns:1fr 1fr;padding-top:56px}.footer-brand{grid-column:1/-1}.footer-brand>p{font-size:.94rem}.footer-brand .amazon-associate{font-size:.78rem}.footer-column h2{font-size:1rem}.footer-column a{font-size:.9rem}.footer-column:last-child{grid-column:1/-1}.footer-bottom .page-shell{flex-direction:column;align-items:center;gap:4px}.footer-bottom small{font-size:.78rem}.page-intro{padding:58px 0 38px}.search-form{grid-template-columns:1fr}.search-status{font-size:.875rem}.article-hero{padding-top:40px;padding-bottom:34px}.breadcrumbs{margin-bottom:28px;font-size:.8125rem}.article-hero h1{font-size:clamp(2rem,9vw,3.3rem)}.article-lead{font-size:1.125rem}.article-meta{font-size:.875rem}.affiliate-disclosure{font-size:.8125rem;line-height:1.7}.article-layout{grid-template-columns:1fr;gap:22px;padding-top:0}.article-toc{position:static}.article-toc h2{font-size:1rem}.article-toc a{padding-block:13px;font-size:.9rem;line-height:1.6}.article-content{font-size:1.1875rem;line-height:1.85}.article-content h2{padding-top:42px;font-size:1.75rem}.article-content h3{font-size:1.5rem}.article-content table{font-size:1rem}.steps>li{padding-left:60px}.source-list p{font-size:.8125rem;line-height:1.7}.echo-history-intro{padding-top:26px}.article-content .echo-history-intro h2{padding-top:0}.echo-history-nav{grid-template-columns:1fr;margin-bottom:44px}.article-content .echo-history-nav a{font-size:.9rem}.echo-history-group{margin-top:58px}.echo-history-group>header{grid-template-columns:1fr;align-items:start;gap:10px}.echo-history-group>header p{font-size:.9rem}.echo-history-grid{grid-template-columns:1fr}.echo-model-image-wrap{min-height:230px}.echo-model-image-wrap img{height:202px}.echo-model-copy small{font-size:.75rem}.echo-model-copy>span{font-size:.875rem}.decision-flow{grid-template-columns:1fr}.decision-flow>div{font-size:1rem}.decision-flow>div:not(:last-child):after{content:"↓";top:auto;bottom:-27px;right:50%}.affiliate-card-link{grid-template-columns:120px 1fr}.affiliate-card-image-wrap{min-height:150px;padding:10px}.affiliate-card-image{max-height:150px}.affiliate-card-copy{padding:18px}.affiliate-card-copy>span{font-size:.94rem}.affiliate-card-copy small{font-size:.78rem}.affiliate-card-compact .affiliate-card-link{grid-template-columns:112px 1fr}.affiliate-card-compact .affiliate-card-image-wrap{min-height:124px}.affiliate-card-compact .affiliate-card-image{max-height:124px}.affiliate-card-compact .affiliate-card-copy strong{font-size:.94rem}.affiliate-card-compact .affiliate-card-copy>span{font-size:.9rem}.policy-page{padding-top:52px}}@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,:before,:after{transition-duration:.01ms!important}}