:root{--teal:#3CA7A8;--cyan:#2F92A9;--navy:#0B2240;--ink:#1c2733;--muted:#51616b;
--line:#e6eef0;--bg:#f4f8f8;--card:#fff}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);
font-family:-apple-system,"Hiragino Kaku Gothic ProN","Noto Sans JP","Yu Gothic",sans-serif;
line-height:1.9;font-size:18px}
a{color:var(--cyan);text-decoration:none}a:hover{text-decoration:underline}
.site{background:var(--navy);padding:16px 20px}
.site .brand{color:#fff;font-weight:800;letter-spacing:.02em;font-size:17px}
.site .brand:hover{text-decoration:none;opacity:.85}
.wrap{max-width:1040px;margin:0 auto;padding:0 28px}
.post{max-width:920px;margin:0 auto;padding:44px 28px 80px}
.post .date{color:var(--teal);font-weight:700;font-size:15px;margin:8px 0 4px;letter-spacing:.04em}
.post h1{font-size:38px;line-height:1.38;color:var(--navy);margin:.2em 0 .4em;font-weight:800}
.post .lead{color:var(--muted);font-size:18px;margin:0 0 24px}
.hero{width:100%;height:auto;border-radius:16px;border:1px solid var(--line);
box-shadow:0 8px 28px rgba(11,34,64,.08);margin:8px 0 28px}
.body{font-size:18px}
.body h2{font-size:25px;color:var(--navy);font-weight:800;margin:1.9em 0 .55em;
padding-left:14px;border-left:6px solid var(--teal)}
.body h3{font-size:20px;color:var(--navy);font-weight:800;margin:1.5em 0 .4em}
.body p{margin:.9em 0}
.body strong{color:var(--navy)}
.body blockquote{margin:1.2em 0;padding:14px 18px;background:#eaf3f3;
border-left:4px solid var(--teal);border-radius:0 10px 10px 0;color:#2b4150}
.body ul,.body ol{padding-left:1.3em}.body li{margin:.35em 0}
.body hr{border:0;border-top:1px solid var(--line);margin:2em 0}
.body table{border-collapse:collapse;width:100%;margin:1.2em 0;font-size:15px}
.body th,.body td{border:1px solid var(--line);padding:8px 10px;text-align:left}
.body th{background:var(--navy);color:#fff;font-weight:700}
.body a{border-bottom:1px solid rgba(47,146,169,.4)}
.body img{display:block;max-width:100%;height:auto;margin:1.7em auto;border-radius:14px;
border:1px solid var(--line);box-shadow:0 8px 24px rgba(11,34,64,.09)}
.post-foot{margin-top:40px;padding-top:20px;border-top:1px solid var(--line)}
.site-foot{text-align:center;color:var(--muted);font-size:13px;padding:28px 20px 40px}
/* index */
.hero-head{background:linear-gradient(135deg,var(--teal),var(--cyan));color:#fff;
padding:72px 20px}
.hero-head .wrap{padding:0 28px}
.hero-head h1{margin:0;font-size:40px;font-weight:800}
.hero-head p{margin:.5em 0 0;opacity:.92;font-size:18px}
.cards{max-width:1040px;margin:0 auto;padding:40px 28px 64px;display:grid;gap:26px;
grid-template-columns:repeat(auto-fill,minmax(450px,1fr))}
.card{display:flex;flex-direction:column;background:var(--card);border:1px solid var(--line);
border-radius:18px;overflow:hidden;box-shadow:0 6px 20px rgba(11,34,64,.06);
transition:transform .12s,box-shadow .12s}
.card:hover{transform:translateY(-3px);box-shadow:0 12px 28px rgba(11,34,64,.13);text-decoration:none}
.card img{display:block;width:100%;height:auto;aspect-ratio:1200/630;object-fit:cover;background:var(--navy)}
.card .meta{padding:20px 24px}
.card .meta .d{display:flex;align-items:center;gap:8px;font-size:13px}
.card .meta .dt{color:var(--muted);font-weight:600;letter-spacing:.02em}
.card .meta h2{margin:.3em 0 .4em;font-size:20px;color:var(--navy);font-weight:800;line-height:1.45}
.card .meta p{margin:0;color:var(--muted);font-size:15px}
.thumb{position:relative;line-height:0}
.badge{position:absolute;top:12px;left:12px;background:var(--navy);color:#fff;
font-weight:800;font-size:14px;padding:5px 12px;border-radius:9px;box-shadow:0 2px 8px rgba(0,0,0,.25)}
.chip{display:inline-block;background:#e3f1f1;color:var(--cyan);font-weight:700;
font-size:12px;padding:3px 11px;border-radius:999px;letter-spacing:.02em}
.filter{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:5}
.filter .wrap{display:flex;flex-wrap:wrap;gap:9px;padding:14px 28px}
.fbtn{border:1px solid var(--line);background:#fff;color:var(--muted);font-weight:700;
font-size:14px;padding:8px 16px;border-radius:999px;cursor:pointer;font-family:inherit}
.fbtn:hover{border-color:var(--teal);color:var(--teal)}
.fbtn.active{background:var(--teal);border-color:var(--teal);color:#fff}
.pmeta{display:flex;align-items:center;gap:10px;margin:6px 0 10px;flex-wrap:wrap}
.pmeta .num{background:var(--navy);color:#fff;font-weight:800;font-size:14px;padding:4px 12px;border-radius:8px}
.pmeta .d{color:var(--teal);font-weight:700;font-size:15px;letter-spacing:.04em}
.pmeta .chip{font-size:13px}
@media(max-width:560px){.cards{grid-template-columns:1fr;padding:28px 18px 48px}
.post h1,.hero-head h1{font-size:25px}}
.subscribe{max-width:920px;margin:8px auto 0;padding:0 24px}
.sub-inner{background:linear-gradient(135deg,var(--teal),var(--cyan));color:#fff;
border-radius:18px;padding:30px 26px;text-align:center;box-shadow:0 8px 26px rgba(11,34,64,.12)}
.sub-inner h3{margin:0 0 6px;font-size:22px;font-weight:800}
.sub-lead{margin:0 0 16px;font-size:14px;opacity:.95}
.sub-form{display:flex;gap:8px;max-width:480px;margin:0 auto;flex-wrap:wrap;justify-content:center}
.sub-form input{flex:1;min-width:220px;border:0;border-radius:10px;padding:13px 15px;font-size:15px;font-family:inherit;color:var(--ink)}
.sub-form button{border:0;border-radius:10px;padding:13px 24px;font-size:15px;font-weight:800;
background:var(--navy);color:#fff;cursor:pointer;font-family:inherit}
.sub-form button:hover{opacity:.9}
.sub-msg{margin:10px 0 0;font-size:13px;min-height:1em;font-weight:700}
.app-cta{margin-top:22px;padding-top:18px;border-top:1px solid rgba(255,255,255,.3)}
.app-cta-label{display:block;font-size:13px;font-weight:700;margin-bottom:10px;opacity:.95}
.app-btns{display:flex;gap:10px;justify-content:center;flex-wrap:wrap}
.app-btn{background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.65);color:#fff;
font-weight:700;font-size:14px;padding:10px 20px;border-radius:10px}
.app-btn:hover{background:rgba(255,255,255,.28);text-decoration:none}
/* audio player (走りながら聞く) */
.audioplayer{max-width:920px;margin:18px auto 0;padding:14px 18px;border:1px solid var(--line);
border-radius:14px;background:linear-gradient(135deg,rgba(90,155,163,.12),rgba(90,155,163,.02))}
.audioplayer .ap-head{display:flex;align-items:center;gap:8px;color:var(--teal);
font-weight:800;font-size:14px;margin-bottom:9px}
.audioplayer .ap-head svg{flex:0 0 auto}
.audioplayer audio{width:100%;height:40px}
.audioplayer .ap-note{margin:8px 2px 0;font-size:12px;color:#6b7a90}
/* paywall (freemium) */
.paywall{max-width:920px;margin:26px auto 0;padding:0 24px}
.pw-inner{background:linear-gradient(135deg,var(--navy),#173355);color:#fff;border-radius:18px;
padding:32px 26px;text-align:center;box-shadow:0 10px 30px rgba(11,34,64,.16)}
.pw-kicker{margin:0 0 6px;font-size:13px;font-weight:700;letter-spacing:.08em;opacity:.85}
.pw-inner h3{margin:0 0 8px;font-size:24px;font-weight:800;color:#fff}
.pw-lead{margin:0 0 18px;font-size:15px;opacity:.95}
.pw-btn{display:inline-block;background:var(--teal);color:#fff;font-weight:800;font-size:16px;
padding:14px 34px;border-radius:12px}
.pw-btn:hover{opacity:.92;text-decoration:none}
.pw-app{margin-top:22px;padding-top:18px;border-top:1px solid rgba(255,255,255,.25)}
.pw-app-label{display:block;font-size:13px;font-weight:700;margin-bottom:10px;opacity:.9}
.pw-tag{display:inline-block;background:#8a6d1d;color:#fff;font-weight:800;font-size:12px;
padding:3px 10px;border-radius:999px;letter-spacing:.02em}
/* 目次(TOC) */
.toc{background:#eef5f5;border:1px solid var(--line);border-radius:14px;padding:16px 20px;margin:6px 0 26px}
.toc-t{margin:0 0 8px;font-weight:800;color:var(--navy);font-size:15px}
.toc ol{margin:0;padding-left:1.4em}
.toc li{margin:.32em 0;font-size:15px}
.toc a{color:var(--cyan);border-bottom:1px solid rgba(47,146,169,.35)}