:root{
  --bg:#f7f8fb;--surface:#ffffff;--surface-2:#f1f5f9;
  --border:rgba(15,23,42,.08);--border-strong:rgba(15,23,42,.14);
  --text:#0f172a;--text-muted:#475569;--text-subtle:#94a3b8;
  --primary:#2563eb;--primary-hover:#1d4ed8;--primary-fg:#fff;
  --accent:#0f172a;--accent-soft:#dbeafe;
  --radius-sm:9px;--radius:14px;--radius-lg:20px;--radius-pill:999px;
  --shadow-sm:0 1px 2px rgba(15,23,42,.05);
  --shadow:0 1px 2px rgba(15,23,42,.05),0 8px 24px rgba(15,23,42,.07);
  --shadow-lg:0 18px 50px rgba(37,99,235,.16);
  --ring:0 0 0 4px color-mix(in srgb,var(--primary) 20%,transparent);
  --ease:cubic-bezier(.32,.72,0,1);
  --sans:'Inter',ui-sans-serif,system-ui,-apple-system,'Segoe UI',sans-serif;
  --serif:'Fraunces',Georgia,'Times New Roman',serif;
}
*{box-sizing:border-box}html,body{margin:0}
html{scroll-behavior:smooth}
body{font:16px/1.6 var(--sans);color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased;letter-spacing:-.006em;
  background-image:radial-gradient(1200px 500px at 50% -200px,rgba(37,99,235,.06),transparent);}
img{max-width:100%;display:block}

/* reading progress */
.readbar{position:fixed;top:0;left:0;right:0;height:4px;background:transparent;z-index:60}
.readbar__fill{height:100%;width:0;background:linear-gradient(90deg,var(--primary),#60a5fa);transition:width .1s linear;box-shadow:0 0 12px rgba(37,99,235,.5)}

/* masthead */
.masthead{position:sticky;top:0;z-index:50;display:flex;align-items:center;justify-content:space-between;
  padding:14px 22px;background:color-mix(in srgb,var(--surface) 88%,transparent);backdrop-filter:blur(12px);
  border-bottom:1px solid var(--border)}
.brand__logo{height:30px;width:auto}
.masthead__tag{font-size:12px;font-weight:600;letter-spacing:.1em;text-transform:uppercase;color:var(--primary);
  background:var(--accent-soft);padding:6px 12px;border-radius:var(--radius-pill)}

/* article */
.article{max-width:720px;margin:0 auto;padding:44px 22px 40px}
.kicker{font-size:12.5px;font-weight:700;letter-spacing:.12em;text-transform:uppercase;color:var(--primary);margin-bottom:14px}
.headline{font-family:var(--serif);font-weight:600;font-size:clamp(2rem,6vw,3.15rem);line-height:1.06;letter-spacing:-.02em;margin:0 0 26px}

.byline{display:flex;align-items:center;gap:13px;padding:16px 0;border-top:1px solid var(--border);border-bottom:1px solid var(--border);margin-bottom:30px;flex-wrap:wrap}
.byline__avatar{width:44px;height:44px;border-radius:50%;background:var(--primary);color:#fff;font-weight:700;font-size:14px;display:grid;place-items:center;letter-spacing:.02em}
.byline__meta{display:flex;flex-direction:column;line-height:1.3}
.byline__name{font-weight:600;font-size:15px}
.byline__sub{font-size:13px;color:var(--text-subtle)}
.byline__trust{margin-left:auto;display:inline-flex;align-items:center;gap:6px;font-size:12.5px;font-weight:600;color:var(--primary)}

.lede{font-size:20px;line-height:1.55;color:var(--text);margin:0 0 20px;font-weight:500}
.body{font-size:17px;line-height:1.66;color:var(--text-muted);margin:0 0 18px}
.body strong{color:var(--text)}
.body--center{text-align:center}

.divider{display:flex;align-items:center;gap:16px;margin:44px 0;color:var(--text-subtle)}
.divider::before,.divider::after{content:"";flex:1;height:1px;background:var(--border-strong)}
.divider span{font-size:12px;font-weight:700;letter-spacing:.14em;text-transform:uppercase}

/* move blocks */
.move{position:relative;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);
  padding:34px 30px 30px;margin:26px 0;box-shadow:var(--shadow);scroll-margin-top:80px}
.move__num{position:absolute;top:-20px;left:26px;width:44px;height:44px;border-radius:50%;
  background:var(--primary);color:#fff;font-family:var(--serif);font-weight:700;font-size:21px;
  display:grid;place-items:center;box-shadow:0 6px 16px rgba(37,99,235,.4);border:3px solid var(--surface)}
.move__head{display:flex;align-items:flex-start;justify-content:space-between;gap:14px;margin:8px 0 4px}
.move__head h2{font-family:var(--serif);font-weight:600;font-size:clamp(1.35rem,3.6vw,1.7rem);line-height:1.2;letter-spacing:-.015em;margin:0}
.move__tag{flex:none;margin-top:4px;font-size:11px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;
  color:var(--primary);background:var(--accent-soft);padding:5px 10px;border-radius:var(--radius-pill);white-space:nowrap}
.illus{margin:18px 0 20px;padding:22px;background:linear-gradient(135deg,#f8fafc,#eef2ff);border:1px solid var(--border);border-radius:var(--radius);display:grid;place-items:center}

/* cta */
.cta{display:inline-flex;align-items:center;gap:9px;background:var(--primary);color:var(--primary-fg);
  font-weight:700;font-size:16.5px;text-decoration:none;padding:15px 26px;border-radius:var(--radius-pill);
  box-shadow:0 6px 18px rgba(37,99,235,.32);transition:transform .16s var(--ease),box-shadow .16s var(--ease),background .16s var(--ease);margin-top:6px}
.cta svg{transition:transform .18s var(--ease)}
.cta:hover{background:var(--primary-hover);transform:translateY(-2px);box-shadow:0 12px 26px rgba(37,99,235,.4)}
.cta:hover svg{transform:translateX(3px)}
.cta:active{transform:translateY(0)}
.cta:focus-visible{outline:none;box-shadow:var(--ring),0 6px 18px rgba(37,99,235,.32)}
.cta--full{display:flex;justify-content:center;width:100%;margin-top:16px}
.cta__sub{font-size:13px;color:var(--text-subtle);margin:10px 0 0;font-weight:500}

/* widget */
.move--widget{background:linear-gradient(180deg,#fff,#f6f9ff)}
.widget{margin-top:22px;background:var(--surface);border:1px solid var(--border-strong);border-radius:var(--radius);padding:22px}
.widget__label{font-weight:700;font-size:15px;margin-bottom:14px}
.agegrid{display:grid;grid-template-columns:repeat(3,1fr);gap:11px}
.agecard{appearance:none;cursor:pointer;font:inherit;font-weight:700;font-size:17px;color:var(--text);
  background:var(--surface);border:1.5px solid var(--border-strong);border-radius:var(--radius-sm);
  min-height:60px;transition:all .16s var(--ease);position:relative}
.agecard:hover{border-color:var(--primary);transform:translateY(-1px)}
.agecard:focus-visible{outline:none;box-shadow:var(--ring)}
.agecard[aria-pressed="true"]{border-color:var(--primary);background:color-mix(in srgb,var(--primary) 8%,#fff);color:var(--primary)}
.agecard[aria-pressed="true"]::after{content:"";position:absolute;top:8px;right:8px;width:16px;height:16px;border-radius:50%;
  background:var(--primary) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6 9 17l-5-5'/%3E%3C/svg%3E") center/11px no-repeat}
#ageCta[aria-disabled="true"]{background:var(--surface-2);color:var(--text-subtle);box-shadow:none;pointer-events:none}

/* footer */
.foot{max-width:720px;margin:20px auto 0;padding:34px 22px 56px;text-align:center;border-top:1px solid var(--border)}
.foot__logo{height:26px;width:auto;margin:0 auto 16px;opacity:.85}
.foot__disc{font-size:12.5px;line-height:1.6;color:var(--text-subtle);max-width:560px;margin:0 auto 14px}
.foot__copy{font-size:12.5px;color:var(--text-subtle);margin:0}

@media(max-width:520px){
  .article{padding:32px 18px 30px}
  .move{padding:30px 20px 26px}
  .move__head{flex-direction:column;gap:8px}
  .agegrid{grid-template-columns:repeat(2,1fr)}
  .cta{width:100%;justify-content:center}
}
@media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto}}