:root{
  --steel:#152b3c; --steel2:#1e3d55; --sky:#2a9dd6; --amber:#f6a821; --amber-d:#d98a10;
  --ink:#16242e; --bg:#eef2f4; --card:#ffffff; --mut:#5d6f7a; --line:#dbe2e6; --deep:#0f2130;
}
*{box-sizing:border-box}
html,body{width:100%;overflow-x:hidden;margin:0}
html{scroll-behavior:smooth}
body{font-family:'Barlow',system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
  color:var(--ink);background:var(--bg);line-height:1.64;font-size:17px}
.shell{max-width:1060px;margin:0 auto;padding:0 22px}
a{color:var(--sky)}
img{max-width:100%;height:auto}
h1,h2,h3{line-height:1.2;color:var(--steel);font-weight:700}
h1{font-size:2.02rem;margin:.15em 0 .35em}
h2{font-size:1.46rem;margin:1.6em 0 .5em}
h3{font-size:1.16rem;margin:1.25em 0 .35em}
p{margin:.65em 0}
main{display:block;padding:4px 0 44px}

/* masthead */
.masthead{background:var(--steel);color:#fff;position:sticky;top:0;z-index:40;box-shadow:0 2px 12px rgba(0,0,0,.2)}
.topbar{display:flex;align-items:center;gap:16px;flex-wrap:nowrap;min-height:62px}
.brand-logo{color:#fff;font-weight:700;font-size:1.22rem;text-decoration:none;white-space:nowrap;letter-spacing:.3px}
.navbar{margin-left:auto;display:flex;align-items:center;gap:3px;flex-wrap:nowrap}
.navbar a{color:#e7edf1;text-decoration:none;padding:8px 9px;border-radius:6px;font-size:.95rem;white-space:nowrap}
.navbar a:hover,.navbar a.on{background:rgba(255,255,255,.13);color:#fff}
.nav-cta{background:var(--amber);color:#20140a !important;font-weight:600;padding:9px 13px;border-radius:7px;white-space:nowrap;margin-left:4px}
.nav-cta:hover{background:var(--amber-d)}
.burger{display:none;margin-left:auto;background:none;border:0;cursor:pointer;padding:8px;width:44px;height:44px}
.burger span{display:block;width:24px;height:2px;background:#fff;margin:5px 0}

/* breadcrumb */
.crumb{font-size:.9rem;color:var(--mut);padding:12px 0 0}
.crumb a{color:var(--sky);text-decoration:none}
.crumb b{color:var(--steel);font-weight:600}

/* hero + lede */
.hero-fig{margin:14px 0 6px}
.hero-fig img{width:100%;display:block;border-radius:10px;box-shadow:0 8px 26px rgba(15,33,48,.2)}
.hero-fig figcaption{color:var(--mut);font-size:.85rem;text-align:center;margin-top:8px}
.lede{font-size:1.11rem;color:#22333f;background:var(--card);border-left:5px solid var(--sky);
  padding:14px 18px;border-radius:9px;margin:14px 0}

/* snapshot table + boxes */
.snapshot{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:6px 20px 14px;margin:18px 0;box-shadow:0 4px 16px rgba(15,33,48,.06)}
.table-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;margin:14px 0}
table{border-collapse:collapse;width:100%;min-width:440px;background:var(--card)}
th,td{border:1px solid var(--line);padding:9px 12px;text-align:left;font-size:.95rem}
th{background:var(--steel2);color:#fff}
ul,ol{padding-left:22px}
li{margin:.3em 0}

/* plus/minus */
.plusminus{display:grid;grid-template-columns:1fr 1fr;gap:16px;margin:16px 0}
.plusminus .col{background:var(--card);border:1px solid var(--line);border-radius:11px;padding:12px 18px}
.plusminus h3{margin-top:.4em}
.plusminus ul{list-style:none;padding-left:0}
.plusminus li{position:relative;padding-left:24px}
.plusminus .good li:before{content:"▲";color:var(--sky);position:absolute;left:0}
.plusminus .bad li:before{content:"▼";color:#c9603f;position:absolute;left:0}

/* promo / spin block */
.promo{background:linear-gradient(135deg,var(--steel2),#2a5876);color:#eaf4fa;border-radius:12px;padding:18px 20px;margin:20px 0}
.promo b{color:var(--amber)}

/* steps */
.steps{counter-reset:s;list-style:none;padding-left:0}
.steps li{position:relative;padding:6px 0 6px 44px;margin:.3em 0}
.steps li:before{counter-increment:s;content:counter(s);position:absolute;left:0;top:6px;width:30px;height:30px;
  background:var(--amber);color:#20140a;border-radius:50%;text-align:center;line-height:30px;font-weight:700}

/* tabs */
.tabset{margin:16px 0}
.tabhead{display:flex;flex-wrap:wrap;gap:8px}
.tabhead button{border:1px solid var(--line);background:var(--card);padding:9px 14px;border-radius:8px;cursor:pointer;font:inherit;color:var(--steel)}
.tabhead button.on{background:var(--sky);color:#fff;border-color:var(--sky)}
.tabpane{display:none;background:var(--card);border:1px solid var(--line);border-radius:0 8px 8px 8px;padding:14px 16px;margin-top:-1px}
.tabpane.on{display:block}

/* calculator */
.calc{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:16px 18px;margin:18px 0}
.calc label{display:block;font-size:.9rem;color:var(--mut);margin:.5em 0 .2em}
.calc input[type=range]{width:100%}
.calc .out{font-size:1.3rem;font-weight:700;color:var(--sky);margin-top:8px}
.calc .rng{display:flex;justify-content:space-between;font-size:.9rem;color:var(--mut)}

/* faq */
.qa details{background:var(--card);border:1px solid var(--line);border-radius:9px;margin:10px 0;padding:2px 16px}
.qa summary{cursor:pointer;font-weight:600;color:var(--steel);padding:12px 0;min-height:44px;list-style:none}
.qa summary::-webkit-details-marker{display:none}
.qa summary:after{content:"+";float:right;color:var(--sky);font-size:1.3rem;line-height:1}
.qa details[open] summary:after{content:"–"}
.qa p{margin:.2em 0 12px}

/* cta */
.cta-strip{text-align:center;margin:26px 0 8px}
.bigbtn{display:inline-block;background:var(--amber);color:#20140a;font-weight:700;text-decoration:none;
  padding:15px 32px;border-radius:11px;font-size:1.06rem;box-shadow:0 6px 18px rgba(246,168,33,.4)}
.bigbtn:hover{background:var(--amber-d)}

/* footer */
.foot{background:var(--steel);color:#c4d1da;margin-top:30px;padding:26px 0 16px;font-size:.93rem}
.foot-cols{display:grid;grid-template-columns:2fr 1fr 1fr;gap:22px}
.foot h4{color:#fff;margin:0 0 8px;font-size:1rem}
.foot a{color:#c4d1da;text-decoration:none}.foot a:hover{color:#fff}
.foot ul{list-style:none;padding:0;margin:0}
.age-row{display:flex;align-items:center;gap:10px;margin:6px 0}
.age{background:var(--amber);color:#20140a;font-weight:700;border-radius:6px;padding:3px 8px;font-size:.85rem}
.legal{border-top:1px solid rgba(255,255,255,.14);margin-top:18px;padding-top:12px;color:#8fa2ad;font-size:.84rem}

/* to top */
#totop{position:fixed;right:16px;bottom:16px;background:var(--sky);color:#fff;border:0;border-radius:50%;
  width:46px;height:46px;font-size:1.2rem;cursor:pointer;display:none;z-index:50;box-shadow:0 4px 14px rgba(0,0,0,.25)}

@media(max-width:980px){
  h1{font-size:1.62rem}h2{font-size:1.3rem}h3{font-size:1.08rem}
  .burger{display:block}
  .navbar{display:none;position:absolute;left:0;right:0;top:62px;background:var(--steel);
    flex-direction:column;align-items:stretch;gap:0;padding:8px 22px 16px;box-shadow:0 12px 20px rgba(0,0,0,.25)}
  .navbar.open{display:flex}
  .navbar a{padding:12px 6px;border-bottom:1px solid rgba(255,255,255,.08)}
  .nav-cta{text-align:center;margin:8px 0 0}
  .topbar{position:relative}
  .plusminus,.foot-cols{grid-template-columns:1fr}
  .shell{padding:0 22px}
}