:root{
  --page-bg:#071427;
  --header-bg:rgba(7,20,39,0.92);
  --text:#e5edff;
  --muted:rgba(226,232,255,0.72);
  --link:#38bdf8;
  --accent:#20D4CB;
  --rule:rgba(148,163,233,0.16);
}

*{box-sizing:border-box;}

html,body{
  margin:0;
  padding:0;
  min-height:100%;
  font-family:Roboto,system-ui,-apple-system,"Segoe UI",Arial,sans-serif;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  color:var(--text);
  background:var(--page-bg);
}

body{
  margin:0;
  padding-bottom:max(32px, env(safe-area-inset-bottom));
}

/* Native-style fixed header with icon-only back button */
.topbar{
  position:sticky;
  top:0;
  z-index:10;
  display:flex;
  align-items:center;
  height:52px;
  padding:env(safe-area-inset-top) 4px 0;
  background:var(--header-bg);
  backdrop-filter:blur(14px);
  -webkit-backdrop-filter:blur(14px);
}

.back-btn{
  display:flex;
  align-items:center;
  justify-content:center;
  width:44px;
  height:44px;
  color:var(--text);
  text-decoration:none;
  border-radius:999px;
}

.back-btn:active{
  background:rgba(255,255,255,0.06);
}

.back-btn svg{
  width:24px;
  height:24px;
}

.page{
  max-width:640px;
  margin:0 auto;
  padding:0 20px;
}

.banner{
  width:100%;
  height:auto;
  display:block;
  border-radius:16px;
  margin-top:4px;
  object-fit:cover;
}

main{
  font-size:13px;
  line-height:1.6;
}

h1{
  margin:14px 0 6px;
  font-size:23px;
  font-weight:900;
}

.meta{
  font-size:13px;
  color:var(--muted);
  margin-bottom:8px;
  padding-bottom:20px;
  border-bottom:1px solid var(--rule);
}

h3{
  margin:0 0 4px;
  font-size:14.5px;
  font-weight:700;
  color:var(--text);
}

p{
  margin:0;
  color:var(--muted);
}

.strong{
  font-weight:700;
  color:var(--text);
}

/* Plain, native-feeling step rows: no card background or border */
.step-row{
  display:flex;
  gap:14px;
  align-items:flex-start;
  padding:18px 0;
  border-bottom:1px solid var(--rule);
}

.step-row:last-of-type{
  border-bottom:none;
}

.step-num{
  flex:none;
  width:26px;
  height:26px;
  margin-top:1px;
  border-radius:999px;
  background:rgba(32,212,203,0.14);
  color:var(--accent);
  font-weight:800;
  font-size:13px;
  display:flex;
  align-items:center;
  justify-content:center;
}

.step-body{
  flex:1;
}

.tip-box{
  margin-top:18px;
  margin-bottom:24px;
  padding:14px 0 0;
  font-size:12.5px;
  color:var(--muted);
}

.cta-btn{
  display:flex;
  align-items:center;
  justify-content:center;
  width:100%;
  height:48px;
  border-radius:999px;
  background:var(--accent);
  color:#071427;
  font-weight:700;
  font-size:14px;
  text-decoration:none;
  margin-top:4px;
}

.cta-btn:active{
  opacity:0.85;
}

/* Tab switcher used on the NIN guide */
.tab-row{
  display:flex;
  gap:8px;
  margin-top:18px;
  margin-bottom:4px;
  overflow-x:auto;
}

.tab-btn{
  flex:none;
  padding:8px 14px;
  border-radius:999px;
  border:1px solid var(--rule);
  background:transparent;
  color:var(--muted);
  font-size:12.5px;
  font-weight:600;
  font-family:inherit;
}

.tab-btn.active{
  background:var(--accent);
  color:#071427;
  border-color:var(--accent);
}

.tab-panel{
  display:none;
}

.tab-panel.active{
  display:block;
}

.section-title{
  margin:20px 0 2px;
  font-size:14px;
  font-weight:800;
  color:var(--text);
}