/* Tank Tracker website
   Layout: a teal "instrument panel" hero, then alternating light sections; one column on phones. */
:root{
  --teal:#0d6a8a; --teal-deep:#0a5571; --teal-ink:#ffffff; --teal-soft:#bfe9f6;
  --bg:#eef1f4; --panel:#ffffff; --fg:#14202b; --muted:#566573; --line:#c9d1da;
  --accent:#0d6a8a; --ok:#1d6b3a; --ok-bg:#dcf2e3; --night:#0b1218; --night-panel:#131d26;
  --cyan:#4cc3e6; --green:#7ad69a;
  --display:'Barlow Semi Condensed','Arial Narrow',system-ui,sans-serif;
  --body:'Barlow',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,system-ui,sans-serif;
  --mono:'IBM Plex Mono',ui-monospace,'SF Mono',Menlo,Consolas,monospace;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){
  :root{--bg:#0b1218;--panel:#131d26;--fg:#e4ebf1;--muted:#93a4b3;--line:#263542;--accent:#4cc3e6;--ok:#7ad69a;--ok-bg:#12301e;color-scheme:dark}
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--bg);color:var(--fg);font:400 18px/1.6 var(--body)}
img{max-width:100%;display:block}
a{color:var(--accent)}
:focus-visible{outline:3px solid var(--cyan);outline-offset:3px;border-radius:4px}
.wrap{max-width:1180px;margin:0 auto;padding-left:max(20px,env(safe-area-inset-left,0px));padding-right:max(20px,env(safe-area-inset-right,0px))}
h1,h2,h3{font-family:var(--display);font-weight:700;line-height:1.02;letter-spacing:-.005em;margin:0;text-wrap:balance}
p{margin:0;text-wrap:pretty}
.eyebrow{font-family:var(--display);font-weight:600;font-size:15px;letter-spacing:.16em;text-transform:uppercase;color:var(--accent)}

/* ---------- Nav ---------- */
.nav{position:absolute;top:0;left:0;right:0;z-index:5;padding-top:calc(18px + env(safe-area-inset-top,0px))}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;gap:16px}
.brand{display:flex;align-items:center;gap:12px;color:#fff;text-decoration:none;font-family:var(--display);font-weight:700;font-size:24px;letter-spacing:.03em}
.brand svg{width:40px;height:40px;flex:none}
.nav ul{display:flex;gap:28px;list-style:none;margin:0;padding:0}
.nav ul a{color:#e3f4fa;text-decoration:none;font-weight:500;font-size:17px}
.nav ul a:hover{color:#fff;text-decoration:underline;text-underline-offset:5px}
@media (max-width:720px){.nav ul{display:none}}

/* ---------- Hero ---------- */
.hero{position:relative;background:var(--teal);color:#fff;overflow:hidden;
  padding:calc(120px + env(safe-area-inset-top,0px)) 0 0}
.hero::before{content:"";position:absolute;inset:0;pointer-events:none;
  background-image:linear-gradient(rgba(255,255,255,.07) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.07) 1px,transparent 1px);background-size:48px 48px}
.hero .wrap{position:relative;display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,.95fr);gap:40px;align-items:center}
.hero .eyebrow{color:var(--teal-soft)}
.hero h1{font-size:clamp(52px,8vw,104px);margin:14px 0 22px}
.hero .lede{font-size:clamp(19px,2.1vw,23px);color:#e3f4fa;max-width:34ch}
.cta{display:flex;flex-wrap:wrap;gap:14px;margin-top:34px;align-items:center}
.btn{display:inline-flex;align-items:center;gap:10px;min-height:56px;padding:0 26px;border-radius:12px;font-family:var(--display);font-weight:700;font-size:20px;letter-spacing:.02em;text-decoration:none;border:2px solid transparent}
.btn-primary{background:#fff;color:var(--teal-deep)}
.btn-primary:hover{background:#e3f4fa}
.btn-ghost{color:#fff;border-color:rgba(255,255,255,.6)}
.btn-ghost:hover{border-color:#fff;background:rgba(255,255,255,.08)}
.btn svg{width:22px;height:22px}
.fine{font-size:15px;color:var(--teal-soft);margin-top:16px}
.phones{position:relative;height:640px;align-self:end}
.phone{position:absolute;width:300px;border-radius:52px;background:#05090c;padding:10px;box-shadow:0 40px 80px rgba(0,0,0,.35),inset 0 0 0 2px #2a333b}
.phone .scr{border-radius:43px;overflow:hidden;padding-top:46px;height:630px}
.phone .scr.l{background:#eef1f4}.phone .scr.d{background:#0b1218}
.phone::after{content:"";position:absolute;top:22px;left:50%;width:84px;height:24px;margin-left:-42px;border-radius:12px;background:#05090c}
.phone.back{left:4%;top:70px;transform:rotate(-5deg)}
.phone.front{right:2%;top:10px;transform:rotate(3deg)}
@media (max-width:900px){
  .hero .wrap{grid-template-columns:minmax(0,1fr)}
  .phones{height:520px;max-width:520px;width:100%;margin:0 auto}
  .phone{width:250px}.phone .scr{height:520px;padding-top:40px}
}
@media (max-width:520px){.phone.back{display:none}.phone.front{left:50%;right:auto;margin-left:-125px;transform:none}}

/* ---------- Sections ---------- */
section{padding:96px 0}
.section-head{max-width:720px;margin-bottom:48px}
.section-head h2{font-size:clamp(38px,5vw,60px);margin:10px 0 16px}
.section-head p{color:var(--muted);font-size:20px}

/* Problem */
.problem .wrap{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:48px;align-items:center}
.gauge{background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:28px;display:grid;gap:18px}
.gauge-row{display:flex;justify-content:space-between;align-items:baseline;gap:12px;border-bottom:1px solid var(--line);padding-bottom:14px}
.gauge-row:last-child{border-bottom:0;padding-bottom:0}
.gauge-k{font-family:var(--display);font-weight:600;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-size:15px}
.gauge-v{font-family:var(--mono);font-weight:600;font-size:34px;font-variant-numeric:tabular-nums}
.gauge-v.q{color:var(--muted)}
@media (max-width:820px){.problem .wrap{grid-template-columns:minmax(0,1fr)}}

/* Steps */
.steps{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px;list-style:none;margin:0;padding:0;counter-reset:s}
.steps li{background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:28px;counter-increment:s}
.steps li::before{content:counter(s);display:grid;place-items:center;width:44px;height:44px;border-radius:50%;background:var(--accent);color:var(--panel);font-family:var(--display);font-weight:700;font-size:22px;margin-bottom:18px}
.steps h3{font-size:28px;margin-bottom:10px}
.steps p{color:var(--muted)}
.steps .ex{font-family:var(--mono);font-weight:600;color:var(--fg);font-size:16px;margin-top:14px;display:block}
@media (max-width:900px){.steps{grid-template-columns:minmax(0,1fr)}}

/* Trip plan (dark band) */
.plan{background:var(--night);color:#e4ebf1}
.plan .eyebrow{color:var(--cyan)}
.plan .section-head p{color:#b8c6d2}
.plan-grid{display:grid;grid-template-columns:minmax(0,.9fr) minmax(0,1.1fr);gap:40px;align-items:start}
@media (max-width:900px){.plan-grid{grid-template-columns:minmax(0,1fr)}}
.calc{background:var(--night-panel);border:1px solid #263542;border-radius:20px;padding:28px}
.calc h3{font-size:26px;margin-bottom:6px;color:#fff}
.calc .sub{color:#93a4b3;font-size:16px;margin-bottom:20px}
.fields{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px}
.field label{display:block;font-family:var(--display);font-weight:600;font-size:14px;letter-spacing:.08em;text-transform:uppercase;color:#93a4b3;margin-bottom:6px}
.field input{width:100%;font:600 26px var(--mono);color:#fff;background:var(--night);border:2px solid #263542;border-radius:10px;padding:10px 12px;font-variant-numeric:tabular-nums}
.field input:focus{outline:none;border-color:var(--cyan)}
.seg{display:grid;grid-template-columns:1fr 1fr;gap:8px}
.seg button{min-height:52px;border-radius:10px;border:2px solid var(--cyan);background:transparent;color:var(--cyan);font:700 18px var(--display);letter-spacing:.06em;cursor:pointer}
.seg button[aria-pressed="true"]{background:var(--cyan);color:#06222c}
.calc-out{margin-top:22px;display:grid;gap:10px}
.calc-row{display:flex;justify-content:space-between;align-items:baseline;gap:12px;border:1px solid #263542;border-radius:12px;padding:12px 14px}
.calc-row.next{border:2px solid var(--cyan)}
.calc-row .t{font-family:var(--display);font-weight:700;letter-spacing:.08em;font-size:16px;color:#fff;min-width:64px}
.calc-row .d{flex:1;min-width:0;color:#b8c6d2;font-size:16px}
@media (max-width:420px){.calc-row{flex-wrap:wrap}.calc-row .d{order:3;flex-basis:100%}}
.calc-row .n{font:600 24px var(--mono);color:#fff;font-variant-numeric:tabular-nums}
.calc-row.land{background:#12301e;border-color:transparent}
.calc-row.land .t,.calc-row.land .n,.calc-row.land .d{color:var(--green)}
.calc-row.low{background:#3d1714}
.calc-row.low .t,.calc-row.low .n,.calc-row.low .d{color:#ff8a80}
.calc-note{font-size:15px;color:#93a4b3}
.calc-note.err{color:#ff8a80}

.table-wrap{overflow-x:auto;border:1px solid #263542;border-radius:16px}
table{border-collapse:collapse;width:100%;min-width:480px;font-size:15px}
th,td{padding:11px 7px;text-align:center;border-bottom:1px solid #263542}
thead th{font-family:var(--display);font-weight:600;letter-spacing:.08em;text-transform:uppercase;font-size:14px;color:#93a4b3;background:var(--night-panel)}
tbody th{text-align:left;font:600 15px var(--mono);color:#fff;white-space:nowrap;padding-left:14px}
td{font-family:var(--mono);color:#e4ebf1;white-space:nowrap}
tr.hit td,tr.hit th{background:rgba(76,195,230,.12)}
tbody tr:last-child th,tbody tr:last-child td{border-bottom:0}
.table-cap{color:#93a4b3;font-size:15px;margin-top:12px}
.plan-points{display:grid;gap:14px;margin-top:28px;padding:0;list-style:none}
.plan-points li{display:flex;gap:12px;color:#d3dde6}
.plan-points svg{flex:none;width:24px;height:24px;color:var(--cyan);margin-top:3px}

/* Features */
.features{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.feature{background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:28px}
.feature svg{width:34px;height:34px;color:var(--accent);margin-bottom:16px}
.feature h3{font-size:26px;margin-bottom:8px}
.feature p{color:var(--muted)}
@media (max-width:900px){.features{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:600px){.features{grid-template-columns:minmax(0,1fr)}}

/* Privacy strip + final CTA */
.private{background:var(--panel);border-top:1px solid var(--line);border-bottom:1px solid var(--line);padding:56px 0}
.private .wrap{display:flex;flex-wrap:wrap;gap:24px 48px;align-items:center;justify-content:space-between}
.private h2{font-size:clamp(30px,4vw,44px)}
.badges{display:flex;flex-wrap:wrap;gap:12px;list-style:none;margin:0;padding:0}
.badges li{font-family:var(--display);font-weight:600;font-size:18px;letter-spacing:.04em;padding:10px 18px;border-radius:999px;background:var(--ok-bg);color:var(--ok)}
.final{background:var(--teal);color:#fff;text-align:center}
.final h2{font-size:clamp(40px,6vw,72px);margin-bottom:14px}
.final p{color:#e3f4fa;font-size:20px;max-width:46ch;margin:0 auto}
.final .cta{justify-content:center}

/* Footer */
footer{padding:40px 0 calc(40px + env(safe-area-inset-bottom,0px));color:var(--muted);font-size:15px}
footer .wrap{display:flex;flex-wrap:wrap;gap:16px 32px;justify-content:space-between}
footer nav{display:flex;flex-wrap:wrap;gap:20px}
footer .disclaimer{flex-basis:100%}