/* Fixfast landing — mobile-first, no frameworks, system fonts */
:root{
  --teal:#0f766e; --teal-d:#115e59; --teal-dd:#0b4a45; --teal-l:#e6f6f3; --teal-ll:#f3fbf9;
  --ink:#0b2b36; --ink-2:#36525c; --muted:#5b707a; --line:#d6e6e3;
  --blue:#0e7490;
  --radius:16px; --shadow:0 1px 2px rgba(11,43,54,.06),0 6px 20px rgba(11,43,54,.06);
  --font:system-ui,-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
body{margin:0;font-family:var(--font);font-size:1rem;line-height:1.6;color:var(--ink);background:#fff;padding-bottom:84px}
@media (min-width:768px){body{padding-bottom:0}}
img,svg{display:block;max-width:100%}
img{height:auto}
h1,h2,h3{line-height:1.25;margin:0 0 .5em;letter-spacing:-.01em}
h1{font-size:clamp(1.9rem,6.2vw,2.9rem);font-weight:800}
h2{font-size:clamp(1.5rem,4.4vw,2.2rem);font-weight:800}
h3{font-size:1.125rem;font-weight:700}
p{margin:0 0 1em}
a{color:var(--teal-d)}
:focus-visible{outline:3px solid #f59e0b;outline-offset:3px;border-radius:6px}
.container{width:100%;max-width:1120px;margin:0 auto;padding:0 20px}
.container-narrow{max-width:780px}
.skip-link{position:absolute;left:-999px;top:8px;background:var(--ink);color:#fff;padding:8px 14px;border-radius:8px;z-index:100}
.skip-link:focus{left:8px}
.ico{width:1.25em;height:1.25em;fill:currentColor;flex:none}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:.5em;font:inherit;font-weight:700;text-decoration:none;border-radius:999px;padding:.8em 1.4em;border:2px solid transparent;cursor:pointer;transition:background .15s,transform .15s,box-shadow .15s;line-height:1.2;min-height:44px}
.btn:active{transform:translateY(1px)}
.btn-primary{background:var(--teal);color:#fff;box-shadow:0 4px 14px rgba(15,118,110,.28)}
.btn-primary:hover{background:var(--teal-d)}
.btn-ghost{background:transparent;color:var(--teal-d);border-color:var(--teal)}
.btn-ghost:hover{background:var(--teal-l)}
.btn-light{background:#fff;color:var(--teal-dd)}
.btn-light:hover{background:var(--teal-l)}
.btn-sm{padding:.55em 1em;font-size:.9rem;min-height:40px}
.btn-lg{padding:.95em 1.6em;font-size:1.06rem}
.btn-block{width:100%}
.btn-zalo{background:#0068FF;color:#fff;box-shadow:0 4px 14px rgba(0,104,255,.28)}
.btn-zalo:hover{background:#0055d4}

/* 2-channel CTA: Zalo left, Facebook right; stack (Zalo on top) below 360px */
.cta-pair{display:flex;gap:10px;width:100%}
.cta-pair .btn{flex:1 1 0;min-width:0;padding-left:.8em;padding-right:.8em;white-space:nowrap}
.hero-actions .cta-pair .btn{font-size:1.06rem;padding-top:.9em;padding-bottom:.9em}
.cta-pair-center{max-width:30rem;margin:0 auto}
.cta-pair-compact{flex-wrap:wrap}
.cta-pair-compact .btn{flex:1 1 auto;font-size:.92rem;padding-left:.7em;padding-right:.7em}
@media (min-width:640px){.cta-pair-compact .ico{display:none}}
@media (max-width:359.98px){.cta-pair:not(.cta-pair-sticky){flex-direction:column}}
.cta-tel{display:inline-block;margin-top:12px;font-weight:700;color:var(--teal-d);text-decoration:underline;text-underline-offset:3px}
.cta-tel span{white-space:nowrap}
.cta-disclaimer{margin:6px 0 0;font-size:.8rem;color:var(--muted)}
.fault-more .cta-pair{margin-top:auto}
.fault-more .cta-disclaimer{color:#cdeee8;margin:8px 0 0}
.final-contact{display:flex;flex-direction:column;align-items:center;gap:4px;margin:14px 0 0!important}
.final-contact .cta-tel{color:#fff;margin:0}
.final-zalo{color:#d9f3ee;font-size:.98rem}
.final-zalo strong{color:#fff;white-space:nowrap}
.final-cta .cta-disclaimer{font-size:.85rem;color:#bfe7df;margin-top:10px!important;margin-bottom:0!important}

/* Header */
.site-header{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.92);backdrop-filter:saturate(1.4) blur(8px);-webkit-backdrop-filter:saturate(1.4) blur(8px);border-bottom:1px solid var(--line)}
.header-inner{display:flex;align-items:center;justify-content:space-between;height:64px;gap:12px}
.brand img{width:128px;height:auto}
@media (min-width:768px){.brand img{width:150px}}


/* Hero */
.hero{background:linear-gradient(180deg,var(--teal-ll) 0%,#fff 100%);padding:28px 0 24px}
.hero-inner{display:grid;gap:20px;align-items:center}
.eyebrow{display:inline-block;font-size:.8rem;font-weight:700;text-transform:uppercase;letter-spacing:.08em;color:var(--teal-d);background:var(--teal-l);padding:.3em .8em;border-radius:999px;margin-bottom:14px}
.hl{color:var(--teal)}
.lead{font-size:1.08rem;color:var(--ink-2);max-width:40em}
.hero-actions{margin:22px 0 18px;max-width:30rem}
.hero-points{list-style:none;padding:0;margin:0;display:grid;gap:8px;color:var(--ink-2);font-size:.95rem}
.hero-points li{position:relative;padding-left:28px}
.hero-points li::before{content:"";position:absolute;left:0;top:.28em;width:18px;height:18px;border-radius:50%;background:var(--teal) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M6 12.5l4 4 8-9' fill='none' stroke='%23fff' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center/12px no-repeat}
.hero-art{max-width:210px;margin:0 auto;width:100%}
.h1-line{display:block}
@media (min-width:900px){
  .hero{padding:64px 0 80px}
  .hero-inner{grid-template-columns:1.25fr .9fr;gap:48px}
  .hero-art{max-width:420px}
}

/* Sections */
.section{padding:56px 0}
.section-alt{background:var(--teal-ll);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.section-intro{color:var(--ink-2);max-width:46em;font-size:1.03rem}
.note{color:var(--muted);font-size:.95rem;margin-top:20px}
.center{text-align:center}
@media (min-width:900px){.section{padding:80px 0}}

/* Myths */
.myth-grid{display:grid;gap:16px;margin-top:24px}
@media (min-width:768px){.myth-grid{grid-template-columns:1fr 1fr}}
.myth{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow)}
.myth-q{font-weight:700;color:var(--ink)}
.myth-a{margin:0;color:var(--ink-2)}
.tag{display:inline-block;font-size:.72rem;font-weight:800;text-transform:uppercase;letter-spacing:.06em;padding:.2em .6em;border-radius:6px;margin-right:.4em;vertical-align:.1em}
.tag-myth{background:#ffe4e6;color:#9f1239}
.tag-fact{background:var(--teal-l);color:var(--teal-dd)}

/* Faults */
.fault-grid{display:grid;gap:16px;margin-top:24px}
@media (min-width:640px){.fault-grid{grid-template-columns:1fr 1fr}}
@media (min-width:1000px){.fault-grid{grid-template-columns:repeat(3,1fr)}}
.fault{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow)}
.fault p{margin:0;color:var(--ink-2)}
.fault h3 small{font-weight:600;color:var(--muted);font-size:.85em}
.fault-ico{width:48px;height:48px;border-radius:12px;background:var(--teal-l);color:var(--teal);display:grid;place-items:center;margin-bottom:14px}
.fault-ico svg{width:26px;height:26px}
.fault-more{background:var(--teal);color:#fff;border-color:var(--teal);display:flex;flex-direction:column;align-items:flex-start}
.fault-more p{color:#e3f6f2;margin-bottom:16px}

/* Brands */
.disclaimer{display:flex;gap:12px;align-items:flex-start;background:#eef6ff;border:1px solid #bcd7f2;border-left:5px solid var(--blue);color:#12384a;border-radius:12px;padding:14px 16px;margin:18px 0 28px}
.disclaimer .ico{color:var(--blue);margin-top:.15em}
.disclaimer p{margin:0;font-size:.95rem}
.group-title{font-size:1.2rem;margin:8px 0 14px;display:flex;align-items:center;gap:10px}
.group-title::after{content:"";flex:1;height:1px;background:var(--line)}
.brand-grid{list-style:none;padding:0;margin:0 0 32px;display:grid;grid-template-columns:repeat(2,1fr);gap:14px}
@media (min-width:768px){.brand-grid{grid-template-columns:repeat(4,1fr);gap:18px}.brand-grid-5{grid-template-columns:repeat(5,1fr)}}
.brand-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:10px 10px 14px;box-shadow:var(--shadow);text-align:center}
.brand-card img{width:100%;aspect-ratio:1/1;object-fit:cover;border-radius:10px;background:#f6f8f8}
.brand-name{font-weight:800;margin:10px 0 0;font-size:1rem}
.brand-model{margin:0;font-size:.82rem;color:var(--muted)}

/* Steps */
.steps{list-style:none;padding:0;margin:28px 0 0;display:grid;gap:14px;counter-reset:step}
.step{position:relative;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:20px 20px 20px 72px;box-shadow:var(--shadow);counter-increment:step}
.step::before{content:counter(step);position:absolute;left:20px;top:20px;width:36px;height:36px;border-radius:50%;background:var(--teal);color:#fff;font-weight:800;display:grid;place-items:center}
.step p{margin:0;color:var(--ink-2)}
@media (min-width:1000px){
  .steps{grid-template-columns:repeat(5,1fr)}
  .step{padding:64px 18px 20px}
  .step::before{left:18px}
}

/* FAQ */
.faq{margin-top:22px;display:grid;gap:10px}
.faq details{background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow)}
.faq summary{cursor:pointer;list-style:none;padding:16px 48px 16px 18px;font-weight:700;position:relative;border-radius:12px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"";position:absolute;right:18px;top:50%;width:10px;height:10px;border-right:2.5px solid var(--teal);border-bottom:2.5px solid var(--teal);transform:translateY(-70%) rotate(45deg);transition:transform .2s}
.faq details[open] summary::after{transform:translateY(-30%) rotate(-135deg)}
.faq details[open] summary{color:var(--teal-d)}
.faq-a{padding:0 18px 16px;color:var(--ink-2)}
.faq-a p{margin:0}

/* Contact */
.contact-grid{display:grid;gap:16px;margin-top:24px}
@media (min-width:768px){.contact-grid{grid-template-columns:1fr 1fr}}
@media (min-width:1000px){.contact-grid{grid-template-columns:repeat(3,1fr)}}
.contact-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);display:flex;flex-direction:column;align-items:flex-start}
.contact-card h3{margin-bottom:.35em}
.contact-card address{font-style:normal;color:var(--ink-2);margin:0 0 16px;flex:1}
.contact-ico{width:44px;height:44px;border-radius:12px;background:var(--teal-l);color:var(--teal);display:grid;place-items:center;margin-bottom:12px}
.contact-ico .ico{width:24px;height:24px}
.phone-list{list-style:none;padding:0;margin:0;display:grid;gap:12px;width:100%}
.phone-label{display:block;font-size:.88rem;color:var(--muted)}
.phone{font-size:1.3rem;font-weight:800;color:var(--teal-d);text-decoration:none;letter-spacing:.02em;white-space:nowrap}
.phone:hover{text-decoration:underline}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}

/* Final CTA */
.final-cta{background:linear-gradient(135deg,var(--teal) 0%,var(--teal-dd) 100%);color:#fff;padding:56px 0;text-align:center}
.final-inner{max-width:720px}
.final-cta h2{color:#fff}
.final-cta p{color:#d9f3ee;font-size:1.05rem;margin-bottom:24px}

/* Footer */
.site-footer{background:#f7faf9;border-top:1px solid var(--line);padding:32px 0;color:var(--muted);font-size:.88rem}
.footer-inner img{width:110px;margin-bottom:12px}
.footer-inner p{max-width:60em}
.copy{margin:0}
.footer-contact{display:grid;gap:14px;margin:0 0 16px}
@media (min-width:768px){.footer-contact{grid-template-columns:1.4fr 1fr;gap:28px}}
.footer-contact ul{list-style:none;padding:0;margin:0;display:grid;gap:4px}
.footer-h{font-weight:700;color:var(--ink);margin:0 0 4px}
.footer-contact a{white-space:nowrap}

/* Sticky mobile CTA */
.sticky-cta{position:fixed;left:0;right:0;bottom:0;z-index:30;padding:10px 16px calc(10px + env(safe-area-inset-bottom));background:rgba(255,255,255,.96);border-top:1px solid var(--line);box-shadow:0 -6px 20px rgba(11,43,54,.08);transition:transform .25s ease}
.sticky-cta.is-hidden{transform:translateY(110%)}
.cta-pair-sticky{gap:8px}
.cta-pair-sticky .btn{padding:.75em .5em;font-size:.98rem}
@media (max-width:359.98px){.cta-pair-sticky .btn{font-size:.9rem;gap:.35em;padding-left:.35em;padding-right:.35em}}
@media (min-width:768px){.sticky-cta{display:none}}
.nf-logo{margin:0 auto 24px}
.hl{white-space:nowrap}
.header-cta{display:none}
@media (min-width:768px){.header-cta{display:inline-flex}}
.footer-entity{margin-bottom:.6em}

/* Simple content pages (privacy policy) */
.page-simple{padding-bottom:0}
.legal h1{font-size:clamp(1.7rem,5vw,2.3rem)}
.legal h2{font-size:1.15rem;margin:1.6em 0 .4em}
.legal p{color:var(--ink-2)}
.legal-updated{font-size:.9rem;color:var(--muted)!important}
.legal-back{margin-top:2em}