/* ============================================================
   SafeKids — Landing page tĩnh (sales, SEO). Tông tươi sáng.
   ============================================================ */
:root{
  --brand-1:#6366F1; --brand-2:#8B5CF6; --brand-subtle:#EAEDFF;
  --cyan:#22C3E6; --success:#10B981;
  --gray-50:#FAFBFF; --gray-100:#F2F4FB; --gray-200:#E8EAF3; --gray-300:#D6D9E6; --gray-400:#A0A4B8; --gray-600:#565C72; --gray-900:#1E2233;
  --ink:#2A3142; --ink-soft:var(--gray-600); --ink-mute:var(--gray-400);
  --r-lg:14px; --r-xl:20px; --r-2xl:28px; --r-full:999px;
  --shadow-1:0 1px 2px rgba(30,34,51,.05),0 0 0 1px rgba(30,34,51,.03);
  --shadow-2:0 4px 14px -2px rgba(30,34,51,.08),0 0 0 1px rgba(30,34,51,.03);
  --font-sans:'Inter',system-ui,sans-serif; --font-display:'Inter Tight','Inter',sans-serif;
  --grad-brand:linear-gradient(135deg,#6366F1,#8B5CF6);
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
html,body{overflow-x:hidden;overflow-x:clip}
body{font-family:var(--font-sans);color:var(--ink);background:#fff;-webkit-font-smoothing:antialiased}
a{text-decoration:none;color:inherit}
img{max-width:100%;display:block}
svg{width:18px;height:18px}
.c{max-width:1160px;margin:0 auto;padding:0 24px}
h1,h2,h3{color:#2A3142}
p,li{color:var(--ink-soft)}
.grad{background:linear-gradient(120deg,#6366F1,#22C3E6 92%);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}
.ck{width:20px;height:20px;color:var(--success);flex-shrink:0}

/* reveal */
.reveal{opacity:0;transform:translateY(22px);transition:opacity .7s cubic-bezier(.16,1,.3,1),transform .7s cubic-bezier(.16,1,.3,1)}
.reveal.in{opacity:1;transform:none}
.d1{transition-delay:.08s}.d2{transition-delay:.16s}.d3{transition-delay:.24s}

/* buttons */
.btn{position:relative;display:inline-flex;align-items:center;justify-content:center;gap:8px;height:46px;padding:0 24px;border-radius:var(--r-full);font-size:15px;font-weight:600;cursor:pointer;border:1px solid transparent;transition:transform .15s,box-shadow .15s,background .15s;white-space:nowrap}
.btn-brand{background:linear-gradient(135deg,#6366F1,#22C3E6);color:#fff;box-shadow:0 12px 28px -8px rgba(56,140,230,.5)}
.btn-brand:hover{transform:translateY(-2px);box-shadow:0 20px 40px -10px rgba(56,140,230,.6)}
.btn-ghost{background:rgba(255,255,255,.7);color:var(--ink);border-color:var(--gray-200)}
.btn-ghost:hover{background:#fff;border-color:var(--gray-300)}
.btn-lg{height:56px;padding:0 32px;font-size:16.5px}
.btn-sm{height:40px;padding:0 18px;font-size:14px}

/* nav */
.nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.78);backdrop-filter:saturate(180%) blur(16px);border-bottom:1px solid rgba(232,234,243,.8)}
.nav-in{display:flex;align-items:center;gap:30px;height:68px}
.nav .logo{height:27px}
.nav-links{display:flex;gap:28px;margin-left:10px}
.nav-links a{font-size:14.5px;font-weight:500;color:var(--ink-soft)}
.nav-links a:hover{color:var(--ink)}
.nav-cta{margin-left:auto;display:flex;align-items:center;gap:12px}

/* hero */
.hero{position:relative;padding:92px 0 96px}
.orbs{position:absolute;inset:0;overflow:hidden;z-index:-1;pointer-events:none}
.orbs::before,.orbs::after{content:'';position:absolute;border-radius:50%;filter:blur(90px);opacity:.45}
.orbs::before{width:640px;height:640px;right:-170px;top:-210px;background:radial-gradient(circle,#C9D4FF,#D6F0FF 60%,transparent 72%)}
.orbs::after{width:540px;height:540px;left:-180px;bottom:-230px;background:radial-gradient(circle,#C7F7E6,#D8F3FF 60%,transparent 72%)}
.hero-in{display:grid;grid-template-columns:1.04fr .96fr;gap:56px;align-items:center}
.hero-in>*{min-width:0}
.badge{display:inline-flex;align-items:center;gap:8px;padding:7px 14px;border-radius:var(--r-full);background:rgba(255,255,255,.75);border:1px solid var(--gray-200);color:var(--brand-1);font-size:12.5px;font-weight:600;margin-bottom:22px;box-shadow:var(--shadow-1)}
.badge .dot{width:7px;height:7px;border-radius:50%;background:var(--success);box-shadow:0 0 0 4px rgba(16,185,129,.18)}
.hero h1{font-family:var(--font-display);font-size:clamp(30px,5.2vw,58px);line-height:1.06;letter-spacing:-.035em;font-weight:800;margin:0 0 20px;overflow-wrap:anywhere}
.hero .lead{font-size:18px;line-height:1.62;color:var(--ink-soft);margin:0 0 30px;max-width:530px}
.hero-cta{display:flex;gap:14px;flex-wrap:wrap}
.trust{display:flex;gap:22px;flex-wrap:wrap;margin-top:26px}
.trust span{display:inline-flex;align-items:center;gap:7px;font-size:13px;color:var(--ink-soft);font-weight:500}
.trust .ck{width:16px;height:16px}
.art{position:relative}
.art .glow{position:absolute;inset:-6% 2% -6% 4%;background:linear-gradient(135deg,#6366F1,#22C3E6);filter:blur(72px);opacity:.18;border-radius:40px;z-index:-1}
.shot{border-radius:15px;background:#fff;border:1px solid var(--gray-200);overflow:hidden;box-shadow:0 44px 90px -26px rgba(30,34,51,.4),0 16px 34px -14px rgba(30,34,51,.2)}
.shot .bar{height:33px;display:flex;align-items:center;gap:7px;padding:0 14px;background:#F4F5FB;border-bottom:1px solid #ECEEF6}
.shot .bar i{width:10px;height:10px;border-radius:50%;display:inline-block}
.shot .bar u{margin-left:12px;font-size:12px;color:var(--ink-mute);font-weight:600;text-decoration:none}
.art-app{position:absolute;right:-22px;bottom:-40px;width:34%;border-radius:20px;box-shadow:0 40px 70px -20px rgba(30,34,51,.42);animation:float 6s ease-in-out infinite}
.art-app img{border-radius:20px}
@keyframes float{0%,100%{transform:translateY(0)}50%{transform:translateY(-12px)}}

/* band */
.band{border-top:1px solid var(--gray-100);border-bottom:1px solid var(--gray-100);background:var(--gray-50)}
.band-in{display:flex;align-items:center;justify-content:center;gap:34px;flex-wrap:wrap;padding:22px 0}
.band .it{display:inline-flex;align-items:center;gap:9px;font-size:14px;font-weight:600;color:var(--ink-soft)}
.band .it svg{width:19px;height:19px;color:var(--brand-1)}

/* sections */
.sec{padding:100px 0;position:relative}
.sec.alt{background:var(--gray-50)}
.head{text-align:center;max-width:660px;margin:0 auto 60px}
.eyebrow{display:inline-block;font-size:12.5px;font-weight:700;letter-spacing:.1em;text-transform:uppercase;color:var(--brand-1);margin-bottom:14px;padding:5px 12px;background:var(--brand-subtle);border-radius:var(--r-full)}
.head h2{font-family:var(--font-display);font-size:clamp(28px,3.6vw,40px);line-height:1.12;letter-spacing:-.03em;font-weight:800;margin:0 0 16px}
.head p{font-size:17px;line-height:1.6;color:var(--ink-soft)}

/* features */
.feats{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.feats>*{min-width:0}
.feat{background:#fff;border:1px solid var(--gray-100);border-radius:var(--r-xl);padding:30px 26px;transition:transform .2s cubic-bezier(.16,1,.3,1),box-shadow .2s}
.feat:hover{transform:translateY(-5px);box-shadow:0 24px 50px -18px rgba(30,34,51,.18)}
.feat .ico{width:50px;height:50px;border-radius:14px;display:flex;align-items:center;justify-content:center;margin-bottom:18px}
.feat .ico svg{width:24px;height:24px}
.feat h3{font-size:18px;font-weight:700;margin:0 0 8px;letter-spacing:-.01em}
.feat p{font-size:14.5px;line-height:1.58}

/* steps */
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:30px;position:relative}
.steps::before{content:'';position:absolute;top:27px;left:16%;right:16%;height:2px;background:linear-gradient(90deg,var(--brand-subtle),#22C3E6,var(--brand-subtle));z-index:0}
.step{text-align:center;position:relative;z-index:1}
.step .n{width:56px;height:56px;margin:0 auto 20px;border-radius:50%;background:linear-gradient(135deg,#6366F1,#22C3E6);color:#fff;font-family:var(--font-display);font-size:23px;font-weight:700;display:flex;align-items:center;justify-content:center;box-shadow:0 14px 30px -8px rgba(56,140,230,.5);border:4px solid #fff}
.step h3{font-size:18.5px;font-weight:700;margin:0 0 9px}
.step p{font-size:15px;line-height:1.56;max-width:300px;margin:0 auto}

/* showcase */
.show{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center}
.show>*{min-width:0}
.show.rev{direction:rtl}.show.rev>*{direction:ltr}
.show h3{font-family:var(--font-display);font-size:clamp(24px,3vw,32px);font-weight:800;letter-spacing:-.025em;margin:14px 0 16px;line-height:1.18}
.show ul{list-style:none;display:flex;flex-direction:column;gap:14px}
.show li{display:flex;gap:12px;font-size:16px;color:var(--ink-soft);line-height:1.5}
.show li .ck{width:22px;height:22px;margin-top:1px}
.show-art{position:relative}
.show-art .glow{position:absolute;inset:4%;background:linear-gradient(135deg,#6366F1,#22C3E6);filter:blur(64px);opacity:.13;z-index:-1;border-radius:40px}
.show-app{text-align:center}
.show-app img{width:290px;margin:0 auto;filter:drop-shadow(0 36px 60px rgba(30,34,51,.28))}

/* faq */
.faq{max-width:760px;margin:0 auto;display:flex;flex-direction:column;gap:14px}
.faq details{background:#fff;border:1px solid var(--gray-200);border-radius:var(--r-lg);padding:4px 22px;transition:border-color .2s,box-shadow .2s}
.faq details[open]{border-color:var(--brand-subtle);box-shadow:var(--shadow-2)}
.faq summary{list-style:none;cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:16px;padding:18px 0;font-size:16.5px;font-weight:600}
.faq summary::-webkit-details-marker{display:none}
.faq summary .pm{width:24px;height:24px;flex-shrink:0;color:var(--brand-1);transition:transform .2s}
.faq details[open] summary .pm{transform:rotate(45deg)}
.faq p{margin:0 0 18px;font-size:15px;line-height:1.6}

/* cta */
.cta{position:relative;background:linear-gradient(135deg,#6366F1 0%,#7A86F2 45%,#22C3E6 100%);border-radius:var(--r-2xl);padding:76px 40px;text-align:center;color:#fff;overflow:hidden}
.cta::before{content:'';position:absolute;width:520px;height:520px;right:-120px;top:-200px;border-radius:50%;background:radial-gradient(circle,rgba(255,255,255,.3),transparent 65%)}
.cta>*{position:relative}
.cta h2{font-family:var(--font-display);font-size:clamp(30px,4vw,42px);font-weight:800;letter-spacing:-.03em;margin:0 0 14px;color:#fff}
.cta p{font-size:18px;opacity:.95;margin:0 0 32px;color:#fff}
.cta .btn-brand{background:#fff;color:#4F46E5;box-shadow:0 16px 36px -10px rgba(0,0,0,.28)}
.cta .lk{color:#fff;opacity:.94;font-size:14.5px;margin-top:18px;display:inline-block}
.cta .lk:hover{text-decoration:underline}

/* footer */
.foot{background:var(--gray-50);border-top:1px solid var(--gray-100);padding:56px 0 32px}
.foot-top{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:40px;padding-bottom:36px;border-bottom:1px solid var(--gray-200)}
.foot-b img{height:26px;margin-bottom:14px}
.foot-b p{font-size:14px;line-height:1.6;color:var(--ink-soft);max-width:300px}
.foot-col h4{font-size:13px;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--ink-mute);margin:0 0 16px}
.foot-col a{display:block;font-size:14.5px;color:var(--ink-soft);margin-bottom:11px}
.foot-col a:hover{color:var(--brand-1)}
.foot-bot{padding-top:26px;display:flex;align-items:center;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:13px;color:var(--ink-mute)}

/* responsive */
@media (max-width:940px){
  .hero{padding:60px 0 70px}
  .hero-in{grid-template-columns:1fr;gap:56px}
  .art-app{width:30%;right:0}
  .feats{grid-template-columns:repeat(2,1fr)}
  .steps{grid-template-columns:1fr;gap:34px}.steps::before{display:none}
  .show,.show.rev{grid-template-columns:1fr;direction:ltr;gap:30px}
  .foot-top{grid-template-columns:1fr 1fr}
  .nav-links{display:none}
}
@media (max-width:560px){
  .feats{grid-template-columns:1fr}
  .sec{padding:64px 0}
  .hero h1{font-size:28px}
  .hero-cta{width:100%}.hero-cta .btn{flex:1}
  .nav .logo{height:23px}
  .nav-cta{gap:8px}.nav-cta .btn-sm{height:38px;padding:0 12px;font-size:12.5px}
  .nav-cta .btn-ghost{display:none}
  .foot-top{grid-template-columns:1fr;gap:28px}
  .band-in{gap:18px}
}