/* EduRemind — trang giới thiệu */
:root{
  --brand:#0f766e;--brand-2:#14b8a6;--brand-50:#ecfdf8;--ink:#0f2a3d;--ink-2:#3b546b;--muted:#64798b;
  --bg:#f6f8f3;--surface:#fff;--line:#e2e9e4;--amber:#f59e0b;--navy:#0c2233;
  --font:'Be Vietnam Pro',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;--display:'Lexend','Be Vietnam Pro',system-ui,sans-serif;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){--ink:#e6eef2;--ink-2:#b8c8d4;--muted:#8ea3b3;--bg:#0b1620;--surface:#12212d;--line:#1f3343;--brand:#2dd4bf;--brand-50:#0f2c2c}
}
:root[data-theme="dark"]{--ink:#e6eef2;--ink-2:#b8c8d4;--muted:#8ea3b3;--bg:#0b1620;--surface:#12212d;--line:#1f3343;--brand:#2dd4bf;--brand-50:#0f2c2c}
*{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
body{margin:0;font:16px/1.65 var(--font);color:var(--ink);background:var(--bg);overflow-x:hidden}
img{max-width:100%;height:auto}
h1,h2,h3{font-family:var(--display);line-height:1.2;margin:0}
a{color:var(--brand)}
.ic{width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round;flex:none}
.wrap{max-width:1160px;margin:0 auto;padding:0 20px}
.wrap.narrow{max-width:820px}
.skip{position:absolute;left:-999px;top:8px;background:var(--surface);padding:8px 12px;border-radius:8px;z-index:99}
.skip:focus{left:8px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:50px;padding:12px 24px;border-radius:14px;font-weight:600;text-decoration:none;border:1.5px solid transparent;transition:transform .1s,filter .15s,background .15s}
.btn:active{transform:translateY(1px)}
.btn.primary{background:linear-gradient(180deg,#14a394,#0f766e);color:#fff;box-shadow:0 8px 22px rgba(15,118,110,.3)}
.btn.primary:hover{filter:brightness(1.06)}
.btn.ghost{border-color:var(--line);color:var(--ink);background:var(--surface)}
.btn.ghost:hover{border-color:var(--brand-2)}
.btn.sm{min-height:40px;padding:8px 16px;font-size:.92rem;border-radius:12px}
.eyebrow{font-weight:700;font-size:.82rem;letter-spacing:.08em;text-transform:uppercase;color:var(--brand);margin:0 0 10px}
.muted{color:var(--muted)}

.nav{position:sticky;top:0;z-index:20;background:color-mix(in srgb,var(--bg) 85%,transparent);backdrop-filter:blur(14px);-webkit-backdrop-filter:blur(14px);border-bottom:1px solid var(--line)}
.nav-in{display:flex;align-items:center;gap:20px;height:68px}
.brand{display:flex;align-items:center;gap:10px;font:700 1.2rem var(--display);color:var(--ink);text-decoration:none}
.links{display:flex;gap:22px;margin-left:auto}
.links a{color:var(--ink-2);text-decoration:none;font-weight:500;font-size:.95rem}
.links a:hover{color:var(--brand)}

.hero{position:relative;padding:56px 0 40px;overflow:hidden}
.hero::before{content:"";position:absolute;inset:-200px -100px auto auto;width:700px;height:700px;background:radial-gradient(circle,rgba(45,212,191,.28),transparent 65%);z-index:-1}
.hero::after{content:"";position:absolute;left:-200px;bottom:-200px;width:520px;height:520px;background:radial-gradient(circle,rgba(251,191,36,.18),transparent 65%);z-index:-1}
.hero-in{display:grid;grid-template-columns:1.1fr 1fr;gap:40px;align-items:center}
.hero h1{font-size:clamp(2rem,4.6vw,3.3rem);font-weight:700;letter-spacing:-.01em}
.hl{background:linear-gradient(90deg,#0d9488,#d97706);-webkit-background-clip:text;background-clip:text;color:transparent}
.lead{font-size:1.12rem;color:var(--ink-2);margin:18px 0 26px;max-width:560px}
.cta{display:flex;gap:12px;flex-wrap:wrap}
.trust{list-style:none;padding:0;margin:30px 0 0;display:grid;grid-template-columns:repeat(3,auto);justify-content:start;gap:28px}
.trust b{display:block;font:700 1.25rem var(--display);color:var(--brand)}
.trust span{font-size:.86rem;color:var(--muted)}
.hero-art{position:relative;height:580px}
.phone{position:absolute;width:270px;border-radius:38px;padding:10px;background:#0c2233;box-shadow:0 30px 60px rgba(12,34,51,.28)}
.phone img{display:block;border-radius:29px;width:100%}
.p1{right:150px;top:0;transform:rotate(-4deg);z-index:2}
.p2{right:0;top:60px;transform:rotate(5deg);opacity:.96}
.bot{position:absolute;left:10px;bottom:40px;z-index:3;animation:float 4s ease-in-out infinite;filter:drop-shadow(0 12px 20px rgba(15,95,115,.25))}
.bubble{position:absolute;left:100px;bottom:150px;z-index:4;background:var(--surface);color:var(--ink);border:1px solid var(--line);border-radius:18px 18px 18px 4px;padding:12px 16px;font-size:.92rem;font-weight:500;box-shadow:0 14px 30px rgba(12,34,51,.15);max-width:240px}
@keyframes float{50%{transform:translateY(-10px)}}

.sec{padding:84px 0}
.sec-head{max-width:720px;margin:0 auto 40px;text-align:center}
.sec h2{font-size:clamp(1.6rem,3.2vw,2.4rem);font-weight:700}
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:24px;transition:transform .2s,box-shadow .2s}
.card:hover{transform:translateY(-3px);box-shadow:0 16px 40px rgba(12,34,51,.08)}
.card h3{font-size:1.1rem;margin:14px 0 8px}
.card p{margin:0;color:var(--ink-2);font-size:.95rem}
.ico{display:grid;place-items:center;width:48px;height:48px;border-radius:14px}
.c1{background:#eef0ff;color:#6366f1}.c2{background:#fff6e5;color:#d97706}.c3{background:#e6fbf7;color:#0f766e}
.c4{background:#e8f6ff;color:#0284c7}.c5{background:#f3edff;color:#7c3aed}.c6{background:#ecfdf3;color:#16a34a}

.sec.dark{background:linear-gradient(160deg,#0c2233,#0f3b4a 70%,#0f5f5a);color:#e6f1f0}
.sec.dark .eyebrow{color:#5eead4}
.sec.dark p{color:#c6d8dc}
.sec-split{display:grid;grid-template-columns:1.1fr 1fr;gap:48px;align-items:center}
.checks{list-style:none;padding:0;margin:22px 0 0;display:flex;flex-direction:column;gap:14px}
.checks li{position:relative;padding-left:34px;color:#c6d8dc}
.checks li::before{content:"✓";position:absolute;left:0;top:1px;width:24px;height:24px;border-radius:50%;background:rgba(45,212,191,.18);color:#5eead4;display:grid;place-items:center;font-weight:700;font-size:.8rem}
.checks b{color:#fff}
.flow{margin:0;background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.1);border-radius:24px;padding:28px;display:flex;flex-direction:column;align-items:center;gap:14px}
.node{width:100%;background:rgba(255,255,255,.07);border-radius:18px;padding:16px 18px;display:flex;flex-direction:column;align-items:center;gap:4px;text-align:center}
.node .ic{width:30px;height:30px;color:#5eead4}
.node b{color:#fff}
.node span{font-size:.88rem;color:#9fb8c0}
.node code{font-size:.95rem;color:#fcd34d;background:rgba(0,0,0,.25);padding:4px 10px;border-radius:8px}
.node.you span{color:#e6f1f0;font-style:italic}
.arrow{position:relative;text-align:center;font-size:.84rem;color:#5eead4;font-weight:600;padding:8px 0 22px}
.arrow::after{content:"↓";display:block;font-size:1.6rem;line-height:1}
.flow figcaption{font-size:.85rem;color:#9fb8c0;text-align:center}

.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;counter-reset:s}
.steps article{background:var(--surface);border:1px solid var(--line);border-radius:20px;padding:26px}
.steps b{display:grid;place-items:center;width:40px;height:40px;border-radius:12px;background:var(--brand);color:#fff;font:700 1.1rem var(--display)}
.steps h3{margin:14px 0 8px;font-size:1.1rem}
.steps p{margin:0;color:var(--ink-2);font-size:.95rem}

.sec.soft{background:linear-gradient(180deg,var(--brand-50),var(--bg))}
.download{display:grid;grid-template-columns:1.4fr 1fr;gap:32px;align-items:center}
.stores{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}
.store{display:flex;align-items:center;gap:12px;background:var(--ink);color:var(--bg);border-radius:16px;padding:12px 18px;text-decoration:none;font-weight:700;min-width:200px}
.store small{display:block;font-weight:500;font-size:.75rem;opacity:.8}
.store:hover{filter:brightness(1.15)}
.dl-bot{justify-self:center;animation:float 4s ease-in-out infinite}

details{background:var(--surface);border:1px solid var(--line);border-radius:16px;padding:0 20px;margin-bottom:12px}
summary{cursor:pointer;font-weight:600;padding:18px 0;list-style:none;display:flex;justify-content:space-between;gap:16px}
summary::-webkit-details-marker{display:none}
summary::after{content:"+";font:600 1.4rem var(--display);color:var(--brand);line-height:1}
details[open] summary::after{content:"–"}
details p{margin:0 0 18px;color:var(--ink-2)}

.foot{border-top:1px solid var(--line);padding:32px 0;font-size:.92rem}
.foot-in{display:flex;flex-wrap:wrap;align-items:center;gap:12px 24px;justify-content:space-between}
.foot p{margin:0}

@media (max-width:960px){
  .links{display:none}
  .nav .btn{margin-left:auto}
  .hero-in,.sec-split,.download{grid-template-columns:1fr}
  .hero-art{height:460px;max-width:460px;margin:0 auto;width:100%}
  .phone{width:210px}.p1{right:auto;left:60px}.p2{right:0;top:50px}
  .bot{left:-6px;bottom:0;width:90px}.bubble{left:60px;bottom:96px;max-width:200px;font-size:.85rem}
  .cards,.steps{grid-template-columns:1fr 1fr}
}
@media (max-width:600px){
  .hero{padding-top:32px}
  .cards,.steps{grid-template-columns:1fr}
  .sec{padding:60px 0}
  .hero-art{height:400px}
  .phone{width:180px;border-radius:30px;padding:8px}.phone img{border-radius:23px}
  .p1{left:10px}.p2{right:6px}
  .store{flex:1 1 100%}
  .trust{gap:18px}
}
@media (prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important;scroll-behavior:auto!important}}