/* ============================================================
   GRAY — Design system dùng chung cho thegray.vn
   ============================================================ */
:root{
  --bg:#0a0a0a; --bg2:#0d0d0d; --panel:#141414; --panel2:#1b1b1b;
  --line:#262626; --txt:#e8e8e8; --dim:#8a8a8a; --faint:#7d7d7d;
  --accent:#FA8C16; --accent-dim:#b3630f; --heart:#ff4d6a;
  --mono:ui-monospace,"SF Mono","JetBrains Mono","Roboto Mono",Menlo,monospace;
  --sans:-apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
  --wrap:1200px;
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{background:var(--bg);color:var(--txt);font:16px/1.65 var(--sans);
  -webkit-font-smoothing:antialiased;min-height:100vh;display:flex;flex-direction:column;overflow-x:hidden}
a{color:var(--accent);text-decoration:none}
img{max-width:100%;display:block}
button{font:inherit;cursor:pointer}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:4px}

/* ---------- header / nav ---------- */
.hdr{position:sticky;top:0;z-index:60;display:flex;align-items:center;gap:16px;
  padding:14px clamp(16px,4vw,40px);border-bottom:1px solid var(--line);
  background:rgba(10,10,10,.9);backdrop-filter:blur(10px)}
.brand{font-size:22px;font-weight:800;letter-spacing:3px;color:#fff;white-space:nowrap}
.brand span{color:var(--accent)}
.nav{margin-left:auto;display:flex;align-items:center;gap:8px}
.nav a{color:var(--dim);font-size:14px;padding:8px 14px;border-radius:8px;transition:color .15s,background .15s}
.nav a:hover{color:var(--txt)}
.nav a.active{color:var(--txt);font-weight:600}
.nav a.cta{background:var(--accent);color:#000;font-weight:700}
.nav a.cta:hover{filter:brightness(1.1);color:#000}
.burger{display:none;margin-left:auto;background:none;border:0;color:var(--txt);padding:8px}
.burger svg{width:26px;height:26px;stroke:currentColor;fill:none;stroke-width:2}

/* ---------- layout ---------- */
main{flex:1;width:100%}
.wrap{max-width:var(--wrap);margin:0 auto;padding:0 clamp(16px,4vw,40px)}
.section{padding:clamp(48px,8vw,96px) 0}
.section.tight{padding:clamp(32px,5vw,56px) 0}
.eyebrow{font:600 12px/1 var(--mono);letter-spacing:3px;text-transform:uppercase;color:var(--accent);margin-bottom:14px}
.h2{font-size:clamp(24px,4vw,36px);font-weight:700;line-height:1.15;letter-spacing:-.5px}
.lead{color:var(--dim);font-size:clamp(15px,2vw,17px);max-width:640px;margin-top:14px}
.center{text-align:center}
.center .lead{margin-left:auto;margin-right:auto}

/* ---------- buttons ---------- */
.btn{display:inline-flex;align-items:center;gap:9px;padding:13px 22px;border-radius:10px;
  font-size:15px;font-weight:600;border:1px solid var(--line);color:var(--txt);background:var(--panel);
  transition:border-color .15s,color .15s,transform .12s}
.btn:hover{border-color:var(--accent);color:var(--accent);transform:translateY(-1px)}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#000}
.btn.primary:hover{filter:brightness(1.1);color:#000}
.btn.lg{padding:15px 28px;font-size:16px}
.btn svg{width:17px;height:17px;stroke:currentColor;fill:none;stroke-width:2;flex:none}

/* ---------- cards / grid ---------- */
.grid{display:grid;gap:16px}
.g4{grid-template-columns:repeat(auto-fit,minmax(230px,1fr))}
.g3{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.g2{grid-template-columns:repeat(auto-fit,minmax(320px,1fr))}
.card{background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:26px;transition:border-color .15s,transform .15s}
.card:hover{border-color:var(--accent)}
.card .ic{width:30px;height:30px;stroke:var(--accent);fill:none;stroke-width:1.7;margin-bottom:16px}
.card h3{font-size:17px;font-weight:650;margin-bottom:8px}
.card p{font-size:14px;color:var(--dim);line-height:1.6}

/* ---------- footer ---------- */
.ftr{border-top:1px solid var(--line);background:var(--bg2);margin-top:auto}
.ftr-in{max-width:var(--wrap);margin:0 auto;padding:44px clamp(16px,4vw,40px) 28px;
  display:flex;flex-wrap:wrap;gap:32px;justify-content:space-between}
.ftr .brand{font-size:20px;margin-bottom:10px}
.ftr-col h4{font:600 12px/1 var(--mono);letter-spacing:2px;text-transform:uppercase;color:var(--faint);margin-bottom:12px}
.ftr-col a,.ftr-col p{display:block;color:var(--dim);font-size:14px;padding:5px 0;margin-bottom:1px}
.ftr-col a:hover{color:var(--accent)}
.ftr-bot{border-top:1px solid var(--line);text-align:center;color:var(--faint);
  font-size:12px;letter-spacing:1px;padding:16px}

/* ---------- misc ---------- */
.pill{display:inline-flex;align-items:center;gap:7px;font:600 12px/1 var(--mono);letter-spacing:1px;
  text-transform:uppercase;color:var(--dim);border:1px solid var(--line);border-radius:20px;padding:7px 13px}
.pill .dot{width:7px;height:7px;border-radius:50%;background:var(--accent)}
.divider{height:1px;background:var(--line);border:0;margin:0}

@media (max-width:760px){
  .nav{position:fixed;inset:56px 0 auto 0;flex-direction:column;align-items:stretch;gap:2px;
    background:var(--bg);border-bottom:1px solid var(--line);padding:10px 16px 18px;
    transform:translateY(-130%);transition:transform .25s;margin:0}
  .nav.open{transform:translateY(0)}
  .nav a{padding:13px 12px;font-size:15px}
  .nav a.cta{text-align:center;margin-top:6px}
  .burger{display:block}
}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}.card,.btn{transition:none}.card:hover,.btn:hover{transform:none}
}