/* ===== Theme ===== */
:root{
  --bg-1:#070b14; --bg-2:#0a1222; --txt:#eaf2ff; --muted:#9fb3df;
  --rose:#f59e0b; /* cam chủ đạo */ --violet:#60a5fa; --cyan:#22d3ee; --emerald:#10b981;
  --glass:rgba(255,255,255,.06); --rad:18px; --rad-lg:26px;
  --ring: conic-gradient(from 180deg at 50% 50%, rgba(225,29,72,.9), rgba(6,182,212,.85), rgba(139,92,246,.9), rgba(225,29,72,.9));
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;color:var(--txt);font-family:Montserrat,system-ui,Segoe UI,Roboto,Helvetica,Arial;
  background:
    radial-gradient(1200px 600px at 0% -10%, rgba(139,92,246,.25), transparent 60%),
    radial-gradient(900px 500px at 100% 10%, rgba(6,182,212,.22), transparent 55%),
    linear-gradient(180deg, var(--bg-1), var(--bg-2));
  overflow-x:hidden
}
a{color:inherit;text-decoration:none}
.container{width:min(1220px,92vw);margin-inline:auto}
.grid{display:grid;gap:18px}
.btn{
  position:relative;display:inline-flex;align-items:center;gap:10px;padding:12px 18px;border-radius:999px;border:0;cursor:pointer;
  font-weight:800;letter-spacing:.3px;color:#fff;isolation:isolate;overflow:hidden;
  background:linear-gradient(135deg,var(--rose),var(--cyan)); box-shadow:0 14px 34px rgba(225,29,72,.35);
  transition:transform .15s ease, box-shadow .2s ease
}
.btn::after{content:"";position:absolute;inset:-1px;border-radius:inherit;background:linear-gradient(90deg,transparent,rgba(255,255,255,.45),transparent);filter:blur(8px);translate:-120% 0;transition:translate .5s}
.btn:hover{transform:translateY(-2px);box-shadow:0 18px 44px rgba(6,182,212,.35)}
.btn:hover::after{translate:120% 0}
.btn.ghost{background:transparent;color:var(--txt);outline:1px solid rgba(255,255,255,.16)}
.chip{display:inline-flex;align-items:center;gap:8px;padding:6px 10px;border-radius:999px;font-size:12px;background:rgba(255,255,255,.08);border:1px solid rgba(255,255,255,.12)}

/* ===== Nav ===== */
.nav{position:fixed;left:0;right:0;top:0;z-index:60;border-bottom:1px solid rgba(255,255,255,.06);
  backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);background:linear-gradient(180deg, rgba(8,10,18,.75), rgba(8,10,18,.35))}
.nav-inner{display:flex;align-items:center;justify-content:space-between;padding:10px 0}
.logo{display:flex;align-items:center;gap:12px;font-weight:900;letter-spacing:.6px}
.logo-badge{width:40px;height:40px;border-radius:12px;display:grid;place-items:center;background:var(--ring);box-shadow:0 8px 40px rgba(6,182,212,.35);font-family:Unbounded,system-ui;font-size:18px}
.links{display:flex;gap:10px;align-items:center}
.links a{padding:8px 10px;border-radius:10px;opacity:.86}
.links a:hover{background:rgba(255,255,255,.06);opacity:1}
.menu{display:none}
@media (max-width:820px){
  .menu{display:inline-flex}
  .links{position:fixed;inset:58px 12px auto 12px;display:grid;gap:8px;padding:12px;border:1px solid rgba(255,255,255,.12);border-radius:14px;background:linear-gradient(180deg,rgba(255,255,255,.08),rgba(255,255,255,.04));opacity:0;pointer-events:none;transform:translateY(-8px);transition:opacity .2s, transform .2s}
  .links.open{opacity:1;pointer-events:auto;transform:none}
}

/* ===== Hero ===== */
header.hero{position:relative;padding-top:86px}
.hero-wrap{min-height:88vh;display:grid;align-items:center}
.hero-grid{display:grid;grid-template-columns:1.2fr .8fr;gap:28px}
@media (max-width:980px){.hero-grid{grid-template-columns:1fr}}
.card{position:relative;padding:30px;border-radius:var(--rad-lg);background:linear-gradient(180deg,rgba(255,255,255,.08),rgba(255,255,255,.05));border:1px solid rgba(255,255,255,.12);box-shadow:0 20px 60px rgba(0,0,0,.35);overflow:hidden}
.card::before{content:"";position:absolute;inset:-1px;border-radius:inherit;padding:1px;background:linear-gradient(90deg, rgba(225,29,72,.6), rgba(6,182,212,.6), rgba(139,92,246,.6));-webkit-mask:linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);-webkit-mask-composite:xor;mask-composite:exclude}
.splash{position:absolute;inset:-30% -10% auto auto;width:420px;height:420px;background:radial-gradient(circle at 30% 30%, rgba(225,29,72,.45), transparent 60%), radial-gradient(circle at 70% 70%, rgba(6,182,212,.35), transparent 60%);filter:blur(40px);opacity:.5;animation:pulse 10s ease-in-out infinite}
@keyframes pulse{50%{transform:translateY(10px) scale(1.03);opacity:.62}}

.hero-title{position:relative;font-family:"Bebas Neue",Inter,system-ui;font-size:clamp(56px,9vw,110px);line-height:.9;letter-spacing:.8px;margin:0}
.hero-title .stroke{color:transparent;-webkit-text-stroke:1.5px rgba(255,255,255,.95);text-stroke:1.5px rgba(255,255,255,.95)}
.hero-title .glow{position:absolute;inset:0;background:linear-gradient(90deg,var(--rose),var(--violet),var(--cyan),var(--rose));background-size:300% 100%;mix-blend-mode:screen;-webkit-background-clip:text;background-clip:text;color:transparent;filter:drop-shadow(0 0 24px rgba(245,158,11,.45));animation:shine 6s linear infinite}
.hero-title .subtitle{display:block;font-size:clamp(18px,2.4vw,28px);letter-spacing:.4px;margin-top:12px;color:var(--muted)}
.hero-title::after{content:"";display:block;width:min(280px,40%);height:4px;margin-top:14px;border-radius:999px;background:linear-gradient(90deg,var(--rose),var(--cyan));filter:drop-shadow(0 0 10px rgba(245,158,11,.45));animation:underlinePulse 2.2s ease-in-out infinite}
@keyframes shine{0%{background-position:0% 50%}100%{background-position:300% 50%}}
@keyframes underlinePulse{0%,100%{transform:scaleX(.94);opacity:.85}50%{transform:scaleX(1.06);opacity:1}}

.lead{color:var(--muted);margin:10px 0 0;max-width:760px}
.cta{display:flex;gap:12px;flex-wrap:wrap;margin-top:10px}

.hero-mini{display:grid;gap:12px;padding:16px;border-radius:16px;background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.12)}
.hero-mini .row{display:flex;align-items:center;justify-content:space-between;gap:10px;flex-wrap:wrap}
.pill{display:inline-flex;align-items:center;gap:8px;padding:7px 12px;border:1px solid rgba(255,255,255,.14);border-radius:999px;background:rgba(255,255,255,.06);font-size:13px}

.progress{position:fixed;left:0;top:0;height:3px;background:linear-gradient(90deg,var(--rose),var(--cyan),var(--violet));box-shadow:0 0 20px rgba(139,92,246,.6);z-index:60;width:0%}

/* ===== Sections ===== */
section{padding:70px 0}
section h2{font-family:Unbounded,Montserrat;font-size:clamp(32px,5.6vw,66px);margin:0 0 12px}
section p.section-lead{color:var(--muted);margin:0 0 22px;max-width:840px}

/* Features */
.features{grid-template-columns:repeat(12,1fr)}
.feature{grid-column:span 4;padding:18px;border-radius:var(--rad);border:1px solid rgba(255,255,255,.12);background:linear-gradient(180deg,rgba(255,255,255,.07),rgba(255,255,255,.04));transition:transform .25s, box-shadow .25s, border-color .25s}
.feature:hover{transform:translateY(-4px);box-shadow:0 18px 50px rgba(6,182,212,.28);border-color:rgba(139,92,246,.45)}
.feature h3{margin:8px 0 6px;font-size:20px}
.feature p{margin:0;color:var(--muted)}
@media (max-width:980px){.feature{grid-column:span 6}}
@media (max-width:640px){.feature{grid-column:span 12}}

/* Steps */
.steps{grid-template-columns:repeat(2,1fr)}
.step{padding:18px;border-radius:16px;border:1px dashed rgba(255,255,255,.16);background:rgba(255,255,255,.03)}
.step b{display:inline-flex;align-items:center;justify-content:center;width:28px;height:28px;border-radius:8px;margin-right:8px;background:linear-gradient(135deg,var(--rose),var(--cyan))}
@media (max-width:820px){.steps{grid-template-columns:1fr}}

/* News + sidebar */
.news-wrap{display:grid;grid-template-columns:2fr 1fr;gap:18px}
@media (max-width:980px){.news-wrap{grid-template-columns:1fr}}
.news{grid-template-columns:repeat(12,1fr)}
.post{grid-column:span 6;display:grid;gap:10px;border:1px solid rgba(255,255,255,.12);border-radius:16px;overflow:hidden;background:rgba(255,255,255,.04)}
.post .meta{display:flex;gap:8px;align-items:center;color:var(--muted);font-size:13px}
.post .body{padding:12px 14px;display:grid;gap:8px}
@media (max-width:980px){.post{grid-column:span 12}}
.thumb{aspect-ratio:16/9;background:linear-gradient(135deg, rgba(29,78,216,.25), rgba(6,182,212,.25))}
.aside{display:grid;gap:12px}
.panel{border:1px solid rgba(255,255,255,.12);border-radius:16px;overflow:hidden;background:rgba(255,255,255,.04)}
.panel h4{margin:0;padding:12px 14px;border-bottom:1px solid rgba(255,255,255,.12);background:rgba(255,255,255,.06)}
/* Mặc định 3 cột trên màn hình rộng */
@media (min-width: 1024px){
  .news .post{ grid-column: span 4; } /* 12/4 = 3 cột */
}
/* Tablet giữ 2 cột */
@media (max-width: 1023px){
  .news .post{ grid-column: span 6; }
}
/* Mobile 1 cột */
@media (max-width: 640px){
  .news .post{ grid-column: span 12; }
}

/* Auth modal */
.modal{position:fixed;inset:0;background:rgba(0,0,0,.5);display:none;align-items:center;justify-content:center;padding:20px;z-index:80}
.modal.open{display:flex}
.sheet{width:min(520px,92vw);border-radius:18px;border:1px solid rgba(255,255,255,.12);background:linear-gradient(180deg,rgba(255,255,255,.09),rgba(255,255,255,.05));box-shadow:0 30px 90px rgba(0,0,0,.5);padding:18px}
.field{display:grid;gap:6px;margin-top:10px}
.field input{padding:12px 14px;border-radius:10px;border:1px solid rgba(255,255,255,.14);background:rgba(255,255,255,.06);color:var(--txt)}

/* Footer */
footer{padding:28px 0 64px;color:var(--muted);font-size:14px;border-top:1px solid rgba(255,255,255,.1)}

/* Reveal */
.reveal{opacity:0;transform:translateY(12px);transition:opacity .6s, transform .6s}
.reveal.show{opacity:1;transform:none}

@media (prefers-reduced-motion: reduce){*{animation:none!important;transition:none!important}}