/* Prevana shared design system — extracted from the Claude Design home
   (public/index.html). Blue is the DEFAULT accent; .theme-teal restores teal.
   Scope: wrap page content in <div class="prevana-root"> (add .theme-teal to switch). */

@import url('https://fonts.googleapis.com/css2?family=Hanken+Grotesk:wght@400;500;600;700;800&family=Be+Vietnam+Pro:wght@300;400;500;600;700&family=Newsreader:ital,opsz,wght@1,6..72,400;1,6..72,500&display=swap');

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0}

/* ---------- Tokens: BLUE default ---------- */
.prevana-root{--t1:#0F6FE8;--t2:#2E90FA;--t3:#6BB6FF;--t4:#06223F;--t5:#0A2C52;--t6:#06203F;--t7:#051A33;--t8:#EFF4FE;--t9:#F2F7FF;--t10:#F4F9FF;--t11:#EAF1FA;--t12:#E1EDFD;--t13:#E6EEF7;--t14:#E3EBF5;--t15:#D6E8FD;--t16:#D8E4F4;--t17:#CFDEF2;--t18:#CFE0F5;--t19:#C8DCF4;--t20:#C2D6F0;--t21:#C2D0E2;--t22:#CFE2FB;--t23:#A8CBF5;--t24:#6BA8F0;--t25:#8FBFF7;--t26:#DCE8F8;--t27:#A6BFDC;--t28:#9DB2CE;--t29:#7C93B4;--t30:#8AA6C8;--t31:#9FB2CC;--t32:#5C77A0;
  font-family:'Be Vietnam Pro',sans-serif;background:#fff;color:var(--t5);overflow-x:hidden}
/* Teal override (optional switch) */
.prevana-root.theme-teal{--t1:#0F766E;--t2:#0FA89C;--t3:#3FD0C3;--t4:#06302C;--t5:#10322F;--t6:#0A2422;--t7:#071F1C;--t8:#EFFAF8;--t9:#F2FBF9;--t10:#F3FBFA;--t11:#E8F5F2;--t12:#DEF3EF;--t13:#E3EEEB;--t14:#E0ECE8;--t15:#D2EFE9;--t16:#D5E8E3;--t17:#CCE2DD;--t18:#CCE5DF;--t19:#C5E0D9;--t20:#C0DBD4;--t21:#BFD2CC;--t22:#CCE9E2;--t23:#A2D7CD;--t24:#5FC1B4;--t25:#83D2C7;--t26:#D9ECE7;--t27:#A0CAC1;--t28:#97C1B8;--t29:#73A59C;--t30:#82B7AD;--t31:#97BAB1;--t32:#5A817A;}
.prevana-root ::selection{background:var(--t2);color:#fff}

/* ---------- Bilingual toggle (VI default) ---------- */
.prevana-root [data-l="en"]{display:none}
.prevana-root.lang-en [data-l="en"]{display:inline}
.prevana-root.lang-en [data-l="vi"]{display:none}
.prevana-root [data-l="en"].blk{display:none}
.prevana-root.lang-en [data-l="en"].blk{display:block}

/* ---------- Typography helpers ---------- */
.prevana-root h1{font:800 54px/1.05 'Hanken Grotesk',sans-serif;color:var(--t5);letter-spacing:-0.02em;margin:0 0 20px}
.prevana-root h2{font:700 36px/1.15 'Hanken Grotesk',sans-serif;color:var(--t5);letter-spacing:-0.015em;margin:0 0 16px}
.prevana-root h3{font:700 20px 'Hanken Grotesk',sans-serif;color:var(--t5);margin:0 0 10px}
.prevana-root p{font:400 16px/1.7 'Be Vietnam Pro',sans-serif;color:#4A5755;margin:0 0 14px}
.prevana-root .eyebrow{display:inline-flex;align-items:center;gap:9px;padding:8px 15px;border-radius:999px;background:var(--t12);color:var(--t1);font:600 13px 'Be Vietnam Pro',sans-serif;margin-bottom:22px}
.prevana-root .eyebrow::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--t2)}
.prevana-root .lead{font:400 19px/1.65 'Be Vietnam Pro',sans-serif;color:var(--t32)}
.prevana-root .muted{color:var(--t32)}
.prevana-root .small{font-size:13px}
.prevana-root .container{max-width:1200px;margin:0 auto;padding:0 32px}
.prevana-root section{padding:88px 0}

/* ---------- Nav ---------- */
.site-nav{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.86);backdrop-filter:blur(14px);border-bottom:1px solid var(--t13)}
.site-nav .wrap{max-width:1200px;margin:0 auto;display:flex;align-items:center;justify-content:space-between;padding:16px 32px}
.site-nav .logo{display:flex;align-items:center;text-decoration:none}
.site-nav .logo img{height:34px;width:auto;display:block}
.nav-center{display:flex;align-items:center;gap:30px}
.navlink{position:relative;text-decoration:none;color:#4A5755;font:500 15px 'Be Vietnam Pro',sans-serif;transition:color .18s}
.navlink:hover,.navlink[aria-current="page"]{color:var(--t1)}
.navlink::after{content:"";position:absolute;left:0;bottom:-6px;width:0;height:2px;background:var(--t2);transition:width .22s}
.navlink:hover::after,.navlink[aria-current="page"]::after{width:100%}
.nav-right{display:flex;align-items:center;gap:18px}
.lang-toggle{display:flex;align-items:center;gap:6px;font:600 14px 'Be Vietnam Pro',sans-serif}
.lt{cursor:pointer;transition:opacity .15s}
.prevana-root .lt-en{opacity:.4}
.prevana-root.lang-en .lt-vi{opacity:.4}
.prevana-root.lang-en .lt-en{opacity:1}

/* ---------- Buttons ---------- */
.btn-primary{display:inline-block;padding:13px 24px;border-radius:9px;background:var(--t1);color:#fff;text-decoration:none;font:600 15px 'Be Vietnam Pro',sans-serif;border:none;cursor:pointer;transition:transform .16s, box-shadow .16s}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 12px 24px -10px rgba(13,118,110,.5)}
.btn-ghost{display:inline-block;padding:13px 24px;border-radius:9px;background:#fff;color:var(--t1);text-decoration:none;font:600 15px 'Be Vietnam Pro',sans-serif;border:1.5px solid var(--t16);cursor:pointer;transition:border-color .16s, background .16s}
.btn-ghost:hover{border-color:var(--t2);background:var(--t8)}

/* ---------- Reveal-on-scroll ---------- */
.reveal{opacity:0;transform:translateY(24px);transition:opacity .7s cubic-bezier(.2,.7,.2,1),transform .7s cubic-bezier(.2,.7,.2,1)}
.reveal.in{opacity:1;transform:none}

/* ---------- FAQ (native details) ---------- */
details.faq{border-bottom:1px solid var(--t13)}
details.faq summary{list-style:none;cursor:pointer;padding:24px 0;display:flex;align-items:center;justify-content:space-between;gap:20px;font:600 19px 'Hanken Grotesk',sans-serif;color:var(--t5)}
details.faq summary::-webkit-details-marker{display:none}
details.faq summary .pm{flex:0 0 auto;width:26px;height:26px;border-radius:50%;border:1.5px solid var(--t20);position:relative;transition:.2s}
details.faq summary .pm::before,details.faq summary .pm::after{content:"";position:absolute;background:var(--t1);transition:.2s}
details.faq summary .pm::before{left:7px;right:7px;top:11.5px;height:1.5px}
details.faq summary .pm::after{top:7px;bottom:7px;left:11.5px;width:1.5px}
details.faq[open] summary .pm{background:var(--t1);border-color:var(--t1)}
details.faq[open] summary .pm::before,details.faq[open] summary .pm::after{background:#fff}
details.faq[open] summary .pm::after{opacity:0}
details.faq .ans{padding:0 46px 26px 0;font:400 16px/1.7 'Be Vietnam Pro',sans-serif;color:#4A5755}

/* ---------- Form fields ---------- */
.fld{width:100%;padding:13px 15px;border:1.5px solid var(--t16);border-radius:10px;font:400 15px 'Be Vietnam Pro',sans-serif;color:var(--t5);background:#fff;transition:border-color .15s}
.fld:focus{outline:none;border-color:var(--t2)}

/* ---------- Cards ---------- */
.card{background:#fff;border:1px solid var(--t13);border-radius:18px;padding:26px}
.scard{transition:transform .2s, box-shadow .2s, border-color .2s}
.scard:hover{transform:translateY(-4px);box-shadow:0 18px 40px -20px rgba(16,50,47,.28);border-color:var(--t19)}
.grid{display:grid;gap:22px}
.grid-2{grid-template-columns:repeat(2,1fr)}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.soft{background:var(--t9)}

/* ---------- Table ---------- */
.ptable{width:100%;border-collapse:collapse;font:400 15px 'Be Vietnam Pro',sans-serif}
.ptable th{text-align:left;padding:14px 16px;background:var(--t11);color:var(--t5);font-weight:700;border-bottom:1px solid var(--t13)}
.ptable td{padding:14px 16px;border-bottom:1px solid var(--t13);color:#4A5755}
.point{display:inline-flex;align-items:center;gap:6px;font:700 14px 'Be Vietnam Pro',sans-serif;color:var(--t1)}
.point::before{content:"●";color:var(--t2)}

/* ---------- Chips / filters ---------- */
.chips{display:flex;flex-wrap:wrap;gap:10px}
.chip{padding:9px 16px;border-radius:999px;border:1.5px solid var(--t16);background:#fff;color:var(--t32);font:600 14px 'Be Vietnam Pro',sans-serif;cursor:pointer;transition:.16s}
.chip:hover{border-color:var(--t2)}
.chip.active{background:var(--t1);color:#fff;border-color:var(--t1)}

/* ---------- Disclaimer ---------- */
.disclaimer{display:flex;gap:12px;align-items:flex-start;padding:16px 18px;background:var(--t11);border-radius:12px;font:400 14px/1.6 'Be Vietnam Pro',sans-serif;color:var(--t32)}
.disclaimer .i{flex:0 0 auto;width:22px;height:22px;border-radius:50%;background:var(--t1);color:#fff;display:grid;place-items:center;font:700 13px 'Be Vietnam Pro',sans-serif}

/* ---------- Breadcrumb ---------- */
.crumbs{font:500 14px 'Be Vietnam Pro',sans-serif;color:var(--t32)}
.crumbs a{color:var(--t1);text-decoration:none}
.crumbs a:hover{text-decoration:underline}

/* ---------- Footer ---------- */
.site-footer{background:var(--t7);color:#fff;padding:64px 0 40px}
.site-footer .fgrid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1.2fr;gap:32px}
.site-footer h4{font:700 15px 'Hanken Grotesk',sans-serif;color:#fff;margin:0 0 14px}
.site-footer a{display:block;color:rgba(255,255,255,.72);text-decoration:none;font:400 14px/2 'Be Vietnam Pro',sans-serif}
.site-footer a:hover{color:#fff}
.site-footer .logo img{height:30px;filter:brightness(0) invert(1)}
.site-footer .fdisc{margin-top:40px;padding-top:24px;border-top:1px solid rgba(255,255,255,.12);font:400 13px/1.7 'Be Vietnam Pro',sans-serif;color:rgba(255,255,255,.6)}

/* ---------- Theme switcher ---------- */
.theme-sw{position:fixed;top:80px;right:18px;z-index:60;background:#fff;border:1px solid #E6E9EE;border-radius:14px;box-shadow:0 10px 30px -12px rgba(16,40,38,.35);padding:7px 9px;display:flex;gap:8px;align-items:center}
.theme-sw .lbl{font:600 11px 'Be Vietnam Pro',sans-serif;color:#8A938F;letter-spacing:.02em}
.sw{width:26px;height:26px;border-radius:8px;cursor:pointer;border:2px solid #fff;box-shadow:0 0 0 1px #DDE3E0;transition:transform .14s, box-shadow .14s}
.sw:hover{transform:scale(1.1)}
.sw-teal{background:#0F766E}
.sw-blue{background:#0F6FE8}
.prevana-root:not(.theme-teal) .sw-blue{box-shadow:0 0 0 2px #0F6FE8}
.prevana-root.theme-teal .sw-teal{box-shadow:0 0 0 2px #0F766E}

/* ---------- Responsive ---------- */
@media (max-width:1024px){
  .prevana-root .grid-4{grid-template-columns:repeat(2,1fr)}
  .prevana-root .grid-3{grid-template-columns:repeat(2,1fr)}
  .prevana-root h1{font-size:46px}
}
@media (max-width:820px){
  .nav-center{display:none}
  .prevana-root .grid-2,.prevana-root .grid-3,.prevana-root .grid-4{grid-template-columns:1fr}
  .prevana-root section{padding:56px 0}
  .prevana-root .container{padding:0 22px}
  .prevana-root h1{font-size:40px;line-height:1.08}
  .prevana-root h2{font-size:30px}
  .site-footer .fgrid{grid-template-columns:1fr 1fr}
}
@media (max-width:480px){
  .prevana-root h1{font-size:33px}
  .prevana-root h2{font-size:26px}
  .theme-sw{top:auto;bottom:16px;right:14px}
  .site-footer .fgrid{grid-template-columns:1fr}
}