/* ============================================================
   NAM HUNG M.E.C — Design tokens
   Palette: clinical navy + instrument teal, cool paper background
   Type: Space Grotesk (display) / IBM Plex Sans (body) / IBM Plex Mono (data)
   Signature: Snellen optotype (eye-chart letter) motif
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=IBM+Plex+Sans:wght@400;500;600&family=IBM+Plex+Sans:ital@1&family=IBM+Plex+Mono:wght@400;500&display=swap');

:root{
  --navy-900:#0A2338;
  --navy-800:#0D3358;
  --navy-700:#16467A;
  --teal-500:#1B5FA3;
  --teal-400:#4E86C4;
  --amber-500:#E2A03F;
  --brand-blue:#114C8D;
  --paper:#F1F4F3;
  --paper-2:#E7ECEA;
  --card:#FFFFFF;
  --ink:#101A20;
  --ink-soft:#4E5E66;
  --ink-faint:#8798A0;
  --line:#D7DEDC;
  --line-dark:#274C5E;
  --radius:2px;
  --maxw:1180px;
  --shadow:0 1px 2px rgba(10,36,50,.06), 0 8px 24px rgba(10,36,50,.06);
}

*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:'IBM Plex Sans',system-ui,sans-serif;
  font-size:16px;
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{
  font-family:'Space Grotesk',system-ui,sans-serif;
  font-weight:600;
  line-height:1.12;
  margin:0 0 .5em;
  letter-spacing:-.01em;
  color:var(--navy-900);
}
p{margin:0 0 1em;color:var(--ink-soft);}
a{color:inherit;text-decoration:none;}
img{max-width:100%;display:block;}
.mono{font-family:'IBM Plex Mono',monospace;}
.container{max-width:var(--maxw);margin:0 auto;padding:0 28px;}
@media(max-width:640px){.container{padding:0 18px;}}

/* -------- Skip link / focus -------- */
a:focus-visible,button:focus-visible,input:focus-visible{
  outline:2px solid var(--teal-400);outline-offset:2px;
}
.skip-link{position:absolute;left:-999px;top:0;background:var(--navy-900);color:#fff;padding:10px 16px;z-index:200;}
.skip-link:focus{left:12px;top:12px;}

/* ============================================================
   HEADER / NAV
   ============================================================ */
.site-header{
  position:sticky;top:0;z-index:100;
  background:var(--navy-900);
  border-bottom:1px solid var(--line-dark);
}
.nav-row{
  display:flex;align-items:center;justify-content:space-between;
  height:72px;
}
.brand{
  display:flex;align-items:center;gap:0;
}
.brand .logo-badge{
  background:#fff;border-radius:8px;padding:6px 10px;display:flex;align-items:center;
  box-shadow:0 1px 4px rgba(0,0,0,.25);
}
.brand img{height:30px;width:auto;display:block;}
@media(max-width:480px){.brand img{height:24px;}.brand .logo-badge{padding:5px 8px;}}

.main-nav{display:flex;align-items:center;gap:2px;}
.main-nav a{
  color:#CADCE3;font-size:.92rem;font-weight:500;padding:10px 16px;border-radius:var(--radius);
  transition:color .15s, background .15s;
}
.main-nav a:hover,.main-nav a.active{color:#fff;background:rgba(255,255,255,.06);}
.nav-cta{
  background:var(--teal-500);color:#fff !important;padding:9px 18px !important;font-weight:600 !important;
}
.nav-cta:hover{background:var(--teal-400) !important;}
.lang-switch{
  display:flex;align-items:center;gap:4px;margin-left:6px;padding-left:14px;border-left:1px solid rgba(255,255,255,.18);
}
.lang-switch a{
  font-family:'IBM Plex Mono';font-size:.76rem;letter-spacing:.03em;color:#8FA6AE;padding:6px 8px;border-radius:2px;
}
.lang-switch a.active{color:#fff;font-weight:600;}
.lang-switch a:hover{color:#fff;}
@media(max-width:900px){
  .lang-switch{margin:14px 0 0;padding:14px 6px 0;border-left:none;border-top:1px solid rgba(255,255,255,.12);justify-content:flex-start;}
}

.nav-toggle{display:none;background:none;border:none;color:#fff;padding:8px;cursor:pointer;}
.nav-toggle svg{width:24px;height:24px;}

@media(max-width:900px){
  .main-nav{
    position:fixed;inset:72px 0 0 0;background:var(--navy-900);
    flex-direction:column;align-items:stretch;padding:12px 22px;
    transform:translateY(-8px);opacity:0;pointer-events:none;transition:.18s;
    overflow-y:auto;
  }
  .main-nav.open{transform:translateY(0);opacity:1;pointer-events:auto;}
  .main-nav a{padding:14px 6px;border-bottom:1px solid rgba(255,255,255,.08);border-radius:0;}
  .nav-cta{margin-top:12px;text-align:center;}
  .nav-toggle{display:block;}
}

/* ============================================================
   HERO — Snellen optotype signature
   ============================================================ */
.hero{
  position:relative;overflow:hidden;
  background:
    linear-gradient(100deg, rgba(9,32,52,.93) 0%, rgba(9,32,52,.82) 32%, rgba(14,46,74,.58) 58%, rgba(14,46,74,.22) 100%),
    url('images/hero-eye.jpg') center 38% / cover no-repeat;
  color:#fff;padding:96px 0 84px;
}
.optotype-field{
  position:absolute;inset:0;pointer-events:none;
  display:flex;flex-direction:column;justify-content:center;
  opacity:.14;font-family:'Space Grotesk',sans-serif;font-weight:700;color:#fff;
  letter-spacing:.08em;white-space:nowrap;user-select:none;
}
.optotype-field div{line-height:1;text-align:center;}
.hero-grid{position:relative;z-index:2;display:grid;grid-template-columns:1.15fr .85fr;gap:48px;align-items:center;}
@media(max-width:900px){.hero-grid{grid-template-columns:1fr;}}
.hero-inner{position:relative;z-index:2;}
.hero-visual{
  position:relative;aspect-ratio:1/1;border-radius:50%;
  background:radial-gradient(circle at 50% 42%, rgba(255,255,255,.16) 0%, rgba(255,255,255,.02) 60%);
  display:flex;align-items:center;justify-content:center;padding:26px;
}
.hero-visual::before{
  content:"";position:absolute;inset:0;border-radius:50%;
  border:1px solid rgba(255,255,255,.28);
}
.hero-visual::after{
  content:"";position:absolute;inset:-40px;border-radius:50%;
  background:radial-gradient(circle, rgba(79,182,189,.35) 0%, rgba(79,182,189,0) 70%);
  z-index:-1;filter:blur(4px);
}
.hero-visual img{
  width:100%;height:100%;object-fit:cover;border-radius:50%;
  box-shadow:0 20px 60px rgba(0,0,0,.45), 0 0 0 1px rgba(255,255,255,.1);
}
@media(max-width:900px){.hero-visual{max-width:280px;margin:0 auto;}}
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-family:'IBM Plex Mono',monospace;font-size:.78rem;letter-spacing:.14em;text-transform:uppercase;
  color:var(--teal-400);margin-bottom:22px;
}
.eyebrow::before{content:"";width:26px;height:1px;background:var(--teal-400);}
.hero h1{
  color:#fff;font-size:clamp(2.1rem,4.6vw,3.4rem);max-width:820px;margin-bottom:.4em;
}
.hero h1 em{color:var(--teal-400);font-style:normal;}
.hero .lede{color:#B9CBD2;font-size:1.12rem;max-width:640px;margin-bottom:34px;}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap;}

.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:13px 26px;border-radius:var(--radius);font-weight:600;font-size:.94rem;
  border:1px solid transparent;transition:.15s;cursor:pointer;
}
.btn-primary{background:var(--teal-500);color:#fff;}
.btn-primary:hover{background:var(--teal-400);}
.btn-ghost{border-color:rgba(255,255,255,.35);color:#fff;}
.btn-ghost:hover{border-color:#fff;background:rgba(255,255,255,.06);}
.btn-dark{border-color:var(--navy-700);color:var(--navy-900);}
.btn-dark:hover{background:var(--navy-900);color:#fff;}

.hero-stats{
  position:relative;z-index:2;display:grid;grid-template-columns:repeat(4,1fr);
  gap:1px;background:rgba(255,255,255,.14);margin-top:64px;border-radius:var(--radius);overflow:hidden;
}
.hero-stats div{background:rgba(9,32,45,.55);padding:20px 22px;}
.hero-stats b{display:block;font-family:'Space Grotesk';font-size:1.5rem;color:#fff;}
.hero-stats span{font-size:.78rem;color:#AEC2C9;}
@media(max-width:760px){.hero-stats{grid-template-columns:repeat(2,1fr);}}

/* ============================================================
   SECTION helpers
   ============================================================ */
.section{padding:84px 0;}
.section-tight{padding:56px 0;}
.section-alt{background:var(--card);}
.section-head{max-width:640px;margin-bottom:48px;}
.section-num{
  font-family:'IBM Plex Mono';font-size:.8rem;color:var(--teal-500);letter-spacing:.1em;
  display:block;margin-bottom:10px;text-transform:uppercase;
}
.section-head h2{font-size:clamp(1.6rem,3vw,2.2rem);}
.section-head p{font-size:1.02rem;}

/* ============================================================
   CARDS — home category tiles
   ============================================================ */
.tri-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px;}
@media(max-width:900px){.tri-grid{grid-template-columns:1fr;}}
.tile{
  position:relative;background:var(--navy-900);border-radius:var(--radius);overflow:hidden;
  aspect-ratio:4/3;color:#fff;display:block;
}
.tile img{width:100%;height:100%;object-fit:cover;opacity:.55;transition:.3s;position:absolute;inset:0;}
.tile:hover img{opacity:.75;transform:scale(1.04);}
.tile::after{content:"";position:absolute;inset:0;background:linear-gradient(0deg,rgba(9,29,41,.92) 0%,rgba(9,29,41,.25) 55%,rgba(9,29,41,.1) 100%);}
.tile-body{position:absolute;left:0;right:0;bottom:0;padding:22px;z-index:2;}
.tile-body span{font-family:'IBM Plex Mono';font-size:.72rem;color:var(--teal-400);letter-spacing:.08em;}
.tile-body h3{color:#fff;margin:6px 0 0;font-size:1.2rem;}

/* ============================================================
   PRODUCT GRID
   ============================================================ */
.cat-nav{
  display:flex;flex-wrap:wrap;gap:8px;margin-bottom:44px;
  border-bottom:1px solid var(--line);padding-bottom:24px;
}
.cat-nav button{
  font-family:'IBM Plex Sans';font-size:.86rem;font-weight:500;color:var(--ink-soft);
  background:var(--card);border:1px solid var(--line);padding:9px 16px;border-radius:20px;cursor:pointer;
  transition:.15s;
}
.cat-nav button:hover{border-color:var(--teal-500);color:var(--navy-900);}
.cat-nav button.active{background:var(--navy-900);border-color:var(--navy-900);color:#fff;}

.cat-section{margin-bottom:64px;scroll-margin-top:96px;}
.cat-title{
  display:flex;align-items:baseline;gap:14px;margin-bottom:6px;padding-bottom:14px;border-bottom:2px solid var(--navy-900);
}
.cat-title h2{font-size:1.5rem;margin:0;}
.cat-title .count{font-family:'IBM Plex Mono';color:var(--teal-500);font-size:.85rem;}

.product-grid{
  display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:20px;margin-top:22px;
}
.p-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;display:flex;flex-direction:column;transition:.18s;
}
.p-card:hover{border-color:var(--teal-500);box-shadow:var(--shadow);transform:translateY(-2px);}
.p-thumb{
  position:relative;aspect-ratio:1/1;
  background:
    radial-gradient(circle at 50% 50%, #fff 0%, #fff 55%, var(--paper-2) 56%, var(--paper-2) 100%);
  display:flex;align-items:center;justify-content:center;
}
.p-thumb img{
  width:78%;height:78%;
  object-fit:contain;
  clip-path:circle(50%);
}
.p-thumb .ring{
  position:absolute;inset:11%;border:1px solid var(--line);border-radius:50%;pointer-events:none;
}
.p-thumb .ring{
  position:absolute;inset:8px;border:1px solid var(--line);border-radius:50%;pointer-events:none;
}
.badge-new{
  position:absolute;top:9%;right:9%;background:var(--amber-500);color:#fff;
  font-family:'IBM Plex Mono';font-size:.66rem;letter-spacing:.06em;padding:3px 8px;border-radius:2px;
  text-transform:uppercase;z-index:3;
}
.p-body{padding:16px 18px 18px;border-top:1px solid var(--line);flex:1;display:flex;flex-direction:column;}
.p-body h3{font-size:.98rem;margin:0 0 4px;line-height:1.3;}
.p-code{font-family:'IBM Plex Mono';font-size:.72rem;color:var(--ink-faint);margin-bottom:10px;}
.p-specs{list-style:none;margin:0;padding:0;font-size:.8rem;color:var(--ink-soft);}
.p-specs li{
  display:flex;justify-content:space-between;gap:10px;padding:4px 0;border-top:1px dashed var(--line);
}
.p-specs li:first-child{border-top:none;}
.p-specs .k{color:var(--ink-faint);}
.p-specs .v{font-family:'IBM Plex Mono';color:var(--navy-800);text-align:right;}
.p-origin{
  margin-top:auto;padding-top:12px;border-top:1px solid var(--line);
  font-size:.78rem;color:var(--teal-500);font-weight:600;display:flex;justify-content:space-between;
}

/* ============================================================
   ABOUT / CONTENT sections
   ============================================================ */
.two-col{display:grid;grid-template-columns:1.1fr .9fr;gap:64px;align-items:start;}
@media(max-width:860px){.two-col{grid-template-columns:1fr;gap:36px;}}
.pillar-list{list-style:none;margin:0;padding:0;}
.pillar-list li{
  display:grid;grid-template-columns:auto 1fr;gap:16px;padding:20px 0;border-top:1px solid var(--line);
}
.pillar-list li:first-child{border-top:none;padding-top:0;}
.pillar-list .letter{
  font-family:'Space Grotesk';font-weight:700;color:var(--teal-500);font-size:1.5rem;width:40px;
}
.pillar-list h4{margin:0 0 4px;font-size:1.02rem;}
.pillar-list p{margin:0;font-size:.92rem;}

.origin-panel{
  background:var(--navy-900);color:#fff;padding:32px;border-radius:var(--radius);
}
.origin-panel h3{color:#fff;font-size:1.1rem;margin-bottom:18px;}
.origin-row{display:flex;justify-content:space-between;padding:10px 0;border-top:1px solid rgba(255,255,255,.12);font-size:.88rem;}
.origin-row:first-of-type{border-top:none;}
.origin-row span:first-child{color:#AEC2C9;}
.origin-row span:last-child{font-family:'IBM Plex Mono';color:var(--teal-400);}

.timeline-block{
  display:flex;gap:20px;padding:26px 0;border-top:1px solid var(--line);
}
.timeline-block:first-child{border-top:none;padding-top:0;}
.timeline-block .date{
  font-family:'IBM Plex Mono';color:var(--teal-500);font-size:.85rem;width:90px;flex-shrink:0;padding-top:4px;
}

/* ============================================================
   SUPPLIERS
   ============================================================ */
.supplier-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:20px;}
.s-card{
  background:var(--card);border:1px solid var(--line);border-radius:var(--radius);
  padding:30px 26px;display:flex;flex-direction:column;gap:18px;transition:.15s;
}
.s-card:hover{border-color:var(--teal-500);box-shadow:var(--shadow);}
.s-logo{height:92px;display:flex;align-items:center;justify-content:center;background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:10px;}
.s-logo img{max-height:84px;max-width:100%;object-fit:contain;}
.s-card h4{font-size:1rem;margin:0;}
.s-card .origin-tag{font-family:'IBM Plex Mono';font-size:.72rem;color:var(--ink-faint);}

/* ============================================================
   CONTACT
   ============================================================ */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:1px;background:var(--line);border:1px solid var(--line);}
@media(max-width:760px){.contact-grid{grid-template-columns:1fr;}}
.contact-cell{background:var(--card);padding:34px;}
.contact-cell.dark{background:var(--navy-900);color:#fff;}
.contact-cell.dark h3{color:#fff;}
.c-row{display:flex;gap:16px;padding:16px 0;border-top:1px solid var(--line);}
.contact-cell.dark .c-row{border-top:1px solid rgba(255,255,255,.12);}
.c-row:first-of-type{border-top:none;padding-top:0;}
.c-icon{
  width:38px;height:38px;border-radius:50%;border:1px solid var(--teal-500);color:var(--teal-500);
  display:flex;align-items:center;justify-content:center;flex-shrink:0;
}
.contact-cell.dark .c-icon{border-color:var(--teal-400);color:var(--teal-400);}
.c-row h5{margin:0 0 3px;font-size:.78rem;text-transform:uppercase;letter-spacing:.08em;color:var(--ink-faint);}
.contact-cell.dark .c-row h5{color:#8FA6AE;}
.c-row p{margin:0;font-size:.95rem;color:var(--ink);}
.contact-cell.dark .c-row p{color:#fff;}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer{background:var(--navy-900);color:#AEC2C9;padding:52px 0 26px;}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:40px;padding-bottom:36px;border-bottom:1px solid rgba(255,255,255,.1);}
@media(max-width:760px){.footer-grid{grid-template-columns:1fr;gap:28px;}}
.footer-grid h5{color:#fff;font-family:'IBM Plex Mono';font-size:.78rem;letter-spacing:.1em;text-transform:uppercase;margin-bottom:16px;}
.footer-grid ul{list-style:none;margin:0;padding:0;}
.footer-grid li{margin-bottom:10px;font-size:.9rem;}
.footer-grid a:hover{color:#fff;}
.footer-bottom{display:flex;justify-content:space-between;padding-top:22px;font-size:.8rem;flex-wrap:wrap;gap:10px;}

/* ============================================================
   BREADCRUMB / page header (inner pages)
   ============================================================ */
.page-hero{
  background:linear-gradient(160deg,var(--navy-900),var(--navy-800));
  color:#fff;padding:52px 0 44px;position:relative;overflow:hidden;
}
.page-hero.has-photo{
  background:
    linear-gradient(120deg, rgba(10,35,56,.90) 0%, rgba(10,35,56,.78) 45%, rgba(15,51,88,.62) 100%),
    url('images/products-hero-bg.jpg') center 38% / cover no-repeat;
}
.page-hero.has-photo-about{
  background:
    linear-gradient(100deg, rgba(10,35,56,.90) 0%, rgba(10,35,56,.72) 40%, rgba(15,51,88,.42) 100%),
    url('images/about-hero-bg.jpg') center 30% / cover no-repeat;
}
.page-hero.has-photo-suppliers{
  background:
    linear-gradient(100deg, rgba(10,35,56,.92) 0%, rgba(10,35,56,.78) 42%, rgba(15,51,88,.48) 100%),
    url('images/suppliers-hero-bg.jpg') center 42% / cover no-repeat;
}
.page-hero.has-photo-contact{
  background:
    linear-gradient(100deg, rgba(10,35,56,.90) 0%, rgba(10,35,56,.75) 42%, rgba(15,51,88,.45) 100%),
    url('images/contact-hero-bg.jpg') center 35% / cover no-repeat;
}
.page-hero-grid{position:relative;z-index:2;display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:center;}
@media(max-width:820px){.page-hero-grid{grid-template-columns:1fr;}}
.page-hero-visual{
  position:relative;display:flex;align-items:center;justify-content:center;
  aspect-ratio:4/3;max-width:440px;justify-self:end;
}
.page-hero-visual img{
  width:100%;height:100%;object-fit:contain;display:block;
  filter:drop-shadow(0 18px 34px rgba(0,0,0,.45));
}
@media(max-width:820px){.page-hero-visual{justify-self:center;max-width:280px;}}
@media(max-width:820px){.page-hero-visual{margin-top:8px;}}
.crumb{font-family:'IBM Plex Mono';font-size:.78rem;color:var(--teal-400);letter-spacing:.06em;margin-bottom:14px;}
.crumb a{color:#AEC2C9;}
.page-hero h1{color:#fff;font-size:clamp(1.9rem,3.6vw,2.6rem);max-width:700px;}
.page-hero p{color:#B9CBD2;max-width:600px;font-size:1.02rem;margin-top:10px;}

/* ============================================================
   BACK TO TOP
   ============================================================ */
.back-to-top{
  position:fixed;right:24px;bottom:24px;z-index:150;
  width:46px;height:46px;border-radius:50%;
  background:var(--navy-900);color:#fff;border:1px solid var(--line-dark);
  display:flex;align-items:center;justify-content:center;cursor:pointer;
  box-shadow:0 4px 14px rgba(10,35,56,.3);
  opacity:0;pointer-events:none;transform:translateY(8px);
  transition:.2s;
}
.back-to-top.show{opacity:1;pointer-events:auto;transform:translateY(0);}
.back-to-top:hover{background:var(--teal-500);}
.back-to-top svg{width:20px;height:20px;}

/* ============================================================
   FLOATING CONTACT (Zalo / Facebook)
   ============================================================ */
.float-contact{
  position:fixed;left:22px;bottom:22px;z-index:150;
  display:flex;flex-direction:column;gap:10px;
}
.float-contact a{
  width:50px;height:50px;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  box-shadow:0 4px 14px rgba(10,35,56,.28);
  color:#fff;font-family:'Space Grotesk';font-weight:700;font-size:.8rem;
  transition:.15s;
}
.float-contact a:hover{transform:translateY(-2px) scale(1.05);}
.float-contact .fc-call{background:var(--teal-500);}
.float-contact .fc-zalo{background:#0068FF;}
.float-contact .fc-messenger{background:linear-gradient(135deg,#00B2FF,#006AFF);}
.float-contact .fc-fb{background:#1877F2;}
.float-contact a svg{width:24px;height:24px;}

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