/* ============================================================
   Việt Nguyên Tố — Hệ thống thiết kế chung
   Phong cách: corporate B2B, tối giản, đáng tin cậy (tham khảo Caldic)
   ============================================================ */

:root{
  --navy-900:#0a2540;
  --navy-800:#0f3556;
  --navy-700:#154169;
  --navy-600:#1c5686;
  --teal-500:#0fa3a3;
  --teal-600:#0c8888;
  --teal-100:#e3f6f6;
  --amber-500:#e8963c;
  --gray-900:#1a2027;
  --gray-700:#454e58;
  --gray-500:#6b7480;
  --gray-300:#c7ced6;
  --gray-100:#eef1f4;
  --gray-50:#f7f9fb;
  --white:#ffffff;
  --radius-sm:6px;
  --radius-md:12px;
  --radius-lg:20px;
  --shadow-sm:0 1px 3px rgba(10,37,64,.08);
  --shadow-md:0 8px 24px rgba(10,37,64,.10);
  --shadow-lg:0 20px 48px rgba(10,37,64,.16);
  --maxw:1180px;
}

*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:"Inter",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  color:var(--gray-900);
  background:var(--white);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
}
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
ul{list-style:none;margin:0;padding:0;}
h1,h2,h3,h4{margin:0 0 .5em;font-weight:700;letter-spacing:-0.01em;color:var(--navy-900);}
p{margin:0 0 1em;color:var(--gray-700);}
.container{max-width:var(--maxw);margin:0 auto;padding:0 24px;}
section{padding:88px 0;}
@media (max-width:768px){section{padding:56px 0;}}

.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-size:13px;font-weight:700;letter-spacing:.08em;text-transform:uppercase;
  color:var(--teal-600);margin-bottom:14px;
}
.eyebrow::before{content:"";width:22px;height:2px;background:var(--teal-500);display:inline-block;}

.section-head{max-width:720px;margin-bottom:48px;}
.section-head.center{margin-left:auto;margin-right:auto;text-align:center;}
.section-head h2{font-size:clamp(26px,3vw,38px);}
.section-head p{font-size:17px;}

/* Buttons */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:13px 26px;border-radius:999px;font-weight:600;font-size:15px;
  border:1.5px solid transparent;cursor:pointer;transition:all .18s ease;white-space:nowrap;
}
.btn-primary{background:var(--teal-500);color:var(--white);}
.btn-primary:hover{background:var(--teal-600);transform:translateY(-1px);}
.btn-outline{border-color:rgba(255,255,255,.55);color:var(--white);}
.btn-outline:hover{background:rgba(255,255,255,.12);}
.btn-navy{background:var(--navy-900);color:var(--white);}
.btn-navy:hover{background:var(--navy-700);}
.btn-ghost{border-color:var(--gray-300);color:var(--navy-900);}
.btn-ghost:hover{border-color:var(--teal-500);color:var(--teal-600);}

/* ===================== HEADER / NAV ===================== */
.site-header{
  position:sticky;top:0;z-index:100;background:rgba(255,255,255,.96);
  backdrop-filter:blur(8px);border-bottom:1px solid var(--gray-100);
}
.nav-row{display:flex;align-items:center;justify-content:space-between;height:76px;gap:24px;}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:19px;color:var(--navy-900);}
.logo .mark{
  width:34px;height:34px;border-radius:9px;background:linear-gradient(135deg,var(--teal-500),var(--navy-700));
  color:#fff;display:flex;align-items:center;justify-content:center;font-size:14px;font-weight:800;flex-shrink:0;
}
.nav-main{display:flex;align-items:center;gap:2px;}
.nav-main>li{position:relative;}
.nav-main>li>a, .nav-main>li>button{
  display:flex;align-items:center;gap:6px;
  padding:10px 16px;font-weight:600;font-size:14.5px;color:var(--gray-900);
  border-radius:8px;background:none;border:none;cursor:pointer;font-family:inherit;
}
.nav-main>li>a:hover,.nav-main>li>button:hover{color:var(--teal-600);}
.nav-actions{display:flex;align-items:center;gap:14px;}
.nav-actions .btn{padding:10px 20px;font-size:14px;}

.dropdown{
  position:absolute;top:calc(100% + 8px);left:50%;transform:translateX(-50%);
  background:var(--white);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);
  border:1px solid var(--gray-100);padding:10px;min-width:280px;
  opacity:0;visibility:hidden;translate:0 6px;transition:all .16s ease;
}
.nav-main>li:hover .dropdown{opacity:1;visibility:visible;translate:0 0;}
.dropdown a{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:8px;font-size:14.5px;font-weight:600;color:var(--gray-900);}
.dropdown a:hover{background:var(--teal-100);color:var(--teal-600);}
.dropdown .ic{font-size:18px;}

.mobile-toggle{display:none;background:none;border:none;font-size:24px;cursor:pointer;color:var(--navy-900);}
@media (max-width:960px){
  .nav-main,.nav-actions .btn-ghost{display:none;}
  .mobile-toggle{display:block;}
}

/* Breadcrumb-ish page hero label */
.crumb{font-size:13px;color:rgba(255,255,255,.7);margin-bottom:10px;}
.crumb a:hover{color:var(--white);}

/* ===================== HERO ===================== */
.hero{
  position:relative;overflow:hidden;color:var(--white);
  background:linear-gradient(120deg,var(--navy-900) 0%,var(--navy-700) 55%,var(--teal-600) 130%);
  padding:110px 0 100px;
}
.hero::before{
  content:"";position:absolute;inset:0;opacity:.16;
  background-image:radial-gradient(circle at 18% 22%, #fff 0, transparent 2px),
                    radial-gradient(circle at 42% 68%, #fff 0, transparent 2px),
                    radial-gradient(circle at 68% 30%, #fff 0, transparent 2px),
                    radial-gradient(circle at 85% 75%, #fff 0, transparent 2px),
                    radial-gradient(circle at 92% 18%, #fff 0, transparent 2px),
                    radial-gradient(circle at 8% 82%, #fff 0, transparent 2px);
  background-size:220px 220px;
}
.hero-grid{position:relative;display:grid;grid-template-columns:1.1fr .9fr;gap:56px;align-items:center;}
@media (max-width:900px){.hero-grid{grid-template-columns:1fr;}}
.hero h1{color:var(--white);font-size:clamp(32px,4.4vw,52px);line-height:1.12;margin-bottom:20px;}
.hero p.lead{color:rgba(255,255,255,.86);font-size:18px;max-width:520px;}
.hero-actions{display:flex;gap:14px;margin-top:32px;flex-wrap:wrap;}
.hero-art{
  position:relative;aspect-ratio:1/1;border-radius:var(--radius-lg);
  background:linear-gradient(155deg,rgba(255,255,255,.14),rgba(255,255,255,.02));
  border:1px solid rgba(255,255,255,.22);display:flex;align-items:center;justify-content:center;
  box-shadow:var(--shadow-lg);font-size:120px;
}

/* Small page hero (inner pages) */
.page-hero{
  background:linear-gradient(120deg,var(--navy-900),var(--navy-700));
  color:var(--white);padding:56px 0 68px;position:relative;overflow:hidden;
}
.page-hero .tag-ic{
  width:56px;height:56px;border-radius:14px;background:rgba(255,255,255,.14);
  display:flex;align-items:center;justify-content:center;font-size:28px;margin-bottom:20px;
  border:1px solid rgba(255,255,255,.2);
}
.page-hero h1{color:var(--white);font-size:clamp(28px,3.6vw,42px);margin-bottom:14px;}
.page-hero p{color:rgba(255,255,255,.85);font-size:17px;max-width:640px;margin-bottom:0;}

/* ===================== STATS BAND ===================== */
.stats-band{background:var(--navy-900);color:var(--white);padding:44px 0;}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;text-align:center;}
@media (max-width:768px){.stats-grid{grid-template-columns:repeat(2,1fr);}}
.stat-num{font-size:clamp(26px,3vw,36px);font-weight:800;color:var(--teal-500);}
.stat-label{font-size:13.5px;color:rgba(255,255,255,.72);margin-top:4px;}

/* ===================== FEATURE GRID (4 values) ===================== */
.feature-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:26px;}
@media (max-width:960px){.feature-grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:560px){.feature-grid{grid-template-columns:1fr;}}
.feature-card{
  background:var(--white);border:1px solid var(--gray-100);border-radius:var(--radius-md);
  padding:30px 26px;box-shadow:var(--shadow-sm);transition:box-shadow .2s ease, transform .2s ease;
}
.feature-card:hover{box-shadow:var(--shadow-md);transform:translateY(-3px);}
.feature-card .ic{
  width:46px;height:46px;border-radius:12px;background:var(--teal-100);color:var(--teal-600);
  display:flex;align-items:center;justify-content:center;font-size:22px;margin-bottom:16px;
}
.feature-card h3{font-size:17px;margin-bottom:8px;}
.feature-card p{font-size:14.5px;margin-bottom:0;}

/* ===================== MARKET / INDUSTRY CARDS ===================== */
.bg-gray{background:var(--gray-50);}
.industry-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;}
@media (max-width:900px){.industry-grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:600px){.industry-grid{grid-template-columns:1fr;}}
.industry-card{
  position:relative;background:var(--white);border-radius:var(--radius-md);
  border:1px solid var(--gray-100);overflow:hidden;box-shadow:var(--shadow-sm);
  transition:transform .2s ease, box-shadow .2s ease;display:flex;flex-direction:column;
}
.industry-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-md);}
.industry-card .top{
  height:8px;background:linear-gradient(90deg,var(--teal-500),var(--navy-600));
}
.industry-card .body{padding:28px 26px 26px;flex:1;display:flex;flex-direction:column;}
.industry-card .ic{font-size:34px;margin-bottom:14px;}
.industry-card .kicker{font-size:12.5px;font-weight:700;color:var(--teal-600);text-transform:uppercase;letter-spacing:.06em;margin-bottom:6px;}
.industry-card h3{font-size:19px;margin-bottom:10px;}
.industry-card p{font-size:14.5px;flex:1;}
.industry-card .go{font-size:14px;font-weight:700;color:var(--navy-800);margin-top:8px;}
.industry-card:hover .go{color:var(--teal-600);}

/* ===================== ALTERNATING CONTENT ROWS ===================== */
.row{display:grid;grid-template-columns:1fr 1fr;gap:56px;align-items:center;}
.row.reverse .visual{order:2;}
@media (max-width:900px){.row{grid-template-columns:1fr;}.row.reverse .visual{order:0;}}
.row + .row{margin-top:88px;}
.visual{
  aspect-ratio:4/3;border-radius:var(--radius-lg);
  background:linear-gradient(140deg,var(--teal-100),var(--gray-50));
  border:1px solid var(--gray-100);position:relative;overflow:hidden;
  display:flex;align-items:center;justify-content:center;
}
.visual .icon-big{font-size:88px;opacity:.85;position:relative;}
.visual::after{
  content:"";position:absolute;inset:0;
  background-image:linear-gradient(rgba(10,37,64,.03) 1px,transparent 1px),
                    linear-gradient(90deg,rgba(10,37,64,.03) 1px,transparent 1px);
  background-size:26px 26px;
}
.check-list li{display:flex;gap:10px;margin-bottom:12px;font-size:15px;color:var(--gray-700);align-items:flex-start;}
.check-list li::before{content:"✓";color:var(--teal-600);font-weight:800;flex-shrink:0;}

/* ===================== TABLE (compact technical reference) ===================== */
.table-wrap{overflow-x:auto;border:1px solid var(--gray-100);border-radius:var(--radius-md);box-shadow:var(--shadow-sm);}
table.ref-table{width:100%;border-collapse:collapse;font-size:14px;min-width:640px;}
table.ref-table th{
  background:var(--navy-900);color:var(--white);text-align:left;padding:13px 16px;font-weight:600;
}
table.ref-table td{padding:12px 16px;border-top:1px solid var(--gray-100);color:var(--gray-700);}
table.ref-table tr:nth-child(even){background:var(--gray-50);}

details.tech-panel{border:1px solid var(--gray-100);border-radius:var(--radius-md);padding:20px 24px;background:var(--gray-50);}
details.tech-panel summary{cursor:pointer;font-weight:700;color:var(--navy-900);font-size:16px;list-style:none;display:flex;align-items:center;justify-content:space-between;}
details.tech-panel summary::-webkit-details-marker{display:none;}
details.tech-panel summary::after{content:"+";font-size:22px;color:var(--teal-600);}
details.tech-panel[open] summary::after{content:"–";}
details.tech-panel .inner{margin-top:18px;}

/* ===================== CTA BANNER ===================== */
.cta-banner{
  background:linear-gradient(120deg,var(--teal-600),var(--navy-800));
  border-radius:var(--radius-lg);color:var(--white);padding:56px 48px;
  display:flex;align-items:center;justify-content:space-between;gap:32px;flex-wrap:wrap;
}
.cta-banner h2{color:var(--white);font-size:26px;margin-bottom:8px;}
.cta-banner p{color:rgba(255,255,255,.85);margin-bottom:0;max-width:520px;}

/* ===================== FOOTER ===================== */
.site-footer{background:var(--navy-900);color:rgba(255,255,255,.78);padding:64px 0 28px;}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:40px;}
@media (max-width:900px){.footer-grid{grid-template-columns:1fr 1fr;}}
@media (max-width:560px){.footer-grid{grid-template-columns:1fr;}}
.footer-grid h4{color:var(--white);font-size:14.5px;text-transform:uppercase;letter-spacing:.06em;margin-bottom:16px;}
.footer-grid li{margin-bottom:10px;font-size:14.5px;}
.footer-grid a:hover{color:var(--teal-500);}
.footer-logo{display:flex;align-items:center;gap:10px;font-weight:800;font-size:19px;color:var(--white);margin-bottom:14px;}
.footer-bottom{
  border-top:1px solid rgba(255,255,255,.12);margin-top:44px;padding-top:22px;
  display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;font-size:13px;color:rgba(255,255,255,.5);
}

/* Utility */
.mt-0{margin-top:0;}
.text-center{text-align:center;}
.badge-row{display:flex;flex-wrap:wrap;gap:10px;margin-top:8px;}
.badge{
  font-size:12.5px;font-weight:700;background:var(--gray-100);color:var(--navy-800);
  padding:6px 12px;border-radius:999px;
}

/* ===================== CONTACT ===================== */
.contact-grid{display:grid;grid-template-columns:.9fr 1.1fr;gap:48px;align-items:start;}
@media (max-width:900px){.contact-grid{grid-template-columns:1fr;}}
.contact-info-card{
  background:var(--navy-900);color:#fff;border-radius:var(--radius-lg);padding:36px 32px;
}
.contact-info-card h3{color:#fff;font-size:20px;}
.contact-line{display:flex;gap:14px;align-items:flex-start;margin-bottom:22px;}
.contact-line .ic{
  width:40px;height:40px;border-radius:10px;background:rgba(255,255,255,.12);
  display:flex;align-items:center;justify-content:center;font-size:18px;flex-shrink:0;
}
.contact-line .label{font-size:12.5px;color:rgba(255,255,255,.6);text-transform:uppercase;letter-spacing:.05em;margin-bottom:2px;}
.contact-line a, .contact-line span.val{font-size:15.5px;font-weight:600;color:#fff;}

.form-card{background:var(--white);border:1px solid var(--gray-100);border-radius:var(--radius-lg);padding:36px 32px;box-shadow:var(--shadow-sm);}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:18px;}
@media (max-width:560px){.form-row{grid-template-columns:1fr;}}
.form-group{margin-bottom:18px;}
.form-group label{display:block;font-size:13.5px;font-weight:700;color:var(--navy-900);margin-bottom:7px;}
.form-group input, .form-group select, .form-group textarea{
  width:100%;padding:12px 14px;border:1.5px solid var(--gray-300);border-radius:8px;
  font-family:inherit;font-size:14.5px;color:var(--gray-900);background:var(--white);
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus{
  outline:none;border-color:var(--teal-500);
}
.form-group textarea{resize:vertical;min-height:110px;}
.form-note{font-size:13px;color:var(--gray-500);margin-top:10px;}

/* Mobile nav panel */
.mobile-panel{
  display:none;position:fixed;inset:76px 0 0 0;background:var(--white);z-index:99;
  overflow-y:auto;padding:24px;
}
.mobile-panel.open{display:block;}
.mobile-panel a{display:block;padding:14px 6px;font-weight:600;font-size:16px;border-bottom:1px solid var(--gray-100);}
.mobile-panel .sub a{padding-left:20px;font-weight:500;color:var(--gray-700);font-size:15px;}