/* ===== Design tokens ===== */
:root{
  --red-600:#c8102e;
  --red-700:#a30d25;
  --red-100:#fdeceb;
  --navy-900:#0e1b2c;
  --navy-800:#152840;
  --navy-700:#1c3454;
  --gray-900:#1a1f27;
  --gray-600:#5b6472;
  --gray-300:#dde2e8;
  --gray-100:#f5f7fa;
  --white:#ffffff;
  --gold:#e8a33d;

  --font:'Be Vietnam Pro', 'Segoe UI', Roboto, Arial, sans-serif;
  --container:1200px;
  --radius:14px;
  --shadow-sm:0 2px 10px rgba(14,27,44,.06);
  --shadow-md:0 10px 30px rgba(14,27,44,.10);
  --shadow-lg:0 20px 50px rgba(14,27,44,.16);
  --transition:.3s cubic-bezier(.4,0,.2,1);
}

/* ===== Reset ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0;}
html{scroll-behavior:smooth;}
body{
  font-family:var(--font);
  color:var(--gray-900);
  background:var(--white);
  line-height:1.6;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img{max-width:100%;display:block;}
a{text-decoration:none;color:inherit;}
ul{list-style:none;}
button{font-family:inherit;cursor:pointer;border:none;background:none;}
input,textarea{font-family:inherit;}
h1,h2,h3,h4{line-height:1.25;font-weight:700;}
.sprite{position:absolute;width:0;height:0;overflow:hidden;}
.icon{width:1em;height:1em;display:inline-block;vertical-align:-.15em;fill:none;stroke:currentColor;}

.container{
  width:100%;
  max-width:var(--container);
  margin-inline:auto;
  padding-inline:24px;
}

/* ===== Buttons ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:14px 30px;border-radius:999px;font-weight:600;font-size:15px;
  transition:transform var(--transition), box-shadow var(--transition), background var(--transition), color var(--transition);
  white-space:nowrap;
}
.btn--primary{background:var(--red-600);color:var(--white);box-shadow:var(--shadow-sm);}
.btn--primary:hover{background:var(--red-700);transform:translateY(-2px);box-shadow:var(--shadow-md);}
.btn--outline{border:2px solid rgba(255,255,255,.7);color:var(--white);}
.btn--outline:hover{background:rgba(255,255,255,.15);transform:translateY(-2px);}
.btn--white{background:var(--white);color:var(--red-600);}
.btn--white:hover{transform:translateY(-2px);box-shadow:var(--shadow-md);}
.btn--outline-dark{background:var(--white);border:2px solid var(--gray-300);color:var(--navy-900);}
.btn--outline-dark:hover{border-color:var(--navy-900);background:var(--gray-300);transform:translateY(-2px);}
.btn--sm{padding:10px 20px;font-size:14px;}
.btn--block{width:100%;}

/* ===== Top bar ===== */
.topbar{background:var(--navy-900);color:#c9d3e0;font-size:13.5px;}
.topbar__inner{display:flex;align-items:center;justify-content:space-between;height:40px;}
.topbar__info{display:flex;gap:22px;align-items:center;}
.topbar__info span{display:inline-flex;align-items:center;gap:6px;}
.topbar__info a{color:#fff;font-weight:600;}
.topbar__social{display:flex;gap:10px;}
.topbar__social a{width:24px;height:24px;border-radius:50%;background:rgba(255,255,255,.1);display:flex;align-items:center;justify-content:center;font-size:10px;font-weight:700;transition:background var(--transition);}
.topbar__social a:hover{background:var(--red-600);}

/* ===== Header ===== */
.header{
  position:sticky;top:0;z-index:100;
  background:var(--white);
  box-shadow:var(--shadow-sm);
  transition:box-shadow var(--transition);
}
.header__inner{display:flex;align-items:center;justify-content:space-between;height:76px;gap:24px;}

.logo{display:flex;flex-direction:column;line-height:1;}
.logo__mark{font-size:24px;font-weight:800;color:var(--navy-900);letter-spacing:.5px;}
.logo__mark::after{content:'';}
.logo__sub{font-size:11px;letter-spacing:2px;color:var(--red-600);font-weight:700;margin-top:2px;}

.nav__list{display:flex;align-items:center;gap:8px;}
.nav__list > li > a{
  display:flex;align-items:center;gap:4px;
  padding:10px 14px;font-weight:600;font-size:15px;color:var(--gray-900);
  border-radius:8px;transition:color var(--transition), background var(--transition);
}
.nav__list > li > a:hover,.nav__list > li > a.active{color:var(--red-600);background:var(--red-100);}
.caret{width:7px;height:7px;border-right:2px solid currentColor;border-bottom:2px solid currentColor;transform:rotate(45deg);margin-top:-3px;}

.has-dropdown{position:relative;}
.dropdown{
  position:absolute;top:100%;left:0;min-width:260px;background:var(--white);
  border-radius:12px;box-shadow:var(--shadow-lg);padding:10px;
  opacity:0;visibility:hidden;transform:translateY(8px);
  transition:opacity var(--transition), transform var(--transition), visibility var(--transition);
}
.has-dropdown:hover .dropdown{opacity:1;visibility:visible;transform:translateY(0);}
.dropdown li a{display:block;padding:10px 14px;border-radius:8px;font-size:14px;color:var(--gray-900);font-weight:500;transition:background var(--transition),color var(--transition);}
.dropdown li a:hover{background:var(--red-100);color:var(--red-600);}

.header__actions{display:flex;align-items:center;gap:16px;}
.burger{display:none;flex-direction:column;gap:5px;width:32px;height:24px;position:relative;z-index:210;}
.burger span{display:block;height:2px;width:100%;background:var(--navy-900);border-radius:2px;transition:transform var(--transition), opacity var(--transition);}
.burger.is-open span:nth-child(1){transform:translateY(7px) rotate(45deg);}
.burger.is-open span:nth-child(2){opacity:0;}
.burger.is-open span:nth-child(3){transform:translateY(-7px) rotate(-45deg);}
.has-dropdown.is-open .caret{transform:rotate(225deg);margin-top:3px;}

/* ===== Hero slider ===== */
.hero{position:relative;overflow:hidden;padding:0;}
.slider{position:relative;height:calc(100vh - 116px);min-height:560px;}
.slide{
  position:absolute;inset:0;display:flex;align-items:center;
  opacity:0;visibility:hidden;transform:scale(1.04);
  transition:opacity .9s ease, transform 1.2s ease, visibility .9s;
  color:var(--white);
}
.slide.is-active{opacity:1;visibility:visible;transform:scale(1);}
.slide::before{content:'';position:absolute;inset:0;z-index:0;background:linear-gradient(120deg, rgba(14,27,44,.92) 10%, rgba(14,27,44,.55) 60%, rgba(14,27,44,.25));}
.slide--1{background:linear-gradient(135deg,#1c3454,#0e1b2c 70%);}
.slide--2{background:linear-gradient(135deg,#2b1216,#0e1b2c 70%);}
.slide--3{background:linear-gradient(135deg,#3a0d12,#0e1b2c 70%);}
.slide__content{position:relative;z-index:1;max-width:640px;}
.slide__tag{color:var(--gold);font-weight:700;letter-spacing:3px;font-size:13px;margin-bottom:16px;}
.slide h1,.slide__heading{font-size:clamp(30px,4.5vw,52px);margin-bottom:18px;}
/* .slide__heading: dùng cho slide thứ 2 trở đi (thẻ <p>, không phải <h1>)
   để mỗi trang chỉ có đúng 1 thẻ H1 nhưng vẫn giữ nguyên hình thức hiển thị. */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0;}
.slide__desc{font-size:17px;color:#dfe6ee;margin-bottom:30px;max-width:520px;}
.slide__actions{display:flex;gap:16px;flex-wrap:wrap;}

.slider__nav{
  position:absolute;top:50%;translate:0 -50%;z-index:2;
  width:46px;height:46px;border-radius:50%;
  background:rgba(255,255,255,.12);color:var(--white);font-size:16px;
  display:flex;align-items:center;justify-content:center;
  transition:background var(--transition);
}
.slider__nav:hover{background:rgba(255,255,255,.28);}
.slider__nav--prev{left:24px;}
.slider__nav--next{right:24px;}
.slider__dots{position:absolute;bottom:26px;left:50%;translate:-50% 0;z-index:2;display:flex;gap:10px;}
.slider__dots button{width:10px;height:10px;border-radius:50%;background:rgba(255,255,255,.4);transition:background var(--transition), width var(--transition);}
.slider__dots button.is-active{background:var(--red-600);width:26px;border-radius:6px;}

/* ===== Stats ===== */
.stats{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;}
.stat__num,.stat__plus{font-size:clamp(28px,3.4vw,42px);font-weight:800;color:var(--gold);}
.stat p{margin-top:8px;color:#c9d3e0;font-size:14.5px;}

/* ===== Section shared ===== */
section{padding:88px 0;}
.eyebrow{color:var(--red-600);font-weight:700;letter-spacing:2px;font-size:13px;text-transform:uppercase;margin-bottom:10px;}
.section-head{max-width:640px;margin-bottom:48px;}
.section-head h2{font-size:clamp(26px,3.2vw,38px);color:var(--navy-900);margin-bottom:14px;}
.section-desc{color:var(--gray-600);font-size:16px;}
.section-head--light .eyebrow{color:var(--gold);}
.section-head--light h2{color:var(--white);}
.section-head--row{
  max-width:none;display:flex;align-items:center;justify-content:space-between;gap:24px;flex-wrap:wrap;
}
.section-head--row h2{margin-bottom:0;}

/* ===== About ===== */
.about{background:var(--gray-100);}
.about__grid{display:grid;grid-template-columns:.85fr 1.15fr;gap:64px;align-items:center;}
.about__frame{
  background:linear-gradient(160deg,var(--navy-800),var(--navy-900));
  border-radius:24px;padding:40px;box-shadow:var(--shadow-lg);
  display:flex;align-items:center;justify-content:center;aspect-ratio:4/4.6;
}
.door-illustration{width:60%;height:auto;}
.door-frame{fill:none;stroke:var(--gold);stroke-width:3;}
.door-panel{fill:rgba(255,255,255,.04);stroke:rgba(255,255,255,.35);stroke-width:2;}
.door-glass{fill:rgba(232,163,61,.18);stroke:rgba(232,163,61,.6);stroke-width:1.5;}
.door-handle{fill:var(--gold);}
.about__lead{color:var(--gray-600);margin-bottom:24px;font-size:16px;}
.about__list{margin-bottom:30px;}
.about__list li{display:flex;align-items:flex-start;gap:10px;margin-bottom:12px;font-size:15px;color:var(--gray-900);}
.about__list .icon{color:var(--red-600);margin-top:3px;flex-shrink:0;}

/* ===== Products ===== */
.product-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px;}
.product-card{
  background:var(--white);border:1px solid var(--gray-300);border-radius:var(--radius);
  padding:32px 28px;transition:transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.product-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-md);border-color:transparent;}
.product-card__icon{
  width:56px;height:56px;border-radius:14px;background:var(--red-100);color:var(--red-600);
  display:flex;align-items:center;justify-content:center;font-size:26px;margin-bottom:20px;
}
.product-card--fire .product-card__icon{background:var(--navy-900);color:var(--gold);}
.product-card h3{font-size:18.5px;margin-bottom:10px;color:var(--navy-900);}
.product-card p{color:var(--gray-600);font-size:14.5px;margin-bottom:16px;}
.card-link{font-weight:700;font-size:14px;color:var(--red-600);}
.card-link:hover{text-decoration:underline;}

/* ===== Solutions ===== */
.solutions{background:var(--navy-900);color:var(--white);}
.solution-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;}
.solution-card{
  background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);
  padding:30px 24px;text-align:center;transition:background var(--transition), transform var(--transition);
}
.solution-card:hover{background:rgba(255,255,255,.08);transform:translateY(-6px);}
.solution-card .icon{width:38px;height:38px;color:var(--gold);margin-bottom:16px;}
.solution-card h3{font-size:17px;margin-bottom:8px;}
.solution-card p{color:#b7c1cf;font-size:14px;}

/* ===== Projects ===== */
.project-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px;}
.project-card{border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow-sm);transition:box-shadow var(--transition), transform var(--transition);}
.project-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-md);}
.project-card__media{display:block;aspect-ratio:4/3;position:relative;}
.project-card__media--1{background:linear-gradient(150deg,#274361,#0e1b2c);}
.project-card__media--2{background:linear-gradient(150deg,#5c1b22,#0e1b2c);}
.project-card__media--3{background:linear-gradient(150deg,#3d3116,#0e1b2c);}
.project-card__media--4{background:linear-gradient(150deg,#1c3d33,#0e1b2c);}
.project-card__body{padding:18px 20px;background:var(--white);}
.tag{display:inline-block;background:var(--red-100);color:var(--red-600);font-size:12px;font-weight:700;padding:4px 10px;border-radius:999px;margin-bottom:10px;}
.project-card__body h3{font-size:16.5px;color:var(--navy-900);margin-bottom:4px;}
.project-card__body p{font-size:13.5px;color:var(--gray-600);}

/* ===== News ===== */
.news{background:var(--gray-100);}
.news-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:28px;}
.news-card{background:var(--white);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow-sm);transition:transform var(--transition), box-shadow var(--transition);}
.news-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-md);}
.news-card__media{display:block;aspect-ratio:16/10;}
.news-card__media--1{background:linear-gradient(150deg,#a30d25,#0e1b2c);}
.news-card__media--2{background:linear-gradient(150deg,#274361,#0e1b2c);}
.news-card__media--3{background:linear-gradient(150deg,#3d3116,#0e1b2c);}
.news-card__body{padding:22px 24px;}
.news-card__meta-row{display:flex;align-items:center;flex-wrap:wrap;gap:10px;margin-bottom:10px;}
.news-card__date{color:var(--red-600);font-weight:700;font-size:12.5px;display:inline-flex;align-items:center;gap:6px;}
.tag--sm{display:inline-flex;align-items:center;margin:0;background:var(--white);box-shadow:var(--shadow-sm);}
.news-card__body h3{font-size:17px;margin:10px 0;color:var(--navy-900);}
.news-card__body p{color:var(--gray-600);font-size:14px;margin-bottom:14px;}

/* ===== CTA ===== */
.cta{background:linear-gradient(120deg,var(--red-600),var(--red-700));color:var(--white);padding:56px 0;}
.cta__inner{display:flex;align-items:center;justify-content:space-between;gap:24px;flex-wrap:wrap;}
.cta h2{font-size:clamp(22px,2.6vw,30px);margin-bottom:8px;}
.cta p{color:#ffe1e1;}

/* ===== Contact ===== */
.contact__grid{display:grid;grid-template-columns:1fr 1fr;gap:64px;}
.contact__list{margin-top:24px;}
.contact__list li{display:flex;align-items:center;gap:12px;margin-bottom:16px;font-size:15px;color:var(--gray-900);}
.contact__list .icon{color:var(--red-600);width:20px;height:20px;flex-shrink:0;}
.contact__form{background:var(--gray-100);padding:36px;border-radius:var(--radius);display:flex;flex-direction:column;gap:16px;}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:16px;}
.form-field{display:flex;flex-direction:column;gap:6px;}
.form-field label{font-size:13.5px;font-weight:600;color:var(--navy-900);}
.contact__form input,.contact__form textarea{
  width:100%;padding:14px 16px;border-radius:10px;border:1px solid var(--gray-300);
  background:var(--white);color:var(--gray-900);font-size:14.5px;transition:border-color var(--transition);
}
.contact__form input:focus,.contact__form textarea:focus{outline:none;border-color:var(--red-600);}
.form-note{font-size:13.5px;color:var(--red-600);font-weight:600;min-height:18px;}

/* ===== Footer ===== */
.footer{background:var(--navy-900);color:#b7c1cf;padding-top:64px;}
.footer__grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1.2fr;gap:40px;padding-bottom:48px;}
.logo--footer .logo__mark{color:var(--white);}
.footer__col p{font-size:14px;margin:14px 0;line-height:1.7;}
.footer__social{display:flex;gap:10px;margin-top:14px;}
.footer__social a{width:32px;height:32px;border-radius:50%;background:rgba(255,255,255,.08);display:flex;align-items:center;justify-content:center;font-size:11px;font-weight:700;color:var(--white);transition:background var(--transition);}
.footer__social a:hover{background:var(--red-600);}
.footer__col h3{color:var(--white);font-size:16px;margin-bottom:18px;}
.footer__col ul li{margin-bottom:11px;}
.footer__col ul a{font-size:14px;transition:color var(--transition);}
.footer__col ul a:hover{color:var(--white);}
.footer__subscribe{display:flex;margin-top:16px;border-radius:999px;overflow:hidden;background:rgba(255,255,255,.06);}
.footer__subscribe input{flex:1;background:transparent;border:none;padding:12px 16px;color:var(--white);font-size:13.5px;}
.footer__subscribe input::placeholder{color:#8b96a6;}
.footer__subscribe button{background:var(--red-600);color:var(--white);padding:0 20px;font-weight:700;font-size:13.5px;transition:background var(--transition);}
.footer__subscribe button:hover{background:var(--red-700);}
.footer__bottom{border-top:1px solid rgba(255,255,255,.08);padding:22px 0;font-size:13px;text-align:center;color:#8b96a6;}

/* ===== Back to top ===== */
.back-to-top{
  position:fixed;right:24px;bottom:24px;z-index:200;
  width:46px;height:46px;border-radius:50%;background:var(--red-600);color:var(--white);
  display:flex;align-items:center;justify-content:center;font-size:18px;box-shadow:var(--shadow-md);
  opacity:0;visibility:hidden;transform:translateY(10px);
  transition:opacity var(--transition), transform var(--transition), visibility var(--transition), background var(--transition);
}
.back-to-top.is-visible{opacity:1;visibility:visible;transform:translateY(0);}
.back-to-top:hover{background:var(--red-700);}

/* ===== Reveal animation ===== */
[data-reveal]{opacity:0;transform:translateY(24px);transition:opacity .7s ease, transform .7s ease;}
[data-reveal].is-visible{opacity:1;transform:translateY(0);}

/* ===== Mobile menu open state ===== */
body.menu-open{overflow:hidden;}
.nav-overlay{
  position:fixed;inset:0;background:rgba(14,27,44,.5);z-index:99;
  opacity:0;visibility:hidden;transition:opacity var(--transition), visibility var(--transition);
}
.nav-overlay.is-active{opacity:1;visibility:visible;}

/* ===== Responsive ===== */
@media (max-width:1080px){
  .about__grid{grid-template-columns:1fr;}
  .about__frame{max-width:360px;margin-inline:auto;}
  .product-grid{grid-template-columns:repeat(2,1fr);}
  .solution-grid,.project-grid{grid-template-columns:repeat(2,1fr);}
  .news-grid{grid-template-columns:repeat(2,1fr);}
  .footer__grid{grid-template-columns:1fr 1fr;}
}

@media (max-width:860px){
  .topbar__info span:nth-child(3){display:none;}
  .nav{
    position:fixed;top:0;right:-100%;height:100vh;width:min(320px,84vw);
    background:var(--white);box-shadow:var(--shadow-lg);
    padding:100px 28px 28px;transition:right var(--transition);
    overflow-y:auto;
  }
  .nav.is-open{right:0;}
  .nav__list{flex-direction:column;align-items:stretch;gap:4px;}
  .nav__list > li > a{justify-content:space-between;}
  .dropdown{position:static;opacity:1;visibility:visible;transform:none;box-shadow:none;display:none;padding-left:12px;}
  .has-dropdown.is-open .dropdown{display:block;}
  .burger{display:flex;}
  .header__actions .btn{display:none;}
  .stats__grid{grid-template-columns:repeat(2,1fr);gap:32px;}
  .contact__grid{grid-template-columns:1fr;}
  .form-row{grid-template-columns:1fr;}
  .cta__inner{justify-content:center;text-align:center;}
}

@media (max-width:600px){
  section{padding:60px 0;}
  .product-grid,.solution-grid,.project-grid,.news-grid{grid-template-columns:1fr;}
  .footer__grid{grid-template-columns:1fr;}
  .slider__nav{width:38px;height:38px;}
  .slide__actions{flex-direction:column;align-items:flex-start;}
}