/* ============================================================
   KA CONCEPT — SHARED SITE STYLESHEET
   Dùng chung cho tất cả các trang. Nạp 1 lần:
   <link rel="stylesheet" href="assets/site.css" />
   Chứa: design tokens, reset, typography, utilities, buttons,
   reveal, header, footer, page-hero, breadcrumb, float-zalo.
   CSS riêng của từng trang đặt trong <style> của trang đó.
   ============================================================ */

/* ---------- 1. DESIGN TOKENS ---------- */
:root{
  --navy:        #115889;
  --navy-dark:   #002F67;
  --blue:        #2972B2;
  --blue-soft:   #E6EEF6;
  --bg-soft:     #F4F8FB;
  --ink:         #0E2742;
  --ink-2:       #38506B;
  --muted:       #6B7C93;
  --line:        #E1EAF2;
  --white:       #FFFFFF;
  --gradient:    linear-gradient(135deg, #115889 0%, #2972B2 100%);
  --gradient-dk: linear-gradient(135deg, #002F67 0%, #0E4D80 52%, #2972B2 100%);
  --radius:      14px;
  --radius-lg:   22px;
  --shadow-sm:   0 4px 14px rgba(15,41,66,.06);
  --shadow-md:   0 10px 30px rgba(15,41,66,.10);
  --shadow-lg:   0 20px 50px rgba(15,41,66,.14);
  --container:   1280px;
  --h-font:      "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", sans-serif;
  --b-font:      "Inter", "Be Vietnam Pro", system-ui, sans-serif;
  --serif:       "Cormorant", "Be Vietnam Pro", Georgia, serif;
}

/* ---------- 2. RESET & BASE ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;font-family:var(--b-font);color:var(--ink);background:var(--white);
  font-size:16px;line-height:1.65;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
img{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
button{font-family:inherit;cursor:pointer;border:none;background:none;}
h1,h2,h3,h4,h5{font-family:var(--h-font);color:var(--navy-dark);margin:0 0 .5em;line-height:1.2;font-weight:700;letter-spacing:-.01em;}
h1{font-size:clamp(2rem,4.5vw,3.4rem);font-weight:800;}
h2{font-size:clamp(1.6rem,3vw,2.4rem);}
h3{font-size:clamp(1.15rem,1.6vw,1.4rem);}
p{margin:0 0 1em;color:var(--ink-2);}

/* ---------- 3. LAYOUT UTILITIES ---------- */
.container{width:100%;max-width:var(--container);margin:0 auto;padding:0 24px;}
.section{padding:96px 0;}
.section--soft{background:var(--bg-soft);}
.section--dark{background:var(--gradient-dk);color:var(--white);}
.section-head{text-align:center;max-width:760px;margin:0 auto 56px;}
.section-head .eyebrow,.eyebrow{
  display:inline-block;font-size:.78rem;font-weight:600;letter-spacing:.18em;text-transform:uppercase;
  color:var(--blue);background:var(--blue-soft);padding:6px 14px;border-radius:99px;margin-bottom:14px;
}
.section--dark .section-head .eyebrow{background:rgba(255,255,255,.14);color:#cfe6f5;}
.section--dark h2{color:#fff;}
.section--dark p{color:#cfdcea;}
.section-head p{font-size:1.05rem;color:var(--muted);}

/* .tag — nhãn hạng mục / diện tích */
.tag{display:inline-flex;align-items:center;gap:6px;font-size:.76rem;font-weight:600;letter-spacing:.04em;
  text-transform:uppercase;color:var(--navy);background:var(--blue-soft);padding:5px 12px;border-radius:99px;}
.tag--solid{background:var(--gradient);color:#fff;}
.tag--ghost{background:rgba(255,255,255,.16);color:#fff;backdrop-filter:blur(4px);}

/* ---------- 4. BUTTONS ---------- */
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 26px;border-radius:99px;font-weight:600;font-size:.95rem;
  transition:transform .25s, box-shadow .25s, background .25s;white-space:nowrap;}
.btn--primary{color:#fff;background:var(--gradient);box-shadow:0 8px 22px rgba(41,114,178,.35);}
.btn--primary:hover{transform:translateY(-2px);box-shadow:0 14px 32px rgba(41,114,178,.45);}
.btn--ghost{color:var(--navy);border:1.5px solid var(--navy);}
.btn--ghost:hover{background:var(--navy);color:#fff;}
.btn--white{background:#fff;color:var(--navy);}
.btn--white:hover{transform:translateY(-2px);}
.btn .arrow{display:inline-block;transition:transform .25s;}
.btn:hover .arrow{transform:translateX(4px);}

/* ---------- 5. REVEAL ON SCROLL ---------- */
.reveal{opacity:0;transform:translateY(28px);transition:opacity .8s ease, transform .8s ease;}
.reveal.in{opacity:1;transform:none;}
.reveal.delay-1{transition-delay:.08s;}
.reveal.delay-2{transition-delay:.16s;}
.reveal.delay-3{transition-delay:.24s;}

/* ---------- 6. HEADER ---------- */
.site-header{position:fixed;top:0;left:0;right:0;z-index:100;background:rgba(255,255,255,.96);
  backdrop-filter:saturate(140%) blur(10px);border-bottom:1px solid transparent;transition:box-shadow .25s,border-color .25s;}
.site-header.scrolled{box-shadow:0 6px 24px rgba(15,41,66,.06);border-bottom-color:var(--line);}
.header-inner{display:flex;align-items:center;justify-content:space-between;gap:24px;padding:14px 24px;max-width:var(--container);margin:0 auto;}
.brand{display:flex;align-items:center;gap:12px;}
.brand-logo{height:38px;width:auto;}
.nav{display:flex;align-items:center;gap:28px;}
.nav a{font-size:.94rem;font-weight:500;color:var(--ink);position:relative;padding:6px 0;transition:color .2s;}
.nav a::after{content:"";position:absolute;left:0;bottom:0;height:2px;width:0;background:var(--gradient);transition:width .3s ease;}
.nav a:hover,.nav a.active{color:var(--navy);}
.nav a:hover::after,.nav a.active::after{width:100%;}
.header-cta{display:flex;align-items:center;gap:14px;}
.hotline-btn{display:inline-flex;align-items:center;gap:10px;padding:11px 20px;border-radius:99px;background:var(--gradient);
  color:#fff;font-weight:700;font-size:.95rem;white-space:nowrap;flex-shrink:0;box-shadow:0 8px 22px rgba(41,114,178,.32);
  transition:transform .25s,box-shadow .25s;}
.hotline-btn:hover{transform:translateY(-2px);box-shadow:0 14px 30px rgba(41,114,178,.45);}
.hotline-btn .ico{width:22px;height:22px;border-radius:50%;background:rgba(255,255,255,.22);display:grid;place-items:center;}
.hamburger{display:none;width:42px;height:42px;border-radius:10px;background:var(--bg-soft);align-items:center;justify-content:center;}
.hamburger span{display:block;width:20px;height:2px;background:var(--navy);position:relative;}
.hamburger span::before,.hamburger span::after{content:"";position:absolute;left:0;width:100%;height:2px;background:var(--navy);transition:transform .3s;}
.hamburger span::before{top:-6px;}.hamburger span::after{top:6px;}
.nav-open .hamburger span{background:transparent;}
.nav-open .hamburger span::before{transform:translateY(6px) rotate(45deg);}
.nav-open .hamburger span::after{transform:translateY(-6px) rotate(-45deg);}

/* ---------- 7. PAGE HERO + BREADCRUMB ---------- */
.page-hero{position:relative;margin-top:70px;min-height:440px;display:flex;align-items:center;overflow:hidden;
  background:center/cover no-repeat;}
.page-hero--sm{min-height:340px;}
.page-hero::after{content:"";position:absolute;inset:0;
  background:linear-gradient(105deg, rgba(0,47,103,.9) 0%, rgba(17,88,137,.7) 55%, rgba(14,39,66,.45) 100%);}
.page-hero .container{position:relative;z-index:2;padding-top:70px;padding-bottom:64px;}
.breadcrumb{display:flex;align-items:center;flex-wrap:wrap;gap:10px;color:#bfd6ea;font-size:.85rem;margin-bottom:18px;}
.breadcrumb a:hover{color:#fff;}
.breadcrumb .sep{opacity:.6;}
.breadcrumb .cur{color:#fff;font-weight:600;}
.page-hero h1{color:#fff;max-width:820px;margin-bottom:14px;}
.page-hero .sub{color:#dbe8f4;font-size:1.12rem;max-width:620px;margin:0;}

/* ---------- 8. FOOTER ---------- */
.site-footer{background:#0B2540;color:#cfdcea;padding:72px 0 24px;}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1.3fr;gap:48px;}
.footer-logo{height:40px;width:auto;margin-bottom:20px;}
.footer-brand .name{font-family:var(--h-font);font-weight:800;font-size:1.02rem;color:#fff;letter-spacing:.02em;margin-bottom:4px;}
.footer-brand p{color:#9bb1c7;font-size:.92rem;margin-bottom:20px;}
.socials{display:flex;gap:10px;}
.socials a{width:38px;height:38px;border-radius:50%;background:rgba(255,255,255,.08);display:grid;place-items:center;color:#cfdcea;transition:.25s;}
.socials a:hover{background:var(--gradient);color:#fff;}
.footer-col h4{font-family:var(--h-font);color:#fff;font-size:1rem;margin-bottom:18px;font-weight:700;}
.footer-col ul{list-style:none;margin:0;padding:0;}
.footer-col ul li{margin-bottom:12px;font-size:.92rem;}
.footer-col ul li a,.footer-col ul li{color:#9bb1c7;}
.footer-col ul li a{transition:color .2s;display:inline-flex;align-items:flex-start;gap:8px;}
.footer-col ul li a:hover{color:#fff;}
.footer-col .ico{color:var(--blue);margin-top:3px;flex-shrink:0;}
.footer-bottom{margin-top:48px;padding-top:24px;border-top:1px solid rgba(255,255,255,.08);display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:14px;font-size:.82rem;color:#6c89a8;}
.zalo-inline{display:inline-flex;align-items:center;gap:8px;padding:11px 18px;background:#0068FF;color:#fff;border-radius:10px;font-weight:600;font-size:.9rem;transition:transform .2s;margin-top:6px;}
.zalo-inline:hover{transform:translateY(-2px);}

/* ---------- 9. FLOATING ZALO ---------- */
.float-zalo{position:fixed;right:24px;bottom:24px;z-index:90;width:56px;height:56px;border-radius:50%;background:#0068FF;color:#fff;
  display:grid;place-items:center;font-weight:700;font-size:.7rem;box-shadow:0 10px 24px rgba(0,104,255,.4);animation:pulse 2.4s infinite;}
@keyframes pulse{0%{box-shadow:0 0 0 0 rgba(0,104,255,.5);}70%{box-shadow:0 0 0 18px rgba(0,104,255,0);}100%{box-shadow:0 0 0 0 rgba(0,104,255,0);}}

/* ---------- 9b. LIGHTBOX (dùng cho trang chi tiết dự án) ---------- */
.lb-overlay{position:fixed;inset:0;z-index:200;background:rgba(8,20,36,.94);display:none;align-items:center;justify-content:center;}
.lb-overlay.on{display:flex;}
.lb-img{max-width:90vw;max-height:85vh;border-radius:10px;box-shadow:0 30px 80px rgba(0,0,0,.5);}
.lb-close{position:absolute;top:22px;right:26px;width:46px;height:46px;border-radius:50%;background:rgba(255,255,255,.12);color:#fff;font-size:1.7rem;line-height:1;display:grid;place-items:center;transition:background .2s;}
.lb-close:hover{background:rgba(255,255,255,.25);}
.lb-nav{position:absolute;top:50%;transform:translateY(-50%);width:52px;height:52px;border-radius:50%;background:rgba(255,255,255,.12);color:#fff;font-size:2rem;line-height:1;display:grid;place-items:center;transition:background .2s;}
.lb-nav:hover{background:rgba(255,255,255,.25);}
.lb-prev{left:24px;}.lb-next{right:24px;}
.lb-cap{position:absolute;bottom:24px;left:0;right:0;text-align:center;color:#cfdcea;font-size:.9rem;padding:0 24px;}
@media(max-width:680px){.lb-nav{width:42px;height:42px;font-size:1.5rem;}.lb-prev{left:10px;}.lb-next{right:10px;}}

/* ---------- 10. SHARED RESPONSIVE (header/footer/hero) ---------- */
@media(max-width:1180px) and (min-width:1025px){
  .nav{gap:20px;}.nav a{font-size:.88rem;}.brand-logo{height:34px;}
  .hotline-btn{padding:11px 16px;font-size:.88rem;}
}
@media(max-width:1024px){
  .section{padding:72px 0;}
  .nav{display:none;}
  .hamburger{display:flex;}
  .hotline-btn .txt-long{display:none;}
  .hotline-btn{padding:11px 16px;font-size:.88rem;}
  .footer-grid{grid-template-columns:1fr 1fr;}
  .nav{position:fixed;top:70px;left:0;right:0;flex-direction:column;background:#fff;padding:24px;gap:0;align-items:stretch;
    box-shadow:0 14px 30px rgba(15,41,66,.08);border-top:1px solid var(--line);transform:translateY(-120%);transition:transform .35s ease;}
  .nav-open .nav{display:flex;transform:none;}
  .nav a{padding:14px 0;border-bottom:1px solid var(--line);}
  .nav a:last-child{border-bottom:none;}
  .nav a::after{display:none;}
}
@media(max-width:680px){
  .section{padding:56px 0;}
  .footer-grid{grid-template-columns:1fr;gap:32px;}
  .footer-bottom{flex-direction:column;align-items:flex-start;}
  .hotline-btn span:not(.ico){display:none;}
  .hotline-btn{padding:11px;}
}