:root{
  --xanh:#0d4f8b; --xanh-dam:#0a3a66; --xanh-nhat:#e8f1fa;
  --cam:#f6921e; --xam:#5b6b7b; --den:#1b2430; --vien:#e3e3e3;
}
*{box-sizing:border-box;margin:0;padding:0}
body{font-family:'Segoe UI',Arial,sans-serif;color:var(--den);line-height:1.6;background:#fff}
a{text-decoration:none;color:inherit}
img{max-width:100%;display:block}
.wrap{max-width:1100px;margin:0 auto;padding:0 16px}
h2.section-title{font-size:26px;text-align:center;color:var(--xanh);margin-bottom:6px}
.section-sub{text-align:center;color:var(--xam);margin-bottom:30px}
section{padding:48px 0}

/* HEADER */
header{background:#fff;border-bottom:1px solid #eee;position:sticky;top:0;z-index:50}
.top-bar{display:flex;align-items:center;justify-content:space-between;padding:12px 0;gap:10px}
.logo{font-weight:800;color:var(--xanh);font-size:17px;line-height:1.2}
.logo span{color:var(--cam)}
nav.menu{display:flex;align-items:center}
nav.menu a{margin:0 10px;font-weight:600;color:var(--den);font-size:15px}
nav.menu a:hover,nav.menu a.active{color:var(--cam)}
.hotline-top{background:var(--cam);color:#fff;padding:8px 16px;border-radius:30px;font-weight:700;white-space:nowrap}
.hamburger{display:none;background:none;border:none;font-size:28px;color:var(--xanh);cursor:pointer;line-height:1}

/* HERO */
.hero{background:linear-gradient(135deg,var(--xanh),var(--xanh-dam));color:#fff;text-align:center;padding:60px 0}
.hero h1{font-size:34px;margin-bottom:14px}
.hero p{font-size:18px;max-width:680px;margin:0 auto 26px;opacity:.95}
.btn{display:inline-block;padding:14px 28px;border-radius:30px;font-weight:700;font-size:17px;margin:6px;cursor:pointer;border:none}
.btn-cam{background:var(--cam);color:#fff}
.btn-vien{border:2px solid #fff;color:#fff;background:transparent}
.btn-xanh{background:var(--xanh);color:#fff}
.btn:hover{opacity:.9}

/* GRID CARDS */
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:18px}
.card{border:1px solid #eee;border-radius:12px;padding:22px;text-align:center;transition:.2s;background:#fff}
.card:hover{box-shadow:0 8px 24px rgba(0,0,0,.08);transform:translateY(-3px)}
.card .ico{font-size:38px}
.card h3{margin:10px 0 6px;color:var(--xanh);font-size:18px}
.card p{color:var(--xam);font-size:14px}

.why{background:var(--xanh-nhat)}
.why .grid .card{border:none}

/* QUY TRINH */
.steps{display:flex;flex-wrap:wrap;gap:16px;justify-content:center}
.step{flex:1 1 180px;text-align:center;padding:16px}
.step .num{width:46px;height:46px;border-radius:50%;background:var(--cam);color:#fff;font-weight:800;font-size:20px;display:flex;align-items:center;justify-content:center;margin:0 auto 10px}

/* BANG GIA */
table{width:100%;border-collapse:collapse;margin-top:10px}
th,td{border:1px solid var(--vien);padding:12px;text-align:left}
th{background:var(--xanh);color:#fff}
tr:nth-child(even){background:#f7f9fb}
.note{text-align:center;color:var(--xam);font-size:13px;margin-top:10px;font-style:italic}

/* BAI VIET (BLOG) */
.post-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:22px}
.post-card{border:1px solid #eee;border-radius:12px;overflow:hidden;transition:.2s;background:#fff;display:flex;flex-direction:column}
.post-card:hover{box-shadow:0 8px 24px rgba(0,0,0,.1);transform:translateY(-3px)}
.post-card .thumb{height:170px;background:var(--xanh-nhat) center/cover no-repeat;display:flex;align-items:center;justify-content:center;font-size:46px;color:#9bb7d4}
.post-card .body{padding:16px;flex:1;display:flex;flex-direction:column}
.post-card h3{color:var(--xanh);font-size:18px;margin-bottom:8px}
.post-card .meta{color:var(--xam);font-size:13px;margin-bottom:8px}
.post-card p{color:var(--xam);font-size:14px;flex:1}
.post-card .more{color:var(--cam);font-weight:700;margin-top:10px}
.empty{text-align:center;color:var(--xam);padding:30px}

/* GALLERY */
.gallery{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px}
.gallery img{width:100%;height:210px;object-fit:cover;border-radius:12px;border:1px solid #e3e3e3;background:#fff;transition:.2s}
.gallery img:hover{box-shadow:0 8px 24px rgba(0,0,0,.12);transform:translateY(-3px)}

/* ARTICLE PAGE */
.article{max-width:780px;margin:0 auto}
.article h1{color:var(--xanh);font-size:30px;margin-bottom:8px}
.article .meta{color:var(--xam);font-size:14px;margin-bottom:18px}
.article img.cover{width:100%;border-radius:12px;margin-bottom:20px}
.article .content{font-size:17px;line-height:1.8}
.article .content p{margin-bottom:16px}
.article .content img{width:100%;border-radius:12px;margin:14px 0}
.article .content h2{color:var(--xanh);margin:22px 0 10px}
.article .content blockquote{border-left:4px solid var(--cam);background:var(--xanh-nhat);padding:12px 16px;border-radius:6px;margin:16px 0;font-style:italic}
.video{position:relative;padding-bottom:56.25%;height:0;margin:18px 0;border-radius:12px;overflow:hidden;background:#000}
.video iframe{position:absolute;top:0;left:0;width:100%;height:100%;border:0}
.tags{display:flex;flex-wrap:wrap;gap:8px;margin:6px 0 18px}
.tags .tag{background:var(--xanh-nhat);color:var(--xanh);font-size:13px;font-weight:600;padding:5px 12px;border-radius:20px}
.back{display:inline-block;margin-bottom:20px;color:var(--cam);font-weight:700}

/* LIEN HE */
.lienhe{background:var(--den);color:#fff}
.lienhe .grid2{display:grid;grid-template-columns:1fr 1fr;gap:30px}
.lienhe h2.section-title{color:#fff}
.lienhe input,.lienhe textarea{width:100%;padding:12px;margin-bottom:12px;border:none;border-radius:8px;font-size:15px;font-family:inherit}
.lienhe button{background:var(--cam);color:#fff;border:none;padding:14px;width:100%;border-radius:8px;font-weight:700;font-size:16px;cursor:pointer}
.lienhe .info p{margin-bottom:10px}
.lienhe .info b{color:var(--cam)}
.map{margin-top:26px}

footer{background:#10171f;color:#9fb0c0;text-align:center;padding:24px 0;font-size:14px}

/* NUT NOI */
.float{position:fixed;right:16px;bottom:16px;z-index:99;display:flex;flex-direction:column;gap:12px}
.float a{width:56px;height:56px;border-radius:50%;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:13px;box-shadow:0 4px 12px rgba(0,0,0,.3);animation:pulse 1.5s infinite}
.f-goi{background:#16a34a}
.f-zalo{background:#0068ff}
@keyframes pulse{0%{transform:scale(1)}50%{transform:scale(1.08)}100%{transform:scale(1)}}

/* ===== ADMIN ===== */
.admin-bg{background:#f0f4f8;min-height:100vh}
.admin-head{background:var(--xanh);color:#fff;padding:14px 0}
.admin-head .wrap{display:flex;justify-content:space-between;align-items:center}
.admin-head a{color:#cfe0f0;font-weight:600}
.panel{background:#fff;border-radius:12px;padding:26px;box-shadow:0 4px 16px rgba(0,0,0,.06);margin-bottom:24px}
.panel h2{color:var(--xanh);margin-bottom:16px;font-size:22px}
.field{margin-bottom:16px}
.field label{display:block;font-weight:600;margin-bottom:6px}
.field input,.field textarea{width:100%;padding:11px;border:1px solid var(--vien);border-radius:8px;font-size:15px;font-family:inherit}
.field textarea{min-height:160px;resize:vertical}
.thumb-prev{margin-top:10px;max-height:160px;border-radius:8px}
.login-box{max-width:380px;margin:80px auto}
.row-actions button{margin-right:8px;padding:7px 14px;border:none;border-radius:6px;font-weight:600;cursor:pointer;font-size:14px}
.btn-edit{background:#e8f1fa;color:var(--xanh)}
.btn-del{background:#fde8e8;color:#c0392b}
.admin-list-item{display:flex;align-items:center;gap:14px;padding:14px 0;border-bottom:1px solid #eee}
.admin-list-item .ti{flex:1}
.admin-list-item .ti b{display:block}
.admin-list-item .ti small{color:var(--xam)}
.admin-list-item .mini{width:64px;height:48px;border-radius:6px;background:var(--xanh-nhat) center/cover;flex-shrink:0}
.msg{padding:12px;border-radius:8px;margin-bottom:16px;font-weight:600}
.msg.ok{background:#e6f7ec;color:#1e7e45}
.msg.err{background:#fde8e8;color:#c0392b}

/* ===== RESPONSIVE ===== */
@media(max-width:820px){
  .hamburger{display:block}
  nav.menu{position:fixed;top:0;right:-100%;width:75%;max-width:300px;height:100vh;background:#fff;
    flex-direction:column;align-items:flex-start;padding:70px 24px;gap:6px;
    box-shadow:-4px 0 20px rgba(0,0,0,.15);transition:right .25s;z-index:60}
  nav.menu.open{right:0}
  nav.menu a{margin:10px 0;font-size:18px;width:100%;border-bottom:1px solid #f0f0f0;padding-bottom:10px}
  .nav-overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.4);z-index:40}
  .nav-overlay.show{display:block}
}
@media(max-width:680px){
  .hero h1{font-size:25px}
  .hero p{font-size:16px}
  h2.section-title{font-size:22px}
  .lienhe .grid2{grid-template-columns:1fr}
  .logo{font-size:14px}
  .hotline-top{font-size:13px;padding:7px 12px}
  table{font-size:14px}
  th,td{padding:9px}
}