:root{
  --bg:#f5f6fa;
  --card:#ffffff;
  --text:#111827;
  --muted:#6b7280;
  --line:#e5e7eb;
  --brand:#2563eb;
  --shadow:0 12px 30px rgba(17,24,39,.06);
}

*{box-sizing:border-box}
html, body { height: 100%; }

body{
  margin:0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial;
  background:var(--bg);
  color:var(--text);
}

a{color:inherit;text-decoration:none}
img{display:block}

/* ===== GLOBAL WRAPPER ===== */
.site-wrap{
  max-width:1040px;
  margin:0 auto;
  padding:0 16px;
}
@media (min-width:768px){
  .site-wrap{padding:0 24px}
}

.site-main{
  flex: 1;           /* đẩy footer xuống đáy */
  padding:16px 0;
}
@media (min-width:768px){
  .site-main{padding:24px 0}
}

/* ===== HEADER ===== */
.site-header{
  position:sticky;
  top:0;
  z-index:100;
  background:rgba(255,255,255,.88);
  backdrop-filter:blur(10px);
  border-bottom:1px solid var(--line);
}

.site-header .site-wrap{
  display:flex;
  align-items:center;
  gap:14px;
  padding:10px 16px;
}
@media (min-width:768px){
  .site-header .site-wrap{padding:12px 24px}
}

/* logo */
.brand{
  display:flex;
  align-items:center;
  gap:10px;
  min-width:0;
}
.brand-logo{
  width:38px;
  height:38px;
  border-radius:10px;
  object-fit:cover;
  border:1px solid var(--line);
  background:#fff;
}
.brand-text{min-width:0}
.brand-title{
  font-weight:900;
  letter-spacing:.3px;
}
.brand-sub{
  font-size:12px;
  color:var(--muted);
  margin-top:2px;
}

/* nav */
.nav{
  display:none;
  gap:10px;
  margin-left:6px;
}
.nav a{
  font-size:13px;
  color:var(--muted);
  padding:8px 10px;
  border-radius:10px;
}
.nav a:hover{
  background:#f3f4f6;
  color:var(--text);
}
@media (min-width:760px){
  .nav{display:flex}
}

/* search */
.top-search{
  margin-left:auto;
  width:min(360px, 44vw);
}
.top-search input{
  width:100%;
  padding:10px 12px;
  border:1px solid var(--line);
  border-radius:12px;
  outline:none;
  background:#fff;
  font-size:14px;
}
.top-search input:focus{
  border-color:rgba(37,99,235,.45);
}

/* ===== FOOTER ===== */
.site-footer{
  margin-top:0px;
  background:#fff;
  border-top:1px solid var(--line);
}

.footer-wrap{
  padding:18px 16px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
}
@media (min-width:768px){
  .footer-wrap{padding:20px 24px}
}

.footer-title{
  font-weight:900;
}
.footer-sub{
  font-size:12px;
  color:var(--muted);
  margin-top:2px;
}

.footer-links{
  display:flex;
  gap:12px;
  flex-wrap:wrap;
}
.footer-links a{
  font-size:13px;
  color:var(--muted);
}
.footer-links a:hover{
  color:var(--brand);
}

/* ===== UTIL ===== */
.hidden{display:none}