:root{
  --bg: #ffffff;
  --muted: #444444;
  --accent: #f88e03; /* cam FPT */
  --accent-2: #ffedd5;
  --card: #ffffff;
  --radius: 14px;
  --maxw: 1600px;
}

*{box-sizing:border-box}
html,body{height:100%;margin:0;padding:0}
body{
  margin:0;
  font-family: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  color: #111827;
  background: linear-gradient(180deg,#7cb2f8,#fff);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  line-height:1.45;
}
.reveal {
  opacity: 0;
  transform: translateY(50px);
  transition: all 0.8s ease-out;
}


.reveal.active {
  opacity: 1;
  transform: translateY(0);
}
#backToTop {
  position: fixed;
  bottom: 30px;
  right: 30px;
  z-index: 99;
  font-size: 18px;
  border: none;
  outline: none;
  background: var(--accent); /* màu cam FPT */
  color: white;
  cursor: pointer;
  padding: 12px 16px;
  border-radius: 50%;
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  display: none; /* ẩn mặc định */
  transition: all 0.3s;
}
#backToTop:hover {
  background: #d97706; /* đậm hơn khi hover */
}
.stats {
  display: flex;
  gap: 50px;
  font-size: 24px;
  font-weight: bold;
}
.stat {
  text-align: center;
}
.num {
  font-size: 28px;
  font-weight: bold;
}

/* Logo */
.logo img {
  height: 50px; /* chỉnh kích thước logo */
  display:block;
}

/* Container giới hạn chiều rộng */
.container{
  max-width:var(--maxw);
  margin:0 auto;
  padding:0 20px;
  width:100%;
}
.card .icon {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  background: var(--accent-2);
  color: var(--accent);
  margin-bottom: 12px;
}

/* NAV */
header{
  background: var(--bg);
  position: fixed;
  top: 0;
  z-index: 40;
  border-bottom: 2px solid #000000;
  backdrop-filter: blur(6px);
  width: 100%;
}
.nav{display:flex;align-items:center;justify-content:space-between;padding:16px 0}
.brand{display:flex;gap:12px;align-items:center}
.brand h1{margin:0;font-size:18px;font-weight:700;letter-spacing:0.2px}
.brand p{margin:0;font-size:12px;color:var(--muted)}

nav.desktop{display:flex;gap:22px;align-items:center}
nav.desktop a{color:inherit;text-decoration:none;font-size:14px}
.btn-primary{
  background: var(--accent);
  color: #fff !important;        /* ép chữ trắng */
  padding: 10px 18px;
  border-radius: 8px;
  border: 0;
  cursor: pointer;
  font-weight: 700;              /* in đậm */
  font-size: 15px;
  transition: all .25s;
}
.btn-primary:hover{
  background: #d97706;           /* đậm hơn khi hover */
}

.btn-ghost{
  background: transparent;
  padding: 10px 18px;
  border-radius: 8px;
  border: 2px solid var(--accent);
  color: var(--accent) !important; /* chữ cam */
  font-weight: 700;                /* in đậm */
  font-size: 15px;
  cursor: pointer;
  transition: all .25s;
}
.btn-ghost:hover{
  background: var(--accent);
  color: #fff !important;         /* hover thì chữ trắng */
}

/* HERO */
.hero{
  width:100%;
  padding:80px 0;
  display:grid;
  grid-template-columns:1fr;
  gap:30px;
  align-items:center;
}
.hero-inner{display:flex;flex-direction:column;gap:18px}
.hero h2{font-size:42px;line-height:1.2;margin:0;font-weight:800}
.hero p{color:var(--muted);margin:0;font-size:18px}
.hero-actions{display:flex;gap:12px;margin-top:12px;flex-wrap:wrap}

.stats{display:flex;gap:18px;margin-top:20px}
.stat{padding:8px 0}
.stat .num{font-weight:700;font-size:22px}
.stat .label{font-size:14px;color:var(--muted)}

.card-visual{
  margin: 20px;
  background:var(--card);
  border-radius:16px;
  padding:16px;
  box-shadow:0 8px 30px rgba(17,24,39,0.06);
}
.card-visual img{width:100%;height:400px;object-fit:cover;border-radius:10px}

/* SECTIONS */
.section{padding:60px 0;width:100%}
.section h3{margin:0;font-size:26px;font-weight:700}
.section p.lead{color:var(--muted);margin-top:6px;font-size:16px}

.grid{display:grid;gap:18px;width:100%}
.grid.cols-4{grid-template-columns:repeat(1,1fr)}
.card{
  background:var(--card);
  border-radius:12px;
  padding:20px;
  border:1px solid #eef2f6;
  transition: all .2s;
}
.card:hover{box-shadow:0 4px 12px rgba(0,0,0,0.08);transform:translateY(-2px)}
.card .icon{
  width:48px;height:48px;
  border-radius:10px;
  display:flex;align-items:center;justify-content:center;
  font-weight:700;
  background:#fff;
  color:var(--accent)
}
.card h4{margin:12px 0 6px 0}
.card p{margin:0;color:var(--muted);font-size:14px}

/* CASES */
.cases-grid{display:grid;grid-template-columns:1fr;gap:18px}
.case{border-radius:12px;overflow:hidden;background:white;box-shadow:0 6px 18px rgba(15,23,42,0.04)}
.case img{width:100%;height:200px;object-fit:cover}
.case .bd{padding:14px}

/* CLIENTS */
.clients {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.client-box {
  width: 200px;        /* cố định khung */
  height: 150px;        /* cố định chiều cao */
  background: white;
  border-radius: 8px;
  padding: 10px;
  border: 1px solid #f1f5f9;
  display: flex;
  align-items: center;
  justify-content: center;
}

.client-box img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain; /* giữ tỉ lệ logo */
}

/* CTA */
.cta{
  background:var(--accent);
  color:white;
  padding:40px;
  border-radius:12px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
}
.cta h4{margin:0;font-size:20px}
.cta p{margin:0;color:rgba(255,255,255,0.9)}

/* FOOTER */
footer{padding:28px 0;background:#fbfbfc;border-top:1px solid #eef2f6}
.footer-grid{display:grid;grid-template-columns:1fr;gap:18px}

/* Responsive */
@media(min-width:720px){
  .grid.cols-4{grid-template-columns:repeat(2,1fr)}
  .cases-grid{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media(min-width:1024px){
  .hero{grid-template-columns:1fr 1fr;gap:36px}
  .grid.cols-4{grid-template-columns:repeat(4,1fr)}
  .cases-grid{grid-template-columns:repeat(3,1fr)}
  .footer-grid{grid-template-columns:2fr 1fr 1fr}
}