/* =========================================================
   00 – BASE (dùng chung cho mọi section)
   Chỉ chứa: màu brand, font, reset, khung .wrap, tiêu đề section,
   nút bấm, logo. KHÔNG viết style riêng của section nào ở đây.
   ========================================================= */

/* Brand VinaCAD (theo vina-cad.com): font Inter, xanh lá chủ đạo */
:root{
  --g-900:#035F46; --g-800:#05724A; --g-700:#098E50; --g-600:#0DAA51; --g-500:#12C64F;
  --g-300:#A7E8C1; --g-50:#E3FFEE; --mint:#F3FFF8;
  --ink:#212930; --muted:#5E6A72; --line:#E4E4E6;
  --red:#D9363E; --gold:#FAAD14;
  --grad:linear-gradient(90deg,var(--g-800) 0%,var(--g-600) 100%);
  --r:12px;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;scroll-padding-top:80px}
body{font-family:Inter,"Source Sans Pro",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;color:var(--ink);background:#fff;line-height:1.6;font-size:16px;-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{color:inherit;text-decoration:none}

/* Khung nội dung + khoảng cách section */
.wrap{max-width:1180px;margin:0 auto;padding:0 20px}
section{padding:96px 0}
.alt{background:linear-gradient(180deg,var(--mint) 0%,var(--g-50) 100%)}

/* Tiêu đề section */
.sec-title{text-align:center;font-size:clamp(26px,3.2vw,38px);font-weight:700;color:var(--g-700);letter-spacing:-.01em;line-height:1.25}
.sec-sub{text-align:center;color:var(--muted);max-width:640px;margin:14px auto 0;font-size:17px}

/* Nút bấm */
.btn{display:inline-flex;align-items:center;gap:10px;font-weight:600;font-size:15px;padding:14px 28px;border-radius:8px;border:1.5px solid transparent;cursor:pointer;transition:transform .15s,box-shadow .15s,filter .15s;font-family:inherit}
.btn:hover{transform:translateY(-1px);filter:brightness(1.05)}
.btn-blue{background:var(--grad);color:#fff;box-shadow:0 8px 20px rgba(9,142,80,.25)}
.btn-line,.btn-outline{background:#fff;color:var(--g-700);border-color:var(--g-700);box-shadow:none}
.btn-line:hover,.btn-outline:hover{background:var(--g-50)}
.btn-sm{padding:10px 20px;font-size:14px}

/* Logo (dùng ở Header và Footer) */
.brand{display:flex;align-items:center;gap:10px}
.brand img{height:36px;width:36px}
.brand-txt{line-height:1.1}
.brand-txt b{display:block;font-size:21px;font-weight:800;color:var(--ink)}
.brand-txt small{font-size:9.5px;font-weight:700;letter-spacing:.14em;color:var(--g-700)}

@media (max-width:600px){
  section{padding:68px 0}
  .wrap{padding:0 16px}
  .brand img{height:32px;width:32px}
}