:root {
  --brand:#16a34a; --brand-dark:#0f7a34; --brand-accent:#0ea5e9; --brand-50:#eaf7ef;
  --ink:#0f172a; --muted:#475569; --bg:#ffffff; --card:#f8fafc; --ring:rgba(22,163,74,.35); --radius:16px;
}
*{box-sizing:border-box}
html,body{margin:0;font-family:'Noto Sans Thai',system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;color:var(--ink);background:var(--bg)}
a{color:var(--brand-dark);text-decoration:none}
a:hover{text-decoration:underline}
.container{width:min(1100px,92%);margin:0 auto}

header.site{position:sticky;top:0;z-index:50;background:linear-gradient(90deg,var(--brand),var(--brand-accent));color:#fff}
.nav{display:flex;align-items:center;justify-content:space-between;padding:14px 0}
.brand{display:flex;align-items:center;gap:12px;color:#fff}
.brand .logo{width:44px;height:44px;border-radius:50%;background:#fff;display:inline-flex;align-items:center;justify-content:center;color:var(--brand-dark);font-weight:700}
.brand h1{font-size:20px;margin:0;line-height:1.2}
.brand small{color:#e0f2e9;font-weight:400;display:block}

.nav ul{list-style:none;display:flex;gap:20px;margin:0;padding:0}
.nav ul li{position:relative}
.nav a{padding:10px 14px;border-radius:999px;color:#fff;font-weight:600;transition:background .2s;display:flex;align-items:center;gap:6px}
.nav a:hover{background:rgba(255,255,255,.2);text-decoration:none}
.nav img.icon{width:18px;height:18px;filter:invert(1)}

/* Submenu */
.submenu{display:none;position:absolute;top:40px;left:0;background:#fff;color:var(--ink);border-radius:12px;box-shadow:0 8px 20px -8px rgba(0,0,0,.3);min-width:200px;padding:10px}
.submenu a{color:var(--ink)!important;padding:8px 12px;display:block;border-radius:8px;font-weight:400}
.submenu a:hover{background:var(--brand-50)}
.nav ul li:hover>.submenu{display:block}

/* Hero */
.hero{background:linear-gradient(135deg,var(--brand-50),#fff);padding:60px 0}
.hero .wrap{display:grid;grid-template-columns:1.2fr .8fr;gap:40px;align-items:center}
.hero h2{font-size:clamp(32px,4vw,44px);margin:0 0 16px;color:var(--brand-dark)}
.hero p{color:var(--muted);margin:0 0 20px;font-size:18px}
.btn{display:inline-block;padding:14px 20px;background:var(--brand);color:#fff;border-radius:12px;font-weight:600;box-shadow:0 8px 24px -8px var(--ring);transition:background .2s, transform .2s}
.btn:hover{background:var(--brand-dark);transform:translateY(-2px);text-decoration:none}
.btn.alt{background:var(--brand-accent)}

/* Section */
section{padding:60px 0}
section:nth-child(even){background:#f9fafb}
section h3{margin:0 0 20px;font-size:26px;color:var(--brand-dark);text-align:center}
section p.lead{text-align:center;margin:0 auto 30px;max-width:700px;color:var(--muted)}

/* Cards / grids */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:24px}
.card{background:#fff;border:1px solid #e2e8f0;border-radius:var(--radius);padding:20px;box-shadow:0 4px 12px -6px rgba(0,0,0,.1)}
.card h4{margin:0 0 10px;font-size:20px;color:var(--brand)}
.meta{color:var(--muted);font-size:14px}

/* Faculty cards */
.faculty{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:24px}
.faculty .person{background:linear-gradient(135deg,#fff,var(--brand-50));border:1px solid #e2e8f0;border-radius:var(--radius);padding:20px;text-align:center;box-shadow:0 4px 12px -6px rgba(0,0,0,.1)}
.avatar{width:90px;height:90px;border-radius:999px;background:linear-gradient(135deg,var(--brand),var(--brand-accent));margin:0 auto 12px;display:grid;place-items:center;color:#fff;font-weight:700;font-size:24px;box-shadow:0 6px 16px -6px rgba(0,0,0,.2)}

/* Footer */
footer{background:linear-gradient(90deg,var(--brand-dark),#000);color:#cbead6;padding:40px 0;text-align:center}
footer a{color:#b7f0cd}