:root{
  --bg:#f4f7f8;--surface:#fff;--ink:#132c3a;--muted:#637786;--line:#d9e3e8;
  --navy:#123f59;--blue:#126b8d;--soft:#eaf4f7;--green:#36745d;--amber:#a86612;
  --shadow:0 12px 30px rgba(22,55,72,.07);--radius:20px;--max:1120px
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,"Noto Sans Thai",Tahoma,sans-serif;line-height:1.65}
a{color:inherit}
.shell{width:min(calc(100% - 32px),var(--max));margin-inline:auto}
.topbar{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.95);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.topbar-inner{min-height:64px;display:flex;align-items:center;justify-content:space-between;gap:20px}
.brand{text-decoration:none;font-weight:850;color:var(--navy);font-size:1.08rem}
.topnav{display:flex;gap:8px;flex-wrap:wrap}
.topnav a{text-decoration:none;color:#385260;padding:8px 10px;border-radius:10px;font-size:.92rem}
.topnav a:hover,.topnav a.active{background:var(--soft);color:var(--navy)}
.hero{background:linear-gradient(145deg,#103f59,#17657d);color:#fff;padding:64px 0 58px}
.hero-grid{display:grid;grid-template-columns:minmax(0,1.5fr) minmax(260px,.7fr);gap:38px;align-items:end}
.eyebrow{font-size:.78rem;letter-spacing:.08em;font-weight:800;color:#bfe0eb;margin-bottom:8px}
.eyebrow.dark{color:var(--blue)}
.hero h1{font-size:clamp(2.15rem,5vw,4.3rem);line-height:1.1;margin:0 0 18px;letter-spacing:-.02em}
.hero p{font-size:1.06rem;color:#e2f0f4;max-width:760px;margin:0}
.hero-principle{border:1px solid rgba(255,255,255,.22);background:rgba(255,255,255,.08);padding:22px;border-radius:18px}
.hero-principle strong,.hero-principle span{display:block}
.hero-principle strong{font-size:1.05rem;margin-bottom:7px}
.hero-principle span{color:#e0edf1;font-size:.95rem}
.controls{padding:28px 0 8px;display:flex;align-items:end;justify-content:space-between;gap:20px}
.searchbox{display:grid;gap:7px;flex:1;max-width:480px;color:#415966;font-size:.86rem;font-weight:700}
.searchbox input{width:100%;border:1px solid #cbd9df;background:#fff;border-radius:14px;padding:13px 15px;font:inherit;outline:none}
.searchbox input:focus{border-color:#6ca6bb;box-shadow:0 0 0 4px rgba(18,107,141,.09)}
.filters{display:flex;gap:8px;flex-wrap:wrap}
.filter{border:1px solid #cad8df;background:#fff;color:#405865;border-radius:999px;padding:9px 12px;cursor:pointer;font:inherit;font-size:.86rem}
.filter:hover,.filter.is-active{background:var(--navy);border-color:var(--navy);color:#fff}
.section-head{display:flex;align-items:end;justify-content:space-between;gap:20px;margin:38px 0 18px}
.section-head h2{margin:0;font-size:clamp(1.4rem,3vw,2.1rem);line-height:1.25}
.result-count{color:var(--muted);font-size:.9rem}
.km-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}
.km-card{display:flex;flex-direction:column;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);min-height:300px}
.km-card.featured{border-color:#b8d5df;background:linear-gradient(180deg,#fff,#f5fbfd)}
.card-top{display:flex;justify-content:space-between;gap:12px;align-items:center}
.badge{display:inline-flex;border-radius:999px;padding:5px 9px;font-size:.77rem;font-weight:800}
.badge.hydrology{background:#e6f2fb;color:#1e6285}
.badge.river{background:#edf5e8;color:#4d722b}
.badge.resilience{background:#fff1df;color:#8a5617}
.badge.system{background:#eeeafb;color:#594990}
.level{font-size:.78rem;color:var(--muted)}
.km-card h3{font-size:1.28rem;line-height:1.38;margin:18px 0 10px}
.km-card p{color:#526b79;margin:0 0 15px}
.keywords{color:#768b96;font-size:.83rem;margin-top:auto;padding-top:10px}
.read{display:inline-flex;margin-top:18px;color:var(--blue);font-weight:800;text-decoration:none}
.read:hover{text-decoration:underline}
.empty-state{margin-top:18px;padding:28px;border:1px dashed #b8c9d1;border-radius:18px;background:#fff;text-align:center;color:var(--muted)}
.learning-path{padding-bottom:58px}
.path-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px}
.path-card{display:flex;flex-direction:column;gap:7px;padding:20px;background:#fff;border:1px solid var(--line);border-radius:16px}
.path-card b{font-size:.78rem;color:var(--blue)}
.path-card strong{font-size:1rem}
.path-card span{font-size:.86rem;color:var(--muted)}
.site-footer{border-top:1px solid var(--line);background:#fff;padding:26px 0 34px}
.footer-grid{display:flex;justify-content:space-between;align-items:center;gap:20px;color:var(--muted)}
.footer-grid strong{color:var(--ink)}
.footer-grid p{margin:3px 0 0}
.footer-grid a{color:var(--blue);font-weight:700;text-decoration:none;white-space:nowrap}
[hidden]{display:none!important}
@media(max-width:800px){
  .hero{padding:42px 0}
  .hero-grid{grid-template-columns:1fr}
  .controls{align-items:stretch;flex-direction:column}
  .searchbox{max-width:none}
  .km-grid{grid-template-columns:1fr}
  .path-grid{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:580px){
  .shell{width:min(calc(100% - 22px),var(--max))}
  .topbar-inner{align-items:flex-start;flex-direction:column;padding:12px 0}
  .topnav{width:100%;overflow-x:auto;flex-wrap:nowrap;padding-bottom:2px}
  .topnav a{white-space:nowrap}
  .hero h1{font-size:2.25rem}
  .filters{flex-wrap:nowrap;overflow-x:auto;padding-bottom:4px}
  .filter{white-space:nowrap}
  .path-grid{grid-template-columns:1fr}
  .footer-grid{align-items:flex-start;flex-direction:column}
}