:root{
  --bg:#fbfaf7;
  --surface:#ffffff;
  --ink:#1a1f1d;
  --muted:#5b6360;
  --line:#e6e2d9;
  --green:#1f7a5a;
  --green-dark:#12503b;
  --access:#c9862b;
  --supply:#2b6fc9;
  --coord:#1f7a5a;
  --amber:#b26a00;
  --accent-soft:#eef4f0;
  --shadow:0 1px 3px rgba(20,30,25,.06),0 8px 30px rgba(20,30,25,.05);
  --radius:14px;
  --maxw:1100px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:'Inter',system-ui,-apple-system,sans-serif;line-height:1.6;-webkit-font-smoothing:antialiased}
.serif{font-family:'Newsreader',Georgia,serif}
a{color:var(--green);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}

/* NAV */
.nav{position:sticky;top:0;z-index:50;background:rgba(251,250,247,.9);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;height:60px}
.nav .brand{font-weight:700;font-size:1rem;letter-spacing:.01em;color:var(--ink)}
.nav .brand:hover{text-decoration:none}
.nav .brand span{color:var(--green)}
.nav .links{display:flex;gap:8px;font-size:.92rem;font-weight:500;align-items:center}
.nav .links a{color:var(--muted);padding:6px 12px;border-radius:999px}
.nav .links a:hover{color:var(--ink);text-decoration:none;background:var(--accent-soft)}
.nav .links a.active{color:var(--green-dark);background:var(--accent-soft)}
.nav .links a.cta{background:var(--green);color:#fff}
.nav .links a.cta:hover{background:var(--green-dark);color:#fff}
@media(max-width:640px){.nav .links a:not(.cta){display:none}}

/* HERO */
.hero{padding:60px 0 40px;border-bottom:1px solid var(--line);background:radial-gradient(1200px 420px at 50% -120px,#eaf3ee 0%,rgba(234,243,238,0) 70%)}
.eyebrow{display:inline-flex;align-items:center;gap:8px;font-size:.76rem;font-weight:600;letter-spacing:.14em;text-transform:uppercase;color:var(--green-dark);background:var(--accent-soft);border:1px solid var(--line);padding:6px 14px;border-radius:999px}
h1.title{font-family:'Newsreader',serif;font-weight:600;font-size:clamp(1.9rem,4.2vw,2.9rem);line-height:1.12;margin:22px 0 12px;max-width:20ch}
.subtitle{font-size:1.08rem;color:var(--muted);max-width:62ch;margin:0 0 24px}
.authors{display:flex;flex-wrap:wrap;gap:6px 20px;font-size:1rem;margin-bottom:6px}
.authors b{font-weight:600}
.affil{color:var(--muted);font-size:.9rem;max-width:72ch;margin-bottom:24px}
.btns{display:flex;flex-wrap:wrap;gap:12px}
.btn{display:inline-flex;align-items:center;gap:8px;font-weight:600;font-size:.92rem;padding:11px 20px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--ink);cursor:pointer;transition:.15s}
.btn:hover{border-color:var(--green);color:var(--green);text-decoration:none;transform:translateY(-1px)}
.btn.primary{background:var(--green);border-color:var(--green);color:#fff}
.btn.primary:hover{background:var(--green-dark);color:#fff}

section{padding:52px 0}
.section-tag{font-size:.76rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;color:var(--green);margin-bottom:10px}
h2{font-family:'Newsreader',serif;font-weight:600;font-size:clamp(1.5rem,3vw,2rem);margin:0 0 16px;line-height:1.18}
h3{font-size:1.1rem;font-weight:700;margin:0 0 8px}
p.lead{font-size:1.05rem;color:var(--ink)}
.muted{color:var(--muted)}

.statement{background:linear-gradient(135deg,var(--green-dark),var(--green));color:#fff;border-radius:var(--radius);padding:32px 36px;box-shadow:var(--shadow)}
.statement .k{font-size:.76rem;font-weight:700;letter-spacing:.14em;text-transform:uppercase;opacity:.85;margin-bottom:12px}
.statement p{font-family:'Newsreader',serif;font-size:clamp(1.12rem,2.3vw,1.45rem);line-height:1.4;margin:0;font-style:italic}

/* CHALLENGE AREAS */
.area{border-top:4px solid var(--green);background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:30px 32px;margin-bottom:26px}
.area.access{border-top:4px solid var(--access)}
.area.supply{border-top:4px solid var(--supply)}
.area.coordination{border-top:4px solid var(--coord)}
.area .anum{font-family:'Newsreader',serif;font-size:1.05rem;font-weight:600;color:var(--muted)}
.area.access .anum{color:var(--access)}
.area.supply .anum{color:var(--supply)}
.area.coordination .anum{color:var(--coord)}
.area h2{margin:4px 0 6px}
.area .aq{font-size:1.02rem;color:var(--muted);margin-bottom:18px;max-width:70ch}

.sub{border-top:1px solid var(--line);padding:18px 0}
.sub:last-child{padding-bottom:0}
.sub .sq{display:flex;gap:12px;align-items:baseline}
.sub .sid{font-weight:700;font-size:.8rem;color:#fff;background:var(--muted);padding:2px 9px;border-radius:6px;flex-shrink:0}
.area.access .sid{background:var(--access)}
.area.supply .sid{background:var(--supply)}
.area.coordination .sid{background:var(--coord)}
.sub .st{font-weight:600;font-size:1rem}
.sub .papers{margin:12px 0 0 0;padding:0;list-style:none}
.sub .papers li{padding:8px 0;border-bottom:1px dotted var(--line);font-size:.93rem}
.sub .papers li:last-child{border-bottom:none}
.sub .papers .pa{color:var(--muted)}
.sub .papers .pv{font-weight:600;color:var(--ink)}
.sub .none{font-size:.88rem;color:var(--muted);font-style:italic;margin-top:8px}

/* LITERATURE */
.litbar{position:sticky;top:60px;z-index:40;background:var(--bg);padding:16px 0;border-bottom:1px solid var(--line);margin-bottom:8px}
.searchrow{display:flex;gap:12px;flex-wrap:wrap;align-items:center}
.search{flex:1;min-width:240px;position:relative}
.search input{width:100%;padding:12px 14px 12px 42px;border:1px solid var(--line);border-radius:999px;font-size:.95rem;background:var(--surface);font-family:inherit}
.search input:focus{outline:none;border-color:var(--green);box-shadow:0 0 0 3px rgba(31,122,90,.12)}
.search svg{position:absolute;left:15px;top:50%;transform:translateY(-50%);color:var(--muted)}
.count{font-size:.88rem;color:var(--muted);white-space:nowrap}
.filters{display:flex;gap:8px;flex-wrap:wrap;margin-top:14px;align-items:center}
.fgroup-label{font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:.1em;color:var(--muted);margin-right:2px}
.chip{font-size:.82rem;font-weight:500;padding:6px 13px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--muted);cursor:pointer;transition:.12s;user-select:none}
.chip:hover{border-color:var(--green);color:var(--ink)}
.chip.active{background:var(--green);border-color:var(--green);color:#fff}
.chip.active.access{background:var(--access);border-color:var(--access)}
.chip.active.supply{background:var(--supply);border-color:var(--supply)}
.chip.active.coordination{background:var(--coord);border-color:var(--coord)}
.clsfilters{margin-top:12px;display:none;flex-wrap:wrap;gap:8px}
.clsfilters.show{display:flex}
.toggle-cls{font-size:.82rem;font-weight:600;color:var(--green);cursor:pointer;background:none;border:none;padding:6px 0;font-family:inherit}
.reset{font-size:.82rem;color:var(--muted);cursor:pointer;background:none;border:none;font-family:inherit;text-decoration:underline}

.litgrid{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;margin-top:8px}
@media(max-width:760px){.litgrid{grid-template-columns:1fr}}
.paper{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:18px 20px;box-shadow:var(--shadow);display:flex;flex-direction:column;transition:.14s}
.paper:hover{transform:translateY(-2px);border-color:#d5cfc2}
.paper .ptitle{font-weight:600;font-size:1rem;line-height:1.35;margin-bottom:6px}
.paper .pmeta{font-size:.86rem;color:var(--muted);margin-bottom:12px}
.paper .pv{font-weight:600;color:var(--ink)}
.paper .ptags{display:flex;gap:6px;flex-wrap:wrap;margin-top:auto}
.tag{font-size:.71rem;font-weight:600;padding:3px 9px;border-radius:999px;letter-spacing:.01em}
.tag.access{background:#faedd7;color:#8a5a10}
.tag.supply{background:#e2edfb;color:#1f4e8f}
.tag.coordination{background:#e2f0ea;color:#14503b}
.tag.cls{background:#f0eee8;color:#5b6360}
.tag.type{background:#f3eaf3;color:#7a4a7a}
.empty{text-align:center;padding:50px;color:var(--muted);font-style:italic}

/* FORMS */
.formcard{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:30px 32px;max-width:720px}
.field{margin-bottom:18px}
.field label{display:block;font-weight:600;font-size:.9rem;margin-bottom:6px}
.field .req{color:var(--amber)}
.field input,.field textarea,.field select{width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:10px;font-size:.95rem;font-family:inherit;background:#fff}
.field input:focus,.field textarea:focus,.field select:focus{outline:none;border-color:var(--green);box-shadow:0 0 0 3px rgba(31,122,90,.12)}
.field textarea{min-height:90px;resize:vertical}
.field .hint{font-size:.8rem;color:var(--muted);margin-top:5px}
.clsgrid{display:grid;grid-template-columns:repeat(2,1fr);gap:6px 14px;margin-top:6px}
@media(max-width:560px){.clsgrid{grid-template-columns:1fr}}
.clsgrid label{display:flex;gap:8px;align-items:center;font-weight:400;font-size:.88rem;margin:0}
.clsgrid input{width:auto}
.note{background:var(--accent-soft);border:1px solid var(--line);border-radius:10px;padding:14px 16px;font-size:.88rem;color:var(--muted);margin-top:18px}

footer{border-top:1px solid var(--line);padding:40px 0;color:var(--muted);font-size:.9rem;margin-top:20px}
footer a{color:var(--muted);text-decoration:underline}
hr.soft{border:none;border-top:1px solid var(--line);margin:0 0 24px}

/* ---- v2 additions: cite, sort, venue, datasets, stats, deep links ---- */
.ext{font-size:.8em;opacity:.6}
.stats{display:flex;gap:26px;flex-wrap:wrap;margin:6px 0 0;font-size:.9rem;color:var(--muted)}
.stats b{color:var(--green-dark);font-size:1.15rem;font-family:'Newsreader',serif;font-weight:600;margin-right:5px}
.seeall{display:inline-block;margin-top:10px;font-size:.86rem;font-weight:600;color:var(--green)}
#venue-filters, #ds-cls-filters{margin-top:12px;display:none;flex-wrap:wrap;gap:8px}
#venue-filters.show, #ds-cls-filters.show{display:flex}
.controls-row{display:flex;gap:16px;flex-wrap:wrap;align-items:center;margin-top:12px}
.sort-wrap{display:flex;align-items:center;gap:8px;font-size:.85rem;color:var(--muted)}
.sort-wrap select{padding:7px 12px;border:1px solid var(--line);border-radius:8px;font-family:inherit;font-size:.85rem;background:var(--surface);color:var(--ink)}
.pactions{display:flex;gap:10px;align-items:center;margin-top:12px;padding-top:10px;border-top:1px dotted var(--line)}
.citebtn{font-size:.78rem;font-weight:600;color:var(--green);background:var(--accent-soft);border:1px solid var(--line);border-radius:7px;padding:5px 11px;cursor:pointer;font-family:inherit}
.citebtn:hover{border-color:var(--green)}
.doilink{font-size:.78rem;font-weight:600;color:var(--muted)}
#sub-banner{display:none;align-items:center;gap:12px;background:var(--accent-soft);border:1px solid var(--line);border-radius:10px;padding:10px 16px;margin:14px 0 0;font-size:.9rem}
#sub-banner button{background:none;border:none;color:var(--green);font-weight:600;cursor:pointer;font-family:inherit;text-decoration:underline}
.dsdesc{font-size:.9rem;color:var(--muted);margin-bottom:12px}
.about-card{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:28px 32px;margin-bottom:20px}
.about-card h3{margin-top:0}
.about-card p{margin:0 0 12px}

/* ---- v3: accordion, sub-challenge filter, suggest-an-edit ---- */
.area-head{display:flex;justify-content:space-between;align-items:flex-start;gap:16px;cursor:pointer}
.area-head-main{flex:1}
.area-head h2{margin:4px 0 0}
.area-head-meta{display:flex;align-items:center;gap:14px;flex-shrink:0;padding-top:6px}
.areacount{font-size:.85rem;color:var(--muted);white-space:nowrap;font-weight:500}
.chev{color:var(--muted);font-size:1.1rem;transition:transform .2s;line-height:1}
.area.open .chev{transform:rotate(180deg)}
.area-body{display:none}
.area.open .area-body{display:block}
.area .aq{margin-top:16px}
#sub-filters{margin-top:12px;display:none;flex-wrap:wrap;gap:8px;align-items:center}
#sub-filters.show{display:flex}
.editbtn{font-size:.78rem;font-weight:600;color:var(--muted);background:none;border:1px solid var(--line);border-radius:7px;padding:5px 11px;cursor:pointer;font-family:inherit;margin-left:auto}
.editbtn:hover{border-color:var(--green);color:var(--green)}

/* ---- v4: nested sub-challenge accordion ---- */
.sub-head{display:flex;justify-content:space-between;align-items:baseline;gap:14px;cursor:pointer}
.sub-head .sq{flex:1;margin:0}
.sub-chev{font-size:.85rem;color:var(--muted);transition:transform .2s;flex-shrink:0;line-height:1}
.sub.open .sub-chev{transform:rotate(180deg)}
.sub-body{display:none}
.sub.open .sub-body{display:block}
.sub:hover .sub-head .st{color:var(--green-dark)}

/* ---- v5: content-type toggle (Suggest content) ---- */
.type-toggle{display:flex;gap:10px;margin-top:18px;flex-wrap:wrap}
.type-btn{font-size:.95rem;font-weight:600;padding:11px 20px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--muted);cursor:pointer;font-family:inherit;transition:.14s}
.type-btn:hover{border-color:var(--green);color:var(--ink)}
.type-btn.active{background:var(--green);border-color:var(--green);color:#fff}