/* Ghelli Study Hub
   Layout: a quiet sidebar and one reading column. No boxes unless something needs setting apart. */
:root{
  --bg:#ffffff; --side:#f8f9f8; --fg:#1b1f1e; --muted:#676e6c; --faint:#a1a7a5;
  --line:#ececea; --hover:#f1f3f2; --press:#e8ebea;
  --accent:#1f6d68; --accent-soft:#e6f1f0;
  --phys:#3563c9; --phys-s:#ebf0fb; --chem:#b56a12; --chem-s:#fbf2e5;
  --bio:#2c8a4c;  --bio-s:#e7f4eb;  --math:#6c4cc2; --math-s:#f0ecfa;
  --done:#2c8a4c;
  --shadow:0 24px 64px -12px rgba(20,32,30,.22),0 2px 8px rgba(20,32,30,.06);
  --sans:"Geist",ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --mono:"Geist Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
  --side-w:248px; --col:760px;
  color-scheme:light;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#151716; --side:#1a1c1b; --fg:#e7eae9; --muted:#9aa19f; --faint:#666d6b;
  --line:#262a29; --hover:#212524; --press:#2a2e2d;
  --accent:#78c2bc; --accent-soft:#1c2f2d;
  --phys:#8eadf2; --phys-s:#1e2840; --chem:#e6a75c; --chem-s:#30261a;
  --bio:#80cc96;  --bio-s:#1b2e21;  --math:#b6a0f2; --math-s:#28223d;
  --done:#80cc96; --shadow:0 24px 64px -12px rgba(0,0,0,.6),0 2px 8px rgba(0,0,0,.3);
  color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#151716; --side:#1a1c1b; --fg:#e7eae9; --muted:#9aa19f; --faint:#666d6b;
  --line:#262a29; --hover:#212524; --press:#2a2e2d;
  --accent:#78c2bc; --accent-soft:#1c2f2d;
  --phys:#8eadf2; --phys-s:#1e2840; --chem:#e6a75c; --chem-s:#30261a;
  --bio:#80cc96;  --bio-s:#1b2e21;  --math:#b6a0f2; --math-s:#28223d;
  --done:#80cc96; --shadow:0 24px 64px -12px rgba(0,0,0,.6),0 2px 8px rgba(0,0,0,.3);
  color-scheme:dark}

*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{background:var(--bg);color:var(--fg);font:15px/1.6 var(--sans);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
a{color:inherit;text-decoration:none}
kbd{font:500 11px var(--mono);color:var(--faint)}
[hidden]{display:none!important}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px;border-radius:6px}
::selection{background:var(--accent-soft)}

.app{display:flex;min-height:100%}

/* ---------- Sidebar ---------- */
.side{width:var(--side-w);flex:none;background:var(--side);height:100vh;position:sticky;top:0;overflow-y:auto;
  padding:14px 10px 20px;padding-left:max(10px,env(safe-area-inset-left));display:flex;flex-direction:column;gap:1px}
.brand{display:flex;align-items:center;gap:10px;padding:4px 8px 18px;font-weight:600;font-size:14.5px;letter-spacing:-.01em}
.brand img{width:22px;height:22px}
.nav{display:flex;align-items:center;gap:9px;width:100%;padding:5px 8px;border-radius:7px;color:var(--muted);font-size:14px;text-align:left;transition:background .12s,color .12s}
.nav:hover{background:var(--hover);color:var(--fg)}
.nav.on{background:var(--press);color:var(--fg);font-weight:500}
.nav svg{width:16px;height:16px;flex:none;opacity:.85}
.nav .chev{width:14px;height:14px;transition:transform .15s;opacity:.6}
.group.open>.nav .chev{transform:rotate(90deg)}
.group-kids{display:none;padding:1px 0 6px 12px}
.group.open>.group-kids{display:block}
.side-label{font-size:11.5px;color:var(--faint);padding:18px 8px 6px;font-weight:500}
.swatch{width:7px;height:7px;border-radius:50%;flex:none}
.side-foot{margin-top:auto;padding:16px 8px 0;font-size:12px;color:var(--faint)}

/* ---------- Top bar ---------- */
.main{flex:1;min-width:0}
.topbar{position:sticky;top:0;z-index:5;display:flex;align-items:center;gap:8px;height:52px;
  background:color-mix(in srgb,var(--bg) 86%,transparent);backdrop-filter:saturate(1.4) blur(10px);-webkit-backdrop-filter:saturate(1.4) blur(10px);
  padding:env(safe-area-inset-top) max(16px,env(safe-area-inset-right)) 0 max(16px,env(safe-area-inset-left))}
.crumbs{display:flex;align-items:center;gap:2px;font-size:13.5px;color:var(--muted);min-width:0;overflow:hidden;white-space:nowrap}
.crumbs a,.crumbs span.cur{padding:3px 6px;border-radius:6px;overflow:hidden;text-overflow:ellipsis}
.crumbs a:hover{background:var(--hover);color:var(--fg)}
.crumbs span.cur{color:var(--fg)}
.crumbs .sep{color:var(--faint);padding:0 1px}
.top-right{margin-left:auto;display:flex;align-items:center;gap:4px}
.icon-btn{width:32px;height:32px;border-radius:8px;display:grid;place-items:center;color:var(--muted);flex:none}
.icon-btn:hover{background:var(--hover);color:var(--fg)}
.icon-btn svg{width:17px;height:17px}
.search-trigger{display:flex;align-items:center;gap:8px;height:32px;padding:0 10px;border-radius:8px;color:var(--muted);font-size:13.5px}
.search-trigger:hover{background:var(--hover);color:var(--fg)}
.search-trigger svg{width:15px;height:15px}
.menu-btn{display:none}

/* ---------- Page ---------- */
.page{max-width:calc(var(--col) + 96px);margin:0 auto;padding:40px max(48px,env(safe-area-inset-right)) 120px max(48px,env(safe-area-inset-left));animation:in .25s ease-out}
@keyframes in{from{opacity:.4;transform:translateY(4px)}to{opacity:1;transform:none}}
.eyebrow{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--muted);margin-bottom:14px;flex-wrap:wrap}
h1{font-size:clamp(30px,4.6vw,42px);line-height:1.12;font-weight:650;letter-spacing:-.028em;margin:0;text-wrap:balance}
.lede{color:var(--muted);font-size:16px;margin:12px 0 0;max-width:58ch}
h2{font-size:13px;font-weight:500;color:var(--muted);margin:48px 0 8px}
.mono{font-family:var(--mono);font-size:.88em;letter-spacing:0}
.tile{display:inline-grid;place-items:center;width:22px;height:22px;border-radius:6px;font-size:10.5px;font-weight:600;flex:none;letter-spacing:0}
.tile.lg{width:48px;height:48px;border-radius:12px;font-size:19px;margin-bottom:18px}
.t-phys{background:var(--phys-s);color:var(--phys)} .t-chem{background:var(--chem-s);color:var(--chem)}
.t-bio{background:var(--bio-s);color:var(--bio)}    .t-math{background:var(--math-s);color:var(--math)}
.s-phys{background:var(--phys)} .s-chem{background:var(--chem)} .s-bio{background:var(--bio)} .s-math{background:var(--math)}

/* Home */
.home{padding-top:4vh}
.home h1{font-size:clamp(34px,5.4vw,52px)}
.lvl-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin-top:40px}
.lvl{position:relative;display:flex;flex-direction:column;gap:4px;padding:22px 22px 20px;border-radius:16px;background:var(--side);
  transition:background .15s,transform .15s}
.lvl:hover{background:var(--hover);transform:translateY(-2px)}
.lvl-name{font-size:23px;font-weight:650;letter-spacing:-.025em;line-height:1.15;padding-right:28px;text-wrap:balance}
.lvl-blurb{font-size:14px;color:var(--muted)}
.lvl-boards{font-size:12.5px;color:var(--faint);margin-top:auto;padding-top:36px;line-height:1.5}
.lvl .arrow{position:absolute;top:22px;right:20px;width:18px;height:18px;color:var(--faint);transition:transform .15s,color .15s}
.lvl:hover .arrow{transform:translateX(3px);color:var(--fg)}
.hero-search{display:flex;align-items:center;gap:10px;margin-top:20px;padding:8px 12px;border-radius:10px;color:var(--muted);font-size:14px;margin-left:-12px}
.hero-search:hover{background:var(--hover);color:var(--fg)}
.hero-search svg{width:16px;height:16px}

/* Level / boards */
.boards{display:grid;grid-template-columns:repeat(auto-fill,minmax(180px,1fr));gap:8px}
.board{display:flex;flex-direction:column;padding:12px 14px;border-radius:12px;background:var(--side);border:1px solid transparent;transition:background .12s,border-color .12s}
.board:hover{background:var(--hover)}
.board.on{background:var(--bg);border-color:var(--fg)}
.board b{font-weight:550;font-size:15px}
.board small{font-size:12.5px;color:var(--muted)}
.list{display:flex;flex-direction:column;margin:0 -8px}
.row{display:flex;align-items:center;gap:10px;padding:7px 8px;border-radius:8px;font-size:14.5px;min-width:0;transition:background .12s}
a.row:hover{background:var(--hover)}
.row .grow{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.row .aside{font-size:12.5px;color:var(--faint);white-space:nowrap;font-variant-numeric:tabular-nums}
.link{color:var(--accent)}

/* Subject */
.facts{display:flex;flex-wrap:wrap;gap:4px 20px;margin-top:14px;font-size:13.5px;color:var(--muted)}
.facts b{color:var(--fg);font-weight:500}
.seg{display:inline-flex;gap:2px;padding:3px;border-radius:10px;background:var(--side);margin-top:22px;flex-wrap:wrap}
.seg a{padding:5px 12px;border-radius:7px;font-size:13.5px;color:var(--muted)}
.seg a:hover{color:var(--fg)}
.seg a.on{background:var(--bg);color:var(--fg);font-weight:500;box-shadow:0 1px 2px rgba(0,0,0,.08),0 0 0 1px var(--line)}
.progress{display:flex;align-items:center;gap:12px;margin-top:22px;font-size:13px;color:var(--muted)}
.bar{width:180px;height:4px;border-radius:9px;background:var(--line);overflow:hidden}
.bar i{display:block;height:100%;background:var(--done);border-radius:9px;transition:width .3s}
.num{font:12px var(--mono);color:var(--faint);width:22px;flex:none;font-variant-numeric:tabular-nums}
.tick{width:16px;height:16px;border-radius:50%;border:1.5px solid var(--line);flex:none;display:grid;place-items:center}
.tick.on{background:var(--done);border-color:var(--done)}
.tick.on::after{content:"";width:7px;height:3.5px;border:solid var(--bg);border-width:0 0 1.75px 1.75px;transform:rotate(-45deg) translate(.5px,-.5px)}

/* Topic */
.done-toggle{display:inline-flex;align-items:center;gap:8px;margin-top:20px;padding:6px 12px 6px 9px;border-radius:999px;background:var(--side);font-size:13.5px;color:var(--muted)}
.done-toggle:hover{background:var(--hover);color:var(--fg)}
.done-toggle.on{color:var(--done)}
.res-group{margin-top:40px}
.res-group h2{margin:0 0 6px;display:flex;align-items:baseline;gap:8px}
.res-group h2 span{font:11.5px var(--mono);color:var(--faint)}
.ftype{width:30px;height:20px;border-radius:5px;display:grid;place-items:center;font:500 9.5px var(--mono);background:var(--side);color:var(--muted);flex:none}
.soon{font-size:12px;color:var(--faint)}
.open{font-size:12.5px;color:var(--accent);font-weight:500}
.row.off{color:var(--muted)}
.pager{display:flex;justify-content:space-between;gap:16px;margin-top:64px;padding-top:20px;border-top:1px solid var(--line)}
.pager a{display:flex;flex-direction:column;min-width:0;max-width:48%;padding:6px 8px;margin:-6px -8px;border-radius:8px}
.pager a:hover{background:var(--hover)}
.pager small{font-size:12px;color:var(--faint)}
.pager b{font-weight:500;font-size:14.5px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.pager .next{text-align:right;margin-left:auto}
.note{margin-top:28px;font-size:13px;color:var(--faint)}

/* Past papers */
.pp{overflow-x:auto;margin:8px -8px 0}
table{border-collapse:collapse;width:100%;min-width:520px;font-size:14px}
th{font-weight:500;font-size:12.5px;color:var(--faint);text-align:left;padding:8px}
td{padding:7px 8px;border-top:1px solid var(--line);white-space:nowrap;font-variant-numeric:tabular-nums}
tr:hover td{background:var(--hover)}
.chip{display:inline-block;font:500 11px var(--mono);padding:2px 6px;border-radius:5px;margin-right:3px;color:var(--faint)}
a.chip{background:var(--accent-soft);color:var(--accent)}
a.chip:hover{filter:brightness(.96)}
.legend{font-size:13px;color:var(--muted);margin-top:28px}

/* ---------- Search palette ---------- */
.scrim{position:fixed;inset:0;z-index:40;background:rgba(12,18,17,.28);display:flex;justify-content:center;align-items:flex-start;
  padding:14vh max(16px,env(safe-area-inset-right)) 16px max(16px,env(safe-area-inset-left));animation:fade .12s}
@keyframes fade{from{opacity:0}}
.palette{width:100%;max-width:600px;background:var(--bg);border-radius:14px;box-shadow:var(--shadow),0 0 0 1px var(--line);overflow:hidden;animation:pop .14s ease-out}
@keyframes pop{from{transform:scale(.98);opacity:0}}
.palette-input{display:flex;align-items:center;gap:10px;padding:0 16px;border-bottom:1px solid var(--line);color:var(--faint)}
.palette-input svg{width:17px;height:17px;flex:none}
.palette input{flex:1;min-width:0;border:0;background:none;padding:16px 0;font:16px var(--sans);color:var(--fg);outline:none}
.results{max-height:min(56vh,440px);overflow-y:auto;padding:6px}
.result{display:flex;align-items:center;gap:10px;width:100%;padding:8px 10px;border-radius:8px;font-size:14px;text-align:left}
.result.sel{background:var(--hover)}
.result .grow{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.result small{color:var(--faint);font-size:12.5px;white-space:nowrap}
.res-label{font-size:11.5px;color:var(--faint);padding:8px 10px 4px}
.empty{padding:28px 16px;text-align:center;color:var(--muted);font-size:14px}

/* ---------- Responsive ---------- */
@media (max-width:900px){
  .lvl-grid{grid-template-columns:1fr}
  .lvl-boards{padding-top:16px}
}
@media (max-width:820px){
  .side{position:fixed;left:0;top:0;bottom:0;height:auto;z-index:30;transform:translateX(-104%);transition:transform .22s ease,box-shadow .22s;box-shadow:none;
    padding-top:calc(14px + env(safe-area-inset-top))}
  .app.nav-open .side{transform:none;box-shadow:var(--shadow)}
  .side-scrim{display:none;position:fixed;inset:0;z-index:25;background:rgba(12,18,17,.3)}
  .app.nav-open .side-scrim{display:block}
  .menu-btn{display:grid}
  .search-trigger span,.search-trigger kbd{display:none}
  .page{padding:24px max(18px,env(safe-area-inset-right)) 96px max(18px,env(safe-area-inset-left))}
  .row .aside.hide-sm{display:none}
}
@media (prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important}}