/* Laboratorio di Fisica — stile comune del sito.
   Layout: quaderno di laboratorio a quadretti; barra superiore sottile, catalogo a schede. */
:root{
  --paper:#eef3f1; --panel:#fbfdfc; --grid:#dde8e4; --line:#c3d2cc;
  --ink:#1b2a31; --muted:#5b6d74; --accent:#cf3f2a; --vel:#2464c9; --acc:#a86d12;
  --chip:#e3ece8;
  --f-display:"Archivo", "Helvetica Neue", Arial, sans-serif;
  --f-body:"Source Sans 3", system-ui, -apple-system, "Segoe UI", sans-serif;
  --f-mono:"JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
  color-scheme:light;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --paper:#0f1619; --panel:#141d21; --grid:#1d2a2f; --line:#2c3c42;
  --ink:#e2ebe7; --muted:#8fa2a8; --accent:#ff6a50; --vel:#71a6ff; --acc:#e3a94b; --chip:#1c282d; color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#0f1619; --panel:#141d21; --grid:#1d2a2f; --line:#2c3c42;
  --ink:#e2ebe7; --muted:#8fa2a8; --accent:#ff6a50; --vel:#71a6ff; --acc:#e3a94b; --chip:#1c282d; color-scheme:dark}

*{box-sizing:border-box}
[hidden]{display:none!important}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.5}
a{color:inherit}
img{max-width:100%;display:block}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}

/* barra superiore comune */
.topbar{position:sticky;top:0;z-index:10;background:var(--panel);border-bottom:1px solid var(--line)}
.topbar-in{max-width:1100px;margin:0 auto;padding-inline:16px;padding-block:10px;display:flex;flex-wrap:wrap;align-items:center;gap:16px;justify-content:space-between}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;font-family:var(--f-display);font-weight:800;font-size:17px;letter-spacing:-.01em}
.brand svg{flex:none}
.topbar-actions{display:flex;gap:8px;align-items:center}
.linkbtn{font:600 14px var(--f-body);color:var(--ink);text-decoration:none;border:1px solid var(--line);background:var(--panel);border-radius:6px;padding:6px 12px;cursor:pointer}
.linkbtn:hover{background:var(--chip)}

/* home */
.home{max-width:1100px;margin:0 auto;padding-inline:16px;padding-block:36px 64px}
.home .eyebrow{font-family:var(--f-mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);margin:0 0 8px}
.home h1{font-family:var(--f-display);font-weight:800;font-size:clamp(32px,5.4vw,56px);line-height:1.02;letter-spacing:-.015em;margin:0 0 14px;text-wrap:balance}
.home .lead{margin:0 0 30px;max-width:60ch;color:var(--muted);font-size:17px}
.filters{display:flex;flex-wrap:wrap;gap:10px 18px;align-items:center;margin-bottom:22px;padding-bottom:18px;border-bottom:1px solid var(--line)}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.chip{font:600 14px var(--f-body);color:var(--muted);background:transparent;border:1px solid var(--line);border-radius:999px;padding:5px 12px;cursor:pointer}
.chip[aria-pressed="true"]{background:var(--ink);color:var(--panel);border-color:var(--ink)}
.search{flex:1 1 220px;max-width:320px;margin-left:auto}
.search input{width:100%;font:15px var(--f-body);color:var(--ink);background:var(--panel);border:1px solid var(--line);border-radius:6px;padding:7px 10px}
.count{font:13px var(--f-mono);color:var(--muted);margin:0 0 14px}

.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:22px}
.card{display:flex;flex-direction:column;background:var(--panel);border:1px solid var(--line);border-radius:8px;overflow:hidden;text-decoration:none;color:inherit;transition:border-color .15s, transform .15s}
.card:hover{border-color:var(--ink);transform:translateY(-2px)}
.card .thumb{aspect-ratio:1200/560;background:var(--chip);border-bottom:1px solid var(--line);overflow:hidden}
.card .thumb img{width:100%;height:100%;object-fit:cover}
.card .body{padding:16px 18px 18px;display:flex;flex-direction:column;gap:8px;min-width:0;flex:1}
.meta{display:flex;flex-wrap:wrap;gap:6px 12px;font:12px var(--f-mono);color:var(--muted);text-transform:uppercase;letter-spacing:.06em}
.meta .area{color:var(--accent);font-weight:600}
.card h2{font-family:var(--f-display);font-weight:700;font-size:22px;line-height:1.15;margin:0}
.card p{margin:0;color:var(--muted)}
.sections{display:flex;flex-wrap:wrap;gap:6px;margin-top:auto;padding-top:8px}
.sections span{font-size:13px;background:var(--chip);border-radius:4px;padding:2px 8px}
.empty{padding:32px;text-align:center;color:var(--muted);border:1px dashed var(--line);border-radius:8px}
.soon{margin-top:26px;font-size:15px;color:var(--muted)}
.foot{max-width:1100px;margin:0 auto;padding-inline:16px;padding-block:24px 40px;border-top:1px solid var(--line);font-size:13px;color:var(--muted);display:flex;flex-wrap:wrap;gap:8px 24px;justify-content:space-between}

@media (prefers-reduced-motion: reduce){.card{transition:none}.card:hover{transform:none}}
@media (max-width:520px){.search{max-width:none;margin-left:0}}