/* Lezioni — stile derivato da Grtlabs (token, tema doppio, animazioni d'ingresso).
   Ogni classe ha una tinta: la pagina ne prende l'accento, lo sfondo la sua scena. */
@font-face{font-family:"Hanken Grotesk";src:url(fonts/hanken-grotesk.woff2) format("woff2");font-weight:100 900;font-display:swap}
@font-face{font-family:"Spline Sans Mono";src:url(fonts/spline-sans-mono.woff2) format("woff2");font-weight:300 700;font-display:swap}

:root{
  --font-sans:"Hanken Grotesk",ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --font-mono:"Spline Sans Mono",ui-monospace,"SF Mono","Cascadia Mono",Consolas,monospace;
  --text-xs:.75rem;--text-sm:.8125rem;--text-base:1rem;--text-lg:1.25rem;--text-xl:1.5rem;
  --display:clamp(2.4rem,5vw + 1rem,4.4rem);
  --space-2xs:.5rem;--space-xs:.75rem;--space-sm:1rem;--space-md:1.5rem;--space-lg:2.5rem;--space-xl:4rem;
  --pad-x:clamp(1.25rem,5vw,4rem);--pad-y:clamp(1.1rem,3.2vh,2rem);
  --radius-sm:8px;--radius-md:12px;--radius-lg:16px;--radius-pill:999px;
  --ease-out-quart:cubic-bezier(.25,1,.5,1);--ease-out-quint:cubic-bezier(.22,1,.36,1);--ease-out-expo:cubic-bezier(.16,1,.3,1);
  --dur:220ms;--dur-slow:420ms;--dur-boot:820ms;

  /* tinte delle classi (hue oklch) */
  --h-home:200;--h-3TELB:62;--h-4TELA:212;--h-4ELEA:292;
  --h:var(--h-home);

  --bg:oklch(.985 .004 220);--surface:oklch(.965 .006 225);--border:oklch(.89 .01 225);--border-strong:oklch(.82 .012 225);
  --ink:oklch(.28 .02 235);--ink-strong:oklch(.2 .02 235);--muted:oklch(.47 .018 235);
  --scrim:oklch(.985 .004 220 / .72);--shadow:0 10px 30px oklch(.2 .02 235 / .12);
  --canvas-blur:1.6px;
}
[data-theme=dark]{
  --bg:oklch(.205 .012 245);--surface:oklch(.245 .014 245);--border:oklch(.34 .016 245);--border-strong:oklch(.42 .018 245);
  --ink:oklch(.93 .01 240);--ink-strong:oklch(.97 .008 240);--muted:oklch(.7 .013 240);
  --scrim:oklch(.205 .012 245 / .68);--shadow:0 14px 36px oklch(0 0 0 / .42);
}
/* l'accento va calcolato dove cambia la tinta (--h): sulla pagina e su ogni scheda,
   altrimenti resterebbe quello della radice */
body,.classe{--acc:oklch(.56 .14 var(--h));--acc-ink:oklch(.47 .13 var(--h));--acc-soft:oklch(.9 .05 var(--h))}
[data-theme=dark] body,[data-theme=dark] .classe{--acc:oklch(.74 .13 var(--h));--acc-ink:oklch(.82 .11 var(--h));--acc-soft:oklch(.34 .07 var(--h))}
body[data-scena="3TELB"]{--h:var(--h-3TELB)}
body[data-scena="4TELA"]{--h:var(--h-4TELA)}
body[data-scena="4ELEA"]{--h:var(--h-4ELEA)}
@property --h{syntax:"<number>";inherits:true;initial-value:200}
body{transition:--h 520ms var(--ease-out-quart)}

html.theme-changing *,html.theme-changing *::before,html.theme-changing *::after{
  transition-property:background-color,color,border-color,fill,stroke,box-shadow,opacity,transform!important;
  transition-duration:var(--dur-slow)!important;transition-timing-function:var(--ease-out-quart)!important}

*,*::before,*::after{box-sizing:border-box}
*{margin:0}
html{color-scheme:light dark;-webkit-text-size-adjust:100%}
body{min-height:100svh;display:flex;flex-direction:column;background:var(--bg);color:var(--ink);
  font-family:var(--font-sans);font-size:var(--text-base);line-height:1.6;-webkit-font-smoothing:antialiased}
[data-theme=dark] body{font-weight:360;letter-spacing:.006em}
a{color:var(--acc-ink);text-decoration:none}
h1,h2,h3{line-height:1.08;letter-spacing:-.025em;text-wrap:balance;color:var(--ink-strong)}
:focus-visible{outline:2px solid var(--acc);outline-offset:3px;border-radius:6px}
.mono{font-family:var(--font-mono);font-feature-settings:"tnum" 1,"zero" 1}

/* sfondo animato */
.sfondo{position:fixed;inset:0;z-index:0;pointer-events:none}
.sfondo canvas{width:100%;height:100%;display:block;filter:blur(var(--canvas-blur))}

/* header */
.header{position:relative;z-index:10;display:flex;align-items:center;justify-content:space-between;gap:1rem;padding:var(--pad-y) var(--pad-x)}
.brand{display:inline-flex;align-items:center;gap:.6rem;color:var(--ink-strong);font-weight:620;letter-spacing:-.01em}
.brand svg{width:26px;height:26px;color:var(--acc)}
.brand .dom{font-family:var(--font-mono);font-size:var(--text-xs);color:var(--muted);font-weight:400}
.back{display:inline-flex;align-items:center;gap:.4rem;font-size:var(--text-sm);color:var(--muted);transition:color var(--dur) var(--ease-out-quart)}
.back:hover{color:var(--acc-ink)}

/* theme toggle (da Grtlabs) */
.track{--thumb:20px;--inset:3px;--travel:22px;position:relative;flex:none;width:48px;height:26px;padding:0;border:1px solid var(--border);
  border-radius:var(--radius-pill);background:color-mix(in oklch,var(--acc-soft) 50%,var(--surface));cursor:pointer;
  transition:background var(--dur-slow) var(--ease-out-quart),border-color var(--dur) var(--ease-out-quart)}
.track:hover{border-color:var(--border-strong)}
[data-theme=dark] .track{background:color-mix(in oklch,var(--acc) 26%,var(--surface))}
.thumb{position:absolute;top:var(--inset);left:var(--inset);display:grid;place-items:center;width:var(--thumb);height:var(--thumb);
  border-radius:var(--radius-pill);background:var(--bg);box-shadow:0 1px 3px oklch(.2 .02 235 / .2);color:oklch(.78 .15 75);
  transition:transform var(--dur-slow) var(--ease-out-quint),color var(--dur-slow) var(--ease-out-quart),background var(--dur-slow)}
[data-theme=dark] .thumb{transform:translateX(var(--travel));color:oklch(.87 .06 280)}
.thumb svg{width:14px;height:14px;overflow:visible}
.cutout{transform-box:fill-box;transform-origin:center;transform:translate(6px,-6px) scale(0);transition:transform var(--dur-slow) var(--ease-out-quint)}
[data-theme=dark] .cutout{transform:translate(5px,-5px) scale(1)}
.beams{transform-box:fill-box;transform-origin:center;transition:transform var(--dur-slow) var(--ease-out-quint),opacity var(--dur)}
[data-theme=dark] .beams{transform:rotate(-40deg) scale(.35);opacity:0}

/* hero */
main{position:relative;z-index:2;flex:1;display:grid;place-items:center;padding:var(--space-md) var(--pad-x) var(--space-xl)}
.inner{position:relative;width:100%;max-width:62rem;display:flex;flex-direction:column;align-items:center;text-align:center;gap:var(--space-md)}
.inner::before{content:"";position:absolute;inset:-12% -14%;z-index:-1;background-color:var(--scrim);
  -webkit-mask-image:radial-gradient(60% 55% at 50% 40%,#000 0%,transparent 74%);mask-image:radial-gradient(60% 55% at 50% 40%,#000 0%,transparent 74%);pointer-events:none}
.kicker{font-family:var(--font-mono);font-size:var(--text-xs);letter-spacing:.16em;color:var(--acc-ink);text-transform:uppercase}
.title{font-size:var(--display);font-weight:660;letter-spacing:-.035em;line-height:.98}
.tagline{font-size:var(--text-lg);color:var(--muted);max-width:40ch;text-wrap:pretty}

/* schede classe */
.classi{list-style:none;padding:0;margin-top:var(--space-sm);width:100%;display:grid;grid-template-columns:repeat(auto-fit,minmax(15rem,1fr));gap:var(--space-sm)}
.classe{--h:var(--hc);position:relative;display:flex;flex-direction:column;gap:.35rem;height:100%;text-align:left;padding:1.35rem 1.35rem 1.1rem;
  border:1px solid var(--border);border-radius:var(--radius-lg);color:var(--ink);overflow:hidden;
  background:color-mix(in oklch,var(--surface) 74%,transparent);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);
  transition:transform var(--dur-slow) var(--ease-out-quint),border-color var(--dur) var(--ease-out-quart),box-shadow var(--dur-slow) var(--ease-out-quart)}
.classe::after{content:"";position:absolute;left:0;right:0;bottom:0;height:3px;background:var(--acc);transform:scaleX(.18);transform-origin:left;
  transition:transform var(--dur-slow) var(--ease-out-quint)}
.classe:hover,.classe:focus-visible,.classe.attiva{transform:translateY(-4px);border-color:color-mix(in oklch,var(--acc) 55%,var(--border));box-shadow:var(--shadow)}
.classe:hover::after,.classe:focus-visible::after,.classe.attiva::after{transform:scaleX(1)}
.classe .glifo{width:44px;height:28px;color:var(--acc);margin-bottom:.2rem}
.classe .etichetta{font-family:var(--font-mono);font-size:var(--text-xs);letter-spacing:.14em;color:var(--muted)}
.classe .sigla{font-size:2.3rem;font-weight:680;letter-spacing:-.03em;line-height:1;color:var(--ink-strong)}
.classe .materia{font-size:var(--text-sm);color:var(--muted);min-height:1.3em}
.classe .piede{display:flex;justify-content:space-between;align-items:center;margin-top:.6rem;font-family:var(--font-mono);font-size:var(--text-xs);color:var(--acc-ink)}
.classe .freccia{transition:transform var(--dur-slow) var(--ease-out-quint)}
.classe:hover .freccia{transform:translateX(5px)}

/* pagina di classe */
.inner.sx{align-items:stretch;text-align:left;max-width:52rem}
.inner.sx::before{inset:-6% -10%}
.lezioni{list-style:none;padding:0;display:grid;gap:var(--space-xs);margin-top:var(--space-2xs)}
.lezione{display:grid;grid-template-columns:auto 1fr;gap:.2rem 1rem;align-items:center;padding:1rem 1.15rem;border:1px solid var(--border);
  border-radius:var(--radius-lg);background:color-mix(in oklch,var(--surface) 76%,transparent);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);
  transition:border-color var(--dur) var(--ease-out-quart),transform var(--dur-slow) var(--ease-out-quint)}
.lezione:hover{border-color:color-mix(in oklch,var(--acc) 45%,var(--border))}
.num{grid-row:span 2;display:grid;place-items:center;width:3rem;height:3rem;border-radius:var(--radius-md);font-family:var(--font-mono);font-weight:600;
  color:var(--acc-ink);background:color-mix(in oklch,var(--acc-soft) 70%,transparent);border:1px solid color-mix(in oklch,var(--acc) 30%,transparent)}
.lezione h2{font-size:1.12rem;font-weight:600;letter-spacing:-.01em}
.azioni{display:flex;flex-wrap:wrap;gap:.5rem;margin-top:.35rem}
.btn{display:inline-flex;align-items:center;gap:.4rem;padding:.42rem .8rem;border-radius:var(--radius-pill);font-size:var(--text-sm);font-weight:520;
  border:1px solid var(--border);color:var(--ink);background:color-mix(in oklch,var(--bg) 60%,transparent);
  transition:border-color var(--dur) var(--ease-out-quart),background var(--dur) var(--ease-out-quart),transform var(--dur) var(--ease-out-quart)}
.btn:hover{border-color:var(--acc);transform:translateY(-1px)}
.btn.primo{background:var(--acc);border-color:var(--acc);color:oklch(.99 0 0)}
[data-theme=dark] .btn.primo{color:oklch(.18 .02 245)}
.btn.primo:hover{background:var(--acc-ink);border-color:var(--acc-ink)}
.vuoto{padding:1.4rem;border:1px dashed var(--border-strong);border-radius:var(--radius-lg);color:var(--muted);
  background:color-mix(in oklch,var(--surface) 60%,transparent);text-align:center}

footer{position:relative;z-index:2;display:flex;flex-wrap:wrap;justify-content:space-between;gap:.5rem 1rem;padding:var(--space-sm) var(--pad-x) var(--pad-y);
  border-top:1px solid var(--border);background:color-mix(in oklch,var(--bg) 86%,transparent);font-size:var(--text-xs);color:var(--muted)}
footer .mono{letter-spacing:.04em}

/* ingresso (solo al primo caricamento) */
@keyframes boot-rise{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}
html.first-load .boot{animation:boot-rise var(--dur-boot) var(--ease-out-expo) both;animation-delay:calc(var(--i,0) * 90ms + 120ms)}

@media (max-width:640px){
  .tagline{font-size:var(--text-base)}
  .classe .sigla{font-size:2rem}
  .brand .dom{display:none}
  main{padding-top:var(--space-2xs)}
  .inner{gap:var(--space-sm)}
}
/* schermi stretti (telefono, schermo esterno del Fold): schede a riga compatta,
   così le tre classi stanno nella prima schermata */
@media (max-width:560px){
  .classi{grid-template-columns:1fr;gap:.6rem;margin-top:.2rem}
  .classe{display:grid;grid-template-columns:auto 1fr auto;grid-template-rows:auto auto;column-gap:.9rem;row-gap:0;align-items:center;padding:.85rem 1rem}
  .classe .glifo{grid-row:span 2;width:38px;height:24px;margin:0}
  .classe .etichetta{display:none}
  .classe .sigla{font-size:1.55rem}
  .classe .materia{grid-column:2;min-height:0;line-height:1.2}
  .classe .piede{grid-column:3;grid-row:1 / span 2;flex-direction:column;align-items:flex-end;gap:.15rem;margin:0}
  .classe:hover,.classe.attiva{transform:translateY(-2px)}
  .title{font-size:clamp(2rem,9vw,2.6rem)}
}
/* schermi bassi (Fold interno in orizzontale, telefoni in orizzontale) */
@media (max-height:700px) and (min-width:561px){
  main{padding-top:0}
  .inner{gap:var(--space-sm)}
  .classe{padding:1.05rem 1.2rem .9rem}
  .classe .sigla{font-size:2rem}
}
@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
}