/* ============================================================
   QUANTUM ARCADE — tema grafico condiviso
   Un solo file di stile per tutto il sito (hub + lezioni).
   ============================================================ */

:root {
  --bg:        #060912;
  --bg-2:      #0a1020;
  --panel:     #0e1526;
  --panel-2:   #131c33;
  --line:      #23304f;
  --line-soft: #1a2440;

  --txt:       #e8edf9;
  --txt-dim:   #9dabc9;
  --txt-mute:  #6c7a9c;

  --cyan:      #22d3ee;
  --violet:    #a78bfa;
  --amber:     #fbbf24;
  --green:     #34d399;
  --pink:      #f472b6;
  --red:       #fb7185;
  --blue:      #60a5fa;

  --radius:    14px;
  --radius-sm: 9px;
  --mono: ui-monospace, "JetBrains Mono", "Fira Code", "SF Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  --shadow: 0 18px 50px rgba(0, 0, 0, .55);
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  background:
    radial-gradient(1200px 700px at 12% -8%, rgba(34, 211, 238, .13), transparent 60%),
    radial-gradient(1000px 620px at 92% 4%, rgba(167, 139, 250, .13), transparent 62%),
    radial-gradient(900px 600px at 50% 108%, rgba(251, 191, 36, .07), transparent 60%),
    var(--bg);
  background-attachment: fixed;
  color: var(--txt);
  font-family: var(--sans);
  font-size: 16.5px;
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--cyan); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }
.wrap-wide { max-width: 1320px; margin: 0 auto; padding: 0 20px; }

/* ---------------- Topbar ---------------- */

.topbar {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(6, 9, 18, .82);
  border-bottom: 1px solid var(--line);
}
.topbar-in {
  display: flex; align-items: center; gap: 14px;
  height: 60px;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 800; letter-spacing: .3px; color: var(--txt);
  font-size: 15.5px;
}
.brand:hover { text-decoration: none; }
.brand .logo {
  width: 34px; height: 34px; border-radius: 10px; display: block;
  box-shadow: 0 0 22px rgba(34, 211, 238, .30);
}
.brand small { display: block; font-weight: 500; color: var(--txt-mute); font-size: 11px; letter-spacing: .8px; text-transform: uppercase; }

.topbar-spacer { flex: 1; }

.xp-wrap { display: flex; align-items: center; gap: 10px; min-width: 220px; }
.xp-bar {
  flex: 1; height: 9px; border-radius: 99px; background: #16203a;
  overflow: hidden; border: 1px solid var(--line);
}
.xp-fill {
  height: 100%; width: 0%;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
  transition: width .55s cubic-bezier(.2, .8, .2, 1);
}
.xp-label { font-family: var(--mono); font-size: 12px; color: var(--txt-dim); white-space: nowrap; }

/* ---------------- Bottoni ---------------- */

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 15px; border-radius: 10px;
  border: 1px solid var(--line);
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  color: var(--txt); font-size: 14px; font-weight: 600;
  cursor: pointer; transition: .16s; font-family: inherit;
  text-decoration: none;
}
.btn:hover { border-color: var(--cyan); transform: translateY(-1px); text-decoration: none; box-shadow: 0 6px 22px rgba(34, 211, 238, .18); }
.btn:active { transform: translateY(0); }
.btn:disabled { opacity: .42; cursor: not-allowed; transform: none; box-shadow: none; }
.btn.primary {
  background: linear-gradient(135deg, var(--cyan), #3aa8f0);
  color: #04121a; border-color: transparent; font-weight: 800;
}
.btn.primary:hover { filter: brightness(1.08); }
.btn.violet { background: linear-gradient(135deg, var(--violet), #7c6cf5); color: #0d0722; border-color: transparent; font-weight: 800; }
.btn.ghost { background: transparent; }
.btn.sm { padding: 6px 11px; font-size: 12.5px; border-radius: 8px; }
.btn.tiny { padding: 3px 8px; font-size: 11.5px; border-radius: 7px; }

.btn-row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }

/* ---------------- Pannelli / card ---------------- */

.panel {
  background: linear-gradient(180deg, rgba(19, 28, 51, .78), rgba(14, 21, 38, .92));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}
.panel + .panel { margin-top: 18px; }
.panel-title {
  display: flex; align-items: center; gap: 9px;
  font-weight: 800; font-size: 14px; letter-spacing: .6px;
  text-transform: uppercase; color: var(--cyan); margin: 0 0 12px;
}
.panel-title .dot { width: 8px; height: 8px; border-radius: 99px; background: var(--cyan); box-shadow: 0 0 12px var(--cyan); }

.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
@media (max-width: 860px) { .grid-2, .grid-3 { grid-template-columns: 1fr; } }

/* ---------------- Tipografia ---------------- */

h1 { font-size: clamp(28px, 4.4vw, 44px); line-height: 1.12; margin: 0 0 10px; letter-spacing: -.6px; }
h2 { font-size: clamp(21px, 2.6vw, 27px); margin: 34px 0 12px; letter-spacing: -.3px; }
h3 { font-size: 18px; margin: 22px 0 8px; }
p { margin: 0 0 13px; }

.lead { font-size: 18px; color: var(--txt-dim); }
.muted { color: var(--txt-mute); }
.dim { color: var(--txt-dim); }
.small { font-size: 13.5px; }
.center { text-align: center; }

code, .mono { font-family: var(--mono); font-size: .92em; }
code {
  background: #101a30; padding: 1.5px 6px; border-radius: 6px;
  border: 1px solid var(--line-soft); color: #b6e9f6;
  /* le formule in linea vanno a capo invece di allargare la pagina sul telefono */
  overflow-wrap: anywhere; word-break: break-word;
}
pre code { overflow-wrap: normal; word-break: normal; }
pre {
  background: #0a1120; border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: 13px 15px; overflow-x: auto; font-family: var(--mono); font-size: 13px;
  color: #cfe6ff; line-height: 1.55;
}
pre code { background: none; border: none; padding: 0; color: inherit; }

ul, ol { margin: 0 0 13px; padding-left: 22px; }
li { margin-bottom: 5px; }

.kbd {
  font-family: var(--mono); font-size: 12px; padding: 2px 7px;
  border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 6px; background: #131c33;
}

.formula {
  font-family: var(--mono); font-size: 16px; text-align: center;
  background: #0a1120; border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
  border-radius: var(--radius-sm); padding: 14px 16px; margin: 14px 0;
  color: #dbe7ff; overflow-x: auto;
}
.formula .hl-k { color: var(--amber); }
.formula .hl-n { color: var(--cyan); }
.formula .hl-N { color: var(--green); }
.formula .hl-x { color: var(--pink); }

.callout {
  border-radius: var(--radius-sm); padding: 13px 16px; margin: 15px 0;
  border: 1px solid var(--line); border-left: 3px solid var(--cyan);
  background: rgba(34, 211, 238, .06);
}
.callout.key    { border-left-color: var(--amber); background: rgba(251, 191, 36, .07); }
.callout.warn   { border-left-color: var(--red);   background: rgba(251, 113, 133, .07); }
.callout.ok     { border-left-color: var(--green); background: rgba(52, 211, 153, .07); }
.callout.think  { border-left-color: var(--violet); background: rgba(167, 139, 250, .07); }
.callout b:first-child { color: var(--txt); }
.callout p:last-child { margin-bottom: 0; }

.tag {
  display: inline-block; font-size: 11px; font-weight: 800; letter-spacing: .7px;
  text-transform: uppercase; padding: 3px 9px; border-radius: 99px;
  border: 1px solid var(--line); color: var(--txt-dim); background: #101a30;
}
.tag.cyan   { color: var(--cyan);   border-color: rgba(34, 211, 238, .45);  background: rgba(34, 211, 238, .10); }
.tag.violet { color: var(--violet); border-color: rgba(167, 139, 250, .45); background: rgba(167, 139, 250, .10); }
.tag.amber  { color: var(--amber);  border-color: rgba(251, 191, 36, .45);  background: rgba(251, 191, 36, .10); }
.tag.green  { color: var(--green);  border-color: rgba(52, 211, 153, .45);  background: rgba(52, 211, 153, .10); }

/* ---------------- Widget: contenitore standard ---------------- */

.widget {
  background: linear-gradient(180deg, #0b1226, #090f1d);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 18px 0;
  box-shadow: var(--shadow);
}
.widget-head {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 11px 15px; border-bottom: 1px solid var(--line);
  background: linear-gradient(90deg, rgba(34, 211, 238, .10), transparent 65%);
}
.widget-head .wt { font-weight: 800; font-size: 14px; letter-spacing: .3px; }
.widget-head .ws { font-size: 12.5px; color: var(--txt-mute); }
.widget-body { padding: 15px; }
.widget-foot {
  padding: 11px 15px; border-top: 1px solid var(--line);
  background: rgba(0, 0, 0, .25); font-size: 13.5px; color: var(--txt-dim);
}
.canvas-host { position: relative; width: 100%; }
.canvas-host canvas { display: block; width: 100%; border-radius: var(--radius-sm); touch-action: none; }

/* controlli */
.ctrls { display: flex; flex-wrap: wrap; gap: 13px 20px; align-items: flex-end; margin-top: 12px; }
.ctrl { min-width: 165px; flex: 1 1 165px; }
.ctrl-lab {
  display: flex; justify-content: space-between; align-items: baseline; gap: 8px;
  font-size: 12.5px; color: var(--txt-dim); margin-bottom: 5px;
}
.ctrl-val { font-family: var(--mono); color: var(--cyan); font-size: 12.5px; }

input[type=range] {
  -webkit-appearance: none; appearance: none;
  width: 100%; height: 20px; background: transparent; cursor: pointer; margin: 0;
}
input[type=range]::-webkit-slider-runnable-track {
  height: 5px; border-radius: 99px; background: #1c2745; border: 1px solid var(--line-soft);
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 16px; height: 16px; border-radius: 99px; margin-top: -6.5px;
  background: linear-gradient(135deg, var(--cyan), var(--violet));
  border: 2px solid #06101f; box-shadow: 0 0 12px rgba(34, 211, 238, .6);
}
input[type=range]::-moz-range-track { height: 5px; border-radius: 99px; background: #1c2745; }
input[type=range]::-moz-range-thumb {
  width: 15px; height: 15px; border: 2px solid #06101f; border-radius: 99px;
  background: linear-gradient(135deg, var(--cyan), var(--violet));
}

select, input[type=text], input[type=number] {
  background: #101a30; color: var(--txt); border: 1px solid var(--line);
  border-radius: 8px; padding: 7px 10px; font-family: inherit; font-size: 13.5px;
}
label.check { display: inline-flex; align-items: center; gap: 7px; font-size: 13.5px; color: var(--txt-dim); cursor: pointer; }
input[type=checkbox] { accent-color: var(--cyan); width: 15px; height: 15px; }

.readout {
  font-family: var(--mono); font-size: 13px; color: var(--txt-dim);
  background: #09101f; border: 1px solid var(--line-soft); border-radius: var(--radius-sm);
  padding: 10px 13px; margin-top: 12px; white-space: pre-wrap; line-height: 1.65;
}
.readout b { color: var(--txt); }
.readout .g { color: var(--green); }
.readout .a { color: var(--amber); }
.readout .c { color: var(--cyan); }
.readout .p { color: var(--pink); }

/* ---------------- Missione / sfida ---------------- */

.mission {
  border: 1px solid rgba(251, 191, 36, .4);
  background: linear-gradient(180deg, rgba(251, 191, 36, .10), rgba(251, 191, 36, .03));
  border-radius: var(--radius); padding: 15px 17px; margin: 18px 0;
}
.mission .mh {
  display: flex; align-items: center; gap: 9px; font-weight: 800;
  color: var(--amber); text-transform: uppercase; letter-spacing: .7px; font-size: 13px; margin-bottom: 7px;
}
.mission.done { border-color: rgba(52, 211, 153, .5); background: linear-gradient(180deg, rgba(52, 211, 153, .12), rgba(52, 211, 153, .03)); }
.mission.done .mh { color: var(--green); }

/* ---------------- Quiz ---------------- */

.quiz-q { border-top: 1px solid var(--line); padding-top: 15px; margin-top: 15px; }
.quiz-q:first-child { border-top: none; padding-top: 0; margin-top: 0; }
.quiz-q .qt { font-weight: 700; margin-bottom: 10px; }
.quiz-opts { display: flex; flex-direction: column; gap: 7px; }
.quiz-opt {
  text-align: left; padding: 10px 13px; border-radius: 10px;
  border: 1px solid var(--line); background: #101a30; color: var(--txt);
  cursor: pointer; font-size: 14.5px; font-family: inherit; transition: .14s; line-height: 1.45;
}
.quiz-opt:hover:not(:disabled) { border-color: var(--cyan); background: #16233f; }
.quiz-opt.right { border-color: var(--green); background: rgba(52, 211, 153, .14); }
.quiz-opt.wrong { border-color: var(--red); background: rgba(251, 113, 133, .13); }
.quiz-opt:disabled { cursor: default; }
.quiz-why {
  margin-top: 9px; font-size: 13.5px; color: var(--txt-dim);
  border-left: 2px solid var(--violet); padding-left: 11px;
}

/* ---------------- Mappa livelli (hub) ---------------- */

.part-head { display: flex; align-items: center; gap: 12px; margin: 38px 0 16px; }
.part-head .num {
  width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center;
  font-weight: 900; font-size: 17px; border: 1px solid var(--line); background: var(--panel-2);
}
.part-head h2 { margin: 0; font-size: 21px; }
.part-head .sub { font-size: 13px; color: var(--txt-mute); }

.levels { display: grid; grid-template-columns: repeat(auto-fill, minmax(268px, 1fr)); gap: 14px; }
.level {
  position: relative; display: block; padding: 15px 16px 14px;
  border-radius: var(--radius); border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(19, 28, 51, .8), rgba(12, 18, 33, .92));
  color: var(--txt); transition: .18s; overflow: hidden;
}
.level:hover { text-decoration: none; transform: translateY(-3px); border-color: var(--cyan); box-shadow: 0 14px 34px rgba(34, 211, 238, .16); }
.level .lv-n {
  font-family: var(--mono); font-size: 11.5px; color: var(--txt-mute); letter-spacing: 1px;
}
.level .lv-t { font-weight: 800; font-size: 16px; margin: 3px 0 5px; line-height: 1.3; }
.level .lv-d { font-size: 13.2px; color: var(--txt-dim); line-height: 1.5; }
.level .lv-f { display: flex; align-items: center; gap: 8px; margin-top: 11px; }
.level .lv-xp { font-family: var(--mono); font-size: 11.5px; color: var(--amber); }
.level.done { border-color: rgba(52, 211, 153, .45); }
.level.done::after {
  content: "✓"; position: absolute; top: 11px; right: 13px;
  color: var(--green); font-weight: 900; font-size: 17px;
}
.level.boss { border-color: rgba(251, 113, 133, .45); background: linear-gradient(180deg, rgba(60, 20, 40, .55), rgba(14, 21, 38, .92)); }

/* ---------------- Header lezione ---------------- */

.lesson-hero { padding: 34px 0 6px; }
.crumbs { font-size: 12.5px; color: var(--txt-mute); margin-bottom: 10px; }
.crumbs a { color: var(--txt-dim); }

.step { margin: 30px 0; }
.step-h { display: flex; gap: 12px; align-items: baseline; margin-bottom: 8px; }
.step-n {
  flex: none; font-family: var(--mono); font-size: 12px; font-weight: 800;
  color: var(--cyan); border: 1px solid rgba(34, 211, 238, .35); background: rgba(34, 211, 238, .08);
  border-radius: 8px; padding: 2px 8px;
}
.step-h h2 { margin: 0; font-size: 22px; }

.nav-foot {
  display: flex; justify-content: space-between; gap: 12px; align-items: center;
  margin: 40px 0 60px; padding-top: 22px; border-top: 1px solid var(--line);
  flex-wrap: wrap;
}

.toast {
  position: fixed; left: 50%; bottom: 26px; transform: translate(-50%, 24px);
  background: linear-gradient(135deg, var(--green), #12b981); color: #062018;
  font-weight: 800; padding: 11px 20px; border-radius: 12px; z-index: 200;
  box-shadow: 0 14px 40px rgba(52, 211, 153, .35); opacity: 0; transition: .35s;
  pointer-events: none; font-size: 14.5px;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------------- Presentazione autore ---------------- */

.author {
  display: flex; gap: 20px; align-items: center; flex-wrap: wrap;
}
.author img {
  width: clamp(220px, 30vw, 320px); aspect-ratio: 1 / 1; border-radius: 22px; object-fit: cover;
  border: 1px solid var(--line);
  box-shadow: 0 0 0 4px rgba(34, 211, 238, .16), 0 24px 60px rgba(0, 0, 0, .6);
  flex: none;
}
.author .cap { font-size: 12px; color: var(--txt-mute); margin-top: 8px; text-align: center; }
.author .who { flex: 1 1 380px; }
.author { align-items: flex-start; gap: 26px; }
.author .who h3 { margin: 0 0 4px; font-size: 20px; }

.table { width: 100%; border-collapse: collapse; font-size: 14px; margin: 14px 0; }
.table th, .table td { border: 1px solid var(--line); padding: 8px 11px; text-align: left; }
.table th { background: #101a30; font-size: 12.5px; text-transform: uppercase; letter-spacing: .6px; color: var(--txt-dim); }
.table td.mono { font-family: var(--mono); }

.hidden { display: none !important; }
.nowrap { white-space: nowrap; }
.flex { display: flex; }
.gap8 { gap: 8px; }
.wrapf { flex-wrap: wrap; }
.mt0 { margin-top: 0; }
.mt12 { margin-top: 12px; }
.mb0 { margin-bottom: 0; }

::-webkit-scrollbar { width: 11px; height: 11px; }
::-webkit-scrollbar-track { background: var(--bg-2); }
::-webkit-scrollbar-thumb { background: #24314f; border-radius: 99px; border: 2px solid var(--bg-2); }
::-webkit-scrollbar-thumb:hover { background: #33456e; }

/* ---------------- Formula esplorabile ---------------- */

.f-box {
  background: #0a1120; border: 1px solid var(--line); border-left: 3px solid var(--violet);
  border-radius: var(--radius-sm); padding: 13px 15px; margin: 16px 0;
}
.f-title { font-size: 12.5px; text-transform: uppercase; letter-spacing: .7px; color: var(--txt-mute); margin-bottom: 9px; font-weight: 700; }
.f-row { display: flex; flex-wrap: wrap; align-items: center; gap: 5px; font-family: var(--mono); font-size: 19px; }
.f-dec { color: #cfe0ff; padding: 0 2px; }
.f-tok {
  font-family: var(--mono); font-size: 19px; line-height: 1.1;
  background: #131f38; border: 1px solid var(--line); border-bottom-width: 2px;
  border-radius: 8px; padding: 4px 9px 3px; cursor: pointer; color: var(--txt);
  transition: .14s; display: inline-flex; flex-direction: column; align-items: center; gap: 1px;
}
.f-tok:hover { transform: translateY(-1px); }
.f-tok .f-v { font-size: 10.5px; color: var(--txt-mute); letter-spacing: .3px; }
.f-tok.c-cyan   { border-color: rgba(34,211,238,.5);  color: var(--cyan); }
.f-tok.c-violet { border-color: rgba(167,139,250,.5); color: var(--violet); }
.f-tok.c-amber  { border-color: rgba(251,191,36,.5);  color: var(--amber); }
.f-tok.c-green  { border-color: rgba(52,211,153,.5);  color: var(--green); }
.f-tok.c-pink   { border-color: rgba(244,114,182,.5); color: var(--pink); }
.f-tok.on { background: #1c2c4d; box-shadow: 0 0 0 2px rgba(34,211,238,.25); }
.f-expl { margin-top: 11px; font-size: 14px; border-top: 1px dashed var(--line); padding-top: 10px; }
.f-name { font-family: var(--mono); font-size: 15px; color: var(--txt); margin-bottom: 3px; }
.f-name span { font-family: var(--sans); font-size: 13px; color: var(--amber); font-weight: 700; }
.f-say { color: var(--txt-dim); }
.f-ex { margin-top: 7px; font-family: var(--mono); font-size: 12.5px; color: #a8d8ea; background: #0d1729; border-radius: 7px; padding: 7px 10px; }

/* ---------------- Stepper ---------------- */

.stepper { border: 1px solid var(--line); border-radius: var(--radius); padding: 14px 16px; background: rgba(10,17,32,.6); margin: 16px 0; }
.stepper-bar { display: flex; gap: 5px; margin-bottom: 11px; }
.stepper-bar .sdot { width: 22px; height: 5px; border-radius: 99px; background: #1e2a48; cursor: pointer; transition: .2s; }
.stepper-bar .sdot.on { background: linear-gradient(90deg, var(--cyan), var(--violet)); }
.stepper-h { font-weight: 800; margin-bottom: 6px; color: var(--cyan); font-size: 15px; }
.stepper-body { min-height: 76px; font-size: 15px; }

/* ---------------- Livelli bloccati ---------------- */

.level.locked {
  opacity: .55; cursor: not-allowed; filter: grayscale(.35);
  border-style: dashed;
}
.level.locked:hover { transform: none; border-color: var(--line); box-shadow: none; }

/* ---------------- Accessibilità e comfort di lettura ----------------
   Basato su linee guida WCAG 2.2 (contrasto, bersagli, focus visibile)
   e su principi di carico cognitivo (riga di lettura ~65-75 caratteri). */

:where(p, li) { max-width: 78ch; }
.lead { max-width: 72ch; }

:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 6px;
}

.btn, .quiz-opt, .f-tok, input[type=range]::-webkit-slider-thumb { min-height: 34px; }
.quiz-opt { min-height: 44px; }          /* bersaglio tattile comodo su mobile */

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .001ms !important; transition-duration: .001ms !important; }
  .xp-fill { transition: none; }
}

.skip-link {
  position: absolute; left: -9999px; top: 0; z-index: 999;
  background: var(--cyan); color: #04121a; padding: 10px 16px; font-weight: 800; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ---------------- Blocchi "metodo"/fonti ---------------- */

.src { font-size: 13.5px; color: var(--txt-dim); }
.src li { margin-bottom: 8px; }
.tldr {
  border: 1px solid rgba(52,211,153,.4); background: rgba(52,211,153,.07);
  border-radius: var(--radius); padding: 14px 16px; margin: 16px 0;
}
.tldr b:first-child { color: var(--green); }

/* ---------------- Attestato ---------------- */

.attestato {
  margin-top: 18px; padding: 34px 30px; border-radius: 16px;
  border: 2px solid var(--cyan);
  background: linear-gradient(160deg, #0d1526, #131c33);
  text-align: center; box-shadow: 0 0 0 6px rgba(34,211,238,.08), var(--shadow);
}
.att-top { font-size: 13px; letter-spacing: 4px; color: var(--cyan); font-weight: 800; }
.att-sub { font-size: 13px; color: var(--txt-mute); margin-top: 4px; letter-spacing: 1px; text-transform: uppercase; }
.att-name {
  font-size: clamp(26px, 5vw, 40px); font-weight: 800; margin: 20px 0 10px;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.att-txt { max-width: 62ch; margin: 0 auto 22px; color: var(--txt-dim); font-size: 15px; }
.att-row { display: flex; justify-content: center; gap: 34px; flex-wrap: wrap; font-size: 13.5px; }
.att-lab { font-size: 10.5px; text-transform: uppercase; letter-spacing: 1px; color: var(--txt-mute); }
.att-note { margin-top: 22px; font-size: 11.5px; color: var(--txt-mute); }

@media print {
  body { background: #fff !important; color: #000; }
  .topbar, .nav-foot, .widget-head, .btn, .quiz-q, h1, h2, .lesson-hero, .callout, .panel { display: none !important; }
  .attestato { display: block !important; border-color: #222; background: #fff; box-shadow: none; }
  .att-name { color: #111 !important; -webkit-text-fill-color: #111; }
  .att-txt, .att-row, .att-note { color: #333 !important; }
  .widget, .widget-body { border: none !important; background: #fff !important; box-shadow: none !important; }
}

/* ---------------- Finestre modali (account) ---------------- */

.modal-back {
  position: fixed; inset: 0; z-index: 300; display: grid; place-items: center;
  background: rgba(4, 8, 18, .72); backdrop-filter: blur(6px); padding: 20px;
}
.modal-card {
  width: min(520px, 100%); background: linear-gradient(180deg, #131c33, #0e1526);
  border: 1px solid var(--line); border-radius: var(--radius); padding: 22px;
  box-shadow: var(--shadow);
  /* Su Safari mobile 100vh è l'altezza della finestra COME SE la barra degli
     indirizzi fosse nascosta: una finestra alta 100vh finisce sotto la barra e
     i bottoni in fondo diventano irraggiungibili. `dvh` è l'altezza davvero
     visibile in questo momento; la riga con vh resta come ripiego per i
     browser vecchi, che ignorano la seconda. */
  max-height: calc(100vh - 40px);
  max-height: calc(100dvh - 40px);
  overflow-y: auto;
}
.modal-card h3 { font-size: 21px; }

/* ---------------- Tutor AI ---------------- */

#qa-tutor { position: fixed; right: 18px; bottom: 18px; z-index: 250; }

.tutor-bubble {
  width: 56px; height: 56px; border-radius: 50%; border: none; cursor: pointer;
  background: linear-gradient(135deg, var(--cyan), var(--violet)); color: #04121a;
  font-size: 24px; box-shadow: 0 10px 30px rgba(34, 211, 238, .35);
  transition: transform .18s;
}
.tutor-bubble:hover { transform: scale(1.06); }
#qa-tutor.open .tutor-bubble { display: none; }

.tutor-panel {
  display: none; flex-direction: column;
  width: min(400px, calc(100vw - 36px));
  height: min(560px, calc(100vh - 120px));
  height: min(560px, calc(100dvh - 120px));   /* vedi nota su dvh in .modal-card */
  background: linear-gradient(180deg, #101a30, #0b1120);
  border: 1px solid var(--line); border-radius: 16px; overflow: hidden;
  box-shadow: 0 24px 60px rgba(0, 0, 0, .6);
}
#qa-tutor.open .tutor-panel { display: flex; }

.tutor-head {
  display: flex; align-items: center; gap: 8px; padding: 11px 14px;
  border-bottom: 1px solid var(--line); font-weight: 800; font-size: 14px;
  background: linear-gradient(90deg, rgba(34, 211, 238, .12), transparent 70%);
}
.tutor-log { flex: 1; overflow-y: auto; padding: 14px; display: flex; flex-direction: column; gap: 10px; }
.tutor-msg {
  max-width: 88%; padding: 10px 13px; border-radius: 14px; font-size: 14.5px; line-height: 1.55;
  border: 1px solid var(--line); white-space: normal;
}
.tutor-msg.bot { align-self: flex-start; background: #131f38; border-bottom-left-radius: 4px; }
.tutor-msg.me { align-self: flex-end; background: rgba(34, 211, 238, .14); border-color: rgba(34, 211, 238, .4); border-bottom-right-radius: 4px; }
.tutor-msg.typing { opacity: .6; font-style: italic; }
.tutor-msg a { word-break: break-word; }
.tutor-src, .tutor-rate, .tutor-quick { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 9px; align-items: center; font-size: 12px; }
.tutor-quick { padding: 0 4px; }
.tutor-foot { display: flex; gap: 8px; padding: 10px; border-top: 1px solid var(--line); align-items: flex-end; }
.tutor-input {
  flex: 1; resize: none; max-height: 96px; background: #0c1425; color: var(--txt);
  border: 1px solid var(--line); border-radius: 10px; padding: 10px 12px;
  font-family: inherit; font-size: 14.5px; line-height: 1.4;
}
.tutor-input:focus { outline: none; border-color: var(--cyan); }

@media (max-width: 520px) {
  #qa-tutor { right: 12px; bottom: 12px; }
  .tutor-panel { height: min(70vh, 520px); }
}

/* ---------------- Form (registrazione, account) ---------------- */

/* Le righe si allineano perché ogni campo ha sempre la riga di suggerimento
   (anche vuota) e le celle sono stirate alla stessa altezza. */
/* min-width:0 sulle celle: senza, gli <input> impongono la loro larghezza
   minima intrinseca (~20 caratteri) e la finestra sborda. */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 14px; margin-top: 14px; align-items: stretch; }
.form-grid > * { min-width: 0; }
.form-grid.one { grid-template-columns: 1fr; }
@media (max-width: 520px) { .form-grid { grid-template-columns: 1fr; } }

.field { display: flex; flex-direction: column; gap: 5px; justify-content: flex-start; }
.field > :nth-child(2) { margin-top: auto; }
.field-lab { font-size: 12.5px; color: var(--txt-dim); font-weight: 600; }
.field-hint { font-size: 11.5px; color: var(--txt-mute); line-height: 1.35; min-height: 15px; }
.field input {
  background: #0c1425; color: var(--txt); border: 1px solid var(--line);
  border-radius: 9px; padding: 10px 12px; font-family: inherit; font-size: 15px;
  width: 100%; min-width: 0;
}
.field input:focus, .field select:focus { outline: none; border-color: var(--cyan); box-shadow: 0 0 0 3px rgba(34,211,238,.15); }

/* data di nascita: giorno / mese / anno */
.birth-row { display: grid; grid-template-columns: 1fr 1.5fr 1.1fr; gap: 6px; min-width: 0; }
.birth-row select { min-width: 0; }
.birth-row select {
  background: #0c1425; color: var(--txt); border: 1px solid var(--line);
  border-radius: 9px; padding: 10px 6px; font-family: inherit; font-size: 14px; width: 100%;
}

.form-msg { min-height: 20px; margin-top: 10px; font-size: 13.5px; color: var(--txt-dim); }
.form-msg.err { color: var(--red); }
.form-msg.ok  { color: var(--green); }

.btn.warn-dot { position: relative; }
.btn.warn-dot::after {
  content: ''; position: absolute; top: -3px; right: -3px;
  width: 9px; height: 9px; border-radius: 99px; background: var(--amber);
  box-shadow: 0 0 8px var(--amber);
}

/* ---------------- Telefono: la barra in alto deve stare nello schermo ----------------
   Su 412 px la riga brand + barra XP + tre bottoni non ci sta: qui la si
   riorganizza su due livelli invece di lasciarla sbordare (che causava
   scorrimento orizzontale su tutte le pagine). */

@media (max-width: 700px) {
  .topbar-in {
    height: auto; padding: 8px 0; gap: 8px 10px;
    flex-wrap: wrap; justify-content: space-between;
  }
  .brand { font-size: 14px; gap: 8px; }
  .brand .logo { width: 28px; height: 28px; }
  .brand small { display: none; }
  .topbar-spacer { display: none; }

  .xp-wrap { order: 3; width: 100%; min-width: 0; }
  .xp-label { font-size: 11px; }

  .wrap, .wrap-wide { padding: 0 14px; }
  h1 { font-size: clamp(25px, 7vw, 34px); }

  .widget-body { padding: 11px; }
  .ctrl { min-width: 130px; flex-basis: 130px; }
  .table { font-size: 13px; }
  .table th, .table td { padding: 6px 8px; }

  /* le tabelle larghe scorrono da sole invece di allargare la pagina */
  .table { display: block; overflow-x: auto; white-space: nowrap; }
  .table td, .table th { white-space: normal; min-width: 90px; }
}

@media (max-width: 420px) {
  .btn { padding: 8px 11px; font-size: 13px; }
  .btn.sm { padding: 5px 9px; font-size: 12px; }
  .att-row { gap: 16px; }
}

/* ---------------- Dita, non frecce del mouse ----------------
   Su un touchscreen il bersaglio non è un pixel: è un polpastrello, largo
   circa 9 mm. Le linee guida (WCAG 2.5.5) chiedono 44×44 px, e i bottoni qui
   erano alti 34. Si alzano i bersagli e si ingrandisce il testo minuto SOLO
   dove si tocca — `pointer: coarse` —, così sul computer la densità resta
   quella pensata e nessuna schermata si allarga.

   I collegamenti dentro un discorso restano come sono, apposta: la stessa
   linea guida li esenta, e ingrossarli spezzerebbe la lettura. */

@media (pointer: coarse) {
  /* niente rettangolo grigio al tocco, e nessuna attesa di mezzo secondo per
     capire se era un doppio tocco: in un gioco quel ritardo si sente */
  .btn, button, .f-tok, .tab, .chip { -webkit-tap-highlight-color: transparent; touch-action: manipulation; }

  .btn, .btn.sm { min-height: 44px; padding-top: 10px; padding-bottom: 10px; font-size: 14px; }
  /* i tasti-icona ("X", "+1", il muto) sono alti ma strettissimi: un dito
     non è più preciso in orizzontale che in verticale */
  .btn, .f-tok { min-width: 44px; justify-content: center; }
  /* Nella barra in alto un'etichetta che va a capo raddoppia l'altezza del
     bottone e sfonda la barra. Solo lì si tiene tutto su una riga: altrove i
     bottoni hanno etichette lunghe e devono poter andare a capo, se no
     sbordano dal bordo destro dello schermo. */
  .topbar .btn { white-space: nowrap; }
  .topbar-in { height: auto; min-height: 60px; padding: 7px 0; }
  .btn.tiny { min-height: 44px; padding: 8px 13px; font-size: 12.5px; }
  .f-tok { min-height: 44px; }
  .brand { min-height: 44px; }

  /* cursori: la pista resta sottile, ma la zona da afferrare diventa un dito */
  input[type=range] { height: 44px; }
  input[type=range]::-webkit-slider-thumb { width: 26px; height: 26px; margin-top: -10.5px; }
  input[type=range]::-moz-range-thumb { width: 24px; height: 24px; }
  input[type=checkbox], input[type=radio] { width: 24px; height: 24px; }

  /* testo minuto: 11 px in mano, in movimento, è sotto la soglia del leggibile */
  /* i collegamenti in fondo alla pagina sono impilati e alti 22px: uno sopra
     l'altro, si sbaglia bersaglio. Restano testo, ma con aria intorno. */
  .nav-foot a { padding: 11px 4px; }

  .tag, .xp-label, .att-note, .field-hint { font-size: 12.5px; }
  .level .lv-n, .level .lv-xp { font-size: 12.5px; }
  .brand small { font-size: 12px; }
  code, td.mono, .table .mono { font-size: 12.5px; }
}

/* ---------------- Telefono girato in orizzontale ----------------
   390 px di altezza in tutto: ogni pixel speso in intestazione è un pixel
   tolto al gioco. La barra si stringe al minimo indispensabile e il
   sottotitolo del marchio sparisce, come già fa sugli schermi stretti. */

@media (max-height: 460px) and (pointer: coarse) {
  .topbar-in { min-height: 0; padding: 5px 0; gap: 9px; }
  .brand small { display: none; }
  .brand { font-size: 14px; }
  h1 { font-size: clamp(22px, 4vw, 28px); }

  /* il pallino del tutor galleggia sopra il gioco: qui si fa più piccolo e si
     sposta nell'angolo, per coprire meno campo da gioco */
  #qa-tutor { right: 10px; bottom: 10px; }
  .tutor-bubble { width: 46px; height: 46px; font-size: 20px; }
}