/* =====================================================================
   Scuola — foglio di stile
   Idea: un quaderno vero. Carta a righe con il margine rosso, penna blu,
         evidenziatore sui titoli, ogni materia è un quaderno con la sua copertina.
   Indice: 1 token · 2 base · 3 struttura · 4 navigazione · 5 home
           6 materia e capitolo · 7 contenuto · 8 riassunti · 9 flashcard/quiz
           10 ricerca · 11 ripasso · 12 animazioni · 13 telefono
   ===================================================================== */

/* ---------- 1. Token ---------- */
:root {
  --paper: #faf8f3;
  --paper-2: #f3f0e8;
  --surface: #ffffff;
  --line: rgb(66 104 168 / 0.085);
  --margin-line: rgb(214 88 100 / 0.42);
  --ink: #1f2430;
  --ink-soft: #4b5262;
  --ink-faint: #868b97;
  --rule: #e6e2d8;
  --rule-strong: #d2ccbf;
  --pen: #2448b8;
  --pen-soft: rgb(36 72 184 / 0.08);
  --on-pen: #ffffff;
  --highlight: #fff27a;
  --highlight-ink: #1f2430;
  --postit: #fff6c4;
  --good: #22864c;
  --bad: #c43a3a;
  --code-bg: #f7f5ef;
  --tok-keyword: #a3249e;
  --tok-string: #2c7a3f;
  --tok-number: #b35c00;
  --tok-comment: #8a8f9c;
  --tok-function: #2448b8;
  --tok-pre: #b0306a;
  --c-mix: 88%;
  --shadow: 0 1px 2px rgb(60 50 30 / 0.06), 0 3px 10px -4px rgb(60 50 30 / 0.12);
  --shadow-up: 0 2px 4px rgb(60 50 30 / 0.06), 0 14px 28px -12px rgb(60 50 30 / 0.3);
  --shadow-lg: 0 18px 50px rgb(31 36 48 / 0.22);
  --scrim: rgb(31 36 48 / 0.4);

  --font-body: "Atkinson Hyperlegible Next", "Atkinson Hyperlegible", "Segoe UI", system-ui, sans-serif;
  --font-display: var(--font-body);
  --font-mono: "Atkinson Hyperlegible Mono", ui-monospace, Menlo, Consolas, monospace;
  --font-hand: "Kalam", "Segoe Print", "Comic Sans MS", cursive;

  --ease: cubic-bezier(0.2, 0.7, 0.2, 1);
  --r: 6px;
  --r-lg: 10px;
  --topbar: 58px;
  --tabbar: 64px;
  --sidebar: 250px;
  --lh: 30px;
  --accent-subject: var(--pen);
  color-scheme: light;
}

/* colore materia leggibile sul bianco */
[style*="--c:"] { --c-ink: color-mix(in srgb, var(--c) var(--c-mix), var(--ink)); }
html[data-subject] { --c: var(--accent-subject); --c-ink: color-mix(in srgb, var(--accent-subject) var(--c-mix), var(--ink)); }

/* ---------- 2. Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-padding-top: calc(var(--topbar) + 24px); -webkit-text-size-adjust: 100%; -webkit-tap-highlight-color: transparent; }
body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--paper);
  /* carta a righe */
  background-image: linear-gradient(transparent calc(var(--lh) - 1px), var(--line) 0);
  background-size: 100% var(--lh);
  color: var(--ink);
  font: 17px/1.62 var(--font-body);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--pen); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
img, svg { max-width: 100%; }
button { font: inherit; color: inherit; }
hr { border: 0; border-top: 1px dashed var(--rule-strong); margin: 2.5rem 0; }
.icon { width: 18px; height: 18px; flex: none; }
kbd { font: 500 11px/1 var(--font-mono); padding: 3px 5px; border: 1px solid var(--rule-strong); border-radius: 4px; background: var(--surface); color: var(--ink-faint); }
::selection { background: var(--highlight); color: var(--highlight-ink); }
:focus-visible { outline: 2px solid var(--pen); outline-offset: 2px; border-radius: 3px; }
.hand { font-family: var(--font-hand); color: var(--pen); font-size: 1.12em; line-height: 1.35; }
.muted-small { font-size: 13px; color: var(--ink-faint); }
[hidden] { display: none !important; }

body:not(.is-ready) > #content { opacity: 0; animation: reveal 0s 0.8s forwards; }
@keyframes reveal { to { opacity: 1; } }

/* ---------- 3. Struttura ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  gap: 8px;
  height: calc(var(--topbar) + env(safe-area-inset-top, 0px));
  padding: env(safe-area-inset-top, 0px) 22px 0;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--rule);
}
.shell { display: flex; min-height: calc(100vh - var(--topbar)); }
.page { position: relative; flex: 1; min-width: 0; display: flex; flex-direction: column; padding: 26px 48px 0 64px; }
/* margine rosso del quaderno */
.page::before { content: ""; position: absolute; top: 0; bottom: 0; left: 30px; border-left: 1.5px solid var(--margin-line); pointer-events: none; }
.page-grid { flex: 1; display: grid; grid-template-columns: minmax(0, 1fr); gap: 56px; }
.page-grid.has-toc { grid-template-columns: minmax(0, 46rem) 210px; }
#content { min-width: 0; max-width: 46rem; width: 100%; padding-bottom: 72px; }
html[data-toc="off"] #content { max-width: 64rem; }
html[data-subject][data-toc="off"] #content { max-width: 48rem; }

.site-footer {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px 24px;
  padding: 18px 0 26px; border-top: 1px solid var(--rule);
  font-size: 13px; color: var(--ink-faint);
}
.site-footer a { color: var(--ink-soft); }

/* ---------- 4. Navigazione ---------- */
.brand { display: flex; align-items: center; gap: 10px; margin-right: 18px; color: var(--ink); text-decoration: none; }
/* un piccolo quaderno: dorso scuro ed etichetta bianca */
.brand-mark {
  position: relative;
  width: 21px; height: 26px;
  border-radius: 2px 5px 5px 2px;
  background: linear-gradient(90deg, rgb(0 0 0 / 0.28) 0 4px, transparent 4px), var(--pen);
  transition: transform 0.25s var(--ease);
}
.brand-mark::after { content: ""; position: absolute; left: 8px; top: 7px; width: 9px; height: 6px; border-radius: 1px; background: #fff; }
.brand:hover .brand-mark { transform: rotate(-8deg); }
.brand-name { font-weight: 800; font-size: 19px; letter-spacing: -0.01em; }

.top-nav { display: flex; gap: 4px; }
.top-link {
  position: relative;
  display: inline-flex; align-items: center; height: 40px; padding: 0 12px;
  color: var(--ink-soft); text-decoration: none; font-weight: 700; font-size: 15.5px;
}
.top-link::after {
  content: ""; position: absolute; left: 12px; right: 12px; bottom: 4px; height: 2px; border-radius: 2px;
  background: var(--pen); transform: scaleX(0); transform-origin: left; transition: transform 0.25s var(--ease);
}
.top-link:hover { color: var(--ink); }
.top-link:hover::after { transform: scaleX(0.5); }
.top-link.is-active { color: var(--pen); }
.top-link.is-active::after { transform: scaleX(1); }

.icon-btn {
  display: inline-grid; place-items: center;
  width: 42px; height: 42px;
  border: 0; border-radius: 8px;
  background: none; color: var(--ink-soft);
  cursor: pointer;
}
.icon-btn:hover { background: var(--paper-2); color: var(--ink); }
.search-icon { display: none; margin-left: auto; }

.search-trigger {
  margin-left: auto;
  display: flex; align-items: center; gap: 10px;
  width: min(320px, 32vw); height: 40px;
  padding: 0 8px 0 12px;
  border: 1px solid var(--rule-strong); border-radius: 8px;
  background: var(--surface); color: var(--ink-faint);
  font-size: 15px; cursor: pointer;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.search-trigger:hover { border-color: var(--pen); color: var(--ink-soft); box-shadow: 0 0 0 3px var(--pen-soft); }
.search-trigger-label { flex: 1; text-align: left; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.sidebar {
  position: sticky; top: var(--topbar);
  flex: none; width: var(--sidebar);
  height: calc(100vh - var(--topbar));
  overflow-y: auto;
  padding: 22px 0 40px;
  background: var(--paper-2);
  border-right: 1px solid var(--rule);
}
.sheet-head { display: none; }
.side-list, .side-pages { list-style: none; margin: 0; padding: 0; }
.side-link {
  position: relative;
  display: flex; align-items: center; gap: 12px;
  min-height: 44px; padding: 6px 16px 6px 0;
  color: var(--ink-soft); text-decoration: none; font-weight: 700; font-size: 15.5px;
}
.side-link .tab { width: 7px; height: 26px; border-radius: 0 4px 4px 0; background: var(--c); opacity: 0.55; transition: width 0.2s var(--ease), opacity 0.2s; }
.side-link:hover { color: var(--ink); }
.side-link:hover .tab { opacity: 1; width: 10px; }
.side-subject.is-open > .side-link { color: var(--ink); }
.side-subject.is-open > .side-link .tab, .side-link.is-active .tab { width: 13px; opacity: 1; }
.side-name { flex: 1; }
.side-count { font: 12.5px var(--font-mono); color: var(--ink-faint); font-variant-numeric: tabular-nums; }
.side-pages { margin: 0 0 10px 30px; border-left: 1px dashed var(--rule-strong); }
.side-pages a { display: flex; align-items: center; gap: 9px; min-height: 38px; padding: 4px 14px; font-size: 15px; color: var(--ink-soft); text-decoration: none; line-height: 1.3; }
.side-pages a:hover { color: var(--ink); }
.side-pages a.is-active { color: var(--c-ink); font-weight: 700; }
.side-pages .side-group { padding: 10px 14px 2px; font-size: 12.5px; font-weight: 800; letter-spacing: 0.06em; text-transform: uppercase; color: var(--ink-faint); }
.side-pages .dot { flex: none; width: 9px; height: 9px; border-radius: 50%; border: 1.5px solid var(--rule-strong); transition: background 0.2s, border-color 0.2s; }
.side-pages a.is-done .dot { background: var(--good); border-color: var(--good); }

.breadcrumb { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; font-size: 14.5px; color: var(--ink-faint); }
.breadcrumb a { color: var(--ink-soft); text-decoration: none; }
.breadcrumb a:hover { color: var(--pen); }

.toc { position: sticky; top: calc(var(--topbar) + 30px); align-self: start; max-height: calc(100vh - var(--topbar) - 60px); overflow-y: auto; font-size: 14px; }
.toc-title { margin: 0 0 10px; font: 400 17px var(--font-hand); color: var(--pen); }
.toc-track { position: relative; }
.toc ul { list-style: none; margin: 0; padding: 0; }
.toc a { display: block; padding: 4px 0 4px 12px; border-left: 2px solid var(--rule); color: var(--ink-soft); text-decoration: none; line-height: 1.35; transition: color 0.2s; }
.toc .toc-h3 a { padding-left: 24px; font-size: 13.5px; }
.toc a:hover { color: var(--ink); }
.toc a.is-active { color: var(--pen); }
.toc-marker {
  position: absolute; left: 0; top: 0; width: 2px; height: 0;
  background: var(--pen); border-radius: 2px; opacity: 0;
  transition: transform 0.3s var(--ease), height 0.3s var(--ease), opacity 0.2s;
}
.toc-marker.is-on { opacity: 1; }
.toc-mobile { display: none; }

.tabbar { display: none; }

/* ---------- 5. Home ---------- */
.home-head { margin: 6px 0 22px; }
#content .home-head h1 { margin: 0; }
#content .home-head .lead { margin: 2px 0 0; }

.continue {
  display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 2px 14px;
  margin: 0 0 24px; padding: 12px 16px 12px 18px;
  border: 1px solid var(--rule-strong); border-left: 5px solid var(--c); border-radius: var(--r-lg);
  background: var(--surface); box-shadow: var(--shadow);
  color: var(--ink); text-decoration: none;
  transition: transform 0.2s var(--ease), box-shadow 0.2s;
}
.continue-label { grid-column: 1; font: 400 15px/1.2 var(--font-hand); color: var(--pen); }
.continue-title { grid-column: 1; font-weight: 700; min-width: 0; }
.continue-subject { margin-right: 8px; color: var(--c-ink); font-size: 14px; }
.continue .icon { grid-column: 2; grid-row: 1 / span 2; color: var(--ink-faint); transition: transform 0.2s var(--ease), color 0.2s; }
.continue:hover { transform: translateY(-2px); box-shadow: var(--shadow-up); }
.continue:hover .icon { transform: translateX(4px); color: var(--pen); }

/* Copertine dei quaderni */
.covers { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 20px; margin: 0 0 30px; }
.cover {
  --spine: color-mix(in srgb, var(--c) 72%, #000);
  position: relative;
  display: flex; flex-direction: column; justify-content: center;
  min-height: 200px;
  padding: 24px 32px 24px 30px;
  border-radius: 4px 12px 12px 4px;
  background:
    linear-gradient(90deg, var(--spine) 0 16px, rgb(255 255 255 / 0.2) 16px 17px, transparent 17px),
    radial-gradient(130% 90% at 90% 0%, rgb(255 255 255 / 0.2), transparent 60%),
    var(--c);
  box-shadow: inset 0 0 0 1px rgb(0 0 0 / 0.08), 0 1px 1px rgb(0 0 0 / 0.08), 0 8px 16px -8px color-mix(in srgb, var(--c) 70%, #000);
  color: var(--ink); text-decoration: none;
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}
/* cuciture sul dorso */
.cover::before { content: ""; position: absolute; left: 7px; top: 12px; bottom: 12px; border-left: 2px dotted rgb(255 255 255 / 0.4); }
/* elastico */
.cover::after { content: ""; position: absolute; top: 0; bottom: 0; right: 16px; width: 8px; background: rgb(0 0 0 / 0.24); box-shadow: inset 1px 0 rgb(255 255 255 / 0.12); }
.cover-label {
  position: relative; z-index: 1;
  display: grid; gap: 3px;
  padding: 12px 14px 13px;
  border-radius: 6px;
  background: #fffdf7;
  box-shadow: 0 1px 2px rgb(0 0 0 / 0.18);
}
.cover-name { font-weight: 800; font-size: 1.22rem; line-height: 1.2; padding-bottom: 5px; border-bottom: 1.5px solid var(--margin-line); }
.cover-desc { color: var(--ink-soft); font-size: 14px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.cover-meta { margin-top: 3px; font-size: 13px; color: var(--ink-faint); }
.cover .progress { margin-top: 4px; }
.cover .progress-track { width: 100%; }
.cover:hover { transform: translateY(-4px) rotate(-0.6deg); box-shadow: inset 0 0 0 1px rgb(0 0 0 / 0.08), 0 2px 2px rgb(0 0 0 / 0.06), 0 18px 26px -12px color-mix(in srgb, var(--c) 70%, #000); }
.cover:active { transform: translateY(-1px) scale(0.985); }

.home-links { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 12px; }
.ex-count { margin: -0.4em 0 1em; font-weight: 700; color: var(--ink-soft); }
.home-sum {
  position: relative;
  display: flex; align-items: center; gap: 16px;
  padding: 16px 18px 16px 30px;
  border: 1px solid var(--rule-strong); border-radius: var(--r-lg);
  background: var(--surface); box-shadow: var(--shadow);
  color: var(--ink); text-decoration: none;
  transition: transform 0.2s var(--ease), box-shadow 0.2s;
}
.home-sum::before { content: ""; position: absolute; left: 16px; top: 0; bottom: 0; border-left: 1.5px solid var(--margin-line); }
.home-sum-text { flex: 1; display: grid; }
.home-sum-text strong { font-size: 1.15rem; }
.home-sum-text span { color: var(--ink-soft); font-size: 15px; }
.home-sum .icon { color: var(--ink-faint); transition: transform 0.2s var(--ease), color 0.2s; }
.home-sum:hover { transform: translateY(-2px); box-shadow: var(--shadow-up); }
.home-sum:hover .icon { transform: translateX(4px); color: var(--pen); }

.field {
  display: flex; align-items: center; gap: 10px;
  padding: 5px 5px 5px 14px;
  border: 1.5px solid var(--rule-strong); border-radius: var(--r-lg);
  background: var(--surface);
  transition: border-color 0.15s, box-shadow 0.15s;
}
.field:focus-within { border-color: var(--pen); box-shadow: 0 0 0 4px var(--pen-soft); }
.field .icon { color: var(--ink-faint); }
.field input { flex: 1; min-width: 0; height: 44px; border: 0; background: none; color: var(--ink); font: inherit; font-size: 17px; outline: none; }
.field input::-webkit-search-cancel-button { display: none; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 46px; padding: 0 20px;
  border: 1.5px solid var(--pen); border-radius: 8px;
  background: var(--pen); color: var(--on-pen);
  font-weight: 700; font-size: 15.5px; text-decoration: none; cursor: pointer;
  transition: transform 0.12s, filter 0.15s, background 0.15s, color 0.15s;
}
.btn:hover { filter: brightness(1.1); }
.btn:active { transform: scale(0.97); }
.btn .icon { width: 16px; height: 16px; }
.btn-ghost { background: transparent; color: var(--pen); }
.btn-ghost:hover { background: var(--pen-soft); filter: none; }

.progress { display: flex; align-items: center; gap: 10px; }
.progress-track { width: 90px; height: 6px; border-radius: 3px; background: var(--rule); overflow: hidden; }
.progress-fill { display: block; height: 100%; background: var(--c, var(--good)); border-radius: 3px; transition: width 0.4s var(--ease); }
.progress-text { font-size: 14px; color: var(--ink-soft); font-variant-numeric: tabular-nums; }

.panel { padding: 18px; border: 1px solid var(--rule-strong); border-radius: var(--r-lg); background: var(--surface); }
#content .panel h2 { margin: 0 0 10px; font-size: 1.15rem; background: none; }
.review-panel { margin-top: 22px; background: var(--pen); border-color: var(--pen); color: var(--on-pen); }
#content .review-panel h2 { margin: 0; font: 400 1.2rem/1.2 var(--font-hand); opacity: 0.9; }
.review-big { display: flex; align-items: baseline; gap: 10px; margin: 6px 0 2px !important; }
.review-big strong { font-weight: 800; font-size: 3rem; line-height: 1; }
.review-panel p { margin: 0 0 14px; }
.review-panel .btn { background: var(--on-pen); color: var(--pen); border-color: var(--on-pen); width: 100%; }
.review-sub { font-size: 14px; opacity: 0.85; }

/* ---------- 6. Materia e capitolo ---------- */
.subject-header {
  position: relative;
  margin: 0 0 22px;
  padding: 22px 46px 22px 36px;
  border-radius: 4px 14px 14px 4px;
  background:
    linear-gradient(90deg, color-mix(in srgb, var(--accent-subject) 72%, #000) 0 16px, transparent 16px),
    radial-gradient(120% 120% at 95% 0%, rgb(255 255 255 / 0.2), transparent 60%),
    var(--accent-subject);
  box-shadow: inset 0 0 0 1px rgb(0 0 0 / 0.08), 0 10px 20px -12px color-mix(in srgb, var(--accent-subject) 70%, #000);
}
.subject-header::after { content: ""; position: absolute; top: 0; bottom: 0; right: 18px; width: 8px; background: rgb(0 0 0 / 0.22); }
.subject-label { position: relative; z-index: 1; max-width: 32rem; padding: 14px 18px 16px; border-radius: 8px; background: #fffdf7; box-shadow: 0 1px 2px rgb(0 0 0 / 0.18); }
#content .subject-label h1 { margin: 0; padding-bottom: 6px; border-bottom: 1.5px solid var(--margin-line); }
#content .subject-label .lead { margin: 8px 0 10px; font-size: 1.02rem; }

/* elenco dei capitoli */
#content .chapters { list-style: none; margin: 0 0 1.4em; padding: 0; display: grid; gap: 12px; }
#content .chapters > li { margin: 0; }
.chapter {
  position: relative;
  border: 1px solid var(--rule-strong); border-radius: var(--r-lg);
  background: var(--surface); box-shadow: var(--shadow);
  overflow: hidden;
  transition: transform 0.2s var(--ease), box-shadow 0.2s;
}
.chapter:hover { transform: translateY(-2px); box-shadow: var(--shadow-up); }
.chapter-main { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; align-items: center; gap: 16px; padding: 16px 14px 14px 16px; color: var(--ink); text-decoration: none; }
.chapter-num {
  display: grid; place-items: center; width: 44px; height: 44px;
  border: 2px solid var(--c-ink, var(--pen)); border-radius: 50%;
  font-weight: 800; font-size: 1.15rem; line-height: 1; color: var(--c-ink, var(--pen));
  transition: background 0.25s, color 0.25s, border-color 0.25s;
}
.chapter.is-done .chapter-num { background: var(--good); border-color: var(--good); color: #fff; }
.chapter-num .icon { width: 20px; height: 20px; }
.chapter-text { display: grid; gap: 2px; }
.chapter-title { font-weight: 800; font-size: 1.18rem; line-height: 1.25; }
.chapter-desc { color: var(--ink-soft); font-size: 15px; line-height: 1.45; }
.chapter-info { font-size: 13.5px; color: var(--ink-faint); }
.chapter-ok { display: inline-flex; align-items: center; gap: 3px; color: var(--good); font-weight: 700; }
.chapter-ok .icon { width: 13px; height: 13px; stroke-width: 3; }
.chapter-go { color: var(--ink-faint); transition: transform 0.2s var(--ease), color 0.2s; }
.chapter-main:hover .chapter-go { transform: translateX(4px); color: var(--pen); }
.chapter-foot { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: start; padding: 0 6px 0 16px; border-top: 1px dashed var(--rule-strong); }
.chapter-parts summary, .chapter-sum {
  display: inline-flex; align-items: center; gap: 7px;
  min-height: 44px; font-size: 14.5px; font-weight: 700; cursor: pointer;
}
.chapter-parts summary { color: var(--ink-soft); list-style: none; }
.chapter-parts summary::-webkit-details-marker { display: none; }
.chapter-parts summary::before { content: ""; width: 7px; height: 7px; margin: 0 3px 0 2px; border-right: 2px solid currentColor; border-bottom: 2px solid currentColor; transform: rotate(-45deg); transition: transform 0.2s var(--ease); }
.chapter-parts[open] summary::before { transform: rotate(45deg); }
.chapter-parts summary:hover { color: var(--ink); }
#content .chapter-parts ol { margin: 0 0 12px; padding-left: 1.6em; font-size: 15px; }
#content .chapter-parts li { margin: 0.15em 0; }
.chapter-parts li a { color: var(--ink); text-decoration: none; }
.chapter-parts li a:hover { color: var(--pen); text-decoration: underline; }
.chapter-sum { padding: 0 10px; border-radius: 6px; color: var(--pen); text-decoration: none; }
.chapter-sum:hover { background: var(--pen-soft); }
.chapter-sum .icon { width: 16px; height: 16px; }

/* testa della pagina capitolo */
.page-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 12px; margin-bottom: 8px; }
.chapter-tag { font-weight: 700; font-size: 14.5px; color: var(--c-ink, var(--pen)); }
.status-pill, .meta-link {
  display: inline-flex; align-items: center; gap: 5px;
  min-height: 32px; padding: 0 12px;
  border: 1px solid var(--rule-strong); border-radius: 999px;
  background: var(--surface); color: var(--ink-soft); font-size: 14px; cursor: pointer; text-decoration: none;
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}
.status-pill { border-style: dashed; }
.status-pill:hover, .meta-link:hover { border-color: var(--pen); color: var(--pen); }
.status-pill .icon, .meta-link .icon { width: 14px; height: 14px; }
.status-pill.is-done { border: 1px solid var(--good); color: var(--good); }

/* fine pagina: studiato + prossimo capitolo */
.page-end { margin-top: 56px; padding-top: 24px; border-top: 1px dashed var(--rule-strong); display: grid; gap: 18px; }
.page-end-done { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 18px; }
#content .page-end .hand { margin: 0; font-size: 1.25rem; }
.btn-done { min-width: 220px; }
.btn-done .icon { width: 18px; height: 18px; stroke-width: 3; }
.btn-done.is-done { background: color-mix(in srgb, var(--good) 10%, var(--surface)); border-color: var(--good); color: var(--good); }
.page-end-links { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 12px; }
.end-link {
  position: relative;
  display: grid; gap: 1px;
  padding: 14px 44px 14px 16px;
  border: 1px solid var(--rule-strong); border-radius: var(--r-lg);
  background: var(--surface); box-shadow: var(--shadow);
  color: var(--ink); text-decoration: none;
  transition: transform 0.2s var(--ease), box-shadow 0.2s, border-color 0.2s;
}
.end-link span { font-size: 13.5px; color: var(--ink-faint); }
.end-link strong { line-height: 1.3; }
.end-link .icon { position: absolute; right: 16px; top: 50%; margin-top: -9px; color: var(--ink-faint); transition: transform 0.2s var(--ease), color 0.2s; }
.end-link:hover { transform: translateY(-2px); box-shadow: var(--shadow-up); border-color: var(--c-ink, var(--pen)); }
.end-link:hover .icon { transform: translateX(4px); color: var(--pen); }
.end-next { border-left: 4px solid var(--c-ink, var(--pen)); }

.empty { padding: 22px 24px; border: 1.5px dashed var(--rule-strong); border-radius: var(--r-lg); color: var(--ink-soft); background: var(--surface); }
#content .empty p { margin: 0; }
#content .empty .hand { margin-bottom: 4px; font-size: 1.3rem; }

.badge {
  display: inline-block; padding: 2px 8px;
  border-radius: 4px;
  font-size: 12.5px; font-weight: 700; line-height: 1.5; letter-spacing: 0.02em;
  color: var(--ink-soft); background: var(--paper-2); white-space: nowrap;
}
.badge-teoria { --b: #2f6fdb; }
.badge-esercizi, .badge-facile { --b: #1f8a4c; }
.badge-laboratorio { --b: #7a4fd0; }
.badge-riassunto, .badge-medio { --b: #b8660f; }
.badge-verifica, .badge-difficile { --b: #c43a3a; }
.badge-vocabolario { --b: #0f8b8d; }
.badge-classroom { --b: #1a73a8; }
.badge[class*="badge-"] { color: color-mix(in srgb, var(--b, var(--ink-soft)) var(--c-mix), var(--ink)); background: color-mix(in srgb, var(--b, var(--ink-soft)) 11%, transparent); }

/* ---------- 7. Contenuto ---------- */
#content h1 { margin: 0 0 10px; font-weight: 800; font-size: clamp(1.95rem, 5vw, 2.6rem); line-height: 1.1; letter-spacing: -0.02em; text-wrap: balance; }
/* titoli dei paragrafi passati con l'evidenziatore */
#content h2 {
  width: fit-content; max-width: 100%;
  margin: 2.4em 0 0.6em; padding: 0 0.15em;
  font-weight: 800; font-size: 1.5rem; line-height: 1.3; letter-spacing: -0.01em; text-wrap: balance;
  background: linear-gradient(transparent 58%, color-mix(in srgb, var(--c, var(--highlight)) 22%, transparent) 58% 90%, transparent 90%) 0 0 / 100% 1lh repeat-y;
}
html:not([data-subject]) #content h2:not([class]) { background-image: linear-gradient(transparent 58%, color-mix(in srgb, var(--highlight) 70%, transparent) 58% 90%, transparent 90%); }
#content h3 { margin: 1.9em 0 0.5em; font-weight: 700; font-size: 1.2rem; line-height: 1.3; }
#content h2 + h3 { margin-top: 0.8em; }
#content p, #content ul, #content ol { margin: 0 0 1em; }
#content li { margin: 0.3em 0; }
#content li::marker { color: var(--c-ink, var(--pen)); }
.lead { font-size: 1.12rem; color: var(--ink-soft); }
strong { font-weight: 700; }

code { font: 0.88em var(--font-mono); font-variant-ligatures: none; padding: 0.1em 0.35em; border-radius: 4px; background: var(--code-bg); border: 1px solid var(--rule); }
.code-block { margin: 0 0 1.4em; border: 1px solid var(--rule-strong); border-radius: var(--r); background: var(--code-bg); overflow: hidden; }
.code-bar { display: flex; justify-content: space-between; align-items: center; min-height: 36px; padding: 0 6px 0 14px; border-bottom: 1px solid var(--rule); font: 12.5px var(--font-mono); color: var(--ink-faint); }
.copy-btn { display: inline-flex; align-items: center; gap: 6px; min-height: 32px; padding: 0 10px; border: 0; border-radius: 5px; background: none; color: var(--ink-soft); font-size: 13px; cursor: pointer; transition: background 0.15s, color 0.15s; }
.copy-btn:hover { background: var(--paper-2); color: var(--ink); }
.copy-btn .icon { width: 14px; height: 14px; }
pre { margin: 0; padding: 14px 16px; overflow-x: auto; font: 14px/1.6 var(--font-mono); font-variant-ligatures: none; tab-size: 4; }
#content :not(pre) > code { overflow-wrap: anywhere; }
pre code { padding: 0; border: 0; background: none; font-size: inherit; }
.tok-keyword { color: var(--tok-keyword); font-weight: 600; }
.tok-string { color: var(--tok-string); }
.tok-number { color: var(--tok-number); }
.tok-comment { color: var(--tok-comment); font-style: italic; }
.tok-function { color: var(--tok-function); }
.tok-pre, .tok-tag { color: var(--tok-pre); }
.tok-attr { color: var(--tok-number); }

/* Box: <div class="callout def|info|tip|warn"><span class="callout-title">…</span>…</div> */
.callout { --cl: var(--pen); margin: 1.5em 0; padding: 12px 18px 14px; border: 1px solid var(--rule); border-left: 4px solid var(--cl); border-radius: 4px var(--r) var(--r) 4px; background: var(--surface); }
.callout > :last-child { margin-bottom: 0 !important; }
.callout-title { display: block; font: 700 1.12rem/1.3 var(--font-hand); color: color-mix(in srgb, var(--cl) var(--c-mix), var(--ink)); }
.callout.info { --cl: #2f6fdb; }
.callout.warn { --cl: #c9711c; background: color-mix(in srgb, #c9711c 5%, var(--surface)); }
/* tip = post-it */
.callout.tip { --cl: #8a6d00; border: 0; border-radius: 2px; background: var(--postit); box-shadow: 0 1px 1px rgb(0 0 0 / 0.06), 0 6px 12px -8px rgb(110 90 0 / 0.5); }
/* def = riquadro fatto a penna */
.callout.def { --cl: var(--pen); border: 1.5px solid var(--pen); border-radius: 3px 8px 4px 9px; }

/* Riferimento alle slide del prof: <p class="ref">Slide 3-5</p> */
#content .ref { margin: -0.4em 0 0.8em; font: 400 15px var(--font-hand); color: var(--ink-faint); }

/* Confronto a due colonne */
.compare { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 12px; margin: 1.2em 0 1.6em; }
.compare > div { padding: 14px 16px; border: 1px solid var(--rule-strong); border-radius: var(--r-lg); background: var(--surface); }
.compare h4 { margin: 0 0 6px; font-weight: 800; font-size: 1.05rem; }
#content .compare p, #content .compare ul { margin: 0 0 0.5em; font-size: 15.5px; }
#content .compare > div > :last-child { margin-bottom: 0; }
.pro { color: var(--good); font-weight: 700; }
.contro { color: var(--bad); font-weight: 700; }

/* Esercizi */
.exercise-tools { display: flex; justify-content: flex-end; margin: -0.4em 0 1em; }
.esercizio { margin: 1.5em 0; border: 1px solid var(--rule-strong); border-radius: var(--r-lg); background: var(--surface); }
.esercizio-head { display: flex; align-items: center; gap: 10px; padding: 12px 16px; border-bottom: 1px solid var(--rule); font-weight: 800; font-size: 1.05rem; }
.esercizio-head .badge { margin-left: auto; }
.esercizio-num { font-weight: 800; font-size: 0.95rem; color: var(--c-ink, var(--pen)); }
.esercizio-body { padding: 14px 16px 2px; }
.esercizio-body > :last-child { margin-bottom: 12px; }
details.soluzione { border-top: 1px dashed var(--rule-strong); }
details.soluzione summary { display: flex; align-items: center; gap: 8px; min-height: 48px; padding: 0 16px; cursor: pointer; list-style: none; font: 700 1.05rem var(--font-hand); color: var(--pen); }
details.soluzione summary::-webkit-details-marker { display: none; }
details.soluzione summary::before { content: "+"; font: 700 18px var(--font-mono); width: 14px; transition: transform 0.2s var(--ease); }
details.soluzione[open] summary::before { content: "−"; }
.soluzione-body { padding: 4px 16px; }
#content .soluzione-body h4 { margin: 1.3em 0 0.45em; font-weight: 800; font-size: 1.02rem; color: var(--c-ink, var(--pen)); }
#content .soluzione-body > h4:first-child { margin-top: 0.6em; }

/* Tabelle */
.table-wrap { overflow-x: auto; margin: 0 0 1.4em; border: 1px solid var(--rule-strong); border-radius: var(--r); background: var(--surface); }
table { width: 100%; border-collapse: collapse; font-size: 15.5px; }
th, td { padding: 9px 14px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--rule); }
th { font-size: 13px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; color: var(--ink-soft); background: var(--paper-2); }
tr:last-child td { border-bottom: 0; }
tbody tr { transition: background 0.15s; }
tbody tr:hover { background: color-mix(in srgb, var(--highlight) 22%, transparent); }

/* Pila a livelli (es. ISO/OSI): <ol class="stack"><li><b>7</b><strong>Nome</strong><span>…</span></li></ol> */
.stack { list-style: none; padding: 0 !important; margin: 1.4em 0 !important; display: grid; gap: 4px; }
#content .stack li { margin: 0; display: grid; grid-template-columns: 2.4rem minmax(0, 9rem) minmax(0, 1fr); align-items: center; gap: 4px 12px; padding: 9px 14px 9px 0; border-radius: var(--r); background: color-mix(in srgb, var(--c, var(--pen)) 7%, var(--surface)); border: 1px solid color-mix(in srgb, var(--c, var(--pen)) 25%, transparent); transition: transform 0.2s var(--ease); }
#content .stack li:hover { transform: translateX(4px); }
.stack b { font-weight: 800; font-size: 1.1rem; text-align: center; color: var(--c-ink, var(--pen)); }
.stack span { color: var(--ink-soft); font-size: 15px; }

/* Linea del tempo */
.timeline { list-style: none; padding: 0 !important; margin: 1.5em 0 !important; position: relative; }
.timeline::before { content: ""; position: absolute; left: 4.6rem; top: 8px; bottom: 8px; border-left: 2px dashed var(--rule-strong); }
#content .timeline li { position: relative; display: grid; grid-template-columns: 4rem minmax(0, 1fr); gap: 1.6rem; margin: 0; padding: 0 0 18px; }
.timeline li::before { content: ""; position: absolute; left: calc(4.6rem - 5px); top: 8px; width: 12px; height: 12px; border-radius: 50%; background: var(--paper); border: 2.5px solid var(--c-ink, var(--pen)); }
.timeline .when { font-weight: 800; font-size: 1.05rem; line-height: 1.6; color: var(--c-ink, var(--pen)); text-align: right; }

/* Schede brevi */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); gap: 10px; margin: 1.2em 0 1.6em; }
.card { padding: 12px 14px; border: 1px solid var(--rule-strong); border-radius: var(--r); background: var(--surface); }
.card > strong { display: block; }
#content .card p { margin: 0; color: var(--ink-soft); font-size: 15px; }

/* Schema di rete */
figure { margin: 1.6em 0; padding: 0; }
.rete-scroll { overflow-x: auto; padding: 8px 0; border: 1px solid var(--rule-strong); border-radius: var(--r-lg); background: var(--surface); }
.rete-svg { display: block; width: 100%; height: auto; margin: 0 auto; }
.rete-link { stroke: var(--ink-faint); stroke-width: 2; }
.rete-halo { fill: var(--surface); stroke: none; }
.rete-node { fill: var(--surface); stroke: var(--c-ink, var(--pen)); stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.rete-node .dotfill { fill: var(--c-ink, var(--pen)); stroke: none; }
.rete-cloud { stroke: var(--ink-faint); }
.rete-name { fill: var(--ink); font: 700 14px var(--font-body); }
.rete-name, .rete-label { paint-order: stroke; stroke: var(--surface); stroke-width: 5px; stroke-linejoin: round; }
.rete-label { fill: var(--ink-soft); font: 12px var(--font-mono); }
figcaption { margin-top: 8px; font-size: 14px; color: var(--ink-soft); text-align: center; }

/* Schema di sequenza */
.seq-box { padding: 10px 8px; border: 1px solid var(--rule-strong); border-radius: var(--r-lg); background: var(--surface); }
.seq-svg { display: block; width: 100%; max-width: 460px; height: auto; margin: 0 auto; }
.seq-actor { fill: var(--paper-2); stroke: var(--rule-strong); }
.seq-actor-name { fill: var(--ink); font: 700 14px var(--font-body); }
.seq-life { stroke: var(--rule-strong); stroke-dasharray: 4 4; }
.seq-msg { stroke-width: 2; }
.seq-req { stroke: var(--pen); }
.seq-res { stroke: var(--c-ink, var(--good)); }
.seq-head { fill: var(--ink-soft); }
.seq-label { fill: var(--ink); font: 12.5px var(--font-mono); paint-order: stroke; stroke: var(--surface); stroke-width: 5px; stroke-linejoin: round; }
.seq-sep { stroke: var(--rule-strong); stroke-dasharray: 2 4; }
.seq-note { fill: var(--pen); font: 15px var(--font-hand); paint-order: stroke; stroke: var(--surface); stroke-width: 6px; stroke-linejoin: round; }

/* Anatomia di un URL: <div class="anatomy"><span data-l="schema">https</span>://…</div> */
.anatomy { overflow-x: auto; margin: 1.2em 0 1.4em; padding: 18px 16px 40px; border: 1px solid var(--rule-strong); border-radius: var(--r-lg); background: var(--surface); font: 15px/1.4 var(--font-mono); white-space: nowrap; }
.anatomy span[data-l] { position: relative; display: inline-block; padding: 2px 3px; border-radius: 4px; background: color-mix(in srgb, var(--k, var(--pen)) 14%, transparent); color: color-mix(in srgb, var(--k, var(--pen)) var(--c-mix), var(--ink)); font-weight: 600; }
.anatomy span[data-l]::after { content: attr(data-l); position: absolute; left: 50%; top: calc(100% + 6px); transform: translateX(-50%); font: 600 10.5px var(--font-body); text-transform: uppercase; letter-spacing: 0.04em; color: var(--ink-soft); white-space: nowrap; }
.anatomy span[data-l]:nth-of-type(even)::after { top: calc(100% + 20px); }
.anatomy .k1 { --k: #2f6fdb; } .anatomy .k2 { --k: #7a4fd0; } .anatomy .k3 { --k: #c8364b; } .anatomy .k4 { --k: #c9711c; }
.anatomy .k5 { --k: #0f8b8d; } .anatomy .k6 { --k: #3a8f4a; } .anatomy .k7 { --k: #a0522d; }

/* Evidenziatore */
mark { background: var(--highlight); color: var(--highlight-ink); border-radius: 0.25em 0.45em 0.3em 0.5em; padding: 0 0.15em; -webkit-box-decoration-break: clone; box-decoration-break: clone; }
mark.hit.is-current { outline: 2px solid var(--pen); outline-offset: 1px; }

/* ---------- 8. Riassunti ---------- */
.riassunti .search-filters { margin: 14px 0 8px; }
.sum-subject { margin-bottom: 26px; }
#content .sum-subject-title { display: flex; align-items: center; gap: 10px; width: auto; margin: 1.4em 0 0.6em; padding: 0; background: none; font-size: 1.3rem; color: var(--c-ink); }
.sum-subject-title .tab { width: 10px; height: 24px; border-radius: 2px 4px 4px 2px; background: var(--c); }
.sum-chapter {
  margin: 0 0 12px;
  border: 1px solid var(--rule-strong); border-left: 4px solid var(--c); border-radius: var(--r-lg);
  background: var(--surface); box-shadow: var(--shadow);
  scroll-margin-top: calc(var(--topbar) + 16px);
}
.sum-chapter > summary {
  display: grid; grid-template-columns: auto minmax(0, 1fr) auto; align-items: center; gap: 14px;
  padding: 14px 14px 14px 16px; cursor: pointer; list-style: none;
}
.sum-chapter > summary::-webkit-details-marker { display: none; }
.sum-num { display: grid; place-items: center; width: 38px; height: 38px; border: 2px solid var(--c-ink); border-radius: 50%; font-weight: 800; font-size: 1.05rem; line-height: 1; color: var(--c-ink); }
.sum-head { display: grid; gap: 1px; }
.sum-title { font-weight: 800; font-size: 1.12rem; line-height: 1.3; }
.sum-breve { color: var(--ink-soft); font-size: 15px; line-height: 1.45; }
.sum-info { font-size: 13.5px; color: var(--ink-faint); }
.sum-toggle { color: var(--ink-faint); transition: transform 0.25s var(--ease), color 0.2s; }
.sum-chapter > summary:hover .sum-toggle { color: var(--pen); }
.sum-chapter[open] .sum-toggle { transform: rotate(90deg); color: var(--pen); }
.sum-body { padding: 4px 16px 18px; border-top: 1px dashed var(--rule-strong); }
#content .sum-cards { list-style: none; margin: 14px 0 16px; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 330px), 1fr)); gap: 12px; }
#content .sum-cards > li { margin: 0; }
/* ogni paragrafo è una scheda */
.sum-card { display: flex; flex-direction: column; padding: 12px 16px 10px; border: 1px solid var(--rule); border-radius: 4px; background: #fffdf7; box-shadow: 0 1px 2px rgb(60 50 30 / 0.08); }
#content .sum-card-title { display: flex; align-items: baseline; gap: 8px; margin: 0 0 8px; padding-bottom: 6px; border-bottom: 1.5px solid var(--margin-line); font-weight: 800; line-height: 1.3; }
.sum-card-title span { flex: none; min-width: 1.1em; color: var(--c-ink); }
#content .sum-card ul { flex: 1; margin: 0 0 8px; padding-left: 1.15em; font-size: 15.5px; line-height: 1.5; }
#content .sum-card li { margin: 0.35em 0; }
.sum-card-link { align-self: flex-start; display: inline-flex; align-items: center; gap: 6px; min-height: 36px; font-size: 14px; font-weight: 700; text-decoration: none; }
.sum-card-link .icon { width: 15px; height: 15px; transition: transform 0.2s var(--ease); }
.sum-card-link:hover .icon { transform: translateX(3px); }

/* ---------- 9. Flashcard e quiz ---------- */
.deck-head { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: baseline; gap: 6px 16px; margin: 1.2em 0 0.6em; font-size: 15px; }
.deck-head a { display: inline-flex; align-items: center; gap: 2px; font-weight: 700; text-decoration: none; }
.deck-head .icon { width: 16px; height: 16px; }
.flashcards { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 14px; margin: 0 0 1.8em; }

/* cartoncino a righe con linea rossa in alto */
.flashcard, .big-card { perspective: 900px; cursor: pointer; min-height: 140px; outline-offset: 4px; }
.fc-inner { position: relative; display: grid; height: 100%; min-height: inherit; transition: transform 0.45s var(--ease); transform-style: preserve-3d; }
.is-flipped > .fc-inner { transform: rotateY(180deg); }
.fc-front, .fc-back {
  grid-area: 1 / 1;
  display: flex; flex-direction: column; justify-content: center; align-items: center; text-align: center;
  padding: 26px 16px 16px;
  border: 1px solid var(--rule-strong); border-radius: 4px;
  background-color: var(--surface);
  background-image:
    linear-gradient(var(--margin-line), var(--margin-line)),
    repeating-linear-gradient(transparent 0 25px, var(--line) 25px 26px);
  background-size: 100% 2px, 100% 100%;
  background-position: 0 18px, 0 18px;
  background-repeat: no-repeat, repeat;
  box-shadow: var(--shadow);
  backface-visibility: hidden; -webkit-backface-visibility: hidden;
  overflow-wrap: anywhere;
}
.fc-front { font-weight: 700; font-size: 1.15rem; line-height: 1.35; }
.fc-back { transform: rotateY(180deg); font-family: var(--font-hand); font-size: 1.15rem; line-height: 1.4; color: var(--pen); }
.fc-front > *, .fc-back > * { margin: 0 !important; }

.quiz { margin: 1.4em 0 2em; display: grid; gap: 14px; }
.quiz-q { padding: 16px; border: 1px solid var(--rule-strong); border-radius: var(--r-lg); background: var(--surface); }
#content .quiz-q > p:first-of-type { font-weight: 700; margin-bottom: 0; }
.quiz-num { display: block; margin-bottom: 4px; font: 400 15px var(--font-hand); color: var(--ink-faint); }
.quiz-options { display: grid; gap: 8px; margin: 12px 0 0; }
.quiz-opt {
  display: flex; align-items: center; gap: 12px; width: 100%;
  min-height: 48px; padding: 8px 12px;
  border: 1.5px solid var(--rule-strong); border-radius: 8px;
  background: var(--paper); text-align: left; cursor: pointer; font-size: 16px;
  transition: border-color 0.15s, background 0.2s, transform 0.12s;
}
.quiz-opt:hover:not(:disabled) { border-color: var(--pen); }
.quiz-opt:active:not(:disabled) { transform: scale(0.99); }
.quiz-opt:disabled { cursor: default; }
.quiz-opt > span:last-child { min-width: 0; }
.quiz-letter { flex: none; display: grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; border: 1.5px solid var(--rule-strong); font: 700 12px var(--font-mono); color: var(--ink-soft); }
.quiz-opt.is-correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 12%, var(--surface)); }
.quiz-opt.is-correct .quiz-letter { background: var(--good); border-color: var(--good); color: var(--surface); }
.quiz-opt.is-chosen-wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 10%, var(--surface)); animation: shake 0.35s; }
.quiz-opt.is-chosen-wrong .quiz-letter { background: var(--bad); border-color: var(--bad); color: var(--surface); }
.quiz-opt:disabled:not(.is-correct):not(.is-chosen-wrong) { opacity: 0.6; }
#content .quiz-why, .quiz-why { margin: 12px 0 0; padding: 10px 12px; border-radius: var(--r); background: var(--paper-2); font-size: 15.5px; }
.quiz-why::before { content: "Perché: "; font-weight: 700; }
.quiz-score { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 16px; padding: 4px 2px; color: var(--ink-soft); font-size: 15px; }
.quiz-total { font-weight: 800; font-size: 1.8rem; color: var(--ink); }
.quiz-score .btn { margin-left: auto; }

/* ---------- 10. Ricerca ---------- */
.search-modal { position: fixed; inset: 0; z-index: 100; display: flex; justify-content: center; align-items: flex-start; padding: 9vh 16px 16px; }
.search-backdrop { position: absolute; inset: 0; background: var(--scrim); animation: fade 0.18s; }
.search-dialog { position: relative; width: 100%; max-width: 640px; max-height: 78vh; display: flex; flex-direction: column; border: 1px solid var(--rule-strong); border-radius: 12px; background: var(--surface); box-shadow: var(--shadow-lg); overflow: hidden; animation: pop 0.2s var(--ease); }
body.search-open { overflow: hidden; }
.search-field { display: flex; align-items: center; gap: 12px; padding: 0 14px; border-bottom: 1px solid var(--rule); }
.search-field .icon { width: 20px; height: 20px; color: var(--pen); }
.search-field input { flex: 1; min-width: 0; height: 58px; border: 0; background: none; color: var(--ink); font: inherit; font-size: 17px; outline: none; }
.search-field input::-webkit-search-cancel-button { display: none; }
.search-field kbd { cursor: pointer; }
.search-close { display: none; }
.search-scope { padding: 10px 14px 0; }
.search-results { overflow-y: auto; padding: 8px; overscroll-behavior: contain; }
.search-label { margin: 6px 10px; font: 400 16px var(--font-hand); color: var(--pen); }
.search-msg { padding: 28px 16px; text-align: center; color: var(--ink-soft); font-size: 15px; }
.search-more { margin: 6px 10px; font-size: 13px; color: var(--ink-faint); }
.search-foot { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 10px 14px; border-top: 1px solid var(--rule); font-size: 13px; color: var(--ink-faint); background: var(--paper-2); }
.search-foot a { font-weight: 700; text-decoration: none; }

.result { display: flex; flex-direction: column; gap: 2px; padding: 10px 12px; border-radius: 8px; color: var(--ink); text-decoration: none; transition: background 0.12s; }
.result:hover, .result.is-active { background: var(--pen-soft); }
.result-recent { flex-direction: row; align-items: center; gap: 10px; color: var(--ink-soft); }
.result-recent .icon { width: 15px; color: var(--ink-faint); }
.res-crumb { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; font-size: 13px; color: var(--ink-faint); }
.res-subject { font-weight: 700; font-size: 13px; color: var(--c-ink); }
.res-title { font-weight: 700; font-size: 16px; }
.res-snippet { font-size: 14.5px; color: var(--ink-soft); line-height: 1.5; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

.chip {
  display: inline-flex; align-items: center; gap: 6px;
  min-height: 38px; padding: 0 14px;
  border: 1px solid var(--rule-strong); border-radius: 999px;
  background: var(--surface); color: var(--ink-soft);
  font-size: 14.5px; font-weight: 700; cursor: pointer;
  transition: background 0.2s, border-color 0.2s, color 0.2s, transform 0.12s;
}
.chip:hover { color: var(--ink); border-color: var(--c-ink, var(--pen)); }
.chip:active { transform: scale(0.96); }
.chip[aria-pressed="true"] { background: var(--c, var(--pen)); border-color: var(--c, var(--pen)); color: #fff; }
.chip:not([style])[aria-pressed="true"] { color: var(--on-pen); }
.chip-n { font: 12px var(--font-mono); opacity: 0.8; }

.search-page .field { margin: 6px 0 14px; }
.search-filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.search-page-info { min-height: 22px; margin: 0 0 16px; color: var(--ink-faint); font-size: 14px; }
.result-group { margin-bottom: 28px; }
#content .result-group-title { display: flex; align-items: center; gap: 10px; width: auto; margin: 0 0 8px; padding: 0; background: none; font-size: 1.1rem; color: var(--c-ink); }
.result-group-title .count { font: 12px var(--font-mono); color: var(--ink-faint); }
.result-card { border: 1px solid var(--rule-strong); background: var(--surface); margin-bottom: 8px; padding: 12px 14px; }
.result-card .res-snippet { -webkit-line-clamp: 3; }

.hit-bar {
  position: fixed; right: 20px; bottom: 20px; z-index: 50;
  display: flex; align-items: center; gap: 2px;
  padding: 5px 5px 5px 12px;
  border: 1px solid var(--rule-strong); border-radius: 10px;
  background: var(--surface); box-shadow: var(--shadow-lg);
  font-size: 14px; color: var(--ink-soft);
  animation: rise 0.25s var(--ease) backwards;
}
.hit-bar .icon { width: 16px; color: var(--pen); }
.hit-count { margin: 0 6px; font-variant-numeric: tabular-nums; }
.hit-count strong { color: var(--ink); }

/* ---------- 11. Ripasso ---------- */
.rip-modes { display: inline-flex; padding: 4px; margin: 6px 0 16px; border: 1px solid var(--rule-strong); border-radius: 10px; background: var(--surface); }
.rip-modes button { min-height: 40px; padding: 0 20px; border: 0; border-radius: 7px; background: none; color: var(--ink-soft); font-weight: 700; cursor: pointer; transition: background 0.2s, color 0.2s; }
.rip-modes button[aria-selected="true"] { background: var(--pen); color: var(--on-pen); }
.rip-filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 22px; }
.rip-stage { max-width: 40rem; }
.rip-intro { padding: 24px; border: 1px solid var(--rule-strong); border-radius: var(--r-lg); background: var(--surface); }
#content .rip-big { margin: 0 0 6px; font-size: 1.15rem; }
.rip-big strong { font-weight: 800; font-size: 2.6rem; line-height: 1; margin-right: 4px; }
.rip-help { color: var(--ink-soft); font-size: 15px; }
.rip-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.boxes { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 8px; height: 120px; margin: 18px 0 14px; }
.box-col { display: grid; grid-template-rows: 1fr auto auto; height: 100%; text-align: center; }
.box-bar { align-self: end; height: calc(max(var(--h), 0.03) * 100%); border-radius: 4px 4px 0 0; background: var(--pen); opacity: 0.85; }
.box-n { font: 700 14px var(--font-mono); margin-top: 4px; }
.box-l { font-size: 11.5px; color: var(--ink-faint); line-height: 1.2; }
.rip-end { text-align: center; }
.rip-end .rip-actions { justify-content: center; }
#content .rip-hand-big { font-size: 1.7rem; margin: 0 0 10px; }
#content .rip-score { margin: 0; font-weight: 700; font-size: 1.6rem; color: var(--ink-soft); }
.rip-score strong { font-size: 4rem; color: var(--ink); }
.end-stats { display: flex; justify-content: center; gap: 40px; }
.end-stats div { display: grid; }
.end-stats strong { font-weight: 800; font-size: 2.4rem; }
.end-stats span { color: var(--ink-soft); font-size: 14px; }
.wrong-list { text-align: left; margin-top: 18px; display: grid; gap: 10px; }
.wrong-item { padding: 12px 14px; border-radius: var(--r); background: var(--paper-2); }
#content .wrong-q > * { margin: 0 0 4px; font-weight: 700; }
#content .wrong-a { display: flex; gap: 6px; align-items: flex-start; margin: 0 0 6px; color: var(--good); }
.wrong-a .icon { margin-top: 4px; }

.session { display: grid; gap: 14px; }
.session-top { display: flex; align-items: center; gap: 12px; font: 13px var(--font-mono); color: var(--ink-soft); }
.session-bar { flex: 1; height: 6px; border-radius: 3px; background: var(--rule); overflow: hidden; }
.session-bar span { display: block; height: 100%; background: var(--pen); transition: width 0.3s; }
.link-btn { border: 0; background: none; color: var(--ink-soft); text-decoration: underline; cursor: pointer; font-size: 14px; min-height: 36px; }
.big-card { min-height: min(52vh, 330px); }
.big-card .fc-front { font-size: clamp(1.4rem, 5vw, 1.9rem); padding: 40px 20px 24px; }
.big-card .fc-back { font-size: clamp(1.3rem, 4.5vw, 1.7rem); padding: 40px 20px 24px; }
.session-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.btn-again { background: transparent; border-color: var(--bad); color: var(--bad); }
.btn-knew { background: var(--good); border-color: var(--good); color: var(--surface); }
#content .session-hint { text-align: center; margin: 0; }
#content .session-src { margin: 0; text-align: center; font-size: 14px; }
.rip-source { display: inline-flex; align-items: center; gap: 8px; color: var(--ink-soft); text-decoration: none; font-size: 14px; }
.rip-source .tab { width: 10px; height: 10px; border-radius: 2px; background: var(--c); }
.rip-source:hover { color: var(--pen); }
.quiz-solo { padding: 20px; }
#content .quiz-solo > p:first-child { font-weight: 700; font-size: 1.2rem; line-height: 1.35; margin-top: 0; }

/* ---------- 12. Animazioni ---------- */
/* Brevi e leggere: servono a far capire cosa succede, non a farsi notare. */
@keyframes fade { from { opacity: 0; } }
@keyframes pop { from { opacity: 0; transform: translateY(-8px) scale(0.98); } }
@keyframes rise { from { opacity: 0; transform: translateY(12px); } }
@keyframes drop { from { opacity: 0; transform: translateY(-6px); } }
@keyframes grow { from { width: 0; } }
@keyframes grow-x { from { transform: scaleX(0); } }
@keyframes press { 0% { transform: scale(1); } 40% { transform: scale(1.06); } 100% { transform: scale(1); } }
@keyframes draw { from { stroke-dashoffset: 24; } to { stroke-dashoffset: 0; } }
@keyframes shake { 25% { transform: translateX(-4px); } 50% { transform: translateX(4px); } 75% { transform: translateX(-2px); } }
@keyframes bump { 40% { transform: translateY(-3px); } }

/* la pagina entra */
.is-ready #content { animation: rise 0.35s var(--ease) backwards; }
/* copertine e capitoli arrivano uno dopo l'altro */
.cover, .chapter { animation: rise 0.45s var(--ease) backwards; animation-delay: calc(var(--i, 0) * 50ms + 60ms); }
.continue, .home-sum { animation: rise 0.45s var(--ease) backwards; animation-delay: 0.1s; }
.sum-chapter { animation: rise 0.4s var(--ease) backwards; }
.sum-chapter[open] .sum-card { animation: rise 0.35s var(--ease) backwards; animation-delay: calc(var(--i, 0) * 45ms); }
/* le barre dei progressi si riempiono */
.progress-fill { animation: grow 0.8s var(--ease) 0.25s backwards; }
/* contenuto delle tendine */
details[open] > :not(summary) { animation: drop 0.25s var(--ease); }
/* risultati della ricerca */
.search-results .result, .result-card { animation: rise 0.25s var(--ease) backwards; }
.search-results .result:nth-child(2), .result-card:nth-child(2) { animation-delay: 30ms; }
.search-results .result:nth-child(3), .result-card:nth-child(3) { animation-delay: 60ms; }
.search-results .result:nth-child(4), .result-card:nth-child(4) { animation-delay: 90ms; }
.search-results .result:nth-child(n+5), .result-card:nth-child(n+5) { animation-delay: 120ms; }
/* "studiato": il pulsante rimbalza e la spunta si disegna */
.just-done { animation: press 0.4s var(--ease); }
.just-done .icon path { stroke-dasharray: 24; animation: draw 0.45s var(--ease) 0.1s backwards; }
/* blocchi che compaiono scorrendo (classe aggiunta da layout.js) */
.rv { opacity: 0; transform: translateY(16px); transition: opacity 0.45s var(--ease), transform 0.45s var(--ease); }
.rv.in { opacity: 1; transform: none; }

/* ---------- 13. Tablet e telefono ---------- */
@media (min-width: 861px) {
  /* su computer il menu laterale serve solo dentro le materie */
  html:not([data-subject]) .sidebar { display: none; }
}
@media (max-width: 1180px) {
  .page-grid.has-toc { grid-template-columns: minmax(0, 1fr); }
  .toc { display: none; }
  .toc-mobile { display: block; margin: 0 0 1.4em; border: 1px solid var(--rule-strong); border-radius: var(--r); background: var(--surface); }
  .toc-mobile summary { display: flex; align-items: center; gap: 8px; min-height: 48px; padding: 0 14px; cursor: pointer; font-weight: 700; color: var(--ink-soft); list-style: none; }
  .toc-mobile summary::-webkit-details-marker { display: none; }
  .toc-mobile .icon { width: 16px; color: var(--pen); }
  #content .toc-mobile ul { list-style: none; margin: 0; padding: 4px 0 8px; border-top: 1px solid var(--rule); }
  #content .toc-mobile li { margin: 0; }
  .toc-mobile a { display: flex; align-items: center; min-height: 42px; padding: 0 16px; color: var(--ink); text-decoration: none; }
  .toc-mobile .toc-h3 a { padding-left: 32px; color: var(--ink-soft); font-size: 15px; }
}
@media (max-width: 860px) {
  body { padding-bottom: calc(var(--tabbar) + env(safe-area-inset-bottom, 0px)); }
  .topbar { padding-left: 16px; padding-right: 6px; }
  .top-nav, .search-trigger { display: none; }
  .search-icon { display: inline-grid; }

  .tabbar {
    position: fixed; left: 0; right: 0; bottom: 0; z-index: 60;
    display: grid; grid-auto-flow: column; grid-auto-columns: 1fr;
    height: calc(var(--tabbar) + env(safe-area-inset-bottom, 0px));
    padding-bottom: env(safe-area-inset-bottom, 0px);
    background: var(--surface);
    border-top: 1px solid var(--rule-strong);
  }
  .tabbar a, .tabbar button {
    position: relative;
    display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 3px;
    border: 0; background: none; color: var(--ink-faint);
    font-size: 12px; font-weight: 700; text-decoration: none; cursor: pointer;
    transition: color 0.2s;
  }
  .tabbar .icon { width: 23px; height: 23px; transition: transform 0.15s; }
  .tabbar span { max-width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .tabbar a:active .icon, .tabbar button:active .icon { transform: scale(0.88); }
  .tabbar .is-active { color: var(--pen); }
  .tabbar .is-active .icon { animation: bump 0.4s var(--ease); }
  .tabbar .is-active::before { content: ""; position: absolute; top: 0; left: 28%; right: 28%; height: 3px; border-radius: 0 0 3px 3px; background: var(--pen); animation: grow-x 0.3s var(--ease); }

  /* menu materie = foglio che sale dal basso */
  .sidebar {
    position: fixed; left: 0; right: 0; top: auto;
    bottom: calc(var(--tabbar) + env(safe-area-inset-bottom, 0px));
    z-index: 55; width: auto; height: auto; max-height: 72vh;
    padding: 0 0 12px;
    border: 0; border-top: 1px solid var(--rule-strong);
    border-radius: 16px 16px 0 0;
    box-shadow: var(--shadow-lg);
    transform: translateY(110%);
    visibility: hidden;
    transition: transform 0.3s var(--ease), visibility 0s 0.3s;
  }
  body.menu-open .sidebar { transform: none; visibility: visible; transition: transform 0.3s var(--ease); }
  body.menu-open .side-subject { animation: rise 0.3s var(--ease) backwards; animation-delay: calc(var(--i, 0) * 30ms + 60ms); }
  .sheet-head { position: sticky; top: 0; z-index: 1; display: flex; align-items: center; justify-content: space-between; padding: 14px 8px 6px 20px; background: var(--paper-2); font-weight: 800; font-size: 1.1rem; }
  .sheet-head::before { content: ""; position: absolute; left: 50%; top: 6px; width: 40px; height: 4px; margin-left: -20px; border-radius: 2px; background: var(--rule-strong); }
  .side-link { min-height: 52px; font-size: 17px; }
  .side-pages a { min-height: 46px; font-size: 16px; }
  .scrim { position: fixed; inset: 0; z-index: 50; background: var(--scrim); opacity: 0; pointer-events: none; transition: opacity 0.25s; }
  body.menu-open .scrim { opacity: 1; pointer-events: auto; }
  body.menu-open { overflow: hidden; }

  .page { padding: 18px 16px 0 30px; }
  .page::before { left: 15px; }
  .hit-bar { left: 12px; right: 12px; bottom: calc(var(--tabbar) + env(safe-area-inset-bottom, 0px) + 10px); }
  .hit-count { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .hit-bar .icon-btn { width: 44px; height: 44px; }

  .search-modal { padding: 0; }
  .search-dialog { max-width: none; max-height: none; height: 100%; border: 0; border-radius: 0; padding-top: env(safe-area-inset-top, 0px); }
  .search-field kbd { display: none; }
  .search-close { display: inline-grid; margin-right: -6px; }
  .search-foot span { display: none; }
  .big-card { min-height: 38vh; }
  .rip-stage { scroll-margin-top: calc(var(--topbar) + 12px); }
}
@media (max-width: 560px) {
  body { font-size: 16.5px; }
  .page { padding-left: 26px; padding-right: 14px; }
  .page::before { left: 12px; }
  .home-head { margin-bottom: 16px; }

  .covers { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 12px; }
  .cover { min-height: 148px; padding: 14px 22px 14px 22px; border-radius: 3px 10px 10px 3px; background-size: auto; }
  .cover { background:
    linear-gradient(90deg, var(--spine) 0 11px, rgb(255 255 255 / 0.2) 11px 12px, transparent 12px),
    radial-gradient(130% 90% at 90% 0%, rgb(255 255 255 / 0.2), transparent 60%),
    var(--c); }
  .cover::before { left: 4px; top: 8px; bottom: 8px; }
  .cover::after { right: 9px; width: 6px; }
  .cover-label { padding: 9px 10px 10px; }
  .cover-name { font-size: 1.02rem; }
  .cover-desc { display: none; }
  .cover-meta { font-size: 12.5px; }
  .cover:hover { transform: none; }

  .subject-header { padding: 16px 30px 16px 24px; }
  .subject-header { background:
    linear-gradient(90deg, color-mix(in srgb, var(--accent-subject) 72%, #000) 0 11px, transparent 11px),
    var(--accent-subject); }
  .subject-header::after { right: 10px; width: 6px; }
  .subject-label { padding: 12px 14px 14px; }

  .chapter-main { gap: 12px; padding: 14px 10px 12px 12px; }
  .chapter-num { width: 38px; height: 38px; font-size: 1.05rem; }
  .chapter-title { font-size: 1.08rem; }
  .chapter-desc { font-size: 14.5px; }
  .chapter-foot { padding-left: 12px; }
  .chapter:hover { transform: none; }

  .sum-chapter > summary { gap: 10px; padding: 12px 10px 12px 12px; }
  .sum-num { width: 34px; height: 34px; font-size: 0.98rem; }
  .sum-body { padding: 2px 10px 14px; }
  .sum-card { padding: 10px 12px 8px; }

  .btn-done { width: 100%; }
  #content h2 { font-size: 1.35rem; }
  #content .stack li { grid-template-columns: 2rem minmax(0, 1fr); padding-right: 10px; }
  .stack span { grid-column: 2; }
  .timeline::before { left: 3.6rem; }
  #content .timeline li { grid-template-columns: 3rem minmax(0, 1fr); gap: 1.4rem; }
  .timeline li::before { left: calc(3.6rem - 5px); }
  .flashcards { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 10px; }
  .flashcard { min-height: 120px; }
  .flashcard .fc-front, .flashcard .fc-back { font-size: 1rem; padding: 24px 10px 12px; }
  .rip-intro { padding: 18px; }
  .rip-modes { display: flex; }
  .rip-modes button { flex: 1; }
  .quiz-score .btn { margin-left: 0; }
  .end-stats { gap: 28px; }
  pre { font-size: 13px; }
}
@media (hover: none) {
  .cover:hover, .chapter:hover, .continue:hover, .home-sum:hover, .end-link:hover { transform: none; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .rv { opacity: 1; transform: none; }
}
@media print {
  .topbar, .sidebar, .toc, .toc-mobile, .site-footer, .hit-bar, .breadcrumb, .copy-btn, .tabbar, .page-end { display: none !important; }
  body { background: #fff; padding: 0; }
  .page { padding: 0; }
  .page::before { display: none; }
  .rv { opacity: 1 !important; transform: none !important; }
}