:root {
  --bg: #f4f5f7; --panel: #ffffff; --text: #1c1f24; --muted: #6b7280; --border: #e3e5e9;
  --accent: #4f46e5; --rec: #dc2626; --stage: #e8eaee; --btn: #eef0f4; --warn-bg: #fef3c7; --warn-text: #78350f;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171b; --panel: #1d2026; --text: #e7e9ee; --muted: #9aa1ad; --border: #2d313a;
    --accent: #818cf8; --rec: #f87171; --stage: #0f1114; --btn: #272b33; --warn-bg: #4a3a10; --warn-text: #fde68a;
  }
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
html, body { height: 100%; margin: 0; overscroll-behavior: none; }
body {
  font: 16px/1.4 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  background: var(--bg); color: var(--text);
}
[hidden] { display: none !important; }

button, .btn, input, select {
  font: inherit; color: var(--text); background: var(--btn);
  border: 1px solid var(--border); border-radius: 10px; padding: 8px 12px;
}
button, .btn { cursor: pointer; user-select: none; -webkit-user-select: none; text-align: center; text-decoration: none; }
button:active, .btn:active { filter: brightness(.94); }
button:disabled { opacity: .5; }
.primary { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }
.danger { color: var(--rec); }
.ghost { background: none; border: none; font-size: 22px; padding: 4px 10px; }
.big { padding: 12px 14px; font-size: 16px; font-weight: 600; }
.hint { color: var(--muted); font-size: 13px; }

.screen { height: 100dvh; display: flex; flex-direction: column; }
.top {
  display: flex; align-items: center; gap: 6px; flex-shrink: 0;
  padding: calc(env(safe-area-inset-top) + 8px) calc(env(safe-area-inset-right) + 10px) 8px calc(env(safe-area-inset-left) + 10px);
  background: var(--panel); border-bottom: 1px solid var(--border);
}
.top h1 { font-size: 19px; margin: 0; flex: 1; }

/* ---- Elenco lezioni ---- */
#home { overflow-y: auto; align-items: center; }
#home > * { width: 100%; max-width: 720px; }
#home > .top { max-width: none; }
#nameBtn { font-size: 14px; color: var(--muted); }
.tip { margin: 12px auto; width: calc(100% - 24px) !important; padding: 10px 12px; border-radius: 12px; background: var(--warn-bg); color: var(--warn-text); font-size: 14px; }
#lessonList { padding: 12px; display: flex; flex-direction: column; gap: 10px; }
.lesson-card { display: block; width: 100%; text-align: left; background: var(--panel); border-radius: 14px; padding: 12px 14px; }
.lesson-card b { display: block; font-size: 16px; margin-bottom: 2px; }
.lesson-card span { color: var(--muted); font-size: 13px; }
.empty { text-align: center; color: var(--muted); padding: 40px 20px; }
.home-actions { display: flex; gap: 10px; padding: 4px 12px 12px; }
.home-actions .primary { flex: 1; }
#homeInfo { padding: 0 14px calc(env(safe-area-inset-bottom) + 14px); margin: 0; }

/* ---- Lezione ---- */
#title { flex: 1; min-width: 0; background: none; border: none; font-weight: 600; padding: 6px 4px; }
#recBar {
  display: flex; align-items: center; gap: 10px; flex-shrink: 0;
  padding: 8px calc(env(safe-area-inset-right) + 12px) 8px calc(env(safe-area-inset-left) + 12px);
  background: var(--panel); border-bottom: 1px solid var(--border);
}
.rec { font-weight: 700; min-width: 128px; }
.rec.on { background: var(--rec); border-color: var(--rec); color: #fff; }
#recTime { font-variant-numeric: tabular-nums; font-weight: 600; }
#recBar.on #recTime { color: var(--rec); }
.meter { width: 54px; height: 8px; border-radius: 4px; background: var(--border); overflow: hidden; }
.meter i { display: block; height: 100%; width: 0; background: var(--rec); }
#recInfo { color: var(--muted); font-size: 12px; flex: 1; text-align: right; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
#warn { padding: 8px 12px; background: var(--warn-bg); color: var(--warn-text); font-size: 14px; flex-shrink: 0; }

#work { flex: 1; min-height: 0; display: flex; flex-direction: column; }
#slidePane { flex: 0 0 auto; display: flex; flex-direction: column; min-height: 0; }
#stage { background: var(--stage); display: flex; align-items: center; justify-content: center; padding: 8px; touch-action: none; }
#canvasBox { position: relative; box-shadow: 0 2px 14px rgba(0,0,0,.2); }
#canvasBox canvas { position: absolute; left: 0; top: 0; width: 100%; height: 100%; display: block; }
#strokeCanvas { opacity: .35; pointer-events: none; }
#drawCanvas, #slideCanvas { pointer-events: none; }
.toolbar {
  display: flex; align-items: center; gap: 3px; flex-shrink: 0; overflow-x: auto;
  padding: 6px calc(env(safe-area-inset-right) + 6px) 6px calc(env(safe-area-inset-left) + 6px);
  background: var(--panel); border-bottom: 1px solid var(--border);
}
.toolbar button { padding: 6px 5px; min-width: 34px; flex: 0 0 auto; }
.toolbar button.active { background: var(--accent); border-color: var(--accent); }
.toolbar .sep { flex: 1; min-width: 6px; }
#pageLabel { font-weight: 600; font-size: 13px; white-space: nowrap; min-width: 48px; text-align: center; }
input[type=color] { width: 32px; height: 34px; padding: 2px; flex: 0 0 auto; }

#notesPane { flex: 1; min-height: 0; display: flex; flex-direction: column; background: var(--panel); }
.pane-head { display: flex; align-items: center; gap: 6px; font-size: 13px; font-weight: 600; color: var(--muted); padding: 6px 10px 4px 14px; }
.pane-head .spacer { flex: 1; }
#notesLabel { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.seg { display: flex; flex-shrink: 0; border: 1px solid var(--border); border-radius: 9px; overflow: hidden; }
.seg button { border: none; border-radius: 0; background: var(--btn); padding: 5px 9px; font-size: 13px; position: relative; }
.seg button + button { border-left: 1px solid var(--border); }
.seg button.active { background: var(--accent); color: #fff; }
.seg button.has::after { content: ""; position: absolute; top: 3px; right: 3px; width: 6px; height: 6px; border-radius: 50%; background: var(--rec); } /* c'è già qualcosa scritto in quel modo */
.mini { padding: 5px 9px; font-size: 13px; flex-shrink: 0; }
@media (max-width: 520px) { .seg button span { display: none; } }

/* foglio per scrivere a mano: la carta è lo sfondo, l'inchiostro sta sopra */
#inkBox { flex: 1; min-height: 120px; position: relative; overflow: hidden; background-color: #fff; touch-action: none; border-top: 1px solid var(--border); }
/* scrivendo o tenendo premuto non devono comparire selezione del testo, lente o menu di iOS */
#inkBox, #stage { -webkit-user-select: none; user-select: none; -webkit-touch-callout: none; }
#inkBox.grid { background-image: linear-gradient(to right, #c9d6ea 1px, transparent 1px), linear-gradient(to bottom, #c9d6ea 1px, transparent 1px); }
#inkBox canvas { position: absolute; left: 0; top: 0; width: 100%; height: 100%; pointer-events: none; }
#inkLive { opacity: .35; }
#inkHint { position: absolute; left: 0; right: 0; bottom: 6px; text-align: center; font-size: 12px; color: #9aa1ad; pointer-events: none; }
/* appunti a tutto schermo: la slide sparisce, ma strumenti e frecce restano in una barra sopra il foglio */
#work.full { flex-direction: column; }
#work.full #stage { display: none; }
#work.full #slidePane { flex: 0 0 auto; border-right: none; }
#interim { color: var(--muted); font-style: italic; min-height: 4px; }
#recBar.text #recTime { color: var(--accent); }
#notes { flex: 1; min-height: 60px; overflow-y: auto; padding: 6px 14px 12px; outline: none; -webkit-user-select: text; user-select: text; }
#notes:empty::before { content: attr(data-placeholder); color: var(--muted); }
#notes blockquote { margin: 6px 0; padding: 6px 10px; border-left: 3px solid var(--accent); background: var(--btn); border-radius: 4px; }
#photoStrip { display: flex; gap: 8px; padding: 6px 12px; overflow-x: auto; flex-shrink: 0; border-top: 1px solid var(--border); }
.thumb { padding: 0; border-radius: 8px; overflow: hidden; flex: 0 0 auto; height: 58px; }
.thumb img { height: 58px; display: block; }
#profBox { flex-shrink: 0; max-height: 34%; overflow-y: auto; border-top: 1px solid var(--border); padding: 6px 14px; font-size: 14px; }
#profBox summary { color: var(--muted); font-size: 13px; }
#profText p { margin: 6px 0; }
#profText p.star { background: color-mix(in srgb, #facc15 25%, transparent); border-radius: 4px; padding: 2px 4px; }

#actions {
  display: flex; gap: 8px; flex-shrink: 0;
  padding: 8px calc(env(safe-area-inset-right) + 10px) calc(env(safe-area-inset-bottom) + 8px) calc(env(safe-area-inset-left) + 10px);
  background: var(--panel); border-top: 1px solid var(--border);
}
#starBtn { flex: 1.4; }
#actions .btn { flex: 1; }

/* tablet e telefono in orizzontale: slide a sinistra, appunti a destra */
@media (min-width: 760px) and (orientation: landscape) {
  #work { flex-direction: row; }
  #slidePane { flex: 1.5 1 0; min-width: 0; border-right: 1px solid var(--border); }
  #stage { flex: 1; min-height: 0; }
  #notesPane { flex: 1 1 0; min-width: 280px; }
}

/* ---- Fogli e finestre ---- */
.overlay { position: fixed; left: 0; right: 0; top: 0; height: 100dvh; z-index: 40; background: rgba(0,0,0,.45); display: flex; flex-direction: column; justify-content: flex-end; }
.sheet-body {
  background: var(--panel); border-radius: 18px 18px 0 0; display: flex; flex-direction: column; gap: 8px;
  padding: 16px 14px calc(env(safe-area-inset-bottom) + 14px); max-width: 560px; width: 100%; margin: 0 auto;
}
.sheet-body h2 { margin: 0 0 4px; font-size: 18px; }
.sheet-body p { margin: 0 0 4px; }
.row { display: block; width: 100%; padding: 13px 14px; font-size: 16px; }
.row.lang { display: flex; align-items: center; justify-content: space-between; text-align: left; }
.row.lang select { padding: 4px 8px; }
.choice { text-align: left; }
.choice b { display: block; margin-bottom: 3px; }
.choice span { display: block; font-size: 13px; color: var(--muted); font-weight: 400; }
.choice.active { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent) inset; }
#viewer { background: #000; justify-content: center; align-items: center; }
#viewerImg { max-width: 100%; max-height: calc(100% - 90px); object-fit: contain; }
.viewer-bar { position: absolute; left: 0; right: 0; bottom: 0; display: flex; gap: 10px; justify-content: space-between; padding: 12px 14px calc(env(safe-area-inset-bottom) + 12px); }

#dim { position: fixed; left: 0; right: 0; top: 0; height: 100dvh; z-index: 60; background: #000; color: #3d3d3d; display: flex; align-items: center; justify-content: center; text-align: center; }
#dimTime { font-size: 44px; font-variant-numeric: tabular-nums; margin-bottom: 10px; color: #5a1a1a; }
#dimHint { font-size: 14px; }

/* in alto, sotto la barra di registrazione: in basso finirebbe sotto la tastiera o la barra del browser */
#toast {
  position: fixed; left: 12px; right: 12px; margin: 0 auto; width: fit-content; max-width: 520px; z-index: 70;
  top: calc(env(safe-area-inset-top) + 116px); background: #1c1f24; color: #fff; border-radius: 12px;
  padding: 10px 14px; font-size: 14px; display: flex; align-items: center; gap: 10px; box-shadow: 0 6px 24px rgba(0,0,0,.3);
}
#toast button { background: #fff; color: #1c1f24; border: none; padding: 5px 10px; font-size: 13px; font-weight: 600; flex-shrink: 0; }

#blocked { position: fixed; left: 0; right: 0; top: 0; height: 100dvh; z-index: 90; background: var(--bg); display: flex; align-items: center; justify-content: center; text-align: center; padding: 30px; }