/* =========================================
   1. COLORI MATERIAL YOU (Sfondi Ultraleggeri)
   ========================================= */
:root {
  /* TEMA HOME (a0) - Ottanio soft su fondo bianco-grigio etereo */
  --primary-color: #006a6a;
  --primary-on: #ffffff;
  --primary-container: #6ff7f6;
  --on-primary-container: #002020;
  
  /* Sfondi quasi impercettibili */
  --page-bg: #fcfbfe;
  --card-bg: #ffffff;
  --surface-color: #f3f0f7;
  --on-surface: #1c1b1f;
  --bar-bg: rgba(252, 251, 254, 0.85);

  /* MATERIE: Sfondi pagina velati al minimo (99% bianchi con 1% tinta) */
  --a1-primary: #98000a; --a1-on: #ffffff; --a1-container: #ffdad6; --a1-page-bg: #fffbfb; /* Fisica */
  --a2-primary: #1b5bb4; --a2-on: #ffffff; --a2-container: #d8e2ff; --a2-page-bg: #f9fafe; /* Matematica */
  --a3-primary: #6d5d00; --a3-on: #ffffff; --a3-container: #ffe082; --a3-page-bg: #fffdf9; /* Chimica */
  --a4-primary: #2d6a22; --a4-on: #ffffff; --a4-container: #b9eaad; --a4-page-bg: #f8fcf7; /* Biologia */
}

@media (prefers-color-scheme: dark) {
  :root {
    /* TEMA HOME DARK (a0) */
    --primary-color: #4cdada;
    --primary-on: #003737;
    --primary-container: #004f4f;
    --on-primary-container: #6ff7f6;
    
    /* Sfondi scuri a basso stacco */
    --page-bg: #141216;
    --card-bg: #1d1b20;
    --surface-color: #26242a;
    --on-surface: #e6e1e5;
    --bar-bg: rgba(20, 18, 22, 0.85);

    /* MATERIE DARK: Velatura scura profonda e morbida */
    --a1-primary: #ffb4ab; --a1-on: #690005; --a1-container: #93000a; --a1-page-bg: #171213;
    --a2-primary: #adc6ff; --a2-on: #002e69; --a2-container: #004299; --a2-page-bg: #12141a;
    --a3-primary: #ffe082; --a3-on: #3a3000; --a3-container: #7a6100; --a3-page-bg: #171611;
    --a4-primary: #9ece93; --a4-on: #003a00; --a4-container: #245114; --a4-page-bg: #121712;
  }
}
/* =========================================
   2. ASSEGNAZIONE VARIABILI PER CLASSE PAGE
   ========================================= */
body.ba1 {
  --primary-color: var(--a1-primary);
  --primary-on: var(--a1-on);
  --primary-container: var(--a1-container);
  --page-bg: var(--a1-page-bg);
}
body.ba2 {
  --primary-color: var(--a2-primary);
  --primary-on: var(--a2-on);
  --primary-container: var(--a2-container);
  --page-bg: var(--a2-page-bg);
}
body.ba3 {
  --primary-color: var(--a3-primary);
  --primary-on: var(--a3-on);
  --primary-container: var(--a3-container);
  --page-bg: var(--a3-page-bg);
}
body.ba4 {
  --primary-color: var(--a4-primary);
  --primary-on: var(--a4-on);
  --primary-container: var(--a4-container);
  --page-bg: var(--a4-page-bg);
}
/* Il tema di base (ba0) usa già le variabili di root di default */

/* =========================================
   3. STILI GLOBALI CON DETTAGLI A TEMA
   ========================================= */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: system-ui, -apple-system, sans-serif;
  background-color: var(--page-bg);
  color: var(--on-surface);
  transition: background-color 0.4s ease, color 0.4s ease;
  padding-bottom: 100px;
  overflow-x: hidden;
}

/* Titoli colorati in base al tema */
h1#h1, h2#h2, h1#search {
  color: var(--primary-color);
  transition: color 0.3s ease;
  text-align: center;
  margin: 16px 0;
}

/* =========================================
   4. BARRA SUPERIORE ED INFERIORE (Fluttuanti)
   ========================================= */
header {
  position: sticky;
  top: 12px;
  z-index: 1000;
  width: 94%;
  max-width: 850px;
  margin: 10px auto;
  background-color: var(--bar-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  padding: 6px 12px;
  border-radius: 32px;
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  /* Bordo sfumato e ombra nel colore della materia */
  border: 1.5px solid var(--primary-color);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06), 0 0 10px var(--primary-container);
  transition: border-color 0.4s ease, box-shadow 0.4s ease;
}

nav#nav {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 6px;
  overflow-x: auto;
  white-space: nowrap;
  flex: 1 1 auto;
  min-width: 0;
  scrollbar-width: none;
  padding: 2px;
}

nav#nav::-webkit-scrollbar {
  display: none;
}

/* Barra di Ricerca */
#searchbar {
  flex: 0 1 140px;
  min-width: 90px;
}

#searchbar input#searchdiv {
  width: 100%;
  padding: 8px 14px;
  font-size: 0.85rem;
  border-radius: 20px;
  border: 1px solid var(--primary-color);
  background-color: var(--card-bg);
  color: var(--on-surface);
  transition: all 0.3s ease;
}

#searchbar input#searchdiv:focus {
  outline: none;
  box-shadow: 0 0 0 3px var(--primary-container);
}

/* Footer Fluttuante a Tema */
footer#footer {
  position: fixed;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  width: 90%;
  max-width: 500px;
  z-index: 1000;
  background-color: var(--bar-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  padding: 8px 16px;
  border-radius: 30px;
  display: flex;
  justify-content: center;
  gap: 10px;
  border: 1.5px solid var(--primary-color);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  transition: border-color 0.4s ease;
}

/* =========================================
   5. PULSANTI E DETTAGLI UI
   ========================================= */
button, select {
  border: 1px solid transparent;
  outline: none;
  border-radius: 20px;
  padding: 8px 16px;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
  background-color: var(--surface-color);
  color: var(--on-surface);
  white-space: nowrap;
  flex-shrink: 0;
}

button:hover, select:hover {
  transform: translateY(-2px);
  border-color: var(--primary-color);
}

/* Tasto a0 e Bottoni Attivi */
#a0, button#a0, .a0 {
  background-color: var(--primary-color) !important;
  color: var(--primary-on) !important;
  font-weight: 700;
}

/* Pulsanti specifici delle materie nei dettagli */
.a1, button.a1, #a1 { background-color: var(--a1-container); color: var(--a1-primary); }
.a2, button.a2, #a2 { background-color: var(--a2-container); color: var(--a2-primary); }
.a3, button.a3, #a3 { background-color: var(--a3-container); color: var(--a3-primary); }
.a4, button.a4, #a4 { background-color: var(--a4-container); color: var(--a4-primary); }

nav#nav button.active {
  box-shadow: 0 0 0 2px var(--primary-color);
}

/* =========================================
   6. TITOLO SEZIONE "TUTTI GLI ARTICOLI"
   ========================================= */
.section-title-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin: 28px 0 12px 0;
}

.section-title-wrapper h2 {
  margin: 0;
  font-size: 1.3rem;
  color: var(--primary-color);
}

.section-title-wrapper select#sort {
  padding: 6px 14px;
  font-size: 0.85rem;
  border-radius: 16px;
  border: 1px solid var(--primary-color);
  background-color: var(--card-bg);
}

/* =========================================
   7. SEZIONI E CARD ARTICOLI
   ========================================= */
#results:empty, #search:empty {
  display: none !important;
}

#recent, #div, #results, #content {
  background-color: var(--card-bg);
  border-radius: 28px;
  padding: 20px;
  margin: 14px auto;
  max-width: 800px;
  width: 92%;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03);
  display: flex;
  flex-direction: column;
  gap: 12px;
  border: 1px solid rgba(0, 0, 0, 0.05);
}

/* Card individuali degli articoli */
#div button, #results button, #recent button {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 16px;
  border-radius: 20px;
  border: 1px solid transparent;
  transition: all 0.3s ease;
}

#div button:hover, #results button:hover, #recent button:hover {
  border-color: var(--primary-color);
  box-shadow: 0 4px 12px var(--surface-color);
}

#div button h1, #recent button h1, #results button h1 {
  font-size: 1.1rem;
  margin: 0;
}

#div button h2, #recent button h2, #results button h2 {
  font-size: 0.82rem;
  margin: 6px 0 0 0;
  opacity: 0.8;
}
/* Stile base per tutti i link interni */
a.internal {
  color: var(--on-surface);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
  font-weight: 600;
  transition: all 0.2s ease;
}

/* Colore della sottolineatura basato sull'ID del link (c + classe) */
#ca0 { text-decoration-color: var(--primary-color); }
#ca1 { text-decoration-color: var(--a1-primary); }
#ca2 { text-decoration-color: var(--a2-primary); }
#ca3 { text-decoration-color: var(--a3-primary); }
#ca4 { text-decoration-color: var(--a4-primary); }

/* Cambio colore del testo al passaggio del mouse */
#ca0:hover { color: var(--primary-color); }
#ca1:hover { color: var(--a1-primary); }
#ca2:hover { color: var(--a2-primary); }
#ca3:hover { color: var(--a3-primary); }
#ca4:hover { color: var(--a4-primary); }
/* Link Esterni */
a.external {
  color: var(--primary-color);
  text-decoration: underline;
  font-weight: 600;
}

/* Immagini Articolo */
.article-image {
  margin: 16px 0;
  text-align: center;
}

.article-image img {
  max-width: 100%;
  height: auto;
  border-radius: 16px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.article-image figcaption {
  font-size: 0.85rem;
  opacity: 0.75;
  margin-top: 6px;
}

/* Formule e GeoGebra */
.math-formula {
  overflow-x: auto;
  padding: 12px 0;
  text-align: center;
}

.geogebra-container {
  width: 100%;
  margin: 20px 0;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}
#content strong {
  color: var(--primary-color);
  font-weight: 700;
  transition: color 0.3s ease;
}