/* =========================================
   0. COLORI MATERIAL YOU (Sfondi Ultraleggeri)
   ========================================= */
:root {
  /* TEMA HOME (a0) - Light */
  --a0-primary: #006a6a;
  --a0-on: #ffffff;
  --a0-container: #6ff7f6;
  --a0-page-bg: #fcfbfe;

  --primary-color: var(--a0-primary);
  --primary-on: var(--a0-on);
  --primary-container: var(--a0-container);
  
  /* Sfondi e superfici */
  --page-bg: var(--a0-page-bg);
  --card-bg: #ffffff;
  --surface-color: #f3f0f7;
  --on-surface: #1c1b1f;
  --bar-bg: rgba(252, 251, 254, 0.85);

  /* MATERIE */
  --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) */
    --a0-primary: #4cdada;
    --a0-on: #003737;
    --a0-container: #004f4f;
    --a0-page-bg: #141216;

    --primary-color: var(--a0-primary);
    --primary-on: var(--a0-on);
    --primary-container: var(--a0-container);
    
    /* Sfondi scuri */
    --page-bg: var(--a0-page-bg);
    --card-bg: #1d1b20;
    --surface-color: #26242a;
    --on-surface: #e6e1e5;
    --bar-bg: rgba(20, 18, 22, 0.85);

    /* MATERIE DARK */
    --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;
  }
}
/* =========================================
   1. ASSEGNAZIONE VARIABILI PER CLASSE PAGE
   ========================================= */
body.ba0 {
  --primary-color: var(--a0-primary);
  --primary-on: var(--a0-on);
  --primary-container: var(--a0-container);
  --page-bg: var(--a0-page-bg);
}
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);
}

/* =========================================
   2. 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;
}

h1#h1, h2#h2, h1#search {
  color: var(--primary-color);
  transition: color 0.3s ease;
  text-align: center;
  margin: 16px 0;
}

/* =========================================
   3. BARRA SUPERIORE ED INFERIORE (PC: PILLOLE)
   ========================================= */
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;
  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;
}

#searchbar {
  flex: 0 1 140px;
  min-width: 90px;
}

#searchbar input#searchdiv {
  width: 100%;
  height: 40px; 
  box-sizing: border-box;
  padding: 0 14px;
  font-size: 0.85rem;
  border-radius: 20px;
  border: 1.5px 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#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;
}

/* =========================================
   4. PULSANTI E SELETTORI (PC: PILLOLE)
   ========================================= */
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);
}

#a0, button#a0, .a0 {
  background-color: var(--primary-color) !important;
  color: var(--primary-on) !important;
  font-weight: 700;
}

.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);
}

.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: 20px;
  border: 1px solid var(--primary-color);
  background-color: var(--card-bg);
  color: var(--on-surface);
}

/* =========================================
   5. CARD ED ELEMENTI CONTENUTO
   ========================================= */
#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);
}

#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;
}

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;
}

#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); }

#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); }

a.external {
  color: var(--primary-color);
  text-decoration: underline;
  font-weight: 600;
}

.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;
}

.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;
}

.card-desc {
  font-size: 0.85rem;
  margin: 8px 0 0 0;
  opacity: 0.85;
  font-weight: 400;
  text-align: center;
  line-height: 1.3;
}

#desc.article-subtitle {
  text-align: center;
  font-size: 1.1rem;
  font-style: italic;
  opacity: 0.8;
  margin: -8px auto 20px auto;
  max-width: 700px;
  width: 90%;
}

.article-quote {
  margin: 24px 0;
  padding: 16px 24px;
  background-color: var(--surface-color);
  border-left: 4px solid var(--primary-color);
  border-radius: 0 8px 8px 0;
  font-style: italic;
}

.article-quote p {
  margin: 0 0 8px 0;
  font-size: 1.1rem;
}

.article-quote cite {
  font-size: 0.9rem;
  font-weight: 600;
  opacity: 0.8;
  display: block;
  text-align: right;
}

.table-container {
  overflow-x: auto;
  margin: 24px 0;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.article-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
}

.article-table th {
  background-color: var(--primary-color);
  color: #ffffff;
  padding: 12px 16px;
  font-weight: 600;
}

.article-table td {
  padding: 12px 16px;
  border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.article-table tbody tr:hover {
  background-color: rgba(0, 0, 0, 0.02);
}

.latex-block {
  margin: 20px 0;
  text-align: center;
  overflow-x: auto;
  padding: 10px 0;
}

.latex-inline {
  padding: 0 4px;
  display: inline-block;
}

#article-title {
  position: sticky;
  top: 75px;
  z-index: 90;
  text-align: center;
  color: var(--primary-color);
  background-color: var(--bar-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  width: 94%;
  max-width: 850px;
  margin: 15px auto 25px auto;
  padding: 10px 20px;
  border-radius: 32px;
  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;
}

.article-date {
  text-align: center;
  font-size: 0.9rem;
  font-style: italic;
  color: var(--on-surface);
  opacity: 0.7;
  margin-top: 40px;
  padding-top: 12px;
  border-top: 1px solid var(--primary-container);
}

/* =========================================================
   6. SELETTORE LINGUA UNIFORME SU TUTTI I DISPOSITIVI
   ========================================================= */
select#lang {
  display: none !important;
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  opacity: 0 !important;
  pointer-events: none !important;
}

.language-picker {
  position: relative;
  flex: 0 0 auto;
  margin-left: auto;
}

.language-picker-toggle {
  min-width: 72px;
  height: 40px;
  padding: 0 14px;
  border: 1.5px solid var(--primary-color);
  border-radius: 20px;
  background-color: var(--surface-color);
  color: var(--primary-color);
  font: inherit;
  font-size: 0.88rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08), 0 0 0 1px var(--primary-container);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.25s ease;
}

.language-picker-toggle::after {
  content: "\25BE";
  margin-left: 6px;
}

.language-picker.is-open .language-picker-toggle,
.language-picker-toggle:hover {
  transform: none;
  background-color: var(--primary-container);
  color: var(--primary-color);
}

.language-picker-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 1100;
  display: none;
  min-width: 100%;
  padding: 6px;
  border: 1.5px solid var(--primary-color);
  border-radius: 16px;
  background-color: var(--card-bg);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.14), 0 0 10px var(--primary-container);
}

.language-picker.is-open .language-picker-menu {
  display: grid;
  gap: 4px;
}

.language-picker-option {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid transparent;
  border-radius: 10px;
  background-color: transparent;
  color: var(--on-surface);
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.language-picker-option:hover,
.language-picker-option.is-selected {
  transform: none;
  border-color: transparent;
  background-color: var(--primary-container);
  color: var(--primary-color);
  font-weight: 700;
}

/* =========================================================
   7. VISUALIZZAZIONE SMARTPHONE FORZATA (< 768px): RECTANGLES
   ========================================================= */
@media (max-width: 768px) {

  body {
    font-size: 20px !important;
    line-height: 1.5 !important;
    padding-bottom: 130px !important;
    padding-top: 85px !important;
  }

  #content p {
    margin: 4px 0 !important; 
    line-height: 1.4 !important;
  }

  /* HEADER TOP FIXED BAR */
  header {
    backdrop-filter: none !important;
    -webkit-backdrop-filter: none !important;
    background: transparent !important;
    border: none !important;
    box-shadow: none !important;
    padding: 14px 15px !important;
    margin: 0 !important;
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    gap: 10px !important;
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    width: 100% !important;
    height: 76px !important;
    z-index: 1001 !important;
    pointer-events: none;
  }

  header > * {
    pointer-events: auto;
  }

  /* Campo Cerca (Sempre a sinistra nella Home) */
  #searchbar {
    order: 1 !important;
    flex: 1 !important;
    display: flex !important;
    margin: 0 !important;
  }

  #searchbar input#searchdiv {
    background-color: var(--bar-bg) !important;
    backdrop-filter: blur(16px) !important;
    -webkit-backdrop-filter: blur(16px) !important;
    border: 1.5px solid var(--primary-color) !important;
    color: var(--primary-color) !important;
    height: 48px !important;
    border-radius: 12px !important;
    font-size: 16px !important;
    padding: 0 15px !important;
    width: 100% !important;
    box-sizing: border-box !important;
  }

  /* Selettore Lingua (Sempre a destra sia in Home che negli Articoli) */
  .language-picker {
    order: 2 !important;
    margin-left: auto !important;
  }

  .language-picker-toggle {
    height: 48px !important;
    border-radius: 12px !important;
    padding: 0 14px !important;
  }

  .language-picker-menu {
    border-radius: 12px !important;
  }

  .language-picker-option {
    border-radius: 8px !important;
  }

  /* Titolo dell'Articolo (Fisso a sinistra del selettore lingua) */
  #article-title {
    order: 1 !important;
    position: fixed !important;
    top: 14px !important;
    left: 15px !important;
    right: 97px !important;
    width: auto !important;
    height: 48px !important;
    border-radius: 12px !important;
    box-sizing: border-box !important;
    line-height: 44px !important;
    padding: 0 16px !important;
    margin: 0 !important;
    font-size: 1.1rem !important;
    background-color: var(--bar-bg) !important;
    backdrop-filter: blur(16px) !important;
    -webkit-backdrop-filter: blur(16px) !important;
    border: 1.5px solid var(--primary-color) !important;
    color: var(--primary-color) !important;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05) !important;
    z-index: 1002 !important;
    text-align: left !important;
    white-space: nowrap !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    pointer-events: auto !important;
  }

  #desc.article-subtitle {
    margin-top: 10px !important;
    font-size: 1.2rem !important;
  }

  h1#h1, h2#h2, h1#search {
    font-size: 1.8rem !important;
    margin: 20px 0 !important;
  }

  button, select {
    border-radius: 12px !important;
  }

  .section-title-wrapper {
    flex-direction: column !important;
    gap: 12px !important;
    margin: 32px 16px 16px 16px !important;
  }

  .section-title-wrapper h2 {
    font-size: 1.8rem !important;
    margin: 0 !important;
    text-align: center !important;
  }

  .section-title-wrapper select#sort {
    width: 100% !important;
    max-width: 280px !important;
    background-color: var(--bar-bg) !important;
    border: 1.5px solid var(--primary-color) !important;
    color: var(--primary-color) !important;
    border-radius: 12px !important;
    padding: 12px 16px !important;
    font-size: 16px !important;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05) !important;
    text-align: center !important; 
    text-align-last: center !important;
  }

  #recent, #div, #results, #content {
    padding: 24px 16px !important;
    margin: 20px auto !important;
    gap: 16px !important;
    border-radius: 16px !important;
  }

  #div button, #results button, #recent button {
    padding: 20px 16px !important;
    margin-bottom: 8px !important;
    border-radius: 12px !important;
    white-space: normal !important;
  }

  #div button h1, #recent button h1, #results button h1 {
    font-size: 1.5rem !important;
    font-weight: 800 !important;
    line-height: 1.2 !important;
  }

  #div button h2, #recent button h2, #results button h2 {
    font-size: 1.1rem !important;
    margin-top: 8px !important;
    opacity: 0.85;
  }

  .card-desc {
    font-size: 1.1rem !important;
    margin-top: 10px !important;
    line-height: 1.4 !important;
  }

  nav#nav {
    position: fixed !important;
    bottom: 0 !important;
    top: auto !important;
    left: 0 !important;
    width: 100% !important;
    background-color: var(--bar-bg) !important;
    backdrop-filter: blur(16px) !important;
    -webkit-backdrop-filter: blur(16px) !important;
    border-radius: 16px 16px 0 0 !important;
    border: 1.5px solid var(--primary-color) !important;
    border-bottom: none !important;
    border-left: none !important;
    border-right: none !important;
    padding: 18px 10px calc(18px + env(safe-area-inset-bottom)) !important;
    justify-content: space-evenly !important;
    z-index: 1000 !important;
  }

  nav#nav button {
    flex-grow: 1 !important;
    padding: 18px 5px !important;
    margin: 0 5px !important;
    font-size: 16px !important;
    font-weight: 700 !important;
    border-radius: 12px !important;
  }

  footer#footer {
    position: static !important;
    transform: none !important;
    margin: 40px auto 140px auto !important; 
    width: max-content !important;
    border-radius: 16px !important;
  }

  footer#footer .contact {
    border-radius: 12px !important;
  }
}