:root {
  --modra: #1a3a6b;
  --modra-bg: #e8eef8;
  --modra-border: #c0cfe8;
  --zelena: #16a34a;
  --zelena-bg: #dcfce7;
  --oranzova: #ea580c;
  --oranzova-bg: #ffedd5;
  --spatne-oranzova: #f59e0b;
  --spatne-oranzova-bg: #fef3c7;
  --cervena: #dc2626;
  --sede: #64748b;
  --pozadi: #f0f2f5;
  --karta: #ffffff;
  --radek-lichy: #ffffff;
  --radek-sudy: #f7f9fc;
  --ohranicka: #e8e8e8;
  --text: #222;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--pozadi);
  color: var(--text);
  font-family: 'Segoe UI', Arial, sans-serif;
  -webkit-tap-highlight-color: transparent;
  overflow-x: hidden;
}

.app {
  max-width: 560px;
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding-bottom: 24px;
}

.vrsek {
  padding: 16px 16px 0;
}

/* Přihlašovací obrazovka */

.prihlaseni-obrazovka {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px 16px;
}

.prihlaseni-obrazovka[hidden] {
  display: none;
}

.prihlaseni-karta {
  width: 100%;
  max-width: 340px;
}

.prihlaseni-form {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.prihlaseni-form[hidden] {
  display: none;
}

.prihlaseni-form label {
  display: flex;
  flex-direction: column;
  gap: 6px;
  font-size: .85em;
  font-weight: 600;
  color: var(--modra);
}

.prihlaseni-form input {
  font-family: inherit;
  font-size: 1em;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1.5px solid var(--modra-border);
  background: var(--modra-bg);
  color: var(--text);
}

.prihlaseni-form button[type="submit"] {
  font-family: inherit;
  font-size: 1em;
  font-weight: 700;
  padding: 12px;
  border-radius: 10px;
  border: none;
  background: var(--modra);
  color: white;
  cursor: pointer;
  margin-top: 4px;
}

.prihlaseni-chyba {
  color: var(--cervena);
  font-size: .85em;
  font-weight: 600;
  margin: 0;
}

.uzivatel-radek {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 10px;
  font-size: .78em;
}

.uzivatel-email {
  color: var(--sede);
  overflow-wrap: break-word;
}

.odhlasit-btn {
  flex-shrink: 0;
  font-family: inherit;
  font-size: 1em;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: 20px;
  border: 1.5px solid var(--modra-border);
  background: none;
  color: var(--sede);
  cursor: pointer;
}

.taby {
  display: flex;
  gap: 8px;
}

.lekce-vyber {
  position: relative;
  flex: 0 0 auto;
}

.lekce-chip {
  flex: 0 0 auto;
  font-family: inherit;
  font-size: .95em;
  font-weight: 700;
  padding: 11px 14px;
  border-radius: 10px;
  border: 1.5px solid var(--modra-border);
  background: var(--modra-bg);
  color: var(--modra);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
}

.lekce-chip::after {
  content: '';
  width: 0;
  height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 5px solid var(--modra);
  margin-top: 2px;
}

.lekce-menu {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  min-width: 160px;
  display: flex;
  flex-direction: column;
  gap: 2px;
  background: var(--karta);
  border: 1.5px solid var(--modra-border);
  border-radius: 10px;
  box-shadow: 0 6px 20px rgba(0,0,0,.14);
  padding: 6px;
  z-index: 10;
}

.lekce-menu[hidden] { display: none; }

.lekce-menu-item {
  font-family: inherit;
  font-size: .95em;
  font-weight: 700;
  padding: 10px 12px;
  border-radius: 8px;
  border: none;
  background: none;
  color: var(--modra);
  cursor: pointer;
  text-align: left;
}

.lekce-menu-item:hover {
  background: var(--modra-bg);
}

.lekce-menu-item.aktivni {
  background: var(--modra);
  color: white;
}

.tab-btn {
  flex: 1;
  font-family: inherit;
  font-size: .95em;
  font-weight: 700;
  padding: 11px 8px;
  border-radius: 10px;
  border: 1.5px solid var(--modra-border);
  background: var(--karta);
  color: var(--modra);
  cursor: pointer;
}

.tab-btn.active {
  background: var(--modra);
  color: white;
  border-color: var(--modra);
}

main {
  padding: 14px 16px 0;
  flex: 1;
}

.tab-obsah { display: none; }
.tab-obsah.active { display: block; }

.karta-bila {
  background: var(--karta);
  border-radius: 10px;
  box-shadow: 0 2px 12px rgba(0,0,0,.08);
  padding: 20px 18px 24px;
}

/* Slovní zásoba */

.progress-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.progress-bar-bg {
  flex: 1;
  background: var(--ohranicka);
  border-radius: 999px;
  height: 8px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: var(--zelena);
  width: 0%;
  transition: width .3s ease;
}

.progress-text {
  flex-shrink: 0;
  font-size: .8em;
  font-weight: 600;
  color: var(--modra);
  background: var(--modra-bg);
  border-radius: 20px;
  padding: 3px 12px;
  white-space: nowrap;
}

.seznam-slov { display: flex; flex-direction: column; }

.slovo-radek {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 10px;
  border-bottom: 1px solid var(--ohranicka);
}

.slovo-radek:nth-child(even) { background: var(--radek-sudy); }
.slovo-radek:last-child { border-bottom: none; }

.slovo-slova {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.slovo-de { font-weight: 700; color: var(--modra); font-size: 1.12em; overflow-wrap: break-word; }
.slovo-cs { color: #333; font-size: 1.12em; overflow-wrap: break-word; }

.slovo-tlacitka {
  display: flex;
  gap: 6px;
  flex-shrink: 0;
}

.chip-btn {
  width: 38px;
  height: 38px;
  flex-shrink: 0;
  font-size: 1.1em;
  line-height: 1;
  border-radius: 9px;
  border: 1.5px solid var(--modra-border);
  background: var(--modra-bg);
  color: var(--sede);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.chip-btn.umim.aktivni { background: var(--zelena); border-color: var(--zelena); color: white; }

.chip-btn.umim.zamceno {
  opacity: .45;
  filter: blur(.4px) grayscale(55%);
}

.tlac-napoveda-wrap {
  position: relative;
  display: inline-flex;
}

.tlac-napoveda {
  display: none;
  position: absolute;
  bottom: calc(100% + 9px);
  left: 50%;
  transform: translateX(-50%);
  width: max-content;
  max-width: 170px;
  background: var(--modra-bg);
  border: 1.5px solid var(--modra-border);
  border-radius: 8px;
  color: var(--modra);
  font-size: .78em;
  font-weight: 600;
  line-height: 1.35;
  padding: 8px 10px;
  box-shadow: 0 4px 14px rgba(0,0,0,.14);
  text-align: center;
  z-index: 20;
}

.tlac-napoveda::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: var(--modra-bg);
}

.tlac-napoveda.zobrazeno { display: block; }

@media (hover: hover) {
  .tlac-napoveda-wrap:hover .tlac-napoveda { display: block; }
}

.chip-btn.tezke {
  width: auto;
  padding: 0 12px;
  font-size: .8em;
  font-weight: 700;
  color: var(--modra);
  white-space: nowrap;
}

.chip-btn.tezke.aktivni { background: var(--oranzova); border-color: var(--oranzova); color: white; }

/* Cvičení */

.cviceni-info {
  font-size: .85em;
  font-weight: 600;
  color: var(--modra);
  margin-bottom: 14px;
  text-align: center;
}

.cviceni-sloupce {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 12px;
}

.sloupec { display: flex; flex-direction: column; gap: 8px; }

.karta-slovo {
  font-family: inherit;
  font-size: .88em;
  font-weight: 600;
  padding: 12px 10px;
  border-radius: 10px;
  border: 1.5px solid var(--modra-border);
  background: var(--modra-bg);
  color: var(--modra);
  cursor: pointer;
  text-align: center;
  line-height: 1.3;
  min-height: 44px;
  overflow-wrap: break-word;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform .12s ease, opacity .3s ease, filter .3s ease, background .3s ease, color .3s ease;
}

.karta-slovo.vybrana {
  border-color: var(--modra);
  background: var(--modra);
  color: white;
}

.karta-slovo.spatne {
  border-color: var(--spatne-oranzova);
  background: var(--spatne-oranzova-bg);
  color: #b45309;
  animation: zatres .3s ease;
}

.karta-slovo.spravne {
  border-color: #0e7a37;
  background: #cdebd7;
  color: #0b3d20;
}

.karta-slovo.vyresena {
  opacity: .7;
  filter: blur(.5px) grayscale(45%);
  pointer-events: none;
  border-color: var(--modra-border);
  background: var(--radek-sudy);
  color: var(--sede);
}

@keyframes zatres {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

.cviceni-hotovo, .cviceni-prazdno {
  text-align: center;
  margin-top: 24px;
}

.hotovo-text { font-size: 1.3em; font-weight: 700; color: var(--modra); }

.drobne { font-size: .82em; color: var(--sede); }

#btn-dalsi-kolo {
  font-family: inherit;
  font-size: 1em;
  font-weight: 700;
  padding: 12px 24px;
  border-radius: 10px;
  border: none;
  background: var(--modra);
  color: white;
  cursor: pointer;
}