/* Jasny/Ciemny motyw */
:root {
  --bg-color: #f5f9ff;
  --text-color: #212121;
  --header-bg: linear-gradient(135deg, #3a86ff, #8338ec);
  --header-text: white;
  --section-bg: white;
  --section-shadow: rgba(0,0,0,0.07);
  --primary-color: #3a86ff;
  --secondary-color: #8338ec;
  --vocab-bg: #e0f0ff;
  --vocab-hover-bg: #a8d0ff;
  --button-bg: #3a86ff;
  --button-hover-bg: #8338ec;
  --border-color: #ddd;
  --quiz-answer-bg: #3a86ff;
  --quiz-answer-border: #3a86ff;
  --quiz-answer-hover-bg: #8338ec;
}

body.dark-theme {
  --bg-color: #121217;
  --text-color: #e0e0e0;
  --header-bg: linear-gradient(135deg, #6a5acd, #4b0082);
  --header-text: #ddd;
  --section-bg: #22222b;
  --section-shadow: rgba(0,0,0,0.8);
  --primary-color: #6a5acd;
  --secondary-color: #4b0082;
  --vocab-bg: #3a3a4f;
  --vocab-hover-bg: #555581;
  --button-bg: #4b0082;
  --button-hover-bg: #6a5acd;
  --border-color: #444455;
  --quiz-answer-bg: #6a5acd;
  --quiz-answer-border: #6a5acd;
  --quiz-answer-hover-bg: #4b0082;
}

/* Reset i globalne */
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
}
header {
  background: var(--header-bg);
  color: var(--header-text);
  padding: 2rem 1rem;
  text-align: center;
  box-shadow: 0 4px 10px var(--section-shadow);
  position: relative;
}
header h1 {
  margin: 0;
  font-size: 2.8rem;
  letter-spacing: 2px;
}
header p {
  font-size: 1.2rem;
  margin-top: 0.5rem;
  font-weight: 300;
}

/* Przycisk ciemnego motywu */
#dark-mode-toggle {
  position: absolute;
  top: 1.75rem;
  right: 1.5rem;
  background: transparent;
  border: 1.5px solid var(--header-text);
  color: var(--header-text);
  padding: 0.5rem 1rem;
  border-radius: 30px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  transition: background-color 0.3s ease, color 0.3s ease;
}
#dark-mode-toggle:hover {
  background: var(--header-text);
}

#dark-mode-toggle span{
  color: rgba(255,255,255,1);
}
#dark-mode-toggle:hover span{
  color: transparent;
  background-image: var(--header-bg);
  background-clip: text;
  text-shadow: none
}

main {
  max-width: 900px;
  margin: 2rem auto;
  padding: 0 1rem 4rem;
}
section {
  background: var(--section-bg);
  margin-bottom: 2rem;
  padding: 1.8rem 2rem;
  border-radius: 12px;
  box-shadow: 0 6px 15px var(--section-shadow);
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}
section h2 {
  color: var(--primary-color);
  margin-top: 0;
  border-bottom: 3px solid var(--primary-color);
  padding-bottom: 6px;
  font-size: 1.8rem;
}
/* Słownictwo */
.tabs {
  display: flex;
  border-bottom: 3px solid var(--primary-color);
  margin-bottom: 1rem;
  user-select: none;
}
.tab {
  padding: 0.7rem 1.5rem;
  margin-right: 0.5rem;
  cursor: pointer;
  border-radius: 8px 8px 0 0;
  background: var(--vocab-bg);
  color: var(--primary-color);
  font-weight: 600;
  transition: background 0.3s ease, color 0.3s ease;
}
.tab:hover {
  background: var(--vocab-hover-bg);
}
.tab.active {
  background: var(--section-bg);
  color: var(--secondary-color);
  border-bottom: 3px solid var(--section-bg);
  font-weight: 700;
  box-shadow: 0 -4px 10px rgba(131,56,236,0.4);
}
.vocab-list {
  list-style: none;
  padding-left: 0;
  max-height: 320px;
  overflow-y: auto;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  transition: border-color 0.3s ease;
}
.vocab-list li {
  background: var(--vocab-bg);
  margin: 0.5rem 0;
  padding: 0.6rem 1rem;
  border-radius: 8px;
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: default;
  transition: background 0.3s ease;
}
.vocab-list li:hover {
  background: var(--vocab-hover-bg);
}
.vocab-list button {
  background: var(--button-bg);
  border: none;
  color: white;
  border-radius: 5px;
  padding: 0.4rem 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.3s ease;
}
.vocab-list button:hover {
  background: var(--button-hover-bg);
}

/* Gramatyka */
.grammar-tips {
  line-height: 1.5;
}
.grammar-tips ul {
  margin: 0.5rem 0 0 1.4rem;
}
.grammar-tips li {
  margin-bottom: 0.5rem;
}

/* Quiz */
.quiz-question {
  font-size: 1.1rem;
  margin-bottom: 0.6rem;
}
.quiz-options {
  list-style: none;
  padding-left: 0;
}
.quiz-options li {
  margin-bottom: 0.6rem;
}
.quiz-options label {
  cursor: pointer;
  user-select: none;
  display: block;
  padding: 0.6rem 1rem;
  border-radius: 8px;
  border: 2px solid var(--quiz-answer-border);
  transition: background 0.3s, border-color 0.3s;
  color: var(--text-color);
}
.quiz-options input[type="radio"] {
  display: none;
}
.quiz-options input[type="radio"]:checked + label {
  background: var(--quiz-answer-bg);
  color: white;
  border-color: var(--quiz-answer-border);
}
button.check-answer {
  margin-top: 1rem;
  background: var(--button-bg);
  color: white;
  font-weight: 700;
  border: none;
  padding: 0.8rem 1.5rem;
  border-radius: 10px;
  cursor: pointer;
  box-shadow: 0 6px 12px rgb(58 134 255 / 0.6);
  transition: background 0.3s ease;
}
button.check-answer:hover {
  background: var(--button-hover-bg);
}
.quiz-result {
  margin-top: 1rem;
  font-weight: 700;
  font-size: 1.2rem;
  min-height: 1.4em;
}
footer {
  text-align: center;
  color: #777;
  font-size: 0.9rem;
  padding: 1rem;
  border-top: 1px solid var(--border-color);
  transition: color 0.3s ease, border-color 0.3s ease;
}

@media (max-width: 600px) {
  header h1 {
    font-size: 2rem;
  }
  main {
    margin: 1rem;
  }
  .tabs {
    flex-wrap: wrap;
  }
  .tab {
    margin-bottom: 0.5rem;
  }
}