:root {
  --bg: #f4f6fa;
  --bg-elevated: #ffffff;
  --text: #1c2536;
  --text-muted: #5b6478;
  --border: #dde2ec;
  --accent: #1d63c9;
  --accent-hover: #164e9f;
  --accent-soft: #e7f0fd;
  --success: #1c8a4b;
  --success-soft: #e4f6ea;
  --danger: #c9341d;
  --danger-soft: #fbe8e4;
  --shadow: 0 2px 10px rgba(20, 30, 60, 0.06);
  --radius: 14px;
}

[data-theme="dark"] {
  --bg: #10131c;
  --bg-elevated: #1a1f2e;
  --text: #eef1f8;
  --text-muted: #9aa3b8;
  --border: #2b3247;
  --accent: #5b9bf5;
  --accent-hover: #7fb0f7;
  --accent-soft: #1e2c47;
  --success: #4cbb7c;
  --success-soft: #163524;
  --danger: #e2604a;
  --danger-soft: #3a2020;
  --shadow: 0 2px 14px rgba(0, 0, 0, 0.35);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #10131c;
    --bg-elevated: #1a1f2e;
    --text: #eef1f8;
    --text-muted: #9aa3b8;
    --border: #2b3247;
    --accent: #5b9bf5;
    --accent-hover: #7fb0f7;
    --accent-soft: #1e2c47;
    --success: #4cbb7c;
    --success-soft: #163524;
    --danger: #e2604a;
    --danger-soft: #3a2020;
    --shadow: 0 2px 14px rgba(0, 0, 0, 0.35);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.app-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
  padding: 0.9rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.app-header h1 {
  font-size: 1.15rem;
  margin: 0;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.icon-btn {
  background: var(--accent-soft);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 10px;
  width: 2.3rem;
  height: 2.3rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.05rem;
}
.icon-btn:hover { filter: brightness(1.05); }

main {
  max-width: 1080px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 4rem;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.hero h2 { margin-top: 0; }
.hero p { color: var(--text-muted); }

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 0.75rem;
  margin: 1rem 0;
}
.stat-box {
  background: var(--accent-soft);
  border-radius: 10px;
  padding: 0.8rem 1rem;
  text-align: center;
}
.stat-box .num {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
}
.stat-box .label {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.btn {
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 0.6rem 1.1rem;
  border-radius: 10px;
  cursor: pointer;
  font-size: 0.92rem;
  font-weight: 600;
}
.btn:hover { background: var(--accent-hover); }
.btn.secondary {
  background: var(--accent-soft);
  color: var(--accent);
}
.btn.ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

select, .select {
  background: var(--bg-elevated);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.5rem 0.7rem;
  font-size: 0.92rem;
}

.row-flex {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.back-link {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  padding: 0;
  margin-bottom: 0.8rem;
  font-size: 0.92rem;
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 0.9rem;
}
.topic-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform 0.12s ease;
}
.topic-card:hover { transform: translateY(-2px); }
.topic-card .icon { font-size: 1.8rem; }
.topic-card h3 { margin: 0.4rem 0 0.2rem; font-size: 1.05rem; }
.topic-card .meta { font-size: 0.8rem; color: var(--text-muted); }
.topic-card .progress-bar-outer {
  margin-top: 0.6rem;
  background: var(--bg);
  border-radius: 999px;
  height: 6px;
  overflow: hidden;
}
.topic-card .progress-bar-inner {
  background: var(--accent);
  height: 100%;
  border-radius: 999px;
}

.section-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 1.6rem 0 0.8rem;
}
.section-title:first-child { margin-top: 0; }
.section-sub { color: var(--text-muted); font-size: 0.88rem; margin: -0.4rem 0 0.9rem; }

.lernziele-list { margin: 0; padding-left: 0; list-style: none; }
.lernziele-list li { margin-bottom: 0.4rem; font-size: 0.92rem; }
.lernziele-list li:last-child { margin-bottom: 0; }
.lernziel-item.done span { color: var(--text-muted); text-decoration: line-through; }

.lernziel-check {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  cursor: pointer;
  padding: 0.3rem 0.4rem;
  border-radius: 8px;
}
.lernziel-check:hover { background: var(--bg); }
.lernziel-check input[type="checkbox"] {
  margin-top: 0.2rem;
  width: 1.05rem;
  height: 1.05rem;
  flex-shrink: 0;
  accent-color: var(--success);
  cursor: pointer;
}

.lernziele-details {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 0.9rem 1.1rem;
  margin-bottom: 1.2rem;
}
.lernziele-details summary { cursor: pointer; font-weight: 600; color: var(--accent); }
.lernziele-details .lernziele-list { margin-top: 0.8rem; }

.thema-tabs {
  display: flex;
  gap: 0.4rem;
  margin-bottom: 1.2rem;
  border-bottom: 1px solid var(--border);
  overflow-x: auto;
}
.thema-tab {
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-muted);
  padding: 0.6rem 0.9rem;
  cursor: pointer;
  font-size: 0.92rem;
  white-space: nowrap;
}
.thema-tab:hover { color: var(--text); }
.thema-tab.active { color: var(--accent); border-bottom-color: var(--accent); font-weight: 600; }
.thema-tab-count {
  font-size: 0.72rem;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 999px;
  padding: 0.05rem 0.45rem;
}
.thema-tab.active .thema-tab-count { background: var(--accent); color: #fff; }

/* Fachbegriff-Karteikarten */
.flash-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 0.8rem;
  margin-bottom: 1.6rem;
}
.flash-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.9rem 1rem;
  box-shadow: var(--shadow);
}
.flash-card.revealed { border-color: var(--accent); }
.flash-term { font-weight: 700; margin-bottom: 0.6rem; }
.flash-def {
  margin-top: 0.6rem;
  padding-top: 0.6rem;
  border-top: 1px dashed var(--border);
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.5;
}
.flash-card .btn { font-size: 0.82rem; padding: 0.4rem 0.8rem; }

/* Selbstbewertung / Auto-Korrektur pro Aufgabe */
.selfscore-row {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.selfscore-row.auto { gap: 0.6rem; font-weight: 600; color: var(--text); }
.selfscore-row.auto.pending { font-weight: 400; font-style: italic; color: var(--text-muted); }
.badge-auto {
  background: var(--success-soft);
  color: var(--success);
  border-radius: 999px;
  padding: 0.2rem 0.6rem;
  font-size: 0.74rem;
  font-weight: 700;
}

/* Aufgaben-Karten */
.meta-bar { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 0.6rem; }
.badge {
  display: inline-block;
  font-size: 0.72rem;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  font-weight: 600;
}
.badge-typ { background: var(--bg); border: 1px solid var(--border); color: var(--text-muted); }

.aufgabe-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem;
  margin-bottom: 1rem;
  background: var(--bg-elevated);
  box-shadow: var(--shadow);
}

.aufgabe-head {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
  flex-wrap: wrap;
}
.aufgabe-nr {
  background: var(--accent);
  color: #fff;
  border-radius: 999px;
  min-width: 1.6rem;
  height: 1.6rem;
  padding: 0 0.35rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.74rem;
  font-weight: 700;
  flex-shrink: 0;
}
.aufgabe-titel { font-weight: 700; }
.aufgabe-frage { margin-bottom: 0.7rem; white-space: pre-line; }

.loesung-block {
  display: none;
  margin-top: 0.9rem;
  padding: 0.8rem 1rem;
  background: var(--success-soft);
  border-radius: 10px;
  font-size: 0.9rem;
  line-height: 1.55;
}
.aufgabe-card.revealed .loesung-block { display: block; }

.answer-input {
  width: 100%;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.55rem 0.7rem;
  font-family: inherit;
  font-size: 0.92rem;
  resize: vertical;
}
.answer-input:focus { outline: none; border-color: var(--accent); }
.shortanswer-input.correct { border-color: var(--success); background: var(--success-soft); }
.shortanswer-input.wrong { border-color: var(--danger); background: var(--danger-soft); }

.mc-block { margin-bottom: 0.9rem; }
.mc-block-label { font-weight: 600; margin-bottom: 0.35rem; font-size: 0.92rem; }
.opt-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.55rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
}
.opt-row:hover { background: var(--accent-soft); }
.opt-row.inline { padding: 0.25rem 0.5rem; }
.aufgabe-card.revealed .opt-row[data-correct="true"] { background: var(--success-soft); font-weight: 600; }
.aufgabe-card.revealed .opt-row:has(input:checked)[data-correct="false"] { background: var(--danger-soft); }

.tf-table { display: flex; flex-direction: column; gap: 0.6rem; }
.tf-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  flex-wrap: wrap;
  border-bottom: 1px dashed var(--border);
  padding-bottom: 0.5rem;
}
.tf-text { flex: 1 1 260px; font-size: 0.9rem; }
.tf-options { display: flex; gap: 0.4rem; flex-wrap: wrap; }

.matchn-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  margin-bottom: 0.5rem;
  flex-wrap: wrap;
}
.matchn-text { font-size: 0.9rem; }
.aufgabe-card.revealed select[data-correct] { outline: 2px solid var(--success); border-radius: 8px; }

.fillblank-text { line-height: 2.6; font-size: 0.95rem; }
.blank-drop {
  display: inline-flex;
  min-width: 7rem;
  justify-content: center;
  background: var(--accent-soft);
  color: var(--accent);
  border: 2px dashed var(--accent);
  border-radius: 8px;
  padding: 0.1rem 0.6rem;
  font-size: 0.88rem;
  margin: 0 0.2rem;
  cursor: pointer;
  vertical-align: middle;
}
.blank-drop.filled { border-style: solid; background: var(--bg-elevated); color: var(--text); font-weight: 600; }
.blank-drop.filled.wrong { border-color: var(--danger); color: var(--danger); }
.blank-drop.filled.correct { border-color: var(--success); color: var(--success); }
.blank-drop:hover { border-color: var(--accent-hover); }

.wordbank { margin-top: 0.9rem; display: flex; flex-wrap: wrap; gap: 0.4rem; }
.chip {
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 999px;
  padding: 0.2rem 0.65rem;
  font-size: 0.78rem;
}
.drag-chip { cursor: grab; user-select: none; border: 1px solid transparent; }
.drag-chip:active { cursor: grabbing; }
.drag-chip:hover { border-color: var(--accent); }

@media (max-width: 480px) {
  .app-header h1 { font-size: 1rem; }
  main { padding: 1rem 0.85rem 3.5rem; }
}