:root {
  --bg: #0e1117;
  --bg-soft: #161b22;
  --bg-elev: #1c2129;
  --bg-code: #0a0d12;
  --border: #2a3038;
  --text: #e6edf3;
  --text-dim: #9aa4b2;
  --accent: #58a6ff;
  --green: #7ee787;
  --orange: #ffa657;
  --pink: #f778ba;
  --red: #f85149;
  --radius: 10px;
  --mono: "SFMono-Regular", ui-monospace, Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.65;
  font-size: 16px;
  -webkit-tap-highlight-color: transparent;
}

/* ===== Topbar ===== */
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--bg-soft);
  border-bottom: 1px solid var(--border);
}
.topbar-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}
.brand { font-size: 20px; font-weight: 700; letter-spacing: 0.3px; }
.brand .angle { color: var(--orange); }
.brand .brand-accent { color: var(--accent); }

.score-wrap { flex: 1; min-width: 200px; max-width: 360px; }
.score-label {
  font-size: 14px;
  color: var(--text-dim);
  margin-bottom: 6px;
  font-weight: 600;
}
.score-bar {
  height: 10px;
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 20px;
  overflow: hidden;
}
.score-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--green));
  border-radius: 20px;
  transition: width .35s ease;
}

/* ===== Main / Hero ===== */
.main { max-width: 960px; margin: 0 auto; padding: 32px 20px; }

.hero { margin-bottom: 26px; }
.hero h1 { font-size: 30px; margin: 0 0 8px; line-height: 1.25; }
.hero h1 .angle { color: var(--orange); }
.hero p.lead { color: var(--text-dim); font-size: 16px; margin: 0 0 16px; }
.hero p.lead strong { color: var(--text); }
.hero .btn { margin-top: 4px; }

/* ===== Task card ===== */
.task {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin: 16px 0;
  transition: border-color .2s;
}
.task.correct { border-color: var(--green); }
.task.wrong { border-color: var(--red); }
.task.answered { border-color: var(--accent); }

.task-head {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}
.task-num {
  font-family: var(--mono);
  color: var(--text-dim);
  font-size: 13px;
  font-weight: 600;
}
.lesson-tag {
  display: inline-block;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: 20px;
}
.status-badge {
  display: none;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 700;
  padding: 2px 12px;
  border-radius: 20px;
}
.task.correct .status-badge,
.task.wrong .status-badge { display: inline-flex; }
.task.answered .status-badge.neutral { display: inline-flex; }
.status-badge.ok { background: rgba(126,231,135,0.15); color: var(--green); }
.status-badge.no { background: rgba(248,81,73,0.15); color: var(--red); }
.status-badge.neutral { background: rgba(88,166,255,0.15); color: var(--accent); }

.task-q { font-weight: 600; font-size: 17px; margin: 0 0 14px; }

/* Options */
.option {
  display: block;
  width: 100%;
  text-align: left;
  padding: 12px 14px;
  margin: 8px 0;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  font-size: 16px;
  color: var(--text);
  font-family: inherit;
  line-height: 1.5;
  transition: border-color .15s, background .15s;
}
.option:hover { border-color: var(--accent); }
.option.selected { border-color: var(--accent); background: rgba(88,166,255,0.12); }
.option:disabled { cursor: default; opacity: 0.85; }
.option.reveal-correct { border-color: var(--green); background: rgba(126,231,135,0.14); }
.option.reveal-wrong { border-color: var(--red); background: rgba(248,81,73,0.14); }

.option code {
  font-family: var(--mono);
  background: var(--bg-code);
  border: 1px solid var(--border);
  padding: 2px 7px;
  border-radius: 5px;
  font-size: 14px;
  color: #7ee787;
  white-space: nowrap;
}
.code-opt {
  display: block;
  font-family: var(--mono);
  font-size: 14px;
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  margin: 4px 0;
  color: #c9d1d9;
  overflow-x: auto;
  white-space: nowrap;
}
.code-opt .t { color: #7ee787; }
.code-opt .a { color: #79c0ff; }
.code-opt .s { color: #ffa657; }

/* Fill-in input */
.fill-input {
  width: 100%;
  min-height: 48px;
  background: var(--bg-code);
  color: var(--text);
  font-family: var(--mono);
  font-size: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
  outline: none;
}
.fill-input:focus { border-color: var(--accent); }
.fill-input:disabled { opacity: 0.7; }

/* Buttons */
.btn {
  background: var(--accent);
  color: #0a0d12;
  border: none;
  padding: 11px 20px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  min-height: 44px;
  transition: filter .15s;
  font-family: inherit;
}
.btn:hover { filter: brightness(1.1); }
.btn:disabled { opacity: 0.5; cursor: default; filter: none; }
.btn.secondary { background: var(--bg-elev); color: var(--text); border: 1px solid var(--border); }
.btn.secondary:hover { border-color: var(--accent); filter: none; }

/* Feedback */
.feedback {
  display: none;
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: 8px;
  font-size: 15px;
}
.feedback.show { display: block; }
.feedback.ok { background: rgba(126,231,135,0.12); border: 1px solid var(--green); }
.feedback.no { background: rgba(248,81,73,0.12); border: 1px solid var(--red); }
.feedback.neutral { background: rgba(88,166,255,0.1); border: 1px solid var(--accent); }
.feedback .fb-head { font-weight: 700; margin-bottom: 4px; }
.feedback .fb-head .ok { color: var(--green); }
.feedback .fb-head .no { color: var(--red); }
.feedback .fb-head .answered { color: var(--accent); }
.feedback .fb-correct { margin-top: 6px; color: var(--text-dim); }
.feedback code {
  font-family: var(--mono);
  background: var(--bg-code);
  border: 1px solid var(--border);
  padding: 1px 6px;
  border-radius: 5px;
  font-size: 14px;
  color: #7ee787;
}

/* ===== Summary ===== */
.summary { margin: 28px 0; }
.summary-card {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  text-align: center;
}
.summary-icon { font-size: 40px; margin-bottom: 6px; }
.summary-card h2 { margin: 0 0 8px; font-size: 24px; }
.summary-card p { color: var(--text-dim); margin: 0 0 18px; }
.summary-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.summary-card.done { border-color: var(--green); }
.summary-card.poor { border-color: var(--orange); }

footer {
  margin-top: 40px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 13px;
  text-align: center;
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .topbar-inner { padding: 12px 14px; }
  .brand { font-size: 18px; }
  .main { padding: 20px 14px; }
  .hero h1 { font-size: 24px; }
  .task { padding: 16px 14px; }
  .task-q { font-size: 16px; }
}

/* ===== Tabs ===== */
.tabs {
  display: flex;
  gap: 6px;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 8px 20px;
  max-width: 960px;
  margin: 0 auto;
}
.tab {
  background: var(--bg-soft);
  color: var(--text-dim);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 16px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  min-height: 44px;
  transition: border-color .15s, color .15s, background .15s;
}
.tab:hover { border-color: var(--accent); color: var(--text); }
.tab.active {
  background: var(--accent);
  color: #0a0d12;
  border-color: var(--accent);
}
.panel[hidden] { display: none; }

/* ===== Code-Aufgaben ===== */
.code-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin: 18px 0 6px;
}
.code-progress {
  font-family: var(--mono);
  color: var(--text-dim);
  font-size: 14px;
  font-weight: 600;
}

.code-task .code-intro {
  color: var(--text-dim);
  margin: 0 0 14px;
  font-size: 15px;
}

.vorgaben-box {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  margin: 0 0 16px;
}
.vorgaben-head {
  margin: 0 0 8px;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--accent);
}
.vorgaben-list {
  margin: 0;
  padding-left: 20px;
  color: var(--text);
  font-size: 15px;
}
.vorgaben-list li { margin: 4px 0; }

.data-box {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  margin: 0 0 16px;
}
.context-head {
  margin: 0 0 8px;
  font-size: 14px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--orange);
}
.context-pre {
  margin: 0;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.55;
  color: #c9d1d9;
  white-space: pre;
  overflow-x: auto;
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
}
.context-pre.mockup {
  color: var(--text);
  letter-spacing: 0.5px;
}

.editor-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-dim);
  margin-bottom: 8px;
}

.code-editor {
  display: block;
  width: 100%;
  min-height: 260px;
  background: var(--bg-code);
  color: #c9d1d9;
  font-family: var(--mono);
  font-size: 16px;
  line-height: 1.6;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
  outline: none;
  resize: vertical;
  white-space: pre;
  tab-size: 2;
}
.code-editor:focus { border-color: var(--accent); }

.code-actions {
  display: flex;
  gap: 12px;
  margin: 14px 0 0;
  flex-wrap: wrap;
}

.code-result {
  margin-top: 18px;
  padding: 16px;
  border-radius: 8px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
}
.result-summary {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
}
.result-summary.all { color: var(--green); }
.result-summary.partial { color: var(--orange); }
.result-summary.none { color: var(--red); }

.checkpoint-list { list-style: none; margin: 0; padding: 0; }
.checkpoint-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  font-size: 15px;
}
.checkpoint-list li:last-child { border-bottom: none; }
.checkpoint-mark { font-weight: 700; flex-shrink: 0; }
.checkpoint-list li.ok .checkpoint-mark { color: var(--green); }
.checkpoint-list li.miss .checkpoint-mark { color: var(--red); }
.checkpoint-list li.ok { color: var(--text); }
.checkpoint-list li.miss { color: var(--text-dim); }
.checkpoint-hint { color: var(--text-dim); font-size: 14px; }
.checkpoint-list li.miss .checkpoint-hint { color: var(--orange); }

/* ===== Responsive (Code-Tab) ===== */
@media (max-width: 600px) {
  .tabs { padding: 8px 14px; }
  .tab { flex: 1; padding: 10px 12px; }
  .code-editor { font-size: 16px; }
  .code-nav { flex-wrap: wrap; }
  .code-progress { order: -1; width: 100%; text-align: center; }
}