:root {
  --bg: #f6f7fb; --card: #fff; --text: #1a1a2e; --muted: #6b7280;
  --primary: #4f46e5; --primary-ink: #fff; --tutor: #eef2ff; --learner: #e8f6ef;
  --border: #e5e7eb; --danger: #dc2626; --accent: #10b981;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1020; --card: #1a1b2e; --text: #e8e8f0; --muted: #9ca3af;
    --primary: #818cf8; --primary-ink: #0f1020; --tutor: #23243d; --learner: #15321f;
    --border: #2a2b45;
  }
}
* { box-sizing: border-box; }
html, body {
  margin: 0; background: var(--bg); color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
.hidden { display: none !important; }

.container { max-width: 620px; margin: 0 auto; padding: 40px 16px; }
.container.wide { max-width: 760px; display: flex; flex-direction: column; min-height: 100vh; }
.title { font-size: 2rem; margin: 0 0 8px; }
.subtitle { color: var(--muted); margin: 0 0 24px; }
.footnote { color: var(--muted); font-size: .85rem; margin-top: 18px; text-align: center; }

.card {
  background: var(--card); border: 1px solid var(--border); border-radius: 16px;
  padding: 24px; box-shadow: 0 1px 3px rgba(0,0,0,.06);
}
.field { display: block; margin-bottom: 18px; }
.field > span { display: block; font-size: .85rem; color: var(--muted); margin-bottom: 6px; }
.field select, .composer input {
  width: 100%; padding: 12px 14px; border: 1px solid var(--border);
  border-radius: 10px; background: var(--bg); color: var(--text); font-size: 1rem;
}

.btn {
  padding: 12px 18px; border: 1px solid var(--border); border-radius: 10px;
  background: var(--card); color: var(--text); font-size: 1rem; cursor: pointer;
}
.btn:hover { transform: translateY(-1px); }
.btn:disabled { opacity: .55; cursor: default; transform: none; }
.btn.primary { background: var(--primary); color: var(--primary-ink); border-color: transparent; }
.btn.small { padding: 8px 12px; font-size: .85rem; }
#start.primary { width: 100%; }

.error { color: var(--danger); font-size: .9rem; margin-top: 12px; min-height: 1em; }
.muted { color: var(--muted); font-size: .9rem; }

.chat-head {
  display: flex; justify-content: space-between; align-items: center;
  padding: 14px 4px; border-bottom: 1px solid var(--border); margin-bottom: 12px;
}
.transcript {
  flex: 1; display: flex; flex-direction: column; gap: 12px;
  overflow-y: auto; padding: 8px 4px;
}
.bubble { padding: 12px 14px; border-radius: 14px; max-width: 85%; }
.bubble.tutor { background: var(--tutor); align-self: flex-start; border-bottom-left-radius: 4px; }
.bubble.learner { background: var(--learner); align-self: flex-end; border-bottom-right-radius: 4px; }
.bubble.typing { opacity: .6; font-style: italic; }
.bubble-text { font-size: 1.05rem; line-height: 1.5; white-space: pre-wrap; }

.help { margin-top: 8px; font-size: .9rem; color: var(--muted); }
.corrections {
  margin: 10px 0 0; padding: 8px 0 0; list-style: none;
  border-top: 1px dashed var(--border);
}
.corrections li { font-size: .88rem; margin-bottom: 4px; }
.corrections .said { text-decoration: line-through; color: var(--danger); }
.corrections .better { color: var(--accent); font-weight: 600; }
.corrections .why { color: var(--muted); }

.composer { display: flex; gap: 8px; padding: 12px 4px; }
.composer input { flex: 1; }

/* mode help on setup */
.mode-help { color: var(--muted); font-size: .85rem; margin: -8px 0 18px; }

/* English translation under a German line */
.translation { margin-top: 6px; font-size: .92rem; color: var(--muted); font-style: italic; }

/* tap-to-send suggestion chips */
.suggestions { display: flex; flex-wrap: wrap; gap: 8px; padding: 4px 4px 0; }
.chip {
  display: flex; flex-direction: column; align-items: flex-start; gap: 2px;
  text-align: left; padding: 8px 12px; border: 1px solid var(--primary);
  background: transparent; color: var(--text); border-radius: 12px; cursor: pointer;
}
.chip:hover { background: var(--tutor); }
.chip-de { font-weight: 600; }
.chip-en { font-size: .78rem; color: var(--muted); }

/* practice: the line to repeat */
.bubble.line { background: var(--tutor); border: 1px solid var(--primary); align-self: stretch; max-width: 100%; }
.line-label { font-size: .78rem; text-transform: uppercase; letter-spacing: .04em; color: var(--muted); margin-bottom: 4px; }
.line-de { font-size: 1.35rem; font-weight: 700; line-height: 1.35; }

/* practice: feedback */
.bubble.feedback { align-self: stretch; max-width: 100%; }
.bubble.feedback.ok { background: var(--learner); }
.bubble.feedback.no { background: rgba(220, 38, 38, 0.12); border: 1px solid var(--danger); }

/* system note */
.bubble.note { align-self: center; background: transparent; color: var(--muted); font-size: .95rem; text-align: center; }