:root {
  --bg:#fafafa; --surface:#ffffff; --text:#18181b; --muted:#71717a; --border:#e4e4e7;
  --accent:#4f46e5; --accent-soft:#eef2ff; --on-accent:#ffffff;
  --good:#15803d; --good-soft:#f0fdf4; --warn:#b45309; --warn-soft:#fffbeb; --bad:#dc2626; --bad-soft:#fef2f2;
  --radius:14px; --radius-sm:10px;
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --gutter: 16px;
}
@media (prefers-color-scheme: dark) { :root {
  --bg:#0b0b0f; --surface:#141418; --text:#f4f4f5; --muted:#a1a1aa; --border:#27272a;
  --accent:#818cf8; --accent-soft:#1e1b4b; --on-accent:#0b0b0f;
  --good:#4ade80; --good-soft:#052e16; --warn:#fbbf24; --warn-soft:#451a03; --bad:#f87171; --bad-soft:#450a0a;
}}
@media (min-width: 640px) { :root { --gutter: 24px; } }

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font-family: var(--font); font-size: 16px; line-height: 1.5;
  overflow-x: hidden;
}
h1, h2, h3, p { margin: 0; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; box-shadow: 0 0 0 4px var(--accent-soft); }

.container { max-width: 720px; margin: 0 auto; padding-left: var(--gutter); padding-right: var(--gutter); }
main.container { padding-top: 24px; padding-bottom: 64px; display: flex; flex-direction: column; gap: 24px; }

/* Header */
.site-header { height: 56px; border-bottom: 1px solid var(--border); background: var(--bg); }
.header-inner { height: 100%; display: flex; align-items: center; justify-content: space-between; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 650; letter-spacing: -0.01em; }
.brand-mark {
  width: 28px; height: 28px; border-radius: 8px; background: var(--accent); color: var(--on-accent);
  display: grid; place-items: center; font-size: 18px; line-height: 1;
}
.nav { display: flex; gap: 4px; }
.nav a { padding: 8px 12px; border-radius: var(--radius-sm); color: var(--muted); font-size: 15px; transition: color 150ms, background-color 150ms; }
.nav a:hover { color: var(--text); }
.nav a.active { color: var(--accent); font-weight: 600; }

/* Typography */
.page-title { font-size: 1.5rem; font-weight: 650; letter-spacing: -0.02em; }
.section-title { font-size: 1rem; font-weight: 650; margin-bottom: 12px; }
.muted { color: var(--muted); }
.small { font-size: 0.875rem; }
.eyebrow { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); font-weight: 600; }
.stack { display: flex; flex-direction: column; gap: 12px; }
.row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.row-between { display: flex; justify-content: space-between; align-items: center; gap: 12px; }

/* Cards */
.card {
  display: block; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px; transition: border-color 150ms;
}
a.card:hover, a.card:focus-visible { border-color: var(--accent); }
.card-title { font-weight: 600; }
.card-sub { color: var(--muted); font-size: 0.875rem; }
.card-foot { margin-top: 12px; display: flex; align-items: center; justify-content: space-between; gap: 8px; font-size: 0.8125rem; color: var(--muted); }
.card-wide { padding: 20px; }
.card-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
@media (min-width: 640px) { .grid { grid-template-columns: repeat(3, minmax(0, 1fr)); } }
.banner { background: var(--accent-soft); border-color: transparent; color: var(--accent); font-weight: 600; display: flex; justify-content: space-between; align-items: center; }
a.banner:hover { border-color: var(--accent); }

/* Badges */
.badge {
  display: inline-block; padding: 2px 10px; border-radius: 999px; font-size: 0.8125rem; font-weight: 600;
  font-variant-numeric: tabular-nums; background: var(--border); color: var(--muted); white-space: nowrap;
}
.badge.good { background: var(--good-soft); color: var(--good); }
.badge.warn { background: var(--warn-soft); color: var(--warn); }
.badge.bad { background: var(--bad-soft); color: var(--bad); }
.badge.muted { background: var(--border); color: var(--muted); }

/* Buttons */
.btn {
  min-height: 44px; padding: 0 20px; border-radius: var(--radius-sm); border: 1px solid var(--border);
  background: transparent; cursor: pointer; font-weight: 600; display: inline-flex; align-items: center; justify-content: center;
  transition: background-color 150ms, border-color 150ms, color 150ms;
}
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn.primary:hover { filter: brightness(1.08); }
.btn.danger { color: var(--bad); }
.btn-row { display: flex; gap: 12px; flex-wrap: wrap; }
.btn-row .btn { flex: 1 1 140px; }

/* Segmented control */
.segmented { display: inline-flex; border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 3px; background: var(--surface); gap: 2px; }
.segmented button {
  min-height: 38px; min-width: 52px; padding: 0 14px; border: 0; border-radius: 8px; background: transparent;
  cursor: pointer; color: var(--muted); font-weight: 600; font-variant-numeric: tabular-nums; transition: background-color 150ms, color 150ms;
}
.segmented button[aria-pressed="true"] { background: var(--accent); color: var(--on-accent); }

/* Training */
.train { display: flex; flex-direction: column; gap: 16px; }
.train-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; font-size: 0.9375rem; }
.back-link { color: var(--muted); padding: 8px 0; }
.back-link:hover { color: var(--text); }
.progress { height: 4px; background: var(--border); border-radius: 999px; overflow: hidden; }
.progress > span { display: block; height: 100%; width: calc(var(--w, 0) * 1%); background: var(--accent); transition: width 150ms; }
.task { text-align: center; padding: 24px 0 8px; display: flex; flex-direction: column; align-items: center; gap: 12px; }
.task-type { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); font-weight: 600; }
.question {
  font-size: clamp(1.75rem, 7vw, 2.75rem); font-weight: 650; letter-spacing: -0.02em; line-height: 1.2;
  font-variant-numeric: tabular-nums; overflow-wrap: anywhere;
}
.question.long { font-size: clamp(1.125rem, 4.5vw, 1.5rem); line-height: 1.4; font-weight: 600; letter-spacing: -0.01em; }
.hint { color: var(--muted); font-size: 0.9375rem; min-height: 1.4em; }
.answer { display: flex; width: 100%; max-width: 360px; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); overflow: hidden; transition: border-color 150ms; }
.answer:focus-within { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
.answer input {
  flex: 1; min-width: 0; border: 0; background: transparent; padding: 14px 16px; font-size: 1.75rem; text-align: center;
  font-variant-numeric: tabular-nums; outline: none;
}
.answer .unit { display: grid; place-items: center; padding: 0 16px; color: var(--muted); border-left: 1px solid var(--border); min-width: 56px; font-size: 0.9375rem; white-space: nowrap; }
.answer input:disabled { color: var(--muted); }
.timer { color: var(--muted); font-variant-numeric: tabular-nums; font-size: 0.875rem; text-align: center; }
.actions { width: 100%; max-width: 360px; display: flex; flex-direction: column; gap: 12px; }
.actions .btn-row .btn { flex: 1 1 120px; }

/* Feedback */
.feedback { width: 100%; max-width: 360px; border-radius: var(--radius); padding: 16px; text-align: left; display: flex; flex-direction: column; gap: 6px; }
.feedback.good { background: var(--good-soft); color: var(--good); }
.feedback.bad { background: var(--bad-soft); color: var(--bad); }
.feedback .fb-title { font-weight: 650; font-size: 1.0625rem; }
.feedback .fb-detail { color: var(--text); font-size: 0.9375rem; font-variant-numeric: tabular-nums; }
.feedback .fb-tip { color: var(--muted); font-size: 0.875rem; }

/* Stat tiles */
.stats { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
@media (min-width: 640px) { .stats { grid-template-columns: repeat(4, minmax(0, 1fr)); } }
.stats.three { grid-template-columns: repeat(2, minmax(0, 1fr)); }
@media (min-width: 640px) { .stats.three { grid-template-columns: repeat(4, minmax(0, 1fr)); } }
.tile { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 14px 16px; }
.tile-value { font-size: 1.5rem; font-weight: 650; font-variant-numeric: tabular-nums; letter-spacing: -0.02em; }
.tile-label { color: var(--muted); font-size: 0.8125rem; }
.tile.good .tile-value { color: var(--good); }
.tile.warn .tile-value { color: var(--warn); }
.tile.bad .tile-value { color: var(--bad); }

/* Lists */
.list { list-style: none; margin: 0; padding: 0; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.list li { display: grid; grid-template-columns: 20px minmax(0, 1fr) auto; gap: 4px 12px; align-items: baseline; padding: 12px 16px; border-top: 1px solid var(--border); font-variant-numeric: tabular-nums; }
.list li:first-child { border-top: 0; }
.list .mark { font-weight: 700; }
.list .mark.good { color: var(--good); }
.list .mark.bad { color: var(--bad); }
.list .item-main { overflow-wrap: anywhere; }
.list .item-meta { color: var(--muted); font-size: 0.8125rem; text-align: right; white-space: nowrap; }
.list .item-sub { grid-column: 2 / 4; color: var(--muted); font-size: 0.875rem; }

/* Category bars */
.bars { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 14px; }
.bar-row { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 4px 12px; align-items: center; }
.bar-name { font-weight: 600; }
.bar-score { font-variant-numeric: tabular-nums; }
.bar-meta { grid-column: 1 / 3; color: var(--muted); font-size: 0.8125rem; }
.bar-track { grid-column: 1 / 3; height: 8px; background: var(--border); border-radius: 999px; overflow: hidden; }
.bar-fill { display: block; height: 100%; width: calc(var(--w, 0) * 1%); border-radius: 999px; background: var(--accent); transition: width 150ms; }
.bar-fill.good { background: var(--good); }
.bar-fill.warn { background: var(--warn); }
.bar-fill.bad { background: var(--bad); }

/* Sparkline */
.spark { width: 100%; height: auto; display: block; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.spark .axis { stroke: var(--border); stroke-width: 1; }
.spark .line { fill: none; stroke: var(--accent); stroke-width: 2; stroke-linejoin: round; stroke-linecap: round; }
.spark .dot { fill: var(--accent); }
.spark text { fill: var(--muted); font-size: 11px; font-family: var(--font); }

.empty { text-align: center; padding: 48px 16px; display: flex; flex-direction: column; gap: 12px; align-items: center; }
.notice { color: var(--warn); background: var(--warn-soft); border-radius: var(--radius-sm); padding: 10px 14px; font-size: 0.9375rem; }

/* v2: Lernen & KI */
.actions { max-width: 520px; }
.btn.small { min-height: 36px; padding: 0 14px; font-size: 0.875rem; }
a.btn { text-decoration: none; }
.linkbtn {
  background: none; border: 0; padding: 8px 0; min-height: 36px; cursor: pointer; font-weight: 600; font-size: 0.9375rem;
  color: var(--accent); text-decoration: underline; text-underline-offset: 3px; display: inline-flex; align-items: center;
}
.linkbtn:hover { filter: brightness(1.15); }
.card-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 12px; }
.section-actions { margin-top: 12px; }
.section-sub { font-weight: 400; font-size: 0.875rem; }

.help-wrap { width: 100%; max-width: 520px; display: flex; flex-direction: column; align-items: center; }
.help { width: 100%; text-align: left; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; display: flex; flex-direction: column; gap: 10px; }
.help[hidden], .example-solution[hidden] { display: none; }

.method { display: flex; flex-direction: column; gap: 12px; text-align: left; }
.method-idea { line-height: 1.55; }
.method-heading { margin: 0 0 6px; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); font-weight: 600; }
.steps { margin: 0; padding-left: 1.4em; font-variant-numeric: tabular-nums; line-height: 1.65; text-align: left; }
.steps li { padding-left: 0.2em; margin: 2px 0; overflow-wrap: anywhere; }
.steps li::marker { color: var(--muted); font-weight: 600; }
.bullets { margin: 0; padding-left: 1.2em; line-height: 1.6; text-align: left; }
.bullets li { overflow-wrap: anywhere; }
.callout { background: var(--accent-soft); color: var(--text); border-radius: var(--radius-sm); padding: 12px 14px; line-height: 1.55; text-align: left; }
.callout-label { display: block; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; font-weight: 700; color: var(--accent); margin-bottom: 2px; }

.fb-section { text-align: left; display: flex; flex-direction: column; gap: 8px; padding: 4px 2px; }
.fb-heading { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); font-weight: 600; }

details.fold { border: 1px solid var(--border); border-radius: var(--radius-sm); background: var(--surface); text-align: left; }
.fold-body { padding: 0 14px 14px; }
.item-steps { grid-column: 2 / 4; }
.item-steps details.fold { border: 0; background: transparent; }
.item-steps .fold-body { padding: 0 0 4px; }
.item-steps summary { padding: 0; min-height: 36px; font-size: 0.875rem; }

summary {
  list-style: none; cursor: pointer; display: flex; align-items: center; gap: 10px; min-height: 44px; padding: 0 14px;
  font-weight: 600; font-size: 0.9375rem;
}
summary::-webkit-details-marker { display: none; }
summary::marker { content: ''; }
summary::before {
  content: ''; flex: none; width: 7px; height: 7px; border-right: 2px solid var(--muted); border-bottom: 2px solid var(--muted);
  transform: rotate(-45deg); transition: transform 150ms; margin-right: 2px;
}
details[open] > summary::before { transform: rotate(45deg); }

.learn-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); transition: border-color 150ms; scroll-margin-top: 16px; }
.learn-card:hover, .learn-card[open] { border-color: var(--accent); }
.learn-card > summary { padding: 8px 16px; flex-wrap: wrap; row-gap: 2px; }
.ls-name { flex: 1 1 140px; min-width: 0; }
.ls-goal { font-size: 0.8125rem; font-weight: 400; font-variant-numeric: tabular-nums; white-space: nowrap; }
.learn-body { padding: 4px 16px 16px; display: flex; flex-direction: column; gap: 16px; }
.example { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 14px; }
.example-prompt { font-size: clamp(1.25rem, 5.5vw, 1.75rem); font-weight: 650; letter-spacing: -0.02em; line-height: 1.25; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; margin-bottom: 6px; }
.example-solution { margin-top: 12px; }

.ai { display: flex; flex-direction: column; gap: 10px; align-items: flex-start; width: 100%; }
.ai-out { width: 100%; }
.ai-box { border: 1px dashed var(--accent); border-radius: var(--radius-sm); padding: 12px 14px; display: flex; flex-direction: column; gap: 8px; text-align: left; line-height: 1.55; width: 100%; }
.ai-box:focus-visible { outline-offset: 2px; }
.ai-label { font-size: 0.75rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.08em; font-weight: 600; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}