:root {
  --bg: #f5f6f8; --card: #ffffff; --text: #1d2330; --muted: #677085; --line: #e2e5eb;
  --accent: #2457d6; --accent-soft: #e6edfc; --ok: #1a8a4a; --ok-soft: #e3f5ea;
  --bad: #c62f2f; --bad-soft: #fbe7e7; --warn: #b26a00; --warn-soft: #fff3dd;
  --mark1: #ffe58a; --mark2: #b9e3ff; --code-bg: #f0f2f6;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  --radius: 10px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12151b; --card: #1b1f27; --text: #e5e8ee; --muted: #959cab; --line: #2c323d;
    --accent: #6d97ff; --accent-soft: #1f2a44; --ok: #4cc47f; --ok-soft: #173326;
    --bad: #ff6b6b; --bad-soft: #3a1d1f; --warn: #f0b04a; --warn-soft: #3a2d14;
    --mark1: #6b5a12; --mark2: #134a6b; --code-bg: #232833;
  }
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.55 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
a { color: var(--accent); }
code, pre, .mono { font-family: var(--mono); }
code { background: var(--code-bg); padding: 1px 5px; border-radius: 4px; font-size: .92em; }
pre { background: var(--code-bg); padding: 12px 14px; border-radius: 8px; overflow-x: auto; }
pre code { background: none; padding: 0; }
h1 { font-size: 1.7rem; margin: .2em 0 .5em; }
h2 { font-size: 1.25rem; }
h3 { font-size: 1.05rem; margin: 0; }
.muted { color: var(--muted); }
.small { font-size: .85rem; }
.upper { text-transform: uppercase; }

.top { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px;
  padding: 10px 20px; background: var(--card); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 10; }
.brand { font-weight: 700; color: var(--text); text-decoration: none; display: flex; align-items: center; gap: 8px; }
.logo { background: var(--accent); color: #fff; font-family: var(--mono); border-radius: 6px; padding: 2px 7px; }
nav { display: flex; gap: 4px; flex-wrap: wrap; }
nav a { text-decoration: none; color: var(--text); padding: 6px 10px; border-radius: 6px; }
nav a:hover { background: var(--accent-soft); }
nav .nav-test { color: var(--accent); font-weight: 600; }

main { max-width: 1000px; margin: 0 auto; padding: 20px 16px 60px; }
main.narrow { max-width: 520px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; margin: 14px 0; }
.card.center, .center { text-align: center; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.grid3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.grid2 > .card, .grid3 > .card { margin: 0; }
.grid3 { margin: 14px 0; }
@media (max-width: 760px) { .grid2, .grid3 { grid-template-columns: 1fr; } }
.row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin: 8px 0; }
.head-row { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 10px; }
.crumbs { font-size: .9rem; color: var(--muted); margin-bottom: 6px; }
.scroll-x { overflow-x: auto; }

.btn { display: inline-block; border: 1px solid var(--line); background: var(--card); color: var(--text);
  padding: 7px 14px; border-radius: 8px; font: inherit; cursor: pointer; text-decoration: none; }
.btn:hover { border-color: var(--accent); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.ghost { background: transparent; }
.btn.warn { color: var(--warn); border-color: var(--warn); }
.btn.danger { color: var(--bad); border-color: var(--bad); margin-top: 8px; }
.btn.small { padding: 3px 9px; font-size: .85rem; }
.btn.big { padding: 12px 28px; font-size: 1.1rem; }

.flash { padding: 10px 14px; border-radius: 8px; margin: 10px 0; background: var(--accent-soft); }
.flash.error { background: var(--bad-soft); color: var(--bad); }
.flash.ok { background: var(--ok-soft); color: var(--ok); }
.flash.warn { background: var(--warn-soft); color: var(--warn); }
.error { color: var(--bad); background: var(--bad-soft); padding: 8px 12px; border-radius: 8px; margin: 8px 0; font-family: var(--mono); font-size: .9rem; white-space: pre-wrap; }

.pill { display: inline-block; font-size: .78rem; padding: 2px 8px; border-radius: 99px; background: var(--code-bg); color: var(--muted); white-space: nowrap; }
.pill.ok { background: var(--ok-soft); color: var(--ok); }
.pill.bad { background: var(--bad-soft); color: var(--bad); }
.pill.run { background: var(--warn-soft); color: var(--warn); }

/* Start */
.hero p { max-width: 680px; }
.progress-wrap { display: flex; align-items: center; gap: 12px; margin-top: 12px; }
.progress { flex: 1; max-width: 360px; height: 10px; background: var(--line); border-radius: 99px; overflow: hidden; }
#progress-bar { height: 100%; width: 0; background: var(--ok); transition: width .4s; }
.lesson-list { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 10px; }
.lesson-list a { display: flex; align-items: center; gap: 12px; padding: 14px 16px; background: var(--card);
  border: 1px solid var(--line); border-radius: var(--radius); color: var(--text); text-decoration: none; }
.lesson-list a:hover { border-color: var(--accent); }
.lesson-list .nr { width: 30px; height: 30px; border-radius: 50%; background: var(--accent-soft); color: var(--accent);
  display: grid; place-items: center; font-weight: 700; flex: none; }
.lesson-list .ttl { flex: 1; }
.badge { font-size: .8rem; color: var(--muted); }
.badge.complete { color: var(--ok); font-weight: 700; }
.badge.complete::before { content: "✓ "; }

/* Lektion */
.prose table { border-collapse: collapse; margin: 10px 0; }
.prose th, .prose td { border: 1px solid var(--line); padding: 5px 10px; text-align: left; }
.prose blockquote { margin: 12px 0; padding: 8px 14px; border-left: 4px solid var(--accent); background: var(--accent-soft); border-radius: 0 8px 8px 0; }
.prose blockquote p { margin: 0; }
.ex-head { margin-top: 30px; }
.ex-title { display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.done-mark { color: var(--ok); font-weight: 600; }
.hint { font-size: .85rem; color: var(--muted); margin: 6px 0; }
.cases { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin: 8px 0; }
@media (max-width: 600px) { .cases { grid-template-columns: 1fr; } }
.caselist h4, .findall h4 { margin: 4px 0; font-size: .8rem; text-transform: uppercase; letter-spacing: .04em; }
.caselist.good h4 { color: var(--ok); }
.caselist.bad h4 { color: var(--bad); }
.case { display: inline-block; margin: 3px 4px 3px 0; padding: 3px 8px; border: 1px solid var(--line); white-space: pre; }
.case.ok { border-color: var(--ok); background: var(--ok-soft); }
.case.bad { border-color: var(--bad); background: var(--bad-soft); }
.text-sample { white-space: pre-wrap; margin: 4px 0 8px; }
.pattern-input { display: flex; align-items: center; border: 2px solid var(--line); border-radius: 8px; background: var(--code-bg);
  font-family: var(--mono); margin-top: 10px; }
.pattern-input:focus-within { border-color: var(--accent); }
.pattern-input .pfx, .pattern-input .sfx { color: var(--muted); padding: 0 6px; }
.pattern-input input { flex: 1; border: 0; background: transparent; color: var(--text); font: 1rem var(--mono); padding: 9px 2px; outline: none; min-width: 0; }
.pattern-input.big input { font-size: 1.15rem; }
.result:empty { display: none; }
.result { margin-top: 10px; }
.summary { font-weight: 700; padding: 6px 0; }
.summary.ok { color: var(--ok); }
.summary.bad { color: var(--bad); }
.fails { margin: 4px 0; padding-left: 20px; }
.fa-cmp { display: grid; gap: 4px; padding: 8px 12px; background: var(--code-bg); border-radius: 8px; margin: 6px 0; }
.pager { display: flex; justify-content: space-between; margin-top: 24px; gap: 10px; }

/* Spielwiese */
.lbl { font-weight: 600; font-size: .9rem; display: block; margin-bottom: 6px; }
.flags { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 10px; font-size: .9rem; }
textarea { width: 100%; font: .95rem/1.5 var(--mono); padding: 10px; border: 1px solid var(--line); border-radius: 8px;
  background: var(--code-bg); color: var(--text); resize: vertical; }
.highlight { white-space: pre-wrap; word-break: break-word; min-height: 200px; margin: 0; font-size: .95rem; line-height: 1.5; }
mark.m0 { background: var(--mark1); color: inherit; border-radius: 3px; }
mark.m1 { background: var(--mark2); color: inherit; border-radius: 3px; }
.zw { display: inline-block; width: 2px; height: 1.1em; background: var(--bad); vertical-align: middle; }
.ws { color: var(--muted); }
.pycode summary { cursor: pointer; color: var(--muted); margin-top: 10px; }

/* Spickzettel */
.cheat { display: grid; grid-template-columns: repeat(auto-fill, minmax(290px, 1fr)); gap: 12px; }
.cheat .card { margin: 0; }
.cheat .wide { grid-column: 1 / -1; }
.cheat table { width: 100%; border-collapse: collapse; }
.cheat td { padding: 4px 6px; border-bottom: 1px solid var(--line); vertical-align: top; }
.cheat td:first-child { white-space: nowrap; width: 40%; }

/* Formulare */
.form { display: grid; gap: 12px; }
.form label { display: grid; gap: 4px; font-weight: 600; font-size: .9rem; }
.form input:not([type=checkbox]) { font: inherit; padding: 9px 11px; border: 1px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--text); }
.form label.chk { display: flex; align-items: flex-start; gap: 8px; font-weight: 400; }
.taskpick { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 6px; }
.taskpick .chk { padding: 8px 10px; border: 1px solid var(--line); border-radius: 8px; }
form.inline { display: inline; }
.card form.inline { display: block; margin: 6px 0; }
td form.inline { display: inline; }

/* Test */
.test-bar { position: sticky; top: 0; z-index: 20; display: flex; justify-content: space-between; align-items: center; gap: 12px;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 10px 16px; margin-bottom: 10px; }
.timer { font: 700 1.8rem var(--mono); }
.timer.low { color: var(--bad); }
.save-state.bad { color: var(--bad); }
.submit-row { text-align: center; margin: 30px 0; }
.score-big { font-size: 1.5rem; font-weight: 700; margin: 10px 0; }

/* Lehrer */
.tbl { width: 100%; border-collapse: collapse; font-size: .92rem; }
.tbl th, .tbl td { padding: 6px 8px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: middle; }
.tbl th { font-size: .8rem; color: var(--muted); font-weight: 600; }
.tbl.small { font-size: .85rem; }
.tbl td.num { text-align: center; font-variant-numeric: tabular-nums; }
.tbl td.full { background: var(--ok-soft); }
.tbl td.part { background: var(--warn-soft); }
.tbl td.zero { background: var(--bad-soft); }
.tbl tr.avg td { font-weight: 600; color: var(--muted); }
.tbl tr.okrow td:first-child { color: var(--ok); }
.tbl tr.badrow td:first-child { color: var(--bad); }
.nowrap { white-space: nowrap; }
.code-big { font-size: 1.05rem; font-weight: 700; }
.code-huge { font: 700 2.4rem var(--mono); letter-spacing: .12em; color: var(--accent); }
.answer { font-size: 1rem; }
.grade-bars { display: flex; gap: 14px; align-items: flex-end; height: 140px; }
.gb { display: flex; flex-direction: column; align-items: center; justify-content: flex-end; height: 100%; width: 48px; }
.gb .bar { width: 100%; background: var(--accent); border-radius: 6px 6px 0 0; min-height: 2px; }
.gb .gl { text-align: center; font-weight: 700; margin-top: 4px; line-height: 1.1; }
details summary { cursor: pointer; }