:root {
  --bg: #f2f2f7; --card: #ffffff; --text: #1c1c1e; --sub: #6e6e73; --line: #e2e2e7;
  --accent: #5C4DD9; --green: #2fa84f; --orange: #e8890c; --red: #e0453a; --purple: #a43fd6; --indigo: #5856d6; --yellow: #f2b705;
  --radius: 16px; --shadow: 0 1px 3px rgba(0,0,0,.06);
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #000; --card: #1c1c1e; --text: #f2f2f7; --sub: #98989f; --line: #2c2c2e; --shadow: none; }
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--text);
  font: 16px/1.45 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, sans-serif; }
body { padding-bottom: 84px; }
a { color: inherit; }
button { font: inherit; cursor: pointer; border: none; background: none; color: inherit; }
.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }

/* Kopfzeile */
.topbar { position: sticky; top: 0; z-index: 20; background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border-bottom: 1px solid var(--line); }
.topbar .wrap { display: flex; align-items: center; gap: 10px; min-height: 54px; }
.topbar .back { width: 38px; height: 38px; border-radius: 50%; background: var(--card); box-shadow: var(--shadow); font-size: 20px; }
.topbar .ttl { flex: 1; min-width: 0; }
.topbar .ttl small { display: block; color: var(--sub); font-size: 12px; }
.topbar .ttl b { display: block; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.account { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--sub); }
.account .dot { width: 8px; height: 8px; border-radius: 50%; background: #aaa; }
.account .dot.ok { background: var(--green); }
#apple-sign-in-button, #apple-sign-out-button { min-height: 0; }
#apple-sign-in-button > *, #apple-sign-out-button > * { transform: scale(.85); transform-origin: right center; }

/* Tabbar */
.tabbar { position: fixed; bottom: 0; left: 0; right: 0; z-index: 20; background: color-mix(in srgb, var(--card) 92%, transparent);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border-top: 1px solid var(--line); padding-bottom: env(safe-area-inset-bottom); }
.tabbar .wrap { display: flex; }
.tabbar a { flex: 1; text-align: center; padding: 8px 0 10px; text-decoration: none; font-size: 11px; color: var(--sub); }
.tabbar a span { display: block; font-size: 22px; line-height: 1.2; }
.tabbar a.on { color: var(--accent); font-weight: 600; }

h1 { font-size: 30px; line-height: 1.15; margin: 20px 0 8px; }
h2 { font-size: 22px; margin: 22px 0 10px; }
h3 { font-size: 15px; margin: 22px 0 8px; color: var(--sub); text-transform: none; }
.muted { color: var(--sub); }
.small { font-size: 13px; }
.card { background: var(--card); border-radius: var(--radius); padding: 16px; box-shadow: var(--shadow); margin: 12px 0; }
.card.tint { background: color-mix(in srgb, var(--tint) 12%, var(--card)); }
.card h4 { margin: 0 0 8px; font-size: 15px; color: var(--tint, var(--text)); display: flex; gap: 6px; align-items: center; }
.row { display: flex; align-items: center; gap: 12px; }
.grow { flex: 1; min-width: 0; }
.list { background: var(--card); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); }
.list > a, .list > div.item { display: flex; align-items: center; gap: 12px; padding: 13px 16px; text-decoration: none; border-bottom: 1px solid var(--line); }
.list > *:last-child { border-bottom: none; }
.list .chev { color: var(--sub); }
.list .disabled { opacity: .55; }
.badge-num { width: 36px; height: 36px; border-radius: 50%; display: grid; place-items: center; font-weight: 700; flex: none;
  background: color-mix(in srgb, var(--tint) 14%, transparent); color: var(--tint); }
.badge-num.done { background: var(--tint); color: #fff; }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; padding: 10px 14px; border-radius: 12px;
  font-weight: 600; background: color-mix(in srgb, var(--c, var(--accent)) 14%, transparent); color: var(--c, var(--accent)); }
.btn.primary { background: var(--c, var(--accent)); color: #fff; width: 100%; padding: 14px; border-radius: 14px; font-size: 17px; }
.btn.block { width: 100%; }
.btn:disabled { opacity: .45; cursor: default; }
.btn.sm { padding: 6px 10px; font-size: 13px; }
.pill { display: inline-block; padding: 3px 9px; border-radius: 99px; font-size: 12px; font-weight: 700; }

.progress { height: 6px; border-radius: 6px; background: var(--line); overflow: hidden; }
.progress > i { display: block; height: 100%; background: var(--tint, var(--accent)); border-radius: 6px; transition: width .3s; }

/* Kursliste */
.course { display: flex; gap: 14px; align-items: center; text-decoration: none; padding: 16px; border-radius: var(--radius); margin: 12px 0;
  background: color-mix(in srgb, var(--tint) 13%, var(--card)); }
.course .ic { width: 58px; height: 58px; border-radius: 50%; display: grid; place-items: center; font-size: 26px; flex: none;
  background: conic-gradient(var(--tint) calc(var(--p) * 1%), color-mix(in srgb, var(--tint) 20%, transparent) 0); }
.course .ic span { width: 48px; height: 48px; border-radius: 50%; background: var(--card); display: grid; place-items: center; }
.course b { display: block; }
.course .meta { font-size: 13px; color: var(--sub); }
.course .stat { font-size: 13px; color: var(--tint); font-weight: 600; margin-top: 4px; }

.ring { width: 120px; height: 120px; border-radius: 50%; display: grid; place-items: center; flex: none;
  background: conic-gradient(var(--tint) calc(var(--p) * 1%), color-mix(in srgb, var(--tint) 18%, transparent) 0); }
.ring > div { width: 100px; height: 100px; border-radius: 50%; background: var(--bg); display: grid; place-items: center; text-align: center; }
.ring b { font-size: 24px; display: block; }

/* Rich Text */
.rich p { margin: 0 0 10px; }
.rich p:last-child { margin-bottom: 0; }
.rich .warn { background: color-mix(in srgb, var(--orange) 14%, transparent); color: var(--orange); padding: 10px 12px; border-radius: 10px; }
.rich .warn::before { content: "⚠️ "; }
.rich h5 { font-size: 16px; margin: 12px 0 6px; }
.rich ul, .rich ol { margin: 0 0 10px; padding-left: 22px; }
.rich li { margin: 4px 0; }
.rich pre { background: color-mix(in srgb, var(--text) 7%, transparent); padding: 12px; border-radius: 10px; overflow-x: auto; font-size: 13px; margin: 0 0 10px; }
.rich pre::before { content: "Stata"; display: block; font: 700 11px -apple-system, sans-serif; color: var(--sub); margin-bottom: 6px; }
.tablewrap { overflow-x: auto; margin: 0 0 10px; border: 1px solid var(--line); border-radius: 10px; }
.rich table { border-collapse: collapse; font-size: 13px; min-width: 100%; }
.rich th, .rich td { text-align: left; vertical-align: top; padding: 8px; border-bottom: 1px solid var(--line); min-width: 110px; }
.rich th { color: var(--accent); }
.rich tr:last-child td { border-bottom: none; }

/* Lerneinheit */
.section { border-radius: 14px; padding: 14px; margin: 12px 0; background: color-mix(in srgb, var(--tint) 12%, var(--card)); }
.section .lbl { font-size: 14px; font-weight: 700; color: var(--tint); margin-bottom: 6px; }
.section.mnemonic .rich { font-style: italic; font-weight: 600; }
.q { border-radius: 16px; padding: 16px; margin: 14px 0; background: color-mix(in srgb, var(--indigo) 9%, var(--card)); }
.q.review { background: color-mix(in srgb, var(--orange) 10%, var(--card)); }
.q .head { display: flex; justify-content: space-between; align-items: center; font-weight: 700; color: var(--indigo); margin-bottom: 8px; }
.q.review .head { color: var(--orange); }
.q .prompt { font-weight: 600; margin: 8px 0 10px; }
.q .ctx { background: color-mix(in srgb, var(--text) 6%, transparent); padding: 10px; border-radius: 10px; font-size: 14px; color: var(--sub); }
.opt { display: flex; gap: 10px; width: 100%; text-align: left; padding: 12px; border-radius: 12px; margin: 8px 0;
  background: color-mix(in srgb, var(--card) 80%, transparent); border: 1px solid var(--line); }
.opt .mk { flex: none; width: 20px; height: 20px; border-radius: 50%; border: 2px solid var(--sub); margin-top: 2px; }
.opt.multi .mk { border-radius: 5px; }
.opt.sel .mk { border-color: var(--accent); background: var(--accent); box-shadow: inset 0 0 0 3px var(--card); }
.opt.right { background: color-mix(in srgb, var(--green) 14%, var(--card)); border-color: var(--green); }
.opt.right .mk { border-color: var(--green); background: var(--green); box-shadow: none; }
.opt.wrong { background: color-mix(in srgb, var(--red) 12%, var(--card)); border-color: var(--red); }
.opt.wrong .mk { border-color: var(--red); background: var(--red); box-shadow: none; }
.fb { margin-top: 10px; font-size: 14px; }
.fb b.ok { color: var(--green); } .fb b.no { color: var(--orange); }
.xp { background: color-mix(in srgb, var(--green) 15%, transparent); color: var(--green); }
.xp.low { background: color-mix(in srgb, var(--orange) 15%, transparent); color: var(--orange); }
.lessonbar { position: fixed; bottom: 0; left: 0; right: 0; z-index: 25; background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border-top: 1px solid var(--line); padding: 10px 0 calc(10px + env(safe-area-inset-bottom)); }
.lessonbar .wrap { display: flex; gap: 10px; }
.lessonbar .prev { width: 54px; flex: none; border-radius: 14px; background: color-mix(in srgb, var(--c) 14%, transparent); color: var(--c); font-size: 20px; }
.hint { color: var(--orange); font-weight: 700; font-size: 13px; text-align: center; margin-bottom: 6px; }
.resume { display: flex; gap: 10px; align-items: center; padding: 8px 12px; border-radius: 12px; margin-top: 10px;
  background: color-mix(in srgb, var(--c) 12%, transparent); color: var(--c); font-size: 13px; font-weight: 700; }
.blocks { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }
.blocks span { width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center; font-size: 12px; font-weight: 700;
  background: color-mix(in srgb, var(--c) 15%, transparent); color: var(--c); position: relative; }
.blocks span.star::after { content: "★"; position: absolute; top: -6px; right: -4px; color: var(--yellow); font-size: 11px; }

/* Modal (KI) */
.modal { position: fixed; inset: 0; z-index: 50; background: rgba(0,0,0,.35); display: flex; align-items: flex-end; justify-content: center; }
.sheet { background: var(--bg); width: 100%; max-width: 760px; height: 92vh; border-radius: 18px 18px 0 0; display: flex; flex-direction: column; overflow: hidden; }
.sheet .bar { display: flex; align-items: center; padding: 12px 16px; border-bottom: 1px solid var(--line); gap: 10px; }
.sheet .bar b { flex: 1; }
.pinned { padding: 10px 16px; background: color-mix(in srgb, var(--indigo) 10%, var(--bg)); border-bottom: 1px solid var(--line); font-size: 14px; max-height: 120px; overflow: auto; }
.pinned.open { max-height: 300px; }
.chat { flex: 1; overflow-y: auto; padding: 12px 16px; }
.bubble { max-width: 85%; padding: 10px 12px; border-radius: 14px; margin: 8px 0; white-space: pre-wrap; }
.bubble.user { margin-left: auto; background: var(--accent); color: #fff; }
.bubble.assistant { background: var(--card); }
.composer { display: flex; gap: 8px; padding: 10px 16px calc(10px + env(safe-area-inset-bottom)); border-top: 1px solid var(--line); }
.composer textarea { flex: 1; resize: none; border-radius: 12px; border: 1px solid var(--line); padding: 10px; font: inherit; background: var(--card); color: var(--text); min-height: 44px; max-height: 140px; }

.toast { position: fixed; left: 50%; top: 70px; transform: translateX(-50%); z-index: 60; background: var(--card); box-shadow: 0 8px 30px rgba(0,0,0,.2);
  border-radius: 18px; padding: 16px 20px; text-align: center; min-width: 240px; }
.toast .big { font-size: 34px; }
.toast .x { color: var(--orange); font-weight: 800; font-size: 20px; }
input[type=date], input[type=text], input[type=password], select { font: inherit; padding: 8px 10px; border-radius: 10px; border: 1px solid var(--line); background: var(--card); color: var(--text); }
.switch { display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.empty { text-align: center; color: var(--sub); padding: 40px 0; }

/* iCloud-Leiste */
.accountbar { border-bottom: 1px solid var(--line); background: var(--bg); }
.accountbar .wrap { display: flex; align-items: center; gap: 8px; min-height: 36px; }
.accountbar .spacer { flex: 1; }