/* ============================================================
   NumCS Trainer — Styles
   Light-first Token-Palette; Dark via prefers-color-scheme und
   [data-theme]. Jede Farbe ist auf :root definiert.
   ============================================================ */

:root {
  --bg:          #f6f7f9;
  --bg-panel:    #ffffff;
  --bg-sunken:   #eef0f4;
  --bg-code:     #f4f5f8;
  --border:      #d8dce4;
  --border-soft: #e6e9ef;
  --text:        #1a1d23;
  --text-soft:   #5a6472;
  --text-faint:  #8a93a1;
  --accent:      #2f5fd0;
  --accent-soft: #e7eeff;
  --ok:          #1a7f4b;
  --ok-soft:     #e3f5ec;
  --err:         #c0392b;
  --err-soft:    #fdeceb;
  --warn:        #8a6400;
  --warn-soft:   #fdf4dd;
  --shadow:      0 1px 2px rgba(20, 26, 40, .06), 0 4px 14px rgba(20, 26, 40, .05);
  --radius:      10px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:          #14171c;
    --bg-panel:    #1b1f26;
    --bg-sunken:   #22272f;
    --bg-code:     #10131a;
    --border:      #30363f;
    --border-soft: #262c34;
    --text:        #e6e9ee;
    --text-soft:   #a3adbb;
    --text-faint:  #717c8b;
    --accent:      #7ca6ff;
    --accent-soft: #1d2740;
    --ok:          #5fd39b;
    --ok-soft:     #14301f;
    --err:         #ff8178;
    --err-soft:    #351a19;
    --warn:        #e2bb5a;
    --warn-soft:   #30290f;
    --shadow:      0 1px 2px rgba(0, 0, 0, .3), 0 4px 14px rgba(0, 0, 0, .25);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg:          #14171c;
  --bg-panel:    #1b1f26;
  --bg-sunken:   #22272f;
  --bg-code:     #10131a;
  --border:      #30363f;
  --border-soft: #262c34;
  --text:        #e6e9ee;
  --text-soft:   #a3adbb;
  --text-faint:  #717c8b;
  --accent:      #7ca6ff;
  --accent-soft: #1d2740;
  --ok:          #5fd39b;
  --ok-soft:     #14301f;
  --err:         #ff8178;
  --err-soft:    #351a19;
  --warn:        #e2bb5a;
  --warn-soft:   #30290f;
  --shadow:      0 1px 2px rgba(0, 0, 0, .3), 0 4px 14px rgba(0, 0, 0, .25);
  color-scheme: dark;
}

:root[data-theme="light"] { color-scheme: light; }

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code, kbd { font-family: var(--mono); font-size: .9em; }
.hidden { display: none !important; }

/* ---------- Topbar ---------- */

.topbar {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 24px;
  padding: 0 20px; height: 54px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 9px; font-weight: 650; color: var(--text); }
.brand:hover { text-decoration: none; }
.brand-mark {
  display: grid; place-items: center;
  width: 26px; height: 26px; border-radius: 7px;
  background: var(--accent); color: #fff;
  font-size: 17px; line-height: 1;
}
.topnav { display: flex; gap: 4px; margin-left: 8px; }
.topnav a {
  padding: 6px 12px; border-radius: 7px;
  color: var(--text-soft); font-size: 14px; font-weight: 500;
}
.topnav a:hover { background: var(--bg-sunken); text-decoration: none; color: var(--text); }
.topnav a.active { background: var(--accent-soft); color: var(--accent); }
.topright { margin-left: auto; display: flex; align-items: center; gap: 12px; }
.pystatus { font-size: 12px; color: var(--text-faint); font-family: var(--mono); white-space: nowrap; }
.icon-btn {
  background: transparent; border: 1px solid var(--border);
  color: var(--text-soft); border-radius: 7px;
  width: 30px; height: 30px; cursor: pointer; font-size: 14px;
}
.icon-btn:hover { background: var(--bg-sunken); color: var(--text); }

/* ---------- Layout ---------- */

.layout { display: grid; grid-template-columns: 250px minmax(0, 1fr); align-items: start; }
.sidebar {
  position: sticky; top: 54px;
  height: calc(100vh - 54px); overflow-y: auto;
  padding: 18px 12px 40px;
  border-right: 1px solid var(--border);
  background: var(--bg-panel);
}
.main { padding: 28px 32px 80px; min-width: 0; max-width: 1000px; }
.footer {
  border-top: 1px solid var(--border); padding: 14px 32px 20px;
  font-size: 12px; color: var(--text-faint); line-height: 1.55;
}
.footer p { margin: 0 0 4px; max-width: 95ch; }
.footer p:last-child { margin-bottom: 0; }

@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { position: static; height: auto; border-right: none; border-bottom: 1px solid var(--border); }
  .main { padding: 20px 16px 60px; }
  .topnav a { padding: 6px 8px; }
  .pystatus { display: none; }
}

/* ---------- Sidebar ---------- */

.side-label {
  font-size: 11px; font-weight: 650; letter-spacing: .07em; text-transform: uppercase;
  color: var(--text-faint); padding: 6px 10px 8px;
}
.side-item {
  display: flex; align-items: center; gap: 9px;
  padding: 7px 10px; border-radius: 7px;
  color: var(--text-soft); font-size: 13.5px;
}
.side-item:hover { background: var(--bg-sunken); color: var(--text); text-decoration: none; }
.side-item.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.side-num {
  flex: 0 0 22px; text-align: center;
  font-family: var(--mono); font-size: 11.5px;
  color: var(--text-faint);
  border: 1px solid var(--border); border-radius: 5px; padding: 1px 0;
}
.side-item.active .side-num { border-color: var(--accent); color: var(--accent); }
.side-item.dim { opacity: .55; }
.side-title { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.side-dot { flex: 0 0 7px; height: 7px; width: 7px; border-radius: 50%; }
.side-dot.full { background: var(--ok); }
.side-dot.part { background: var(--warn); }
.side-dot.none { background: transparent; border: 1px solid var(--border); }

/* ---------- Typo ---------- */

h1 { font-size: 26px; line-height: 1.25; margin: 0 0 6px; letter-spacing: -.01em; }
h2 { font-size: 19px; margin: 34px 0 12px; letter-spacing: -.005em; }
h3 { font-size: 15.5px; margin: 22px 0 8px; }
p  { margin: 0 0 12px; }
.lede { color: var(--text-soft); margin: 0 0 4px; }
.kicker {
  font-size: 11.5px; font-weight: 650; letter-spacing: .08em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 6px;
}
.muted { color: var(--text-soft); }
.faint { color: var(--text-faint); font-size: 13px; }

/* ---------- Pills & Badges ---------- */

.pill {
  display: inline-block; padding: 1.5px 8px; border-radius: 999px;
  font-size: 11.5px; font-weight: 600; line-height: 1.5;
  border: 1px solid var(--border); color: var(--text-soft); background: var(--bg-sunken);
  white-space: nowrap;
}
.pill-ok   { background: var(--ok-soft);   color: var(--ok);   border-color: transparent; }
.pill-err  { background: var(--err-soft);  color: var(--err);  border-color: transparent; }
.pill-warn { background: var(--warn-soft); color: var(--warn); border-color: transparent; }
.pill-acc  { background: var(--accent-soft); color: var(--accent); border-color: transparent; }

.ref {
  display: inline-block;
  font-family: var(--mono); font-size: 11.5px;
  padding: 1px 7px; border-radius: 5px;
  background: var(--accent-soft); color: var(--accent);
  white-space: nowrap;
}

/* ---------- Karten ---------- */

.card {
  background: var(--bg-panel); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 18px; margin-bottom: 14px;
  box-shadow: var(--shadow);
}
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 12px; }
.week-card { display: block; color: inherit; }
.week-card:hover { text-decoration: none; border-color: var(--accent); }
.week-card-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 6px; }
.week-card h3 { margin: 0 0 6px; font-size: 15px; }
.bar { height: 5px; border-radius: 3px; background: var(--bg-sunken); overflow: hidden; margin-top: 10px; }
.bar > i { display: block; height: 100%; background: var(--ok); }

/* ---------- Tabs ---------- */

.tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--border); margin: 20px 0 22px; }
.tabs a {
  padding: 8px 14px; font-size: 14px; font-weight: 550; color: var(--text-soft);
  border-bottom: 2px solid transparent; margin-bottom: -1px;
}
.tabs a:hover { color: var(--text); text-decoration: none; }
.tabs a.active { color: var(--accent); border-bottom-color: var(--accent); }
.tabs .pill { margin-left: 6px; }

/* ---------- Zusammenfassung ---------- */

.sum-item { border-left: 3px solid var(--accent); padding: 2px 0 2px 14px; margin: 0 0 20px; }
.sum-head { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; margin-bottom: 5px; }
.sum-head h3 { margin: 0; }
.sum-formula {
  background: var(--bg-sunken); border-radius: 8px;
  padding: 10px 14px; margin: 10px 0; overflow-x: auto;
}
.merke {
  background: var(--warn-soft); border-radius: 8px;
  padding: 9px 13px; margin: 10px 0 0; font-size: 13.5px; color: var(--text);
}
.merke b { color: var(--warn); }

/* ---------- Quiz ---------- */

.q { margin-bottom: 16px; }
.q-head { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 10px; }
.q-no { font-family: var(--mono); font-size: 12px; color: var(--text-faint); }
.q-body { margin-bottom: 12px; }
.q-body p:last-child { margin-bottom: 0; }

.opt {
  display: flex; align-items: flex-start; gap: 10px;
  padding: 9px 12px; margin-bottom: 6px;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--bg-panel); cursor: pointer;
}
.opt:hover { border-color: var(--accent); }
.opt input { margin: 4px 0 0; flex: 0 0 auto; accent-color: var(--accent); }
.opt-text { flex: 1; min-width: 0; overflow-x: auto; }
.opt.is-correct { border-color: var(--ok); background: var(--ok-soft); }
.opt.is-wrong   { border-color: var(--err); background: var(--err-soft); }
.opt.locked { cursor: default; }
.opt-mark { font-weight: 700; flex: 0 0 auto; }
.opt-mark.ok  { color: var(--ok); }
.opt-mark.err { color: var(--err); }

.numrow { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; flex-wrap: wrap; }
.numrow .numlabel { min-width: 90px; }
.numrow input {
  width: 180px; padding: 6px 10px; font-family: var(--mono); font-size: 13px;
  border: 1px solid var(--border); border-radius: 7px;
  background: var(--bg-panel); color: var(--text);
}
.numrow input:focus { outline: 2px solid var(--accent); outline-offset: -1px; border-color: transparent; }
.numrow input.is-correct { border-color: var(--ok); background: var(--ok-soft); }
.numrow input.is-wrong   { border-color: var(--err); background: var(--err-soft); }
.numrow .verdict { font-size: 12.5px; font-weight: 600; }

/* ---------- Feedback ---------- */

.fb { border-radius: 8px; padding: 11px 14px; margin-top: 12px; font-size: 14px; }
.fb-ok   { background: var(--ok-soft);  border-left: 3px solid var(--ok); }
.fb-err  { background: var(--err-soft); border-left: 3px solid var(--err); }
.fb-info { background: var(--bg-sunken); border-left: 3px solid var(--text-faint); }
.fb h4 { margin: 0 0 6px; font-size: 13.5px; }
.fb p:last-child { margin-bottom: 0; }

.notice {
  display: flex; gap: 10px; align-items: flex-start;
  background: var(--warn-soft); border-radius: 8px;
  padding: 10px 13px; margin: 0 0 16px; font-size: 13.5px;
}
.notice-icon { flex: 0 0 auto; }

/* ---------- Buttons ---------- */

.btn {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 7px 14px; border-radius: 8px; cursor: pointer;
  font-family: inherit; font-size: 13.5px; font-weight: 550;
  border: 1px solid var(--border); background: var(--bg-panel); color: var(--text);
}
.btn:hover { background: var(--bg-sunken); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent); filter: brightness(1.08); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; margin-top: 12px; }

/* ---------- Code / CodeExpert ---------- */

.stage-tabs { display: inline-flex; border: 1px solid var(--border); border-radius: 8px; overflow: hidden; }
.stage-tabs button {
  border: none; background: var(--bg-panel); color: var(--text-soft);
  padding: 7px 14px; font: inherit; font-size: 13px; cursor: pointer;
  border-right: 1px solid var(--border);
}
.stage-tabs button:last-child { border-right: none; }
.stage-tabs button:hover { background: var(--bg-sunken); color: var(--text); }
.stage-tabs button.active { background: var(--accent); color: #fff; }

pre.code, .gapcode {
  background: var(--bg-code); border: 1px solid var(--border);
  border-radius: 8px; padding: 14px 16px; margin: 12px 0;
  font-family: var(--mono); font-size: 12.5px; line-height: 1.75;
  overflow-x: auto; white-space: pre; color: var(--text);
  tab-size: 4;
}
.gapcode { white-space: pre-wrap; word-break: normal; }

.gap-select, .gap-input {
  font-family: var(--mono); font-size: 12.5px;
  padding: 1px 6px; border-radius: 5px;
  border: 1px solid var(--accent); background: var(--accent-soft); color: var(--text);
  max-width: 100%;
}
.gap-input { min-width: 180px; }
.gap-select.is-correct, .gap-input.is-correct { border-color: var(--ok); background: var(--ok-soft); }
.gap-select.is-wrong,   .gap-input.is-wrong   { border-color: var(--err); background: var(--err-soft); }

textarea.editor {
  width: 100%; min-height: 380px; resize: vertical;
  background: var(--bg-code); color: var(--text);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 14px 16px; margin: 12px 0;
  font-family: var(--mono); font-size: 12.5px; line-height: 1.7;
  tab-size: 4;
}
textarea.editor:focus { outline: 2px solid var(--accent); outline-offset: -1px; border-color: transparent; }

.out {
  background: var(--bg-code); border: 1px solid var(--border); border-radius: 8px;
  padding: 11px 14px; margin-top: 10px;
  font-family: var(--mono); font-size: 12px; line-height: 1.6;
  white-space: pre-wrap; word-break: break-word;
  max-height: 320px; overflow-y: auto;
}
.out.err { border-color: var(--err); color: var(--err); }

.plots { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 12px; margin-top: 12px; }
.plot figure { margin: 0; }
.plot img {
  width: 100%; height: auto; display: block;
  background: #fff; border: 1px solid var(--border); border-radius: 8px;
}
.plot figcaption { font-size: 12px; color: var(--text-faint); margin-top: 5px; }

details.disclose { margin-top: 10px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg-panel); }
details.disclose > summary {
  cursor: pointer; padding: 8px 13px; font-size: 13.5px; font-weight: 550; color: var(--text-soft);
  list-style: none;
}
details.disclose > summary::-webkit-details-marker { display: none; }
details.disclose > summary::before { content: "▸ "; color: var(--text-faint); }
details.disclose[open] > summary::before { content: "▾ "; }
details.disclose > summary:hover { color: var(--text); }
details.disclose .disclose-body { padding: 0 13px 10px; }
details.disclose .disclose-body pre.code { margin-top: 0; }

/* ---------- Tabellen ---------- */

.tbl-wrap { overflow-x: auto; margin: 12px 0; }
table.tbl { border-collapse: collapse; width: 100%; font-size: 13.5px; }
table.tbl th, table.tbl td { text-align: left; padding: 7px 11px; border-bottom: 1px solid var(--border-soft); }
table.tbl th { font-weight: 650; color: var(--text-soft); font-size: 12px; text-transform: uppercase; letter-spacing: .04em; }

/* ---------- Leerzustand ---------- */

.empty { text-align: center; padding: 50px 20px; color: var(--text-faint); }
.empty-mark { font-size: 32px; margin-bottom: 10px; }

/* KaTeX soll bei breiten Formeln scrollen statt die Seite zu sprengen */
.katex-display { overflow-x: auto; overflow-y: hidden; padding: 2px 0; }