/* ============================================================
   Kurvendiskussion – Lernseite
   Design-System: verspielt & bunt, Indigo als Anker
   ============================================================ */

:root {
  /* --- Grundfarben (Indigo, leicht getönt) --- */
  --bg:            oklch(0.985 0.008 275);
  --bg-deep:       oklch(0.955 0.018 275);
  --surface:       oklch(1 0 0);
  --ink:           oklch(0.30 0.045 275);
  --ink-soft:      oklch(0.46 0.04 275);
  --ink-faint:     oklch(0.62 0.03 275);
  --line:          oklch(0.90 0.02 275);
  --line-soft:     oklch(0.94 0.015 275);

  /* --- Marke --- */
  --indigo:        oklch(0.52 0.19 274);
  --indigo-deep:   oklch(0.40 0.16 274);
  --indigo-soft:   oklch(0.93 0.05 274);
  --indigo-ring:   oklch(0.52 0.19 274 / 0.30);

  /* --- Bunte Kapitel-Akzente (gleiche L/C, Hue variiert) --- */
  --c-red:    oklch(0.66 0.18 22);
  --c-orange: oklch(0.70 0.16 55);
  --c-amber:  oklch(0.78 0.15 85);
  --c-green:  oklch(0.68 0.16 150);
  --c-teal:   oklch(0.69 0.13 195);
  --c-blue:   oklch(0.62 0.16 245);
  --c-indigo: oklch(0.55 0.19 274);
  --c-violet: oklch(0.58 0.18 305);
  --c-pink:   oklch(0.66 0.19 350);

  /* per-section accent (overridden inline) */
  --accent:      var(--indigo);
  --accent-soft: var(--indigo-soft);

  --radius:    20px;
  --radius-sm: 12px;
  --radius-lg: 28px;
  --shadow-sm: 0 1px 2px oklch(0.4 0.05 275 / 0.06), 0 2px 6px oklch(0.4 0.05 275 / 0.05);
  --shadow:    0 4px 14px oklch(0.4 0.08 275 / 0.08), 0 12px 34px oklch(0.4 0.08 275 / 0.07);
  --shadow-lg: 0 10px 30px oklch(0.4 0.1 275 / 0.13), 0 30px 70px oklch(0.4 0.1 275 / 0.10);

  --font-display: "Fredoka", system-ui, sans-serif;
  --font-body:    "Lexend", system-ui, sans-serif;
  --font-mono:    "Space Mono", ui-monospace, monospace;

  --sidebar-w: 280px;
  --content-max: 880px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--ink);
  background:
    radial-gradient(1200px 700px at 88% -8%, oklch(0.93 0.07 305 / 0.5), transparent 60%),
    radial-gradient(1000px 600px at -5% 8%, oklch(0.93 0.06 245 / 0.45), transparent 55%),
    var(--bg);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 { font-family: var(--font-display); font-weight: 600; line-height: 1.12; color: var(--ink); margin: 0; }
p { margin: 0 0 1em; text-wrap: pretty; }
a { color: var(--indigo); }
strong { font-weight: 600; color: var(--ink); }
code, .mono { font-family: var(--font-mono); }

/* ============================================================
   Layout: Sidebar + Content
   ============================================================ */
.layout { display: block; min-height: 100vh; }

.sidebar {
  width: var(--sidebar-w);
  position: fixed;
  top: 0; left: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 26px 18px 40px 26px;
  background: oklch(1 0 0 / 0.6);
  backdrop-filter: blur(14px);
  border-right: 1px solid var(--line);
  scrollbar-width: thin;
}
.sidebar::-webkit-scrollbar { width: 7px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--line); border-radius: 4px; }

.brand { display: flex; align-items: center; gap: 11px; margin-bottom: 22px; text-decoration: none; }
.brand-mark {
  width: 42px; height: 42px; border-radius: 13px; flex: 0 0 42px;
  background: linear-gradient(135deg, var(--indigo), oklch(0.6 0.19 305));
  display: grid; place-items: center; color: #fff;
  box-shadow: var(--shadow-sm); position: relative; overflow: hidden;
}
.brand-mark svg { width: 26px; height: 26px; }
.brand-text { display: flex; flex-direction: column; line-height: 1.05; }
.brand-text b { font-family: var(--font-display); font-size: 1.08rem; color: var(--ink); }
.brand-text span { font-size: 0.72rem; color: var(--ink-faint); letter-spacing: 0.02em; }

.toc-label {
  font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.14em;
  color: var(--ink-faint); font-weight: 600; margin: 6px 0 10px 12px;
}
.toc { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 1px; }
.toc a {
  display: flex; align-items: center; gap: 11px;
  padding: 8px 12px; border-radius: 11px;
  text-decoration: none; color: var(--ink-soft); font-size: 0.9rem; font-weight: 400;
  transition: background 0.16s, color 0.16s, transform 0.16s;
}
.toc a:hover { background: var(--bg-deep); color: var(--ink); }
.toc .dot {
  width: 11px; height: 11px; border-radius: 50%; flex: 0 0 11px;
  background: var(--tc, var(--indigo)); box-shadow: 0 0 0 3px color-mix(in oklch, var(--tc, var(--indigo)) 18%, transparent);
}
.toc .num { font-family: var(--font-mono); font-size: 0.72rem; color: var(--ink-faint); width: 18px; }
.toc a.active {
  background: var(--surface); color: var(--ink); font-weight: 500;
  box-shadow: var(--shadow-sm); transform: translateX(2px);
}
.toc a.active .dot { box-shadow: 0 0 0 4px color-mix(in oklch, var(--tc, var(--indigo)) 24%, transparent); }

.sidebar-foot { margin-top: 26px; padding: 14px; border-radius: var(--radius-sm); background: var(--bg-deep); font-size: 0.78rem; color: var(--ink-soft); }
.sidebar-foot b { font-family: var(--font-display); }

.content { min-width: 0; margin-left: var(--sidebar-w); padding: 0 clamp(20px, 5vw, 72px); }
.wrap { max-width: var(--content-max); margin: 0 auto; }

/* ============================================================
   Mobile top bar + drawer
   ============================================================ */
.topbar {
  display: none;
  position: sticky; top: 0; z-index: 60;
  align-items: center; gap: 12px;
  padding: 11px 16px;
  background: oklch(1 0 0 / 0.82); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.topbar .brand { margin: 0; }
.topbar .brand-mark { width: 34px; height: 34px; flex-basis: 34px; border-radius: 10px; }
.topbar .brand-mark svg { width: 21px; height: 21px; }
.menu-btn {
  margin-left: auto; display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-display); font-size: 0.92rem; color: var(--ink);
  background: var(--surface); border: 1px solid var(--line); border-radius: 11px;
  padding: 8px 14px; cursor: pointer; box-shadow: var(--shadow-sm);
}
.menu-btn svg { width: 18px; height: 18px; }
.scrim { display: none; position: fixed; inset: 0; background: oklch(0.3 0.05 275 / 0.4); z-index: 70; backdrop-filter: blur(2px); }

/* ============================================================
   Hero
   ============================================================ */
.hero { padding: clamp(40px, 7vw, 92px) 0 36px; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.8rem; font-weight: 500; color: var(--indigo-deep);
  background: var(--indigo-soft); border: 1px solid color-mix(in oklch, var(--indigo) 22%, transparent);
  padding: 6px 14px; border-radius: 100px; margin-bottom: 22px;
}
.hero-badge .pulse { width: 8px; height: 8px; border-radius: 50%; background: var(--indigo); box-shadow: 0 0 0 0 var(--indigo-ring); animation: pulse 2.2s infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 var(--indigo-ring); } 70% { box-shadow: 0 0 0 11px transparent; } 100% { box-shadow: 0 0 0 0 transparent; } }

.hero h1 { font-size: clamp(2.4rem, 6vw, 4.1rem); letter-spacing: -0.02em; margin-bottom: 16px; }
.hero h1 .grad {
  background: linear-gradient(115deg, var(--indigo), var(--c-violet) 45%, var(--c-pink));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero .lead { font-size: clamp(1.05rem, 2.2vw, 1.3rem); color: var(--ink-soft); max-width: 640px; margin-bottom: 30px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 40px; }
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  font-family: var(--font-display); font-size: 1rem; font-weight: 500;
  padding: 13px 22px; border-radius: 14px; border: none; cursor: pointer;
  text-decoration: none; transition: transform 0.14s, box-shadow 0.14s;
}
.btn svg { width: 19px; height: 19px; }
.btn-primary { background: var(--indigo); color: #fff; box-shadow: 0 6px 18px var(--indigo-ring); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 26px var(--indigo-ring); }
.btn-ghost { background: var(--surface); color: var(--ink); border: 1px solid var(--line); box-shadow: var(--shadow-sm); }
.btn-ghost:hover { transform: translateY(-2px); box-shadow: var(--shadow); }

.hero-stats { display: flex; flex-wrap: wrap; gap: 28px; padding-top: 8px; }
.hero-stats .stat b { font-family: var(--font-display); font-size: 1.7rem; color: var(--ink); display: block; line-height: 1; }
.hero-stats .stat span { font-size: 0.82rem; color: var(--ink-faint); }

/* chapter color chips row in hero */
.chip-row { display: flex; gap: 7px; margin-top: 8px; }
.chip-row i { width: 26px; height: 8px; border-radius: 6px; display: block; }

/* ============================================================
   Section
   ============================================================ */
.section { padding: 46px 0; border-top: 1px solid var(--line-soft); scroll-margin-top: 84px; }
.section:first-of-type { border-top: none; }

.sec-head { display: flex; align-items: flex-start; gap: 18px; margin-bottom: 26px; }
.sec-num {
  font-family: var(--font-display); font-weight: 600; font-size: 1.15rem; color: #fff;
  width: 52px; height: 52px; flex: 0 0 52px; border-radius: 16px;
  display: grid; place-items: center;
  background: linear-gradient(140deg, var(--accent), color-mix(in oklch, var(--accent) 70%, black));
  box-shadow: 0 8px 20px color-mix(in oklch, var(--accent) 40%, transparent);
}
.sec-titles { padding-top: 2px; }
.sec-kicker { font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.13em; font-weight: 600; color: var(--accent); margin-bottom: 4px; }
.sec-head h2 { font-size: clamp(1.6rem, 3.4vw, 2.25rem); letter-spacing: -0.01em; }

/* ============================================================
   Cards & content blocks
   ============================================================ */
.card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: clamp(18px, 3vw, 28px);
  box-shadow: var(--shadow-sm); margin-bottom: 22px;
}
.card.lift { box-shadow: var(--shadow); }

.prose p:last-child { margin-bottom: 0; }
.prose ul, .prose ol { margin: 0 0 1em; padding-left: 1.3em; }
.prose li { margin-bottom: 0.4em; }
.prose li::marker { color: var(--accent); }

.lead-q {
  font-family: var(--font-display); font-size: 1.15rem; color: var(--ink);
  display: flex; align-items: center; gap: 10px; margin-bottom: 12px;
}
.lead-q::before {
  content: "?"; font-size: 0.9rem; width: 26px; height: 26px; flex: 0 0 26px;
  display: grid; place-items: center; border-radius: 8px; color: #fff;
  background: var(--accent);
}

/* "Merke" callout */
.merke {
  border-radius: var(--radius-sm);
  background: color-mix(in oklch, var(--accent) 9%, var(--surface));
  border: 1px solid color-mix(in oklch, var(--accent) 28%, transparent);
  border-left: 4px solid var(--accent);
  padding: 14px 18px; margin: 18px 0; font-size: 0.96rem;
}
.merke b { color: color-mix(in oklch, var(--accent) 80%, black); }
.merke .tag {
  display: inline-flex; align-items: center; gap: 6px; font-family: var(--font-display);
  font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--accent); margin-bottom: 4px; font-weight: 600;
}

/* Warning / Achtung */
.achtung {
  border-radius: var(--radius-sm);
  background: oklch(0.97 0.04 60); border: 1px solid oklch(0.85 0.09 60);
  border-left: 4px solid var(--c-orange); padding: 12px 16px; margin: 16px 0; font-size: 0.92rem;
}
.achtung .tag { color: oklch(0.5 0.13 50); font-weight: 600; font-family: var(--font-display); margin-right: 6px; }

/* ============================================================
   Tables
   ============================================================ */
.tbl-wrap { overflow-x: auto; margin: 16px 0; border-radius: var(--radius-sm); border: 1px solid var(--line); }
table.t { width: 100%; border-collapse: collapse; font-size: 0.92rem; background: var(--surface); }
table.t th, table.t td { padding: 10px 14px; text-align: left; border-bottom: 1px solid var(--line-soft); }
table.t thead th { background: var(--bg-deep); font-family: var(--font-display); font-weight: 500; font-size: 0.86rem; color: var(--ink); }
table.t tr:last-child td { border-bottom: none; }
table.t td:first-child { font-weight: 500; }

/* ============================================================
   Method steps (numbered)
   ============================================================ */
.steps { counter-reset: stp; display: flex; flex-direction: column; gap: 12px; margin: 16px 0; }
.steps .stp { display: flex; gap: 14px; }
.steps .stp .n {
  counter-increment: stp; flex: 0 0 30px; width: 30px; height: 30px; border-radius: 9px;
  display: grid; place-items: center; font-family: var(--font-display); font-weight: 600; font-size: 0.92rem;
  background: var(--accent-soft); color: color-mix(in oklch, var(--accent) 75%, black);
}
.steps .stp .n::before { content: counter(stp); }
.steps .stp .b { padding-top: 3px; }

/* ============================================================
   Plotter
   ============================================================ */
.plot-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; box-shadow: var(--shadow); margin: 20px 0; }
.plot-head { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 10px; margin-bottom: 10px; }
.plot-title { font-family: var(--font-display); font-size: 0.98rem; color: var(--ink); display: flex; align-items: center; gap: 8px; }
.plot-title .fx { font-family: var(--font-mono); font-size: 0.85rem; color: var(--accent); background: var(--accent-soft); padding: 2px 9px; border-radius: 7px; }
.plot-canvas-wrap { position: relative; width: 100%; border-radius: var(--radius-sm); overflow: hidden; background: oklch(0.995 0.004 275); }
canvas.plot { display: block; width: 100%; height: auto; touch-action: pan-y; }

.plot-legend { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.legend-toggle {
  display: inline-flex; align-items: center; gap: 8px; cursor: pointer;
  font-size: 0.84rem; padding: 6px 12px; border-radius: 100px;
  border: 1px solid var(--line); background: var(--surface); color: var(--ink-soft);
  transition: all 0.15s; user-select: none;
}
.legend-toggle .swatch { width: 22px; height: 4px; border-radius: 3px; }
.legend-toggle.off { opacity: 0.45; }
.legend-toggle:hover { border-color: var(--ink-faint); }
.legend-toggle.on { background: var(--bg-deep); color: var(--ink); border-color: var(--line); }

/* slider controls under a plot */
.controls { display: flex; flex-direction: column; gap: 14px; margin-top: 14px; }
.ctrl { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 14px; }
.ctrl label { font-size: 0.88rem; color: var(--ink-soft); font-family: var(--font-mono); }
.ctrl output { font-family: var(--font-mono); font-size: 0.9rem; color: var(--accent); font-weight: 700; min-width: 56px; text-align: right; }
input[type="range"] {
  -webkit-appearance: none; appearance: none; height: 6px; border-radius: 100px;
  background: var(--line); outline: none; cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 22px; height: 22px; border-radius: 50%;
  background: var(--accent); border: 3px solid #fff; box-shadow: var(--shadow-sm); cursor: grab;
}
input[type="range"]::-moz-range-thumb {
  width: 22px; height: 22px; border-radius: 50%; background: var(--accent);
  border: 3px solid #fff; box-shadow: var(--shadow-sm); cursor: grab;
}

/* ============================================================
   Interactive sign table (Vorzeichentabelle)
   ============================================================ */
.vzt { margin: 18px 0; }
.vzt-grid { width: 100%; border-collapse: collapse; font-family: var(--font-mono); font-size: 0.9rem; }
.vzt-grid th, .vzt-grid td { border: 1px solid var(--line); padding: 9px 8px; text-align: center; }
.vzt-grid th:first-child, .vzt-grid td:first-child { text-align: left; font-family: var(--font-body); font-size: 0.84rem; color: var(--ink-soft); white-space: nowrap; background: var(--bg-deep); }
.vzt-grid thead th { background: var(--bg-deep); font-family: var(--font-body); font-weight: 500; color: var(--ink); }
.vzt-cell { cursor: pointer; transition: background 0.15s; position: relative; }
.vzt-cell .q { color: var(--ink-faint); }
.vzt-cell.revealed.pos { background: oklch(0.94 0.06 150); color: oklch(0.4 0.13 150); font-weight: 700; }
.vzt-cell.revealed.neg { background: oklch(0.95 0.05 25); color: oklch(0.5 0.15 25); font-weight: 700; }
.vzt-mono-row td { color: var(--ink); }
.vzt-hint { font-size: 0.82rem; color: var(--ink-faint); margin-top: 8px; display: flex; align-items: center; gap: 7px; }
.vzt-arrow.up { color: oklch(0.5 0.13 150); }
.vzt-arrow.down { color: oklch(0.55 0.15 25); }
.vzt-reveal-btn { margin-top: 6px; }

/* ============================================================
   Step-by-step animated solution
   ============================================================ */
.stepper { margin: 20px 0; border-radius: var(--radius); border: 1px solid var(--line); background: var(--surface); box-shadow: var(--shadow-sm); overflow: hidden; }
.stepper-head { display: flex; align-items: center; gap: 12px; padding: 14px 18px; background: linear-gradient(120deg, var(--accent-soft), transparent); border-bottom: 1px solid var(--line-soft); }
.stepper-head .ic { width: 30px; height: 30px; border-radius: 9px; background: var(--accent); color: #fff; display: grid; place-items: center; flex: 0 0 30px; }
.stepper-head .ic svg { width: 18px; height: 18px; }
.stepper-head b { font-family: var(--font-display); font-weight: 500; font-size: 1rem; }
.stepper-head .prog { margin-left: auto; font-family: var(--font-mono); font-size: 0.8rem; color: var(--ink-faint); }
.stepper-body { padding: 8px 18px 4px; }
.step-line {
  display: flex; gap: 13px; padding: 11px 0; border-bottom: 1px dashed var(--line-soft);
  opacity: 0; transform: translateY(8px); transition: opacity 0.4s, transform 0.4s;
}
.step-line:last-child { border-bottom: none; }
.step-line.show { opacity: 1; transform: none; }
.step-line .si {
  flex: 0 0 26px; width: 26px; height: 26px; border-radius: 8px; display: grid; place-items: center;
  font-family: var(--font-mono); font-size: 0.78rem; font-weight: 700;
  background: var(--accent-soft); color: color-mix(in oklch, var(--accent) 75%, black);
}
.step-line .sc { padding-top: 2px; }
.step-line .sc .note { font-size: 0.85rem; color: var(--ink-faint); display: block; margin-top: 2px; }
.stepper-foot { padding: 12px 18px 16px; display: flex; gap: 10px; align-items: center; }
.step-btn {
  font-family: var(--font-display); font-size: 0.92rem; font-weight: 500;
  padding: 9px 18px; border-radius: 11px; border: none; cursor: pointer;
  background: var(--accent); color: #fff; transition: transform 0.13s, filter 0.13s;
}
.step-btn:hover { transform: translateY(-1px); filter: brightness(1.05); }
.step-btn.ghost { background: var(--surface); color: var(--ink-soft); border: 1px solid var(--line); }
.step-btn:disabled { opacity: 0.4; cursor: default; transform: none; }
.step-done { font-size: 0.85rem; color: oklch(0.5 0.13 150); font-weight: 600; display: none; align-items: center; gap: 6px; }
.step-done.show { display: inline-flex; }

/* ============================================================
   Practice / Übungsaufgabe (collapsible solution)
   ============================================================ */
.aufgabe {
  border-radius: var(--radius); border: 1.5px solid color-mix(in oklch, var(--accent) 30%, var(--line));
  background: color-mix(in oklch, var(--accent) 4%, var(--surface));
  padding: clamp(16px, 2.6vw, 24px); margin: 18px 0; box-shadow: var(--shadow-sm);
}
.aufgabe-tag {
  display: inline-flex; align-items: center; gap: 8px; font-family: var(--font-display);
  font-size: 0.74rem; text-transform: uppercase; letter-spacing: 0.08em; font-weight: 600;
  color: var(--accent); margin-bottom: 10px;
}
.aufgabe-tag .src { color: var(--ink-faint); font-family: var(--font-mono); text-transform: none; letter-spacing: 0; }
.aufgabe-tag .be { margin-left: auto; background: var(--accent-soft); color: color-mix(in oklch, var(--accent) 75%, black); padding: 2px 9px; border-radius: 7px; }
.aufgabe .frage { font-size: 1rem; color: var(--ink); margin-bottom: 6px; }
.sol-toggle {
  display: inline-flex; align-items: center; gap: 9px; margin-top: 12px; cursor: pointer;
  font-family: var(--font-display); font-weight: 500; font-size: 0.92rem; color: var(--accent);
  background: var(--surface); border: 1px solid color-mix(in oklch, var(--accent) 35%, var(--line));
  padding: 9px 16px; border-radius: 11px; transition: all 0.15s;
}
.sol-toggle:hover { background: var(--accent-soft); }
.sol-toggle .chev { transition: transform 0.25s; display: inline-flex; }
.sol-toggle.open .chev { transform: rotate(180deg); }
.sol-body {
  display: grid; grid-template-rows: 0fr; transition: grid-template-rows 0.32s ease;
  margin-top: 0;
}
.sol-body.open { grid-template-rows: 1fr; margin-top: 14px; }
.sol-inner { overflow: hidden; }
.sol-inner > div {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-sm);
  padding: 16px 18px; font-size: 0.94rem;
}
.sol-inner .erg { margin-top: 10px; padding-top: 10px; border-top: 1px dashed var(--line); font-weight: 500; }
.sol-inner .erg .lbl { color: var(--accent); font-family: var(--font-display); font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; display: block; margin-bottom: 3px; }

/* ============================================================
   Method-pick chips (Lösungsmethoden reihenfolge)
   ============================================================ */
.methodflow { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin: 14px 0; }
.methodflow .m {
  font-size: 0.86rem; padding: 8px 14px; border-radius: 11px; background: var(--surface);
  border: 1px solid var(--line); box-shadow: var(--shadow-sm); font-weight: 500; color: var(--ink);
}
.methodflow .m b { color: var(--accent); font-family: var(--font-mono); margin-right: 6px; }
.methodflow .arr { color: var(--ink-faint); }

/* ============================================================
   Polynomdivision – ausgerichtetes Rechenschema
   ============================================================ */
.polydiv-wrap { overflow-x: auto; margin: 16px 0; }
.polydiv {
  font-family: var(--font-mono); font-size: 0.96rem; line-height: 1.5;
  border-collapse: collapse; min-width: max-content;
}
.polydiv td { padding: 5px 6px; text-align: right; white-space: nowrap; color: var(--ink); }
.polydiv td.sign { width: 16px; padding-right: 2px; color: var(--ink-faint); text-align: center; }
.polydiv td.term { min-width: 50px; }
.polydiv .head td { padding-bottom: 9px; }
.polydiv .head .lead-term { font-weight: 700; }
.polydiv .rule td:not(.sign) { border-top: 2px solid color-mix(in oklch, var(--accent) 55%, var(--line)); padding-top: 1px; }
.polydiv .bring td { color: var(--ink-soft); }
.polydiv tr.prod td { color: color-mix(in oklch, var(--accent) 72%, black); }
.polydiv .zero { color: oklch(0.5 0.13 150); font-weight: 700; }
.polydiv-quot {
  display: inline-flex; align-items: baseline; gap: 8px; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: 1.02rem; margin-bottom: 4px;
}
.polydiv-quot .res { color: var(--accent); font-weight: 700; background: var(--accent-soft); padding: 2px 10px; border-radius: 8px; }
.polydiv-note { font-size: 0.82rem; color: var(--ink-faint); margin-top: 8px; display: flex; align-items: center; gap: 7px; }
.polydiv-caption { font-size: 0.84rem; font-weight: 600; color: color-mix(in oklch, var(--accent) 75%, black); margin: 14px 0 2px; font-family: var(--font-display); }

/* ============================================================
   Prüfungs-Kapitel
   ============================================================ */
.exam-year { margin: 0 0 14px; }
.exam-year-head {
  display: flex; align-items: center; gap: 14px; scroll-margin-top: 84px;
  margin: 38px 0 18px; padding: 14px 18px; border-radius: var(--radius);
  background: linear-gradient(115deg, color-mix(in oklch, var(--accent) 16%, white), color-mix(in oklch, var(--accent) 4%, white));
  border: 1px solid color-mix(in oklch, var(--accent) 26%, transparent);
}
.exam-year-head .yr {
  font-family: var(--font-display); font-weight: 700; font-size: 1.5rem; color: #fff;
  background: linear-gradient(140deg, var(--accent), color-mix(in oklch, var(--accent) 68%, black));
  padding: 6px 16px; border-radius: 12px; box-shadow: 0 6px 16px color-mix(in oklch, var(--accent) 38%, transparent);
}
.exam-year-head .yr-sub { font-size: 0.9rem; color: var(--ink-soft); }
.exam-year-head .yr-sub b { font-family: var(--font-display); color: var(--ink); display: block; font-size: 1.05rem; }

.task {
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface);
  box-shadow: var(--shadow-sm); margin: 0 0 22px; overflow: hidden;
}
.task-head { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; padding: 18px 20px 4px; }
.task-head .badge {
  font-family: var(--font-display); font-weight: 600; font-size: 0.78rem; letter-spacing: 0.04em;
  color: #fff; background: var(--accent); padding: 4px 12px; border-radius: 8px; text-transform: uppercase;
}
.task-head h4 { font-size: 1.15rem; }
.task-head .topic { font-size: 0.82rem; color: var(--ink-faint); margin-left: auto; }
.task-intro { padding: 6px 20px 4px; font-size: 0.95rem; color: var(--ink-soft); }
.task-intro .fxbox {
  font-family: var(--font-mono); background: var(--bg-deep); border: 1px solid var(--line);
  border-radius: 10px; padding: 9px 14px; margin: 8px 0; display: inline-block; color: var(--ink);
}
.task-body { padding: 8px 20px 18px; }

.subtask { border-top: 1px dashed var(--line); padding: 16px 0 4px; }
.subtask:first-child { border-top: none; }
.sub-q { display: flex; gap: 11px; align-items: baseline; }
.sub-q .sn {
  flex: 0 0 auto; font-family: var(--font-mono); font-weight: 700; font-size: 0.84rem;
  color: color-mix(in oklch, var(--accent) 78%, black); background: var(--accent-soft);
  padding: 2px 9px; border-radius: 7px; min-width: 40px; text-align: center;
}
.sub-q .qt { flex: 1 1 auto; font-size: 0.97rem; color: var(--ink); }
.sub-q .be { flex: 0 0 auto; font-family: var(--font-mono); font-size: 0.76rem; color: var(--ink-faint); align-self: center; }
.sub-draw { display: flex; align-items: center; gap: 8px; margin: 10px 0 4px; font-size: 0.88rem; color: var(--accent); font-weight: 500; }
.sub-draw svg { width: 17px; height: 17px; }

/* sub-nav chips for years */
.toc .sub-toc { margin: 2px 0 6px 30px; display: flex; flex-direction: column; gap: 1px; }
.toc .sub-toc a { padding: 5px 10px; font-size: 0.82rem; }
.toc .sub-toc a .num { width: auto; }

/* ============================================================
   Pills / inline tags
   ============================================================ */
.pill { display: inline-flex; align-items: center; gap: 6px; font-size: 0.8rem; font-weight: 500; padding: 3px 11px; border-radius: 100px; background: var(--accent-soft); color: color-mix(in oklch, var(--accent) 78%, black); }

/* reveal on scroll */
.reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.6s cubic-bezier(.2,.7,.2,1), transform 0.6s cubic-bezier(.2,.7,.2,1); }
.reveal.in { opacity: 1; transform: none; }

/* MathJax sizing */
mjx-container { color: var(--ink); }
mjx-container[display="true"] { margin: 0.7em 0 !important; overflow-x: auto; overflow-y: hidden; }

/* footer */
.foot { padding: 50px 0 70px; border-top: 1px solid var(--line); color: var(--ink-faint); font-size: 0.88rem; text-align: center; }
.foot b { font-family: var(--font-display); color: var(--ink-soft); }
.foot .heart { color: var(--c-pink); }

/* back-to-top */
.totop {
  position: fixed; right: 22px; bottom: 22px; z-index: 50;
  width: 46px; height: 46px; border-radius: 14px; border: none; cursor: pointer;
  background: var(--indigo); color: #fff; box-shadow: var(--shadow);
  display: grid; place-items: center; opacity: 0; transform: translateY(14px) scale(0.9); pointer-events: none;
  transition: opacity 0.25s, transform 0.25s;
}
.totop svg { width: 22px; height: 22px; }
.totop.show { opacity: 1; transform: none; pointer-events: auto; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 920px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .topbar { display: flex; }
  .content { padding: 0 clamp(16px, 5vw, 30px); margin-left: 0; }
  .sidebar.drawer-open {
    display: block; position: fixed; top: 0; left: 0; bottom: 0; z-index: 80;
    width: min(86vw, 320px); height: 100vh; box-shadow: var(--shadow-lg);
    animation: slidein 0.25s ease; background: oklch(1 0 0 / 0.97);
  }
  @keyframes slidein { from { transform: translateX(-100%); } to { transform: none; } }
  .scrim.show { display: block; }
  .ctrl { grid-template-columns: 1fr; gap: 6px; }
  .ctrl output { text-align: left; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  * { animation-duration: 0.001s !important; }
}