/* ============================================================
   Lernpage — Designstil "Kineto" (aus animejs.zip übernommen)
   Inhalte bleiben gleich, nur der grafische Stil ist neu.
   ============================================================ */

/* ------- Theme-Tokens ------- */
:root,
[data-theme="dark"] {
  --bg: oklch(0.13 0.008 250);
  --bg-2: oklch(0.16 0.01 250);
  --bg-3: oklch(0.19 0.012 250);
  --line: oklch(0.27 0.012 250);
  --line-soft: oklch(0.22 0.012 250);
  --fg: oklch(0.97 0.003 250);
  --fg-dim: oklch(0.72 0.01 250);
  --fg-faint: oklch(0.5 0.012 250);
  --accent: oklch(0.88 0.22 128);
  --accent-ink: oklch(0.18 0.05 128);
  --shadow: 0 1px 0 oklch(1 0 0 / 0.05) inset, 0 20px 60px -20px oklch(0 0 0 / 0.6);

  /* --- shadcn-Vokabular: Aliase auf unsere bestehenden Tokens ---
     Diese Variablen referenzieren --bg, --fg, --accent etc. — die folgen
     automatisch dem aktiven Theme (dark/light), weil var() dynamisch auflöst. */
  --background: var(--bg);
  --foreground: var(--fg);
  --card: var(--bg-2);
  --card-foreground: var(--fg);
  --muted: var(--bg-3);
  --muted-foreground: var(--fg-dim);
  --border: var(--line);
  --input: var(--line);
  --ring: var(--accent);
  --primary: var(--accent);
  --primary-foreground: var(--accent-ink);
  --secondary: var(--bg-3);
  --secondary-foreground: var(--fg);
  --destructive: oklch(0.6 0.2 25);
  --destructive-foreground: oklch(0.98 0 0);
  --radius: 0.5rem;
}
[data-theme="light"] {
  --bg: oklch(0.985 0.003 250);
  --bg-2: oklch(0.96 0.005 250);
  --bg-3: oklch(0.93 0.006 250);
  --line: oklch(0.85 0.008 250);
  --line-soft: oklch(0.9 0.006 250);
  --fg: oklch(0.18 0.01 250);
  --fg-dim: oklch(0.42 0.012 250);
  --fg-faint: oklch(0.6 0.012 250);
  --accent: oklch(0.72 0.21 128);
  --accent-ink: oklch(0.98 0.02 128);
  --shadow: 0 1px 0 oklch(1 0 0 / 0.6) inset, 0 20px 60px -20px oklch(0 0 0 / 0.18);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--fg);
  font-family: "Geist", ui-sans-serif, system-ui, sans-serif;
  font-feature-settings: "ss01", "cv11";
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  transition: background 0.5s ease, color 0.5s ease;
  min-height: 100vh;
}
::selection { background: var(--accent); color: var(--accent-ink); }
.mono { font-family: "Geist Mono", ui-monospace, monospace; }

/* ------- Seitengerüst ------- */
.page {
  position: relative;
  min-height: 100vh;
  display: grid;
  grid-template-rows: auto 1fr auto;
  isolation: isolate;
}
.bg-field {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

/* ------- Navigationsleiste ------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 40px;
  border-bottom: 1px solid var(--line-soft);
  background: color-mix(in oklab, var(--bg) 80%, transparent);
  backdrop-filter: blur(12px);
}
.nav-left { display: flex; align-items: center; gap: 28px; }
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--fg);
  text-decoration: none;
}
.nav-logo-dot {
  width: 14px; height: 14px;
  background: var(--accent);
  border-radius: 3px;
}
.nav-version {
  font-size: 11px;
  color: var(--fg-dim);
  border: 1px solid var(--line);
  padding: 2px 6px;
  border-radius: 4px;
  margin-left: 4px;
}
.nav-links { display: flex; gap: 22px; }
.nav-link {
  font-size: 13px;
  color: var(--fg-dim);
  text-decoration: none;
  position: relative;
  padding: 4px 0;
  cursor: pointer;
  transition: color 0.2s;
}
.nav-link:hover { color: var(--fg); }
.nav-link.active { color: var(--fg); }
.nav-link::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s cubic-bezier(0.7, 0, 0.2, 1);
}
.nav-link:hover::after,
.nav-link.active::after { transform: scaleX(1); }

.nav-right { display: flex; align-items: center; gap: 12px; }
.theme-toggle {
  width: 32px; height: 32px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--bg-2);
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: border-color 0.2s, transform 0.2s;
  padding: 0;
  color: var(--fg);
}
.theme-toggle { transition: border-color 0.2s, transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1) !important; }
.theme-toggle:hover { border-color: var(--accent); transform: rotate(20deg); }
.theme-toggle svg { width: 16px; height: 16px; }

/* ------- Hauptbereich ------- */
.main {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 70px 40px 48px;
}

/* Hero (Startseite) */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  color: var(--fg-dim);
  margin-bottom: 28px;
}
.eyebrow-dot {
  width: 6px; height: 6px; border-radius: 999px;
  background: var(--accent);
  box-shadow: 0 0 0 4px color-mix(in oklab, var(--accent) 25%, transparent);
  animation: pulse 2.4s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 color-mix(in oklab, var(--accent) 50%, transparent); }
  50% { box-shadow: 0 0 0 8px color-mix(in oklab, var(--accent) 0%, transparent); }
}

.hero-title {
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 0.95;
  font-size: clamp(40px, 7vw, 88px);
  margin: 0 0 4px;
  max-width: 14ch;
}
/* Buchstabenweiser Motion-Effekt (per JS aktiviert):
   Wörter bleiben als Block zusammen (sauberer Umbruch),
   die einzelnen Buchstaben staffeln sich ein und reagieren auf Hover. */
[data-stagger] .word { display: inline-block; }
[data-stagger] .ltr {
  display: inline-block;
  transform-origin: 50% 70%;
  will-change: transform;
}
/* Startzustand: unsichtbar, ohne Transition (kein Aufblitzen beim Laden) */
.stagger-ready .ltr {
  opacity: 0;
  transform: translateY(0.5em) rotate(-8deg);
  transition: none;
}
/* Eingeblendet – diese Transition gilt auch für den Hover-Effekt */
.stagger-in .ltr {
  opacity: 1;
  transform: translateY(0) rotate(0deg);
  transition: transform 0.6s cubic-bezier(0.2, 0.8, 0.2, 1), opacity 0.5s ease;
}

.hero-sub {
  max-width: 520px;
  font-size: 17px;
  line-height: 1.5;
  color: var(--fg-dim);
  margin: 24px 0 32px;
  letter-spacing: -0.005em;
}
.hero-sub b { color: var(--fg); font-weight: 500; }

.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--bg-2);
  color: var(--fg);
  font-weight: 500;
  font-size: 13px;
}
.badge::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 999px;
  background: var(--accent);
}

/* ------- Karte (Themenseite) ------- */
.card {
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--bg-2);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.card-head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--line-soft);
  background: var(--bg-3);
  font-size: 12px;
  color: var(--fg-faint);
}
.card-head-dot {
  width: 8px; height: 8px;
  border-radius: 999px;
  background: var(--accent);
}
.card-body { padding: 32px; }
.topic-title {
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin: 0 0 16px;
}
.topic-text {
  font-size: 17px;
  line-height: 1.65;
  color: var(--fg-dim);
  max-width: 60ch;
  margin: 0;
}

/* ------- Buttons ------- */
.btn {
  height: 40px;
  padding: 0 18px;
  border-radius: 8px;
  font-size: 13.5px;
  font-weight: 500;
  cursor: pointer;
  border: 1px solid transparent;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: transform 0.15s ease, background 0.2s, border-color 0.2s, color 0.2s;
  font-family: inherit;
  letter-spacing: -0.005em;
  text-decoration: none;
  margin-top: 28px;
}
.btn:active { transform: translateY(1px); }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { background: color-mix(in oklab, var(--accent) 85%, white); }
.btn-ghost { background: transparent; color: var(--fg); border-color: var(--line); }
.btn-ghost:hover { background: var(--bg-2); border-color: var(--fg-faint); }

/* ------- Login-Formular (Übung 1 — Feinschliff folgt in Übung 2) ------- */
.card--narrow { max-width: 420px; margin-left: auto; margin-right: auto; }
.login-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 20px;
}
.field { display: flex; flex-direction: column; gap: 6px; }
.field label { font-size: 13px; color: var(--fg-dim); }
.field input {
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  color: var(--fg);
  font: inherit;
}
.field input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in oklab, var(--accent) 30%, transparent);
}
.login-form .btn { margin-top: 4px; justify-content: center; }

/* „Passwort anzeigen"-Toggle */
.password-wrap { position: relative; }
.password-wrap input { padding-right: 44px; }
.password-toggle {
  position: absolute;
  right: 6px;
  top: 50%;
  transform: translateY(-50%);
  background: transparent;
  border: 0;
  padding: 6px;
  color: var(--fg-faint);
  cursor: pointer;
  display: grid;
  place-items: center;
  border-radius: 6px;
  transition: color 0.15s, background 0.15s;
}
.password-toggle:hover { color: var(--fg); background: var(--bg-2); }
.password-toggle:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; color: var(--fg); }
.password-toggle svg { width: 18px; height: 18px; display: block; }

/* ------- Feature-Ticker ------- */
.ticker {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  background: color-mix(in oklab, var(--bg) 90%, transparent);
  overflow: hidden;
}
.ticker-track {
  display: flex;
  gap: 56px;
  padding: 14px 0;
  animation: ticker 40s linear infinite;
  width: max-content;
  white-space: nowrap;
}
.ticker:hover .ticker-track { animation-play-state: paused; }
@keyframes ticker {
  to { transform: translateX(-50%); }
}
.ticker-item {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-family: "Geist Mono", ui-monospace, monospace;
  font-size: 12px;
  color: var(--fg-dim);
}
.ticker-item b { color: var(--fg); font-weight: 500; }
.ticker-item::before {
  content: "";
  width: 4px; height: 4px;
  background: var(--accent);
  border-radius: 999px;
}

/* ------- Footer ------- */
.foot {
  position: relative;
  z-index: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 18px 40px;
  font-size: 12px;
  color: var(--fg-faint);
  border-top: 1px solid var(--line-soft);
  font-family: "Geist Mono", ui-monospace, monospace;
}
.foot-brand { color: var(--fg-dim); }
.foot-right { display: flex; gap: 18px; }
.foot a { color: var(--fg-dim); text-decoration: none; }
.foot a:hover { color: var(--fg); }

/* ------- Übung 4: Animation-Showcases -------
   Werden automatisch von prefers-reduced-motion auf 0.001ms reduziert. */

/* pulse-ring: Keyframe-Loop, Scale 1 → 2.2 + Fade-out */
@keyframes pulse-ring {
  0%   { transform: scale(1);   opacity: 0.6; }
  100% { transform: scale(2.2); opacity: 0;   }
}
.pulse-ring {
  animation: pulse-ring 1.6s cubic-bezier(0.4, 0, 0.6, 1) infinite;
}

/* Flip-Card: 3D-Drehung um die Y-Achse */
.flip-card { perspective: 800px; }
.flip-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
}
.flip-card:hover .flip-card-inner { transform: rotateY(180deg); }
.flip-card-front, .flip-card-back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}
.flip-card-back { transform: rotateY(180deg); }

/* Typewriter: steps()-Animation macht den sanften Übergang zu diskreten Schritten */
@keyframes type-in-out {
  0%, 100% { width: 0; }
  25%, 75% { width: 21ch; }
}
@keyframes blink-caret {
  50% { border-color: transparent; }
}
.typewriter {
  display: inline-block;
  overflow: hidden;
  white-space: nowrap;
  vertical-align: middle;
  border-right: 2px solid var(--accent);
  animation: type-in-out 5s steps(21, end) infinite, blink-caret 0.7s step-end infinite;
}

/* ------- Responsiv ------- */
@media (max-width: 760px) {
  .nav { padding: 14px 20px; }
  .nav-links { gap: 16px; }
  .main { padding: 48px 20px 36px; }
  .card-body { padding: 22px; }
  .foot { padding: 14px 20px; flex-direction: column; gap: 8px; align-items: flex-start; }
}

/* ------- Bewegung reduzieren (Barrierefreiheit) ------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .stagger-ready .ltr { opacity: 1; transform: none; }
}