:root {
  --bg-0: #0b1020;
  --bg-1: #131a36;
  --bg-glow: #1f2a55;

  --ink: #f4f6ff;
  --ink-soft: #aab2d4;
  --line: rgba(255,255,255,0.08);
  --line-strong: rgba(255,255,255,0.18);
  --surface: rgba(255,255,255,0.04);
  --surface-2: rgba(255,255,255,0.07);

  /* Layer palette */
  --application:    #f3a847;
  --application-2:  #c97f1a;
  --support:        #4ad295;
  --support-2:      #1f8f5b;
  --system:         #6aa9ff;
  --system-2:       #2d6cd9;
  --hardware:       #6e7aa6;
  --hardware-2:     #424c70;

  --accent: #ffd166;
  --packet: #ffe066;

  --radius: 14px;
  --radius-sm: 8px;
  --shadow-md: 0 18px 40px -10px rgba(0,0,0,0.55);

  /* 3D depth */
  --depth: 26px;
  --slab-h: 86px;
  --slab-gap: 14px;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  line-height: 1.5;
  min-height: 100vh;
  padding: 28px;
  background:
    radial-gradient(1200px 600px at 80% -10%, var(--bg-glow), transparent 60%),
    radial-gradient(900px 500px at -10% 110%, #2a1d56, transparent 55%),
    linear-gradient(180deg, var(--bg-0), var(--bg-1));
  background-attachment: fixed;
  overflow-x: hidden;
}

.page {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  gap: 24px;
}

/* HEADER */
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 11px;
  color: var(--ink-soft);
  margin: 0 0 6px 0;
}
.page__header h1 {
  margin: 0 0 6px 0;
  font-size: clamp(24px, 2.6vw, 36px);
  letter-spacing: -0.01em;
  line-height: 1.15;
}
.subtitle {
  margin: 0;
  color: var(--ink-soft);
  font-size: 15px;
}

/* ACTIONS */
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.action {
  appearance: none;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  font: inherit;
  padding: 10px 14px;
  border-radius: 999px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: background 120ms ease, border-color 120ms ease, transform 120ms ease;
}
.action:hover {
  background: var(--surface-2);
  border-color: var(--line-strong);
}
.action:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}
.action.is-active {
  background: linear-gradient(135deg, #ffd16633, #ff8b5c33);
  border-color: var(--accent);
  box-shadow: 0 0 0 1px var(--accent) inset;
}
.action__icon { font-size: 18px; line-height: 1; }
.action__label { font-size: 14px; }

/* STAGE: scene + panel side by side */
.stage {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 28px;
  align-items: stretch;
}
@media (max-width: 980px) {
  .stage { grid-template-columns: 1fr; }
}

/* SCENE */
.scene {
  position: relative;
  background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 56px 40px 40px;
  min-height: 560px;
  overflow: hidden;
}

.user-marker {
  position: absolute;
  top: 18px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  z-index: 3;
  pointer-events: none;
}
.user-marker__avatar {
  width: 38px; height: 38px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, #fff5d2, #ffb454);
  display: grid; place-items: center;
  font-size: 20px;
  box-shadow: 0 6px 16px rgba(255,180,80,0.45);
}
.user-marker__label {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

/* AXIS HINTS */
.axis-hints {
  position: absolute;
  top: 60px; bottom: 36px;
  right: 16px;
  display: flex; flex-direction: column;
  justify-content: space-between;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-soft);
  pointer-events: none;
}
.axis-hints span {
  background: rgba(0,0,0,0.25);
  padding: 4px 8px;
  border-radius: 999px;
  border: 1px solid var(--line);
}

/* THE STACK (3D) */
.stack {
  position: relative;
  margin: 36px auto 12px;
  width: min(440px, 90%);
  perspective: 1400px;
  perspective-origin: 50% 30%;
  display: flex;
  flex-direction: column;
  gap: var(--slab-gap);
  transform-style: preserve-3d;
}

.layer {
  appearance: none;
  border: 0;
  background: transparent;
  padding: 0;
  cursor: pointer;
  font: inherit;
  color: inherit;
  display: block;
  position: relative;
  height: var(--slab-h);
  transform-style: preserve-3d;
  transform: rotateX(56deg) rotateZ(-30deg);
  transition: transform 320ms cubic-bezier(.2,.7,.2,1), filter 220ms ease;
  will-change: transform, filter;
}

.layer__top {
  position: absolute; inset: 0;
  transform-style: preserve-3d;
}

.layer__face {
  position: absolute;
  border-radius: 10px;
  backface-visibility: hidden;
}
.layer__face--front {
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 14px 22px;
  gap: 4px;
  border: 1px solid rgba(255,255,255,0.18);
}
.layer__face--top {
  left: 0; right: 0;
  height: var(--depth);
  top: calc(-1 * var(--depth));
  transform-origin: 50% 100%;
  transform: rotateX(-90deg);
  background: rgba(255,255,255,0.12);
  border-radius: 10px 10px 0 0;
}
.layer__face--side {
  top: 0; bottom: 0;
  width: var(--depth);
  right: calc(-1 * var(--depth));
  transform-origin: 0% 50%;
  transform: rotateY(90deg);
  background: rgba(0,0,0,0.30);
  border-radius: 0 10px 10px 0;
}

.layer[data-layer="application"] .layer__face--front {
  background: linear-gradient(135deg, var(--application), var(--application-2));
  color: #2a1700;
}
.layer[data-layer="support"] .layer__face--front {
  background: linear-gradient(135deg, var(--support), var(--support-2));
  color: #06291b;
}
.layer[data-layer="system"] .layer__face--front {
  background: linear-gradient(135deg, var(--system), var(--system-2));
  color: #04143b;
}
.layer[data-layer="hardware"] .layer__face--front {
  background: linear-gradient(135deg, var(--hardware), var(--hardware-2));
  color: #ffffff;
}

.layer__title {
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.005em;
}
.layer__hint {
  font-size: 12.5px;
  opacity: 0.78;
}

/* Hover effect for clickable layers */
button.layer:hover {
  filter: brightness(1.06) saturate(1.05);
  transform: rotateX(56deg) rotateZ(-30deg) translateZ(8px);
}

/* Active / pulsing layer */
.layer.is-pulsing {
  animation: pulseLayer 800ms cubic-bezier(.2,.7,.2,1);
}
@keyframes pulseLayer {
  0%   { filter: brightness(1.0)  saturate(1.0); transform: rotateX(56deg) rotateZ(-30deg) translateZ(0); }
  35%  { filter: brightness(1.35) saturate(1.25); transform: rotateX(56deg) rotateZ(-30deg) translateZ(28px); }
  100% { filter: brightness(1.0)  saturate(1.0); transform: rotateX(56deg) rotateZ(-30deg) translateZ(0); }
}

.layer.is-static-active .layer__face--front {
  outline: 2px solid var(--accent);
  outline-offset: -2px;
}

/* PACKET */
.packet {
  position: absolute;
  left: 50%;
  top: -22px;
  width: 22px; height: 22px;
  transform: translate(-50%, 0) translateZ(60px);
  pointer-events: none;
  opacity: 0;
  transition: top 600ms cubic-bezier(.6,.05,.3,1), opacity 200ms ease;
  z-index: 4;
  filter: drop-shadow(0 0 14px rgba(255,224,102,0.85));
}
.packet.is-visible { opacity: 1; }
.packet__inner {
  display: block; width: 100%; height: 100%;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #fffae0, var(--packet) 55%, #cf9f1c 100%);
  box-shadow:
    0 0 0 4px rgba(255,224,102,0.18),
    0 0 24px rgba(255,224,102,0.55);
  animation: spin 2.4s linear infinite;
}
@keyframes spin {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* PANEL */
.panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-height: 100%;
}
.panel__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}
.panel__title {
  margin: 0;
  font-size: 22px;
  letter-spacing: -0.005em;
}
.panel__step {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-soft);
  background: var(--surface-2);
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
}
.panel__lead {
  margin: 0;
  color: var(--ink-soft);
  font-size: 14.5px;
}

.panel__steps {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.panel__steps li {
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 10px;
  align-items: start;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.02);
  border: 1px solid transparent;
  transition: background 200ms ease, border-color 200ms ease, transform 200ms ease;
}
.panel__steps li.is-active {
  background: rgba(255,209,102,0.10);
  border-color: rgba(255,209,102,0.35);
  transform: translateX(2px);
}
.panel__steps li.is-done {
  opacity: 0.55;
}
.step-num {
  display: grid; place-items: center;
  width: 24px; height: 24px;
  border-radius: 50%;
  background: var(--surface-2);
  font-size: 12px;
  font-weight: 700;
  color: var(--ink-soft);
}
.panel__steps li.is-active .step-num {
  background: var(--accent);
  color: #2a1d00;
}
.step-body strong { display: block; font-size: 14px; margin-bottom: 2px; }
.step-body span { color: var(--ink-soft); font-size: 13px; }

/* CONTROLS */
.panel__controls {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  border-top: 1px solid var(--line);
  padding-top: 14px;
}
.ctrl {
  appearance: none;
  border: 1px solid var(--line-strong);
  background: var(--surface-2);
  color: var(--ink);
  font: inherit;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 13px;
  transition: background 120ms ease, transform 120ms ease;
}
.ctrl:hover:not(:disabled) { background: rgba(255,255,255,0.10); }
.ctrl:disabled { opacity: 0.4; cursor: not-allowed; }
.ctrl--play {
  background: linear-gradient(135deg, #ffd166, #ff8b5c);
  color: #2a1700;
  border: 0;
  font-weight: 600;
}
.ctrl--play:hover { transform: translateY(-1px); }

.speed {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12px; color: var(--ink-soft);
  margin-left: auto;
}
.speed select {
  appearance: none;
  background: var(--surface-2);
  color: var(--ink);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 4px 10px;
  font: inherit;
  font-size: 12px;
}

/* STATIC INFO (Erkundungs-Modus) */
.panel__static h3 {
  margin: 4px 0 6px 0;
  font-size: 18px;
}
.panel__static h4 {
  margin: 14px 0 4px 0;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--ink-soft);
}
.panel__static p { margin: 0; font-size: 14px; }
.panel__static ul { margin: 0; padding-left: 20px; }
.panel__static li { font-size: 14px; margin-bottom: 4px; }

/* Subkategorien (z.B. Anwendungssoftware → BWL / Technisch / Querschnitt) */
.subcats {
  display: grid;
  gap: 10px;
  margin-top: 14px;
}
.subcat {
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--line);
  border-left: 3px solid var(--application);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
}
.subcat__head {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 4px;
}
.subcat__icon {
  font-size: 18px;
  line-height: 1;
}
.subcat__title {
  margin: 0;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  text-transform: none;
  letter-spacing: 0;
}
.subcat__desc {
  margin: 0 0 8px 0;
  font-size: 13px;
  color: var(--ink-soft);
}
.subcat__examples {
  margin: 0;
  padding-left: 18px;
}
.subcat__examples li {
  font-size: 13.5px;
  margin-bottom: 3px;
  color: var(--ink);
}

/* FOOTER */
.page__footer {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 12px;
  color: var(--ink-soft);
  border-top: 1px solid var(--line);
  padding-top: 12px;
}

@media (prefers-reduced-motion: reduce) {
  .packet { transition: top 0ms; }
  .layer.is-pulsing { animation: none; filter: brightness(1.2); }
  .packet__inner { animation: none; }
}