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

:root {
  --bg: #f0f0f0;
  --surface: #ffffff;
  --accent: #1a1a1a;
  --blue: #0032ea;
  --blue-soft: rgba(0,50,234,0.08);
  --blue-soft-2: rgba(0,50,234,0.14);
  --key-size: 72px;
  --key-gap: 10px;
}

body {
  width: 100vw;
  height: 100svh;
  overflow: hidden;
  background: var(--bg);
  color: var(--accent);
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  display: grid;
  grid-template-rows: auto 1fr;
}

header {
  position: relative;
  z-index: 1;
  padding: 20px 24px;
  font-size: 11px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  opacity: 0.4;
}

.bg-watermark {
  position: fixed;
  inset: 0;
  z-index: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0;
  pointer-events: none;
  user-select: none;
}

.wm-word {
  font-size: clamp(80px, 26vw, 280px);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: -0.01em;
  line-height: 0.95;
  color: var(--accent);
  opacity: 0.035;
  white-space: nowrap;
}

.wm-gap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  padding: 18px 0;
  pointer-events: auto;
}

.hint {
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  opacity: 0.25;
  text-align: center;
}

/* ── Gyroskop-Aktivierungs-Button ── */
/* Liegt als Overlay über der ganzen Seite, unabhängig vom Layout,
   da er ohnehin nach Aktivierung wieder verschwindet */
.gyro-btn {
  display: none; /* per JS eingeblendet, nur wenn benötigt (iOS) */
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 250;
  background: var(--surface);
  color: var(--accent);
  border: 1px solid rgba(0,0,0,0.1);
  border-radius: 50px;
  padding: 12px 22px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-align: center;
  cursor: pointer;
  white-space: nowrap;
  box-shadow: 0 4px 16px rgba(0,0,0,0.08);
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}
.gyro-btn.visible {
  display: inline-flex;
}
.gyro-btn:hover {
  background: var(--blue);
  color: #fff;
  border-color: var(--blue);
}
.gyro-btn:active {
  background: #0026b8;
  border-color: #0026b8;
}

/* ── Lasche ── */
#kb-tab {
  position: fixed;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  z-index: 90;
  cursor: pointer;
  /* leicht hochstehend, wie eine echte Lasche */
  filter: drop-shadow(0 -2px 8px rgba(0,0,0,0.10));
}

.kb-tab-inner {
  background: var(--surface);
  border-radius: 14px 14px 0 0;
  padding: 10px 28px 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  min-width: 220px;
  border: 1px solid rgba(0,0,0,0.08);
  border-bottom: none;
  transition: background 0.15s, border-color 0.15s;
}
#kb-tab:hover .kb-tab-inner {
  background: #f8f8f8;
  border-color: var(--blue-soft-2);
}

/* Buchstabenvorschau in Helvetica Neue */
.kb-tab-letters {
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.22em;
  color: var(--accent);
  opacity: 0.55;
  white-space: nowrap;
}

#kb-tab:hover .kb-tab-letters {
  color: var(--blue);
  opacity: 0.85;
}

/* Pfeil-Icon */
.kb-tab-arrow {
  font-size: 14px;
  opacity: 0.3;
  line-height: 1;
  padding-bottom: 6px;
  transition: opacity 0.15s, transform 0.15s, color 0.15s;
}
#kb-tab:hover .kb-tab-arrow {
  opacity: 0.9;
  transform: translateY(-2px);
  color: var(--blue);
}

#kb-tab:active .kb-tab-inner {
  background: var(--blue-soft);
}
/* Lasche verstecken wenn Tastatur offen */
#kb-overlay.open ~ #kb-tab,
#kb-tab.hidden {
  opacity: 0;
  pointer-events: none;
}

/* ── Keyboard Overlay ── */
#kb-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-end;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.35s ease;
}
#kb-overlay.open {
  opacity: 1;
  pointer-events: all;
}

.kb-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(200,200,200,0.6);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.kb-panel {
  position: relative;
  z-index: 1;
  width: 100%;
  padding: 32px 24px 40px;
  background: var(--surface);
  border-radius: 20px 20px 0 0;
  transform: translateY(100%);
  transition: transform 0.4s cubic-bezier(0.32, 0.72, 0, 1);
}
#kb-overlay.open .kb-panel {
  transform: translateY(0);
}

.kb-handle {
  width: 36px;
  height: 4px;
  background: var(--blue-soft-2);
  border-radius: 2px;
  margin: 0 auto 28px;
}

/* ── Letter Keys Grid ── */
.kb-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--key-gap);
  max-width: 620px;
  margin: 0 auto;
}

.key {
  width: var(--key-size);
  height: var(--key-size);
  background: #ebebeb;
  border-radius: 10px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s, transform 0.1s;
  border: 1px solid rgba(0,0,0,0.07);
  position: relative;
  overflow: hidden;
  /* Helvetica Neue für die Buchstaben-Labels */
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 26px;
  font-weight: 400;
  color: var(--accent);
  letter-spacing: -0.01em;
}
.key:hover  { background: var(--blue); color: #fff; border-color: var(--blue); }
.key:active { transform: scale(0.93); background: #0026b8; color: #fff; border-color: #0026b8; }
.key.active { background: var(--blue); color: #fff; border-color: var(--blue); }

/* ── Full-screen Letter Stage ── */
#letter-stage {
  position: fixed;
  inset: 0;
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.2s;
}
#letter-stage.visible {
  opacity: 1;
  pointer-events: all;
}

.stage-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(240,240,240,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

/* ── 3D Scene ── */
.scene {
  position: relative;
  z-index: 1;
  perspective: 1800px;
  perspective-origin: center center;
}

.letter-wrapper {
  position: relative;
  transform-style: preserve-3d;
}

.letter-img {
  position: absolute;
  top: -0.5px; left: -0.5px;
  width: calc(100% + 1px); /* 1px Überlapp, zentriert auf allen 4 Seiten */
  height: calc(100% + 1px);
  display: block;
  pointer-events: none;
  user-select: none;
  /* Knalliges Dunkelblau – per Maske statt Filter, damit jeder Browser
     (auch mobile Safari) exakt dieselbe Farbe zeigt */
  background-color: #0032ea;
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-size: 100% 100%;
  mask-size: 100% 100%;
  -webkit-mask-position: center;
  mask-position: center;
}

/* Keine manuelle Spiegelung — die 3D-Rotation übernimmt das */
.mirrored-x { transform: none; }
.mirrored-y { transform: none; }

/* ── Scharniere ── */
.hinge {
  transition: transform 0.35s ease-out;
  position: absolute;
  transform-style: preserve-3d;
  pointer-events: none;
  z-index: 0;
}

.hinge-left {
  top: 0; left: 0;
  width: 0; height: 100%;
  transform-origin: left center;
}
.hinge-right {
  top: 0; left: 100%;
  width: 0; height: 100%;
  transform-origin: left center;
}
.hinge-top {
  top: 0; left: 0;
  width: 100%; height: 0;
  transform-origin: center top;
}
.hinge-bottom {
  top: 100%; left: 0;
  width: 100%; height: 0;
  transform-origin: center top;
}

.flap {
  position: absolute;
  transform-style: preserve-3d;
  opacity: 0.9;
}

.flap-left  { top: 0; left: 0; }
.flap-right { top: 0; }
.flap-top   { top: 0; left: 0; }
.flap-bottom { left: 0; }

#img-base {
  z-index: 1;
  position: relative;
}

/* ── Close button ── */
#stage-close {
  position: fixed;
  top: 24px; right: 24px;
  z-index: 201;
  background: rgba(0,0,0,0.07);
  border: none;
  color: #1a1a1a;
  font-size: 22px;
  line-height: 1;
  width: 40px; height: 40px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}
#stage-close:hover {
  background: var(--blue);
  color: #fff;
}

@media (prefers-reduced-motion: reduce) {
  .hinge, #kb-overlay, .kb-panel, #kb-tab { transition: none; }
}