:root {
  color-scheme: dark;
  --bg: #020617;
  --panel: rgba(2, 6, 23, 0.28);
  --panel-strong: rgba(2, 6, 23, 0.6);
  --line: rgba(255, 255, 255, 0.16);
  --line-soft: rgba(255, 255, 255, 0.1);
  --text: rgba(255, 255, 255, 0.96);
  --text-soft: rgba(255, 255, 255, 0.78);
  --text-faint: rgba(255, 255, 255, 0.58);
  --shadow: 0 24px 80px rgba(15, 23, 42, 0.28);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  font-family: "Segoe UI", system-ui, sans-serif;
}

button,
input,
textarea,
select {
  font: inherit;
}

.hidden {
  display: none !important;
}

.viewer-shell,
.viewer-frame {
  width: 100%;
  height: 100%;
}

.page-nav {
  position: absolute;
  top: 18px;
  right: 18px;
  z-index: 40;
}

.page-nav-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 18px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 999px;
  background: rgba(2, 6, 23, 0.68);
  color: var(--text);
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
  text-decoration: none;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: transform 120ms ease, border-color 120ms ease, background 120ms ease;
}

.page-nav-link:hover {
  transform: translateY(-1px);
  border-color: rgba(255, 255, 255, 0.34);
  background: rgba(15, 23, 42, 0.82);
}

.viewer-frame {
  position: relative;
  overflow: hidden;
  background: #000;
}

#viewerIframe {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  background: #000;
}

.loading-overlay,
.activation-overlay {
  position: absolute;
  inset: 0;
}

.loading-overlay {
  z-index: 30;
  display: grid;
  place-items: center;
  background: linear-gradient(180deg, rgba(2, 6, 23, 0.72), rgba(15, 23, 42, 0.82));
  backdrop-filter: blur(10px);
}

.loading-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  color: white;
}

.loading-spinner {
  width: 40px;
  height: 40px;
  border: 4px solid rgba(255, 255, 255, 0.2);
  border-top-color: rgba(255, 255, 255, 0.9);
  border-radius: 999px;
  animation: spin 0.9s linear infinite;
}

.loading-dots {
  display: flex;
  gap: 8px;
}

.loading-dots span {
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.6);
  animation: bounce 0.8s infinite alternate;
}

.loading-dots span:nth-child(2) {
  animation-delay: 0.1s;
}

.loading-dots span:nth-child(3) {
  animation-delay: 0.2s;
}

.activation-overlay {
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  border: 0;
  color: var(--text);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.01), rgba(15, 23, 42, 0.08));
  backdrop-filter: blur(0.5px);
  cursor: pointer;
}

.activation-overlay:hover {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.03), rgba(15, 23, 42, 0.14));
}

.guide-card {
  width: min(84vw, 48rem);
  padding: 20px 24px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 24px;
  background: var(--panel);
  text-align: center;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

.guide-title {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 700;
}

.guide-subtitle,
.guide-footnote {
  margin: 8px 0 0;
  font-size: 0.76rem;
  color: var(--text-faint);
}

.guide-description {
  margin: 10px 0 0;
  font-size: 0.94rem;
  line-height: 1.55;
  color: var(--text-soft);
}

.guide-section {
  margin-top: 18px;
  padding: 16px;
  border: 1px solid var(--line-soft);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.05);
  text-align: left;
}

.guide-label {
  margin: 0;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.guide-grid {
  display: grid;
  gap: 12px;
  margin-top: 12px;
}

.guide-grid-desktop {
  grid-template-columns: 1.2fr 1fr 1fr;
}

.guide-grid-mobile {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.guide-item {
  padding: 16px;
  border: 1px solid var(--line-soft);
  border-radius: 18px;
  background: rgba(15, 23, 42, 0.4);
}

.guide-item-center {
  display: flex;
  flex-direction: column;
  justify-content: center;
  text-align: center;
}

.guide-item-heading {
  margin: 0;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-align: center;
  color: var(--text-faint);
}

.guide-item-title {
  margin: 10px 0 0;
  font-size: 0.95rem;
  font-weight: 600;
  text-align: center;
}

.guide-item-copy {
  margin: 4px 0 0;
  font-size: 0.76rem;
  text-align: center;
  color: var(--text-faint);
}

.key-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-top: 10px;
}

.key-row-single {
  margin-top: 14px;
}

.key-row-center {
  margin-top: 18px;
}

.keycap,
.touch-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 16px;
  background: linear-gradient(to bottom, rgba(255, 255, 255, 0.2), rgba(255, 255, 255, 0.05));
  color: var(--text);
  font-size: 1.05rem;
  font-weight: 700;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.25);
}

.key-separator {
  color: rgba(255, 255, 255, 0.45);
}

.mouse-chip {
  margin: 18px auto 0;
  padding: 12px 14px;
  border: 1px solid var(--line-soft);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.05);
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.86);
}

.joystick-icon {
  display: flex;
  justify-content: center;
}

.joystick-base {
  position: relative;
  display: block;
  width: 48px;
  height: 48px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.05);
}

.joystick-thumb {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 16px;
  height: 16px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.78);
  transform: translate(-50%, -8px);
}

.viewer-actions {
  position: absolute;
  left: 24px;
  bottom: 24px;
  z-index: 25;
  display: flex;
  align-items: center;
  gap: 10px;
}

.icon-button,
.text-button {
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: var(--panel-strong);
  color: var(--text);
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

.icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 14px;
}

.icon-button svg {
  width: 20px;
  height: 20px;
  fill: currentColor;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.text-button {
  min-height: 44px;
  padding: 0 14px;
  border-radius: 14px;
  font-size: 0.8rem;
  font-weight: 600;
}

@media (max-width: 800px) {
  .page-nav {
    top: 16px;
    right: 16px;
  }

  .page-nav-link {
    min-height: 44px;
    padding: 0 14px;
    font-size: 0.72rem;
  }

  .activation-overlay {
    padding: 16px;
  }

  .guide-card {
    width: min(92vw, 34rem);
    padding: 18px;
  }

  .guide-grid-desktop {
    grid-template-columns: 1fr;
  }

  .guide-grid-mobile {
    grid-template-columns: 1fr 1fr;
  }

  .viewer-actions {
    left: 16px;
    bottom: 16px;
    gap: 8px;
  }

  .icon-button {
    width: 42px;
    height: 42px;
  }

  .text-button {
    min-height: 42px;
    padding: 0 12px;
  }
}

@media (max-width: 560px) {
  .guide-grid-mobile {
    grid-template-columns: 1fr;
  }

  .guide-description {
    font-size: 0.88rem;
  }
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes bounce {
  from {
    transform: translateY(0);
  }

  to {
    transform: translateY(-4px);
  }
}