:root {
  color-scheme: dark;
  --bg: #03040a;
  --panel: rgba(8, 10, 22, 0.62);
  --panel-strong: rgba(255, 255, 255, 0.11);
  --text: #f8fbff;
  --muted: #a8b2c7;
  --cyan: #00f5ff;
  --green: #62ff7b;
  --pink: #ff2bd6;
  --violet: #8b5cf6;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html, body { height: 100%; }

body {
  margin: 0;
  overflow: hidden;
  color: var(--text);
  background:
    radial-gradient(circle at 18% 18%, rgba(139, 92, 246, 0.34), transparent 27rem),
    radial-gradient(circle at 82% 32%, rgba(0, 245, 255, 0.24), transparent 26rem),
    radial-gradient(circle at 52% 92%, rgba(255, 43, 214, 0.20), transparent 28rem),
    var(--bg);
}

.app-shell {
  position: relative;
  width: 100vw;
  height: 100dvh;
  min-height: 620px;
  overflow: hidden;
}

#webcam,
#landmarks,
#three-root,
#three-root canvas,
#ripple-root,
#ripple-root canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

#webcam {
  z-index: 0;
  object-fit: cover;
  transform: scaleX(-1);
  opacity: 0.56;
  filter: saturate(1.1) contrast(1.04) brightness(0.72);
  pointer-events: none;
}

#webcam:not(.live) {
  opacity: 0;
}

#ripple-root {
  z-index: 2;
  opacity: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 50% 42%, rgba(0, 245, 255, 0.45), transparent 18rem),
    linear-gradient(135deg, #03040a 0%, #101d5c 45%, #040715 100%);
  mix-blend-mode: screen;
  transition: opacity 280ms ease;
}

#ripple-root::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 24% 28%, rgba(255,255,255,.18), transparent 15rem),
    radial-gradient(circle at 80% 72%, rgba(255,43,214,.18), transparent 18rem),
    repeating-linear-gradient(110deg, rgba(255,255,255,.045) 0 1px, transparent 1px 18px);
  mix-blend-mode: screen;
}

#ripple-root canvas {
  z-index: 1;
  opacity: .88;
  pointer-events: none !important;
}

#landmarks {
  z-index: 4;
  transform: scaleX(-1);
  pointer-events: none;
  mix-blend-mode: screen;
}

#landmarks.hidden-lines {
  opacity: 0;
}

#three-root {
  z-index: 3;
  pointer-events: none;
  transition: opacity 280ms ease, transform 280ms ease;
}

#three-root canvas,
#landmarks,
#ripple-root {
  pointer-events: none !important;
}

.app-shell[data-mode="ripples"] #three-root {
  opacity: 0;
  transform: scale(.92);
}

.app-shell[data-mode="ripples"] #ripple-root {
  opacity: .74;
}

.app-shell[data-mode="ripples"] #webcam.live {
  opacity: .78;
  filter: saturate(1.18) contrast(1.08) brightness(.82);
}

.app-shell::before {
  content: "";
  position: absolute;
  inset: -20%;
  z-index: 1;
  pointer-events: none;
  background:
    linear-gradient(90deg, rgba(255,255,255,.045) 1px, transparent 1px),
    linear-gradient(rgba(255,255,255,.045) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(circle at center, black, transparent 72%);
  animation: drift 18s linear infinite;
}

.hud,
.instructions {
  position: absolute;
  z-index: 10;
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: linear-gradient(145deg, var(--panel), rgba(12, 16, 32, 0.38));
  box-shadow: 0 26px 90px rgba(0, 0, 0, 0.46);
  backdrop-filter: blur(22px) saturate(1.18);
  transition: opacity 180ms ease, transform 180ms ease, visibility 180ms ease;
}

.hud {
  top: clamp(16px, 4vw, 34px);
  left: clamp(16px, 4vw, 34px);
  width: min(480px, calc(100vw - 32px));
  padding: clamp(18px, 4vw, 28px);
  border-radius: 30px;
}

.back-link {
  display: inline-flex;
  margin-bottom: 16px;
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
}

.back-link:hover { color: var(--text); }

.eyebrow {
  margin: 0 0 8px;
  color: var(--cyan);
  font-size: 0.75rem;
  font-weight: 850;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(2.9rem, 8vw, 5.8rem);
  line-height: 0.84;
  letter-spacing: -0.075em;
}

.lede {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.65;
}

.lede strong:nth-of-type(1) { color: var(--green); }
.lede strong:nth-of-type(2) { color: var(--cyan); }

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

button {
  cursor: pointer;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  padding: 0.86rem 1.05rem;
  color: var(--text);
  background: rgba(255, 255, 255, 0.09);
  font: inherit;
  font-weight: 850;
  box-shadow: inset 0 1px rgba(255,255,255,.14), 0 14px 40px rgba(0, 0, 0, .24);
}

button:first-child {
  background: linear-gradient(135deg, var(--violet), var(--pink));
}

button[aria-pressed="true"]:not(:first-child) {
  border-color: rgba(0, 245, 255, .45);
  background: rgba(0, 245, 255, .14);
}

button:hover { transform: translateY(-1px); }
button:active { transform: translateY(0); }
button:focus-visible, a:focus-visible { outline: 3px solid rgba(0, 245, 255, .45); outline-offset: 3px; }

.status-grid {
  display: grid;
  gap: 8px;
  margin-top: 18px;
  color: var(--muted);
  font-size: .9rem;
}

.status-grid span {
  border-radius: 999px;
  padding: .6rem .75rem;
  background: rgba(255, 255, 255, .075);
}

.instructions {
  right: clamp(16px, 4vw, 34px);
  bottom: clamp(16px, 4vw, 34px);
  display: grid;
  gap: 10px;
  width: min(400px, calc(100vw - 32px));
  padding: 16px;
  border-radius: 24px;
}

.instructions div {
  display: grid;
  grid-template-columns: 96px 1fr;
  gap: 12px;
  align-items: center;
  border-radius: 18px;
  padding: 12px;
  background: var(--panel-strong);
}

.instructions b {
  color: var(--text);
  text-transform: uppercase;
  letter-spacing: .08em;
  font-size: .73rem;
}

.instructions span {
  color: var(--muted);
  font-size: .9rem;
  line-height: 1.35;
}

.overlays-hidden .overlay-panel {
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px) scale(.985);
  pointer-events: none;
}

.restore-overlays {
  position: absolute;
  top: 16px;
  right: 16px;
  z-index: 11;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 180ms ease, transform 180ms ease, visibility 180ms ease;
}

.restore-overlays.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.overlay-panel,
.overlay-panel *,
.restore-overlays {
  pointer-events: auto;
}

@keyframes drift {
  from { transform: translate3d(0, 0, 0) rotate(0deg); }
  to { transform: translate3d(-56px, -56px, 0) rotate(1deg); }
}

@media (max-width: 820px) {
  body { overflow: auto; }
  .app-shell { min-height: 100dvh; }
  .hud { top: 12px; left: 12px; width: calc(100vw - 24px); }
  .instructions { left: 12px; right: 12px; bottom: 12px; width: auto; }
  h1 { max-width: 7ch; }
}

@media (max-width: 520px) {
  .instructions { display: none; }
  .status-grid { grid-template-columns: 1fr; }
  button { padding: .75rem .88rem; }
}