/*
 * GestureSense visual system
 * Created and maintained by Saad Kamal.
 *
 * The app uses fixed-position HUD regions and stable hand panel slots so the
 * interface feels anchored while the live ML values update.
 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --cyan: #00f0ff;
  --magenta: #ff006e;
  --purple: #8338ec;
  --green: #39ff14;
  --bg: #0a0a12;
  --glass: rgba(10, 10, 20, 0.55);
  --border: rgba(0, 240, 255, 0.25);
  --font-display: 'Orbitron', sans-serif;
  --font-body: 'Rajdhani', sans-serif;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: #e0e8ff;
  font-family: var(--font-body);
}

#app {
  width: 100vw;
  height: 100vh;
  position: relative;
}

.screen {
  position: absolute;
  inset: 0;
  display: none;
}

.screen.active {
  display: flex;
}

/* ── Start screen ── */
#start-screen {
  align-items: center;
  justify-content: center;
  background: var(--bg);
}

.start-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 40%, rgba(131, 56, 236, 0.15), transparent),
    radial-gradient(ellipse 60% 50% at 20% 80%, rgba(0, 240, 255, 0.08), transparent),
    radial-gradient(ellipse 50% 40% at 80% 20%, rgba(255, 0, 110, 0.08), transparent),
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 2px,
      rgba(0, 240, 255, 0.02) 2px,
      rgba(0, 240, 255, 0.02) 4px
    );
  animation: bgShift 12s ease-in-out infinite alternate;
}

@keyframes bgShift {
  from { opacity: 0.8; }
  to { opacity: 1; }
}

.start-content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 2rem;
}

.logo-ring {
  width: 100px;
  height: 100px;
  margin: 0 auto 1.5rem;
  color: var(--cyan);
  animation: logoPulse 3s ease-in-out infinite;
}

@keyframes logoPulse {
  0%, 100% { filter: drop-shadow(0 0 12px rgba(0, 240, 255, 0.4)); transform: scale(1); }
  50% { filter: drop-shadow(0 0 28px rgba(0, 240, 255, 0.7)); transform: scale(1.04); }
}

.logo-icon {
  width: 100%;
  height: 100%;
}

#start-screen h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

#start-screen h1 span {
  color: var(--cyan);
  text-shadow: 0 0 30px rgba(0, 240, 255, 0.5);
}

.tagline {
  font-size: 1.15rem;
  color: rgba(224, 232, 255, 0.6);
  letter-spacing: 0.08em;
  margin-bottom: 2.5rem;
}

.btn-primary {
  position: relative;
  border: 1px solid var(--cyan);
  background: rgba(0, 240, 255, 0.08);
  color: var(--cyan);
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  padding: 1rem 2.5rem;
  cursor: pointer;
  overflow: hidden;
  transition: background 0.3s, box-shadow 0.3s, transform 0.15s;
}

.btn-primary:hover {
  background: rgba(0, 240, 255, 0.18);
  box-shadow: 0 0 40px rgba(0, 240, 255, 0.3), inset 0 0 20px rgba(0, 240, 255, 0.05);
}

.btn-primary:active {
  transform: scale(0.97);
}

.btn-glow {
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(0, 240, 255, 0.15), transparent);
  transform: translateX(-100%);
  animation: btnShimmer 3s ease-in-out infinite;
}

@keyframes btnShimmer {
  0% { transform: translateX(-100%); }
  50%, 100% { transform: translateX(100%); }
}

.btn-text {
  position: relative;
  z-index: 1;
}

.hint {
  margin-top: 1.5rem;
  font-size: 0.85rem;
  color: rgba(224, 232, 255, 0.35);
  letter-spacing: 0.05em;
}

.hint.browser-warn {
  margin-top: 0.75rem;
  color: rgba(255, 180, 80, 0.85);
  max-width: 320px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.4;
}

.hidden {
  display: none !important;
}

/* ── Tracking screen ── */
#tracking-screen {
  background: #000;
}

#webcam {
  display: none;
}

#view {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: #000;
}

#overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 2;
}

.scanlines {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 5;
  opacity: 0.04;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    #000 2px,
    #000 4px
  );
}

/* ── HUD ── */
.hud {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 10;
}

.hud-corner {
  position: absolute;
  width: 40px;
  height: 40px;
  border-color: var(--cyan);
  border-style: solid;
  opacity: 0.5;
}

.hud-tl { top: 16px; left: 16px; border-width: 2px 0 0 2px; }
.hud-tr { top: 16px; right: 16px; border-width: 2px 2px 0 0; }
.hud-bl { bottom: 16px; left: 16px; border-width: 0 0 2px 2px; }
.hud-br { bottom: 16px; right: 16px; border-width: 0 2px 2px 0; }

.hud-header {
  position: absolute;
  top: 24px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 2rem;
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  padding: 0.6rem 1.5rem;
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.hud-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--cyan);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 8px var(--green);
  animation: dotPulse 1.5s ease-in-out infinite;
}

@keyframes dotPulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.8); }
}

.hud-status {
  color: rgba(224, 232, 255, 0.7);
}

.hud-status .divider {
  margin: 0 0.75rem;
  opacity: 0.3;
}

.stream-ok {
  color: var(--green);
}

.stream-bad {
  color: #ff6b6b;
  animation: dotPulse 0.8s ease-in-out infinite;
}

.hand-panels {
  position: absolute;
  top: 80px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 220px;
}

.expression-panel {
  position: absolute;
  top: 80px;
  left: 24px;
  display: flex;
  align-items: center;
  gap: 14px;
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  padding: 0.85rem 1.25rem;
  min-width: 180px;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.expression-panel.hidden {
  display: none;
}

.expression-emoji {
  font-size: 2.4rem;
  line-height: 1;
  filter: drop-shadow(0 0 8px rgba(255, 255, 255, 0.2));
}

.expression-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.expression-label {
  font-family: var(--font-display);
  font-size: 0.85rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.expression-confidence {
  font-size: 0.75rem;
  color: rgba(224, 232, 255, 0.45);
  letter-spacing: 0.08em;
}

.hand-panel {
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  padding: 0.75rem 1rem;
  animation: panelIn 0.4s ease-out;
}

.hand-panel.inactive {
  opacity: 0.55;
  border-color: rgba(255, 255, 255, 0.12);
}

@keyframes panelIn {
  from { opacity: 0; transform: translateX(20px); }
  to { opacity: 1; transform: translateX(0); }
}

.hand-panel.left-hand { border-color: rgba(0, 240, 255, 0.4); }
.hand-panel.right-hand { border-color: rgba(255, 0, 110, 0.4); }

.hand-panel-title {
  font-family: var(--font-display);
  font-size: 0.65rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
  opacity: 0.8;
}

.left-hand .hand-panel-title { color: var(--cyan); }
.right-hand .hand-panel-title { color: var(--magenta); }

.signal-badge {
  display: inline-block;
  margin-bottom: 0.65rem;
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
  font-family: var(--font-display);
  font-size: 0.58rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(224, 232, 255, 0.9);
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.hand-panel.inactive .signal-badge {
  color: rgba(224, 232, 255, 0.38);
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(255, 255, 255, 0.08);
}

.signal-badge.motion {
  color: var(--green);
  background: rgba(57, 255, 20, 0.12);
  border-color: rgba(57, 255, 20, 0.35);
}

.finger-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.finger-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.9rem;
  letter-spacing: 0.05em;
}

.finger-name {
  opacity: 0.6;
}

.finger-status {
  font-family: var(--font-display);
  font-size: 0.6rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 2px 8px;
  border-radius: 2px;
}

.finger-status.up {
  background: rgba(57, 255, 20, 0.15);
  color: var(--green);
  border: 1px solid rgba(57, 255, 20, 0.3);
}

.finger-status.down {
  background: rgba(255, 255, 255, 0.05);
  color: rgba(224, 232, 255, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.hud-footer {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--glass);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  padding: 0.5rem 1.5rem;
  font-family: var(--font-display);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: rgba(224, 232, 255, 0.6);
}

/* ── Loading ── */
.loading {
  position: absolute;
  inset: 0;
  z-index: 20;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--cyan);
}

.loading.hidden {
  display: none;
}

.loading-spinner {
  width: 48px;
  height: 48px;
  border: 2px solid rgba(0, 240, 255, 0.15);
  border-top-color: var(--cyan);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

/* ── Site credits (corners) ── */
.site-credits {
  position: fixed;
  bottom: 14px;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0 18px;
  pointer-events: none;
}

.site-credits-link,
.site-credits-built,
.site-credits-built a {
  pointer-events: auto;
}

.site-credits-github {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: rgba(224, 232, 255, 0.55);
  text-decoration: none;
  transition: color 0.2s, text-shadow 0.2s;
}

.site-credits-github:hover {
  color: var(--cyan);
  text-shadow: 0 0 12px rgba(0, 240, 255, 0.35);
}

.github-icon {
  width: 16px;
  height: 16px;
}

.site-credits-built {
  font-family: var(--font-body);
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  color: rgba(224, 232, 255, 0.45);
  text-align: right;
}

.site-credits-built a {
  color: rgba(224, 232, 255, 0.72);
  text-decoration: none;
  transition: color 0.2s, text-shadow 0.2s;
}

.site-credits-built a:hover {
  color: var(--cyan);
  text-shadow: 0 0 10px rgba(0, 240, 255, 0.3);
}

/* ── Tablet ── */
@media (max-width: 900px) {
  .hud-header {
    gap: 1rem;
    padding: 0.5rem 1rem;
    font-size: 0.65rem;
  }

  .hand-panels {
    top: 72px;
    right: 16px;
    max-width: 190px;
  }

  .expression-panel {
    top: 72px;
    left: 16px;
    min-width: 150px;
    padding: 0.65rem 0.9rem;
  }

  .hud-footer {
    max-width: calc(100% - 32px);
    padding: 0.45rem 1rem;
    font-size: 0.62rem;
    text-align: center;
  }
}

/* ── Mobile: left sidebar stack ── */
@media (max-width: 768px) {
  .hud-corner {
    display: none;
  }

  .hud {
    inset: 0 auto 0 0;
    width: min(44vw, 172px);
    max-width: 172px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 5px;
    padding:
      max(6px, env(safe-area-inset-top))
      max(6px, env(safe-area-inset-right))
      max(48px, calc(env(safe-area-inset-bottom) + 40px))
      max(6px, env(safe-area-inset-left));
    overflow-x: hidden;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    background: linear-gradient(
      90deg,
      rgba(8, 8, 16, 0.92) 0%,
      rgba(8, 8, 16, 0.72) 78%,
      rgba(8, 8, 16, 0) 100%
    );
    pointer-events: auto;
  }

  .hud-header,
  .expression-panel,
  .hand-panels,
  .hud-footer {
    position: static;
    top: auto;
    left: auto;
    right: auto;
    bottom: auto;
    transform: none;
    width: 100%;
    max-width: none;
  }

  .hud-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.28rem;
    padding: 0.38rem 0.48rem;
    font-size: 0.48rem;
    letter-spacing: 0.08em;
  }

  .hud-brand {
    gap: 0.35rem;
    font-size: 0.52rem;
    line-height: 1.2;
  }

  .pulse-dot {
    width: 5px;
    height: 5px;
  }

  .hud-status {
    display: flex;
    flex-wrap: wrap;
    gap: 0.12rem 0.35rem;
    width: 100%;
    font-size: 0.42rem;
    letter-spacing: 0.04em;
    line-height: 1.25;
  }

  .hud-status .divider {
    display: none;
  }

  .expression-panel {
    min-width: 0;
    padding: 0.34rem 0.48rem;
    gap: 0.38rem;
  }

  .expression-emoji {
    font-size: 1.05rem;
  }

  .expression-label {
    font-size: 0.46rem;
    letter-spacing: 0.08em;
  }

  .expression-confidence {
    font-size: 0.4rem;
  }

  .hand-panels {
    gap: 4px;
  }

  .hand-panel {
    padding: 0.34rem 0.42rem;
    animation: none;
  }

  .hand-panel-title {
    font-size: 0.42rem;
    letter-spacing: 0.12em;
    margin-bottom: 0.22rem;
  }

  .signal-badge {
    font-size: 0.38rem;
    letter-spacing: 0.08em;
    padding: 0.12rem 0.32rem;
    margin-bottom: 0.28rem;
  }

  .finger-list {
    gap: 2px;
  }

  .finger-row {
    font-size: 0.52rem;
    letter-spacing: 0.03em;
  }

  .finger-status {
    font-size: 0.36rem;
    letter-spacing: 0.06em;
    padding: 1px 4px;
  }

  .hud-footer {
    padding: 0.34rem 0.48rem;
    font-size: 0.4rem;
    letter-spacing: 0.07em;
    line-height: 1.35;
    text-align: left;
    white-space: normal;
    word-break: break-word;
  }

  .site-credits {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.2rem;
    bottom: max(6px, env(safe-area-inset-bottom));
    padding: 0 max(8px, env(safe-area-inset-right)) 0 max(8px, env(safe-area-inset-left));
  }

  .site-credits-built {
    text-align: left;
    font-size: 0.48rem;
    line-height: 1.25;
  }

  .site-credits-github {
    font-size: 0.48rem;
  }

  .github-icon {
    width: 11px;
    height: 11px;
  }

  #start-screen h1 {
    font-size: clamp(1.35rem, 8.5vw, 2rem);
    letter-spacing: 0.1em;
  }

  .tagline {
    font-size: 0.82rem;
    margin-bottom: 1.35rem;
  }

  .logo-ring {
    width: 68px;
    height: 68px;
    margin-bottom: 0.85rem;
  }

  .btn-primary {
    font-size: 0.68rem;
    letter-spacing: 0.12em;
    padding: 0.65rem 1.35rem;
  }

  .hint {
    font-size: 0.68rem;
    margin-top: 1rem;
  }

  .start-content {
    padding: 1rem 0.85rem 3.5rem;
  }

  .loading {
    font-size: 0.62rem;
  }

  .loading-spinner {
    width: 36px;
    height: 36px;
  }
}

@media (max-width: 480px) {
  .hud {
    width: min(48vw, 158px);
    max-width: 158px;
    gap: 4px;
  }

  .hud-brand {
    font-size: 0.48rem;
  }

  .hud-status {
    font-size: 0.38rem;
  }

  .finger-row {
    font-size: 0.48rem;
  }
}

@media (max-height: 520px) and (orientation: landscape) {
  .hud {
    width: min(34vw, 150px);
    max-width: 150px;
    gap: 3px;
    padding-bottom: max(36px, calc(env(safe-area-inset-bottom) + 28px));
  }

  .expression-emoji {
    font-size: 0.9rem;
  }

  .hand-panel {
    padding: 0.28rem 0.38rem;
  }

  .finger-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: 4px;
  }

  .site-credits {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .site-credits-built {
    text-align: right;
    font-size: 0.42rem;
  }
}