:root {
  --bg: #050507;
  --panel: rgba(10, 10, 14, 0.72);
  --panel2: rgba(10, 10, 14, 0.52);
  --text: rgba(255,255,255,0.82);
  --muted: rgba(255,255,255,0.62);
  --accent: #B7D7FF;
  --accent2: #BCA7FF;
  --shadow: rgba(0,0,0,0.55);
  --radius: 14px;
  --gap: 12px;
  --tap: 44px;
}

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, "Apple Color Emoji","Segoe UI Emoji";
}

#app {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

#viz {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  background: var(--bg);
}

#ui {
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 16px;
  background: var(--panel);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius);
  box-shadow: 0 16px 40px var(--shadow);
  padding: 14px 14px 10px 14px;
  backdrop-filter: blur(10px);
}

#caption {
  font-size: 15px;
  line-height: 1.35;
  color: var(--text);
  margin-bottom: 10px;
}

@media (min-width: 980px) {
  #controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-areas:
      "slider slider"
      "back   next"
      "phase  phase";
    gap: var(--gap);
    align-items: center;
  }

  #angleWrap  { grid-area: slider; }
  #back       { grid-area: back; }
  #next       { grid-area: next; justify-self: end; }
  #togglePhase{ grid-area: phase; }
}


button {
  min-height: var(--tap);
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.14);
  background: rgba(255,255,255,0.06);
  color: var(--text);
  cursor: pointer;
  user-select: none;
}

button:hover { background: rgba(255,255,255,0.09); }
button:active { transform: translateY(1px); }

.control {
  display: flex;
  gap: 10px;
  align-items: center;
  min-height: var(--tap);
  padding: 8px 10px;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.10);
  background: rgba(255,255,255,0.04);
}

#angleWrap {
  justify-content: space-between;
}

#angleLabel {
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
}

#angle {
  width: 100%;
  accent-color: var(--accent);
}

#togglePhase {
  white-space: nowrap;
}

#stepDots {
  margin-top: 10px;
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: rgba(255,255,255,0.22);
}
.dot.active {
  background: var(--accent);
}

#hint {
  margin-top: 8px;
  font-size: 12px;
  color: var(--muted);
}

@media (min-width: 980px) {
  #ui {
    right: 20px;
    left: auto;
    bottom: 20px;
    width: min(420px, 40vw);
    background: var(--panel2);
  }

  #controls {
    grid-template-columns: auto 1fr;
  }

  #togglePhase { grid-column: 1 / -1; }
  #back { grid-column: 1; }
  #next { grid-column: 2; justify-self: end; }
  #angleWrap { grid-column: 1 / -1; }
}

/* ===============================
   Site header (title + sources)
   =============================== */

.site-header {
  position: fixed;
  top: 16px;
  left: 16px;
  right: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  pointer-events: none;
  z-index: 20;
}

.site-title {
  font-family: "Inter", "IBM Plex Sans", "Source Sans 3", system-ui, sans-serif;
  font-size: 1.05rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: rgba(255,255,255,0.82);
  pointer-events: auto;
}

.site-sources {
  font-family: "Inter", "IBM Plex Sans", "Source Sans 3", system-ui, sans-serif;
  font-size: 0.9rem;
  font-weight: 500;
  color: rgba(183,215,255,0.85);
  text-decoration: none;
  border-bottom: 1px solid rgba(183,215,255,0.25);
  pointer-events: auto;
}

.site-sources:hover {
  color: rgba(183,215,255,1);
  border-bottom-color: rgba(183,215,255,0.6);
}