/* =============================================================
   Black hole — rainsday Lab 01
   Full-screen ray-marched gravitational-lensing renderer
   ============================================================= */

:root {
  --cosmic: #000000;
  --space: #06070f;
  --panel: rgba(4, 5, 8, 0.62);
  --panel-strong: rgba(4, 5, 8, 0.82);
  --panel-line: rgba(255, 255, 255, 0.16);
  --warm: #ffb15d;
  --ice: #dfe8ff;
}

html,
body.black-hole-experience {
  min-height: 100%;
  overflow: hidden;
  background: var(--cosmic);
}

body.black-hole-experience {
  margin: 0;
  color: var(--paper);
  color-scheme: dark;
}

.black-hole-lab {
  position: relative;
  width: 100%;
  height: 100dvh;
  min-height: 620px;
  overflow: hidden;
  background: var(--space);
  isolation: isolate;
}

#black-hole-canvas {
  position: absolute;
  inset: 0;
  z-index: 1;
  width: 100%;
  height: 100%;
  display: block;
  background: var(--space);
  outline: none;
  touch-action: none;
}

#black-hole-canvas:focus-visible {
  box-shadow: inset 0 0 0 2px var(--lime);
}

.black-hole-lab::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background:
    linear-gradient(90deg, rgba(0, 0, 0, 0.48), transparent 28%, transparent 72%, rgba(0, 0, 0, 0.56)),
    linear-gradient(180deg, rgba(0, 0, 0, 0.42), transparent 24%, transparent 70%, rgba(0, 0, 0, 0.66));
}

.black-hole-fallback {
  position: absolute;
  inset: 0;
  z-index: 3;
  display: grid;
  place-items: center;
  overflow: hidden;
  background:
    radial-gradient(circle at 50% 50%, rgba(255, 177, 93, 0.16), transparent 36%),
    var(--space);
}

.black-hole-fallback[hidden] {
  display: none !important;
}

.fallback-system {
  position: relative;
  width: min(78vw, 760px);
  aspect-ratio: 1;
}

.fallback-disc,
.fallback-ring,
.fallback-core,
.fallback-star {
  position: absolute;
  display: block;
  border-radius: 999px;
}

.fallback-disc {
  inset: 18%;
  background:
    radial-gradient(circle, transparent 0 21%, rgba(0, 0, 0, 0.94) 22% 28%, transparent 29%),
    conic-gradient(from -18deg, transparent 0 12%, #fff4d8 17%, #ff9f42 29%, transparent 42%, transparent 56%, #ffe6b5 64%, #9a2e11 76%, transparent 88%);
  filter: blur(0.7px) drop-shadow(0 0 78px rgba(255, 159, 66, 0.36));
  transform: rotateX(69deg) rotateZ(-9deg);
}

.fallback-ring {
  inset: 36%;
  border: 2px solid rgba(255, 236, 196, 0.72);
  box-shadow: 0 0 24px rgba(255, 210, 140, 0.8);
}

.fallback-core {
  inset: 39%;
  background: #000;
  box-shadow:
    0 0 0 18px rgba(0, 0, 0, 0.52),
    0 0 100px rgba(255, 177, 93, 0.28);
}

.fallback-star {
  width: 3px;
  height: 3px;
  background: #fff;
  box-shadow: 0 0 14px currentColor;
}

.fallback-star--one { top: 21%; left: 76%; color: #dfe8ff; }
.fallback-star--two { top: 68%; left: 16%; color: #fff4d8; }
.fallback-star--three { top: 34%; left: 27%; color: #ffb15d; }

.black-hole-fallback p,
.black-hole-noscript {
  position: absolute;
  left: 50%;
  bottom: 34px;
  width: min(480px, calc(100vw - 40px));
  margin: 0;
  transform: translateX(-50%);
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: 0.08em;
  text-align: center;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.72);
}

.black-hole-noscript {
  z-index: 10;
  padding: 14px 18px;
  border: 1px solid var(--panel-line);
  background: var(--panel-strong);
}

.black-hole-topline,
.black-hole-readouts,
.black-hole-controls,
.black-hole-physics-line,
.black-hole-title-overlay {
  position: absolute;
  z-index: 5;
}

.black-hole-topline {
  top: 24px;
  left: 28px;
  display: grid;
  gap: 14px;
  pointer-events: auto;
}

.black-hole-back {
  width: max-content;
  color: var(--paper);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-decoration: none;
  text-transform: uppercase;
  transition: color 180ms var(--ease);
}

.black-hole-back:hover,
.black-hole-back:focus-visible {
  color: var(--lime);
}

.black-hole-kicker {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  width: max-content;
  padding: 5px 8px;
  background: var(--lime);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.black-hole-kicker .square {
  width: 7px;
  height: 7px;
  background: currentColor;
}

.black-hole-title-overlay {
  left: clamp(24px, 7vw, 112px);
  top: 50%;
  max-width: min(780px, calc(100vw - 48px));
  transform: translateY(-50%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 800ms var(--ease), transform 900ms var(--ease);
}

.black-hole-title-overlay.is-visible {
  opacity: 1;
  transform: translateY(calc(-50% - 10px));
}

.black-hole-title-overlay h1 {
  margin: 0;
  font-family: var(--display);
  font-size: clamp(5.4rem, 12vw, 13.5rem);
  font-weight: 800;
  line-height: 0.78;
  letter-spacing: 0;
  color: var(--paper);
  text-shadow: 0 34px 96px rgba(0, 0, 0, 0.72);
}

.black-hole-title-overlay p {
  margin: 18px 0 0;
  max-width: 520px;
  font-size: clamp(15px, 1.5vw, 20px);
  line-height: 1.45;
  color: rgba(255, 255, 255, 0.74);
}

.black-hole-title-overlay .black-hole-title-kicker {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--lime);
}

.black-hole-readouts {
  left: 28px;
  bottom: 28px;
  width: min(390px, calc(50vw - 44px));
  display: grid;
  gap: 1px;
  border: 1px solid var(--panel-line);
  background: rgba(255, 255, 255, 0.12);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.34);
  backdrop-filter: blur(18px) saturate(130%);
  -webkit-backdrop-filter: blur(18px) saturate(130%);
}

.readout-row {
  display: grid;
  grid-template-columns: minmax(128px, 0.88fr) minmax(0, 1.12fr);
  gap: 14px;
  align-items: center;
  min-height: 52px;
  padding: 12px 14px;
  background: var(--panel);
}

.readout-row span,
.control-meta,
.black-hole-hint,
.black-hole-physics-line {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.readout-row span {
  color: rgba(255, 255, 255, 0.48);
}

.bh-label-short {
  display: none;
}

.readout-row strong {
  min-width: 0;
  color: var(--paper);
  font-family: var(--mono);
  font-size: clamp(13px, 1.4vw, 17px);
  font-weight: 700;
  letter-spacing: 0;
  white-space: nowrap;
}

.black-hole-controls {
  right: 28px;
  bottom: 28px;
  width: min(474px, calc(50vw - 44px));
  display: grid;
  gap: 10px;
  pointer-events: auto;
}

.black-hole-hint {
  justify-self: end;
  margin: 0;
  color: rgba(255, 255, 255, 0.62);
  transition: opacity 500ms var(--ease);
}

.black-hole-hint.is-muted {
  opacity: 0;
}

.control-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  padding: 8px;
  border: 1px solid var(--panel-line);
  background: var(--panel);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.34);
  backdrop-filter: blur(18px) saturate(130%);
  -webkit-backdrop-filter: blur(18px) saturate(130%);
}

.black-hole-controls button {
  min-width: 0;
  min-height: 42px;
  padding: 0 10px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 0;
  background: rgba(255, 255, 255, 0.08);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition:
    background 180ms var(--ease),
    border-color 180ms var(--ease),
    color 180ms var(--ease);
}

.black-hole-controls button:hover,
.black-hole-controls button:focus-visible {
  border-color: var(--lime);
  background: var(--lime);
  color: var(--ink);
}

.control-meta {
  display: flex;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 10px 14px;
  color: rgba(255, 255, 255, 0.5);
}

.control-meta [data-bh-status] {
  color: var(--lime);
}

.black-hole-physics-line {
  left: 50%;
  bottom: 16px;
  width: min(680px, calc(100vw - 56px));
  margin: 0;
  transform: translateX(-50%);
  text-align: center;
  color: rgba(255, 255, 255, 0.34);
  pointer-events: none;
}

@media (max-width: 900px) {
  .black-hole-lab {
    min-height: 100dvh;
  }

  .black-hole-topline {
    top: 18px;
    left: 18px;
  }

  .black-hole-title-overlay {
    left: 18px;
    top: 41%;
  }

  .black-hole-readouts,
  .black-hole-controls {
    left: 18px;
    right: 18px;
    width: auto;
  }

  .black-hole-controls {
    bottom: 18px;
  }

  .black-hole-readouts {
    bottom: 172px;
  }

  .black-hole-physics-line {
    bottom: 146px;
    width: calc(100vw - 36px);
  }
}

@media (max-width: 620px) {
  .black-hole-title-overlay h1 {
    font-size: clamp(4.3rem, 22vw, 7.2rem);
  }

  .black-hole-title-overlay p:not(.black-hole-title-kicker) {
    max-width: 330px;
    font-size: 14px;
  }

  .black-hole-readouts {
    bottom: 188px;
  }

  .readout-row {
    grid-template-columns: 1fr;
    gap: 6px;
    min-height: 0;
    padding: 10px 12px;
  }

  .readout-row strong {
    white-space: normal;
  }

  .control-row {
    grid-template-columns: 1fr;
  }

  .black-hole-controls button {
    min-height: 38px;
  }

  .control-meta,
  .black-hole-hint {
    justify-content: flex-start;
    justify-self: start;
    font-size: 9px;
  }

  .black-hole-physics-line {
    bottom: 164px;
    font-size: 8px;
    line-height: 1.45;
  }
}

@media (max-width: 720px) {
  .black-hole-title-overlay {
    top: 38%;
    max-width: calc(100vw - 36px);
  }

  .black-hole-title-overlay h1 {
    font-size: clamp(3.4rem, 18vw, 6.8rem);
    white-space: nowrap;
  }

  .black-hole-readouts {
    left: 12px;
    right: 12px;
    bottom: calc(env(safe-area-inset-bottom, 0px) + 82px);
    width: auto;
    max-height: 56px;
    box-sizing: border-box;
    display: flex;
    align-items: stretch;
    gap: 0;
    padding: 6px 8px;
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.14);
    background: rgba(10, 10, 10, 0.55);
    backdrop-filter: blur(18px) saturate(130%);
    -webkit-backdrop-filter: blur(18px) saturate(130%);
  }

  .readout-row {
    flex: 0.52 1 0;
    min-width: 0;
    min-height: 0;
    display: grid;
    grid-template-columns: 1fr;
    align-content: center;
    gap: 3px;
    padding: 0 6px;
    background: transparent;
  }

  .readout-row + .readout-row {
    border-left: 1px solid rgba(255, 255, 255, 0.12);
  }

  .readout-row:first-child {
    flex-grow: 1.95;
    padding-left: 0;
  }

  .readout-row:last-child {
    padding-right: 0;
  }

  .readout-row span {
    min-width: 0;
    overflow: hidden;
    color: rgba(255, 255, 255, 0.48);
    font-size: 9px;
    line-height: 1;
    letter-spacing: 0.07em;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .bh-label-full {
    display: none;
  }

  .bh-label-short {
    display: inline;
  }

  .readout-row strong {
    min-width: 0;
    overflow: hidden;
    font-size: clamp(12px, 3vw, 13px);
    line-height: 1.12;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .black-hole-controls {
    left: 12px;
    right: 12px;
    bottom: calc(env(safe-area-inset-bottom, 0px) + 12px);
    width: auto;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 6px;
  }

  .black-hole-hint,
  .black-hole-physics-line {
    display: none;
  }

  .control-row {
    display: flex;
    justify-content: flex-end;
    gap: 6px;
    width: max-content;
    max-width: 100%;
    padding: 6px;
  }

  .black-hole-controls button {
    flex: 0 1 auto;
    min-height: 34px;
    height: 34px;
    min-width: 0;
    padding: 0 8px;
    font-size: 10px;
    line-height: 1;
    white-space: nowrap;
  }

  .control-meta {
    justify-content: flex-end;
    gap: 8px;
    font-size: 9px;
  }

  .control-meta [data-bh-fps],
  .control-meta [data-bh-scale] {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .black-hole-title-overlay,
  .black-hole-hint,
  .black-hole-controls button,
  .black-hole-back {
    transition: none;
  }
}