/* =============================================
   DEEP BLUE AQUARIUM — CSS
   ============================================= */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --ocean-deep:    #020d1a;
  --ocean-mid:     #04243d;
  --ocean-light:   #0a4a7a;
  --ocean-surface: #0d6eaa;
  --ray-color:     rgba(130, 210, 255, 0.12);
  --accent:        #48d4ff;
  --accent-warm:   #ffce70;
  --text-light:    rgba(255,255,255,0.85);
  --text-dim:      rgba(255,255,255,0.45);
  --night-overlay: rgba(0,0,20,0.72);
}

html, body {
  width: 100%; height: 100%;
  overflow: hidden;
  background: var(--ocean-deep);
  font-family: 'Lato', sans-serif;
  cursor: crosshair;
}

/* ── Canvas ── */
#aquarium {
  display: block;
  width: 100vw; height: 100vh;
  position: fixed; top: 0; left: 0; z-index: 0;
}

/* ── Water surface shimmer ── */
#water-surface {
  position: fixed; top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none; z-index: 1;
  background: linear-gradient(
    180deg,
    rgba(10,90,150,0.18) 0%,
    transparent 30%
  );
  animation: surface-shimmer 6s ease-in-out infinite alternate;
}
@keyframes surface-shimmer {
  0%   { opacity: 0.6; }
  100% { opacity: 1; }
}

/* ── Light rays ── */
#light-rays {
  position: fixed; top: -10%; left: 0;
  width: 100%; height: 80%;
  pointer-events: none; z-index: 2;
  overflow: hidden;
}
.ray {
  position: absolute;
  top: 0;
  width: 80px;
  height: 100%;
  background: linear-gradient(180deg, var(--ray-color) 0%, transparent 100%);
  transform-origin: top center;
  filter: blur(18px);
  animation: ray-sway 8s ease-in-out infinite;
}
.ray:nth-child(1) { left: 8%;  width: 60px;  animation-delay: 0s;    animation-duration: 9s; }
.ray:nth-child(2) { left: 22%; width: 100px; animation-delay: -2s;   animation-duration: 11s; }
.ray:nth-child(3) { left: 45%; width: 80px;  animation-delay: -4s;   animation-duration: 8s; }
.ray:nth-child(4) { left: 65%; width: 60px;  animation-delay: -1s;   animation-duration: 13s; }
.ray:nth-child(5) { left: 82%; width: 90px;  animation-delay: -3.5s; animation-duration: 10s; }

@keyframes ray-sway {
  0%, 100% { transform: skewX(-4deg) scaleX(1);   opacity: 0.7; }
  50%       { transform: skewX( 4deg) scaleX(1.1); opacity: 1;   }
}

/* ── UI Overlay ── */
#ui-overlay {
  position: fixed; top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none; z-index: 10;
  display: flex; flex-direction: column;
  align-items: flex-start;
  padding: 2.2rem 2.5rem;
}

#title-block {
  margin-bottom: auto;
}
#title-block h1 {
  font-family: 'Cinzel', serif;
  font-size: clamp(1.8rem, 4vw, 3.2rem);
  font-weight: 600;
  letter-spacing: 0.35em;
  color: var(--accent);
  text-shadow: 0 0 40px rgba(72,212,255,0.5), 0 2px 4px rgba(0,0,0,0.6);
  line-height: 1;
}
.subtitle {
  font-family: 'Lato', sans-serif;
  font-weight: 300;
  font-size: clamp(0.7rem, 1.3vw, 0.9rem);
  letter-spacing: 0.5em;
  color: var(--text-dim);
  margin-top: 0.4rem;
  text-transform: uppercase;
}

#instruction {
  position: absolute;
  bottom: 4.5rem; left: 50%;
  transform: translateX(-50%);
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--text-dim);
  display: flex; align-items: center; gap: 0.5rem;
  animation: pulse-fade 3s ease-in-out infinite;
  white-space: nowrap;
}
.dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent);
  animation: dot-pulse 3s ease-in-out infinite;
}
@keyframes pulse-fade {
  0%, 100% { opacity: 0.5; } 50% { opacity: 0.9; }
}
@keyframes dot-pulse {
  0%, 100% { transform: scale(1); } 50% { transform: scale(1.5); }
}

/* ── Controls ── */
#controls {
  pointer-events: all;
  display: flex; gap: 0.6rem;
  position: absolute; top: 2rem; right: 2rem;
}
#controls button {
  background: rgba(255,255,255,0.07);
  border: 1px solid rgba(255,255,255,0.15);
  color: var(--text-light);
  width: 40px; height: 40px;
  border-radius: 50%;
  font-size: 1.1rem;
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
  backdrop-filter: blur(6px);
}
#controls button:hover {
  background: rgba(72,212,255,0.18);
  transform: scale(1.1);
}

/* ── Ripple effect ── */
#ripple-container {
  position: fixed; top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none; z-index: 5;
  overflow: hidden;
}
.ripple {
  position: absolute;
  border-radius: 50%;
  border: 2px solid rgba(72,212,255,0.6);
  transform: translate(-50%, -50%) scale(0);
  animation: ripple-out 1.4s ease-out forwards;
}
@keyframes ripple-out {
  0%   { transform: translate(-50%,-50%) scale(0);   opacity: 1; }
  100% { transform: translate(-50%,-50%) scale(4.5); opacity: 0; }
}

/* ── Night mode ── */
body.night #light-rays { opacity: 0.2; }
body.night #water-surface { background: linear-gradient(180deg, rgba(0,0,30,0.4) 0%, transparent 40%); }
body.night::after {
  content: '';
  position: fixed; inset: 0; z-index: 3;
  background: var(--night-overlay);
  pointer-events: none;
  animation: night-in 1.5s ease forwards;
}
@keyframes night-in { from { opacity: 0; } to { opacity: 1; } }
body.day::after { animation: night-out 1.5s ease forwards; }
@keyframes night-out { from { opacity: 1; } to { opacity: 0; } }

/* ── Footer ── */
#footer {
  position: fixed; bottom: 0; left: 0;
  width: 100%; z-index: 20;
  display: flex; align-items: center; justify-content: center; gap: 0.5rem;
  padding: 0.7rem 1rem;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--text-dim);
  background: linear-gradient(0deg, rgba(2,13,26,0.9) 0%, transparent 100%);
  user-select: none;
}
#footer a {
  display: flex; align-items: center; gap: 0.35rem;
  color: var(--accent);
  text-decoration: none;
  font-weight: 400;
  letter-spacing: 0.06em;
  transition: color 0.2s, text-shadow 0.2s;
}
#footer a:hover {
  color: #fff;
  text-shadow: 0 0 12px var(--accent);
}
#footer a svg { vertical-align: middle; }

/* ── Responsive ── */
@media (max-width: 600px) {
  #ui-overlay { padding: 1.4rem 1.2rem; }
  #controls { top: 1.2rem; right: 1.2rem; }
  .ray { filter: blur(10px); }
}