:root {
  /* Light mode colors (default) */
  --bg-color: #f5f5f5;
  --text-color: #222;
  --button-bg: #999;
  --button-bg-hover: #ffb84d;
  --button-text: #111;
  --shadow-color: rgba(0,0,0,0.15);
  --img-shadow: rgba(0,0,0,0.2);
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Dark mode colors */
    --bg-color: #111;
    --text-color: #fff;
    --button-bg: #999;
    --button-bg-hover: #ffb84d;
    --button-text: #111;
    --shadow-color: rgba(0,0,0,0.3);
    --img-shadow: rgba(0,0,0,0.5);
  }
}

body {
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  background: var(--bg-color);
  flex-direction: column;
  font-family: sans-serif;
  color: var(--text-color);
  overflow: hidden;
}

img {
  max-width: 66vw;
  max-height: 66vh;
  object-fit: contain;
  border-radius: 12px;
  box-shadow: 0 0 20px var(--img-shadow);
  margin-bottom: 0.5em;
  cursor: pointer;
  transition: opacity 0.3s ease-in-out;
}

button {
  padding: 0.5em 1em;
  font-size: 1em;
  border-radius: 6px;
  border: none;
  background: var(--button-bg);
  color: var(--button-text);
  cursor: pointer;
  box-shadow: 0 2px 6px var(--shadow-color);
}

button:hover {
  background: var(--button-bg-hover);
}

#date {
  font-size: 0.75em;
  text-align: right;
}

.spinner {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 40px;
  height: 40px;
  border: 4px solid var(--shadow-color);
  border-top-color: var(--button-bg);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease-in-out;
}

.spinner.visible {
  opacity: 1;
}

@keyframes spin {
  to { transform: translate(-50%, -50%) rotate(360deg); }
}