:root {
  --gap: 1rem;
  --border-width: 4px;
  --border-radius: 8px;
  --transition-speed: 0.2s;
  --color-yes: #28a745;
  --color-no: #dc3545;
  --btn-bg: #007bff;
  --btn-hover: #0056b3;
  --btn-color: #fff;
}

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

body {
  margin: 0;
  font-family: system-ui, -apple-system, sans-serif;
  line-height: 1.5;
  color: #333;
  padding: var(--gap);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

header, footer {
  text-align: center;
  margin-bottom: var(--gap);
}

main {
  flex: 1;
}

#controls {
  display: flex;
  flex-wrap: wrap;
  gap: var(--gap);
  align-items: center;
  margin-bottom: var(--gap);
}

.file-input {
  position: relative;
  overflow: hidden;
  display: inline-block;
  cursor: pointer;
  background: var(--btn-bg);
  color: var(--btn-color);
  padding: 0.5em 1em;
  border-radius: var(--border-radius);
  transition: background var(--transition-speed);
}

.file-input:hover {
  background: var(--btn-hover);
}

.file-input input {
  position: absolute;
  opacity: 0;
  inset: 0;
  cursor: pointer;
}

button {
  background: var(--btn-bg);
  color: var(--btn-color);
  border: none;
  padding: 0.5em 1em;
  border-radius: var(--border-radius);
  cursor: pointer;
  transition: background var(--transition-speed);
}

button:hover:not([disabled]) {
  background: var(--btn-hover);
}

button[disabled] {
  opacity: 0.5;
  cursor: not-allowed;
}

#status {
  font-weight: bold;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--gap);
}

.cell {
  position: relative;
  border: var(--border-width) solid var(--color-no);
  border-radius: var(--border-radius);
  overflow: hidden;
  cursor: pointer;
  transition: transform var(--transition-speed), border-color var(--transition-speed);
}

.cell[data-label="yes"] {
  border-color: var(--color-yes);
}

.cell:hover {
  transform: scale(1.03);
}

.cell img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

#pagination {
  display: flex;
  justify-content: center;
  gap: var(--gap);
  margin-top: var(--gap);
}