:root {
  --bg: #0b0c10;
  --card: #14161a;
  --text: #e8e8e8;
  --muted: #a9b0bd;
  --border: #2a2f3a;
  --btn: #2b6cff;
  --btn2: #2a2f3a;
  --danger: #ff5a5a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

.container {
  max-width: 980px;
  margin: 0 auto;
  padding: 28px 16px 60px;
}

h1 {
  margin: 0 0 6px;
  font-size: 28px;
}

.sub {
  margin: 0 0 18px;
  color: var(--muted);
}

.card {
  border: 1px solid var(--border);
  background: var(--card);
  border-radius: 14px;
  padding: 16px;
}

.file input {
  display: none;
}

.file span {
  display: inline-block;
  padding: 10px 12px;
  border: 1px dashed var(--border);
  border-radius: 10px;
  cursor: pointer;
  color: var(--muted);
}

.row {
  display: flex;
  gap: 10px;
  margin-top: 12px;
  flex-wrap: wrap;
}

button {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 10px 12px;
  cursor: pointer;
  color: var(--text);
  background: var(--btn2);
}

button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

#removeBtn:not(:disabled) {
  background: var(--btn);
  border-color: transparent;
}

.status {
  margin: 12px 0 0;
  min-height: 18px;
  color: var(--muted);
}

.status.error {
  color: var(--danger);
}

.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 14px;
}

@media (min-width: 840px) {
  .grid {
    grid-template-columns: 1fr 1fr;
  }
}

.preview {
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  background: #0f1115;
  height: 340px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.preview img {
  max-width: 100%;
  max-height: 100%;
  display: block;
}

.checker {
  background-image:
    linear-gradient(45deg, #222 25%, transparent 25%),
    linear-gradient(-45deg, #222 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #222 75%),
    linear-gradient(-45deg, transparent 75%, #222 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
}

.footer {
  margin-top: 14px;
  color: var(--muted);
}