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

body {
  font-family: system-ui, sans-serif;
  margin: 0;
  padding: 2rem 1rem;
  min-height: 100vh;
  background: #f5f5f5;
  color: #1a1a1a;
  display: flex;
  flex-direction: column;
  align-items: center;
}

header {
  text-align: center;
  margin-bottom: 2rem;
}

header h1 {
  margin: 0 0 0.4rem;
  font-size: 2rem;
}

header p {
  margin: 0;
  color: #555;
}

main {
  width: 100%;
  max-width: 640px;
}

/* Drop zone */
#drop-zone {
  border: 2px dashed #bbb;
  border-radius: 12px;
  background: #fff;
  padding: 3rem 2rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
  color: #555;
}

#drop-zone:hover,
#drop-zone.drag-over {
  border-color: #0070f3;
  background: #f0f7ff;
  color: #0070f3;
}

#drop-zone svg {
  display: block;
  margin: 0 auto 1rem;
}

#drop-zone p {
  margin: 0;
  font-size: 1.05rem;
}

#drop-zone .sub {
  margin-top: 0.4rem;
  font-size: 0.9rem;
  color: #888;
}

#drop-zone input[type="file"] {
  display: none;
}

.file-label {
  color: #0070f3;
  cursor: pointer;
  text-decoration: underline;
}

/* Error */
#error-msg {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  background: #fff0f0;
  border: 1px solid #f5a0a0;
  border-radius: 8px;
  color: #c00;
  font-size: 0.9rem;
}

/* Preview */
#preview-section {
  margin-top: 2rem;
  background: #fff;
  border-radius: 12px;
  padding: 1.5rem;
  border: 1px solid #e0e0e0;
}

#preview-wrap {
  background: repeating-conic-gradient(#e0e0e0 0% 25%, #fff 0% 50%) 0 0 / 20px 20px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 200px;
  overflow: hidden;
  margin-bottom: 1.25rem;
}

#preview-img {
  max-width: 100%;
  max-height: 400px;
  display: block;
}

/* Controls */
#controls {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.field label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
  color: #444;
}

.scale-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

#scale-slider {
  flex: 1;
  accent-color: #0070f3;
}

#scale-input {
  width: 64px;
  padding: 0.3rem 0.5rem;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 0.95rem;
  text-align: center;
}

#dimensions {
  margin: 0;
  font-size: 0.85rem;
  color: #777;
}

#download-btn {
  padding: 0.65rem 1.4rem;
  background: #0070f3;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  align-self: flex-start;
  transition: background 0.15s;
}

#download-btn:hover {
  background: #005cc5;
}

footer {
  margin-top: 3rem;
  font-size: 0.85rem;
  color: #888;
}

footer a {
  color: #888;
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}