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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: #f5f7fa;
  color: #333;
  min-height: 100vh;
  padding: 40px 20px;
}

.container {
  max-width: 860px;
  margin: 0 auto;
}

header {
  text-align: center;
  margin-bottom: 36px;
}

header h1 {
  font-size: 2rem;
  font-weight: 700;
  color: #1a1a2e;
}

.subtitle {
  margin-top: 8px;
  color: #666;
  font-size: 1rem;
}

/* Upload Area */
.upload-area {
  border: 2px dashed #c0c8d8;
  border-radius: 16px;
  background: #fff;
  padding: 60px 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
}

.upload-area:hover,
.upload-area.dragover {
  border-color: #4f6ef7;
  background: #f0f3ff;
}

.upload-icon {
  font-size: 3rem;
  margin-bottom: 16px;
}

.upload-area p {
  color: #555;
  font-size: 1rem;
  margin-bottom: 6px;
}

.upload-area .link {
  color: #4f6ef7;
  font-weight: 600;
  cursor: pointer;
}

.upload-area .hint {
  font-size: 0.85rem;
  color: #999;
}

/* Result Area */
.result-area {
  background: #fff;
  border-radius: 16px;
  padding: 32px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.07);
}

.compare {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 28px;
}

@media (max-width: 600px) {
  .compare { grid-template-columns: 1fr; }
}

.compare-item {
  text-align: center;
}

.compare-item .label {
  font-size: 0.9rem;
  font-weight: 600;
  color: #888;
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.compare-item img {
  width: 100%;
  max-height: 360px;
  object-fit: contain;
  border-radius: 10px;
  border: 1px solid #eee;
}

.checker-bg {
  background-image: linear-gradient(45deg, #ccc 25%, transparent 25%),
    linear-gradient(-45deg, #ccc 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #ccc 75%),
    linear-gradient(-45deg, transparent 75%, #ccc 75%);
  background-size: 20px 20px;
  background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
  border-radius: 10px;
  border: 1px solid #eee;
}

.checker-bg img {
  border: none;
}

.actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.btn-primary {
  background: #4f6ef7;
  color: #fff;
  border: none;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

.btn-primary:hover { background: #3a57e8; }

.btn-secondary {
  background: #f0f3ff;
  color: #4f6ef7;
  border: 1px solid #c0c8d8;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

.btn-secondary:hover { background: #e0e6ff; }

/* Loading */
.loading {
  text-align: center;
  padding: 60px 20px;
  background: #fff;
  border-radius: 16px;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid #e0e6ff;
  border-top-color: #4f6ef7;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  margin: 0 auto 16px;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading p {
  color: #666;
  font-size: 1rem;
}

/* Error */
.error {
  background: #fff0f0;
  border: 1px solid #ffcccc;
  color: #cc0000;
  border-radius: 10px;
  padding: 16px 20px;
  margin-top: 16px;
  text-align: center;
  font-size: 0.95rem;
}