body { font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif; }
.container { max-width: 100%; margin: 40px auto; padding: 0 16px; }

.main-content { display: flex; flex-direction: column; gap: 20px; }

@media (min-width: 620px) {
  .main-content { flex-direction: row; }
  .form-container, .result-container-wrapper { flex: 1; }
  .form-container { padding: 0 10px 0 0; }
}

form { display: grid; gap: 12px; }
label { display: grid; gap: 6px; font-size: 14px; }
input { padding: 10px; border: 1px solid #ddd; border-radius: 8px; }
button { padding: 12px 16px; border: 0; border-radius: 8px; background: #111; color: #fff; cursor: pointer; }
.result-text {
  white-space: pre-wrap;
  line-height: 1.6;
  border: 1px solid #eee;
  padding: 16px;
  border-radius: 8px;
  background: #fafafa;
  height: 100%;
  box-sizing: border-box;
  overflow-y: auto;
}
.result-container {
  position: relative;
  height: 100%;
}
.copy-button { position: absolute; top: 10px; right: 10px; background: #eee; border: 1px solid #ddd; padding: 6px; border-radius: 6px; cursor: pointer; }
.copy-button:hover { background: #ddd; }
.copy-feedback { position: absolute; top: 12px; right: 50px; background: #333; color: white; padding: 4px 8px; border-radius: 4px; font-size: 12px; opacity: 0; transition: opacity 0.3s; }