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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: #f8fafc;
  color: #1e293b;
  line-height: 1.6;
  min-height: 100vh;
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 20px;
}

header {
  text-align: center;
  margin-bottom: 40px;
}

header h1 {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: #0f172a;
}

.subtitle {
  margin-top: 8px;
  color: #64748b;
  font-size: 1.05rem;
}

.form-group {
  margin-bottom: 20px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
  font-size: 0.95rem;
  color: #334155;
}

input[type="text"],
textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  font-size: 1rem;
  font-family: inherit;
  background: white;
  transition: border-color 0.15s, box-shadow 0.15s;
}

input[type="text"]:focus,
textarea:focus {
  outline: none;
  border-color: #3b82f6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

textarea {
  resize: vertical;
  min-height: 140px;
}

.radio-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 12px;
}

.radio-card {
  position: relative;
  cursor: pointer;
}

.radio-card input {
  position: absolute;
  opacity: 0;
}

.radio-card span {
  display: block;
  padding: 14px 16px;
  border: 2px solid #e2e8f0;
  border-radius: 12px;
  text-align: center;
  font-weight: 500;
  background: white;
  transition: all 0.15s;
}

.radio-card input:checked + span {
  border-color: #3b82f6;
  background: #eff6ff;
  color: #1d4ed8;
}

.radio-card:hover span {
  border-color: #93c5fd;
}

.generate-btn {
  width: 100%;
  padding: 14px 20px;
  background: #0f172a;
  color: white;
  border: none;
  border-radius: 12px;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  margin-top: 10px;
  transition: background 0.15s;
}

.generate-btn:hover {
  background: #1e293b;
}

.result-section {
  margin-top: 40px;
  padding: 24px;
  background: white;
  border-radius: 16px;
  border: 1px solid #e2e8f0;
  box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

.result-section.hidden {
  display: none;
}

.result-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.result-header h2 {
  font-size: 1.35rem;
  font-weight: 650;
}

.copy-btn {
  padding: 8px 16px;
  background: #3b82f6;
  color: white;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  font-size: 0.95rem;
}

.copy-btn:hover {
  background: #2563eb;
}

.copy-btn.copied {
  background: #16a34a;
}

.prompt-output {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  padding: 18px;
  white-space: pre-wrap;
  word-wrap: break-word;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.92rem;
  line-height: 1.55;
  color: #1e293b;
  max-height: 480px;
  overflow-y: auto;
}

.tip {
  margin-top: 12px;
  font-size: 0.9rem;
  color: #64748b;
}

footer {
  margin-top: 50px;
  text-align: center;
  color: #94a3b8;
  font-size: 0.9rem;
}

@media (max-width: 640px) {
  .form-row {
    grid-template-columns: 1fr;
  }
  header h1 {
    font-size: 1.75rem;
  }
  .container {
    padding: 24px 16px;
  }
}