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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
  color: #f8fafc;
  min-height: 100vh;
  line-height: 1.6;
}

.container {
  max-width: 700px;
  margin: 0 auto;
  padding: 2rem;
}

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

.back {
  display: inline-block;
  color: #60a5fa;
  text-decoration: none;
  margin-bottom: 1rem;
  font-size: 0.9rem;
  transition: color 0.2s;
}

.back:hover {
  color: #93c5fd;
}

h1 {
  font-size: 2.25rem;
  margin-bottom: 0.5rem;
}

.subtitle {
  color: #94a3b8;
  font-size: 1.1rem;
}

main {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.input-section {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 12px;
  padding: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
  margin-top: 1rem;
  color: #e2e8f0;
}

label:first-child {
  margin-top: 0;
}

.required {
  color: #f87171;
}

input[type="text"],
input[type="url"],
select,
textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 2px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.3);
  color: #f8fafc;
  font-size: 1rem;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: #3b82f6;
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.3);
}

input::placeholder,
textarea::placeholder {
  color: #64748b;
}

select option {
  background: #1e293b;
  color: #f8fafc;
}

textarea {
  resize: vertical;
  min-height: 80px;
}

.char-count {
  text-align: right;
  font-size: 0.8rem;
  color: #64748b;
  margin-top: 0.25rem;
}

.primary-btn {
  width: 100%;
  padding: 1rem;
  margin-top: 1.5rem;
  border: none;
  border-radius: 8px;
  background: linear-gradient(135deg, #3b82f6, #2563eb);
  color: white;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

.primary-btn:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 4px 20px rgba(59, 130, 246, 0.4);
}

.primary-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.results-section {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 12px;
  padding: 1.5rem;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

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

.results-section h2 {
  margin-bottom: 1rem;
  font-size: 1.25rem;
}

.overall-status {
  padding: 1rem;
  border-radius: 8px;
  text-align: center;
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: 1rem;
}

.overall-status.pass {
  background: rgba(34, 197, 94, 0.2);
  border: 1px solid #22c55e;
  color: #4ade80;
}

.overall-status.warn {
  background: rgba(234, 179, 8, 0.2);
  border: 1px solid #eab308;
  color: #facc15;
}

.overall-status.fail {
  background: rgba(239, 68, 68, 0.2);
  border: 1px solid #ef4444;
  color: #f87171;
}

.checks-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.check-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 6px;
}

.check-icon {
  font-size: 1.25rem;
  width: 28px;
  text-align: center;
}

.check-label {
  font-weight: 500;
  min-width: 120px;
}

.check-message {
  color: #94a3b8;
  font-size: 0.9rem;
  flex: 1;
}

.check-item.pass .check-icon { color: #22c55e; }
.check-item.warn .check-icon { color: #eab308; }
.check-item.fail .check-icon { color: #ef4444; }

.suggestions {
  margin-top: 1rem;
  padding: 1rem;
  background: rgba(234, 179, 8, 0.1);
  border-radius: 8px;
  border: 1px solid rgba(234, 179, 8, 0.3);
}

.suggestions.hidden {
  display: none;
}

.suggestions h3 {
  font-size: 1rem;
  margin-bottom: 0.5rem;
  color: #facc15;
}

.suggestions ul {
  list-style: none;
  padding-left: 0;
}

.suggestions li {
  padding: 0.25rem 0;
  color: #fef9c3;
  font-size: 0.9rem;
}

.suggestions li::before {
  content: "→ ";
  color: #eab308;
}

.api-payload {
  margin-top: 1rem;
  padding: 1rem;
  background: rgba(34, 197, 94, 0.1);
  border-radius: 8px;
  border: 1px solid rgba(34, 197, 94, 0.3);
}

.api-payload.hidden {
  display: none;
}

.api-payload h3 {
  font-size: 1rem;
  margin-bottom: 0.5rem;
  color: #4ade80;
}

.api-payload p {
  color: #bbf7d0;
  font-size: 0.9rem;
  margin-bottom: 0.75rem;
}

.api-payload pre {
  background: rgba(0, 0, 0, 0.4);
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 0.85rem;
  color: #a5f3fc;
  margin-bottom: 0.75rem;
}

.copy-btn {
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 6px;
  background: #22c55e;
  color: white;
  font-size: 0.9rem;
  cursor: pointer;
  transition: background 0.2s;
}

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

footer {
  text-align: center;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

footer p {
  color: #64748b;
  font-size: 0.9rem;
}

footer a {
  color: #60a5fa;
  text-decoration: none;
}

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

.note {
  margin-top: 0.5rem;
  font-size: 0.85rem;
}

@media (max-width: 600px) {
  .container {
    padding: 1rem;
  }

  h1 {
    font-size: 1.75rem;
  }

  .check-item {
    flex-wrap: wrap;
  }

  .check-message {
    width: 100%;
    margin-top: 0.25rem;
  }
}