:root {
  --bg: #fafafa;
  --surface: #ffffff;
  --text: #111827;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --primary: #0d9488;
  --primary-hover: #0f766e;
  --primary-light: #ecfdf5;
  --success: #059669;
  --success-bg: #ecfdf5;
  --warning: #d97706;
  --warning-bg: #fffbeb;
  --error: #dc2626;
  --error-bg: #fef2f2;
  --info: #2563eb;
  --info-bg: #eff6ff;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 4px 16px rgba(0, 0, 0, 0.04);
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text);
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--primary), #0891b2);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 14px;
}

.nav-links {
  display: flex;
  gap: 24px;
  align-items: center;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--text);
}

/* Hero */
.hero {
  padding: 48px 0 32px;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 16px;
}

.hero h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
  line-height: 1.2;
}

.hero p {
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 560px;
  margin: 0 auto;
}

/* Tool card */
.tool-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 32px;
  margin-bottom: 32px;
}

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

.form-group label {
  display: block;
  font-weight: 600;
  font-size: 0.875rem;
  margin-bottom: 8px;
  color: var(--text);
}

.form-group .hint {
  font-weight: 400;
  color: var(--text-muted);
  font-size: 0.8rem;
  margin-top: 4px;
}

input[type="text"],
input[type="url"],
textarea,
select {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--text);
  background: var(--surface);
  transition: border-color 0.15s, box-shadow 0.15s;
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
}

textarea {
  resize: vertical;
  min-height: 120px;
  font-family: "SF Mono", "Fira Code", Consolas, monospace;
  font-size: 0.85rem;
}

.form-divider {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 24px 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.form-divider::before,
.form-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

.btn-row {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: 8px;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: background 0.15s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--primary);
  color: white;
}

.btn-primary:hover {
  background: var(--primary-hover);
}

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

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background: var(--bg);
}

/* Results */
.results {
  display: none;
  margin-top: 32px;
}

.results.visible {
  display: block;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px;
  text-align: center;
}

.stat-value {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

.score-ring {
  width: 80px;
  height: 80px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 800;
  margin: 0 auto 4px;
  border: 4px solid var(--primary);
}

.score-ring.good { border-color: var(--success); color: var(--success); }
.score-ring.ok { border-color: var(--warning); color: var(--warning); }
.score-ring.bad { border-color: var(--error); color: var(--error); }

.result-section {
  margin-bottom: 24px;
}

.result-section h3 {
  font-size: 1rem;
  font-weight: 700;
  margin: 0 0 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.issue-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.issue-item {
  padding: 10px 14px;
  border-radius: 8px;
  margin-bottom: 8px;
  font-size: 0.9rem;
  display: flex;
  gap: 10px;
  align-items: flex-start;
}

.issue-item.error { background: var(--error-bg); color: var(--error); }
.issue-item.warning { background: var(--warning-bg); color: var(--warning); }
.issue-item.info { background: var(--info-bg); color: var(--info); }

.rules-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.rules-table th,
.rules-table td {
  padding: 10px 12px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.rules-table th {
  background: var(--bg);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-muted);
}

.rules-table code {
  background: var(--bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85em;
}

.tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.tag.allow { background: var(--success-bg); color: var(--success); }
.tag.disallow { background: var(--error-bg); color: var(--error); }

.sitemap-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.sitemap-list li {
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  word-break: break-all;
}

.raw-content {
  background: #1e1e2e;
  color: #cdd6f4;
  padding: 16px;
  border-radius: 8px;
  font-family: "SF Mono", "Fira Code", Consolas, monospace;
  font-size: 0.8rem;
  overflow-x: auto;
  white-space: pre-wrap;
  max-height: 300px;
  overflow-y: auto;
}

.alert {
  padding: 14px 16px;
  border-radius: 8px;
  font-size: 0.9rem;
  margin-bottom: 16px;
}

.alert-error {
  background: var(--error-bg);
  color: var(--error);
  border: 1px solid #fecaca;
}

.alert-success {
  background: var(--success-bg);
  color: var(--success);
  border: 1px solid #a7f3d0;
}

/* Tools grid (index page) */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  padding: 32px 0 64px;
}

.tool-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  transition: box-shadow 0.2s, border-color 0.2s;
  display: flex;
  flex-direction: column;
}

.tool-card:hover {
  box-shadow: var(--shadow);
  border-color: #c7d2fe;
}

.tool-card h2 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0 0 8px;
}

.tool-card p {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin: 0 0 16px;
  flex: 1;
}

.tool-card .btn {
  align-self: flex-start;
}

.tool-card.coming-soon {
  opacity: 0.7;
}

/* Other tools sidebar */
.other-tools {
  padding: 48px 0 64px;
  border-top: 1px solid var(--border);
}

.other-tools h2 {
  text-align: center;
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.other-tools > p {
  text-align: center;
  color: var(--text-muted);
  margin-bottom: 32px;
}

/* Footer */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 32px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

.spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

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

@media (max-width: 640px) {
  .tool-panel {
    padding: 20px;
  }

  .btn-row {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }
}