/* Modern utility-inspired palette (slate + indigo) */
:root {
  --slate-50: #f8fafc;
  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-700: #334155;
  --slate-800: #1e293b;
  --slate-900: #0f172a;
  --indigo-500: #6366f1;
  --indigo-600: #4f46e5;
  --indigo-700: #4338ca;
  --emerald-500: #10b981;
  --emerald-600: #059669;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgb(15 23 42 / 0.08), 0 4px 12px rgb(15 23 42 / 0.06);
  --font: "Inter", system-ui, -apple-system, sans-serif;
}

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

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--slate-800);
  background: linear-gradient(165deg, var(--slate-50) 0%, var(--slate-100) 45%, #eef2ff 100%);
}

.page {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

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

.logo {
  margin: 0 0 0.5rem;
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--slate-900);
  background: linear-gradient(135deg, var(--slate-900) 0%, var(--indigo-600) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.tagline {
  margin: 0;
  color: var(--slate-600);
  font-size: 0.95rem;
  max-width: 36rem;
  margin-inline: auto;
}

.tool {
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--slate-200);
  padding: 1.25rem;
  margin-bottom: 3rem;
}

@media (min-width: 900px) {
  .tool {
    padding: 1.5rem;
  }
}

.panels {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

@media (min-width: 900px) {
  .panels {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: stretch;
    gap: 1.25rem;
  }

  .panel {
    flex: 1 1 calc(50% - 4.5rem);
    min-width: 0;
  }

  .actions {
    flex: 0 0 auto;
    width: 10rem;
    flex-direction: column;
    justify-content: center;
    align-self: stretch;
    padding: 0 0.25rem;
  }
}

.panel__label {
  display: block;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--slate-500);
  margin-bottom: 0.5rem;
}

.textarea {
  width: 100%;
  min-height: 220px;
  padding: 0.875rem 1rem;
  font-family: var(--font);
  font-size: 0.9375rem;
  line-height: 1.55;
  color: var(--slate-800);
  background: var(--slate-50);
  border: 1px solid var(--slate-200);
  border-radius: var(--radius-sm);
  resize: vertical;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.textarea:focus {
  outline: none;
  border-color: var(--indigo-500);
  box-shadow: 0 0 0 3px rgb(99 102 241 / 0.2);
}

.textarea--readonly {
  background: var(--slate-100);
  color: var(--slate-700);
}

.textarea::placeholder {
  color: var(--slate-400);
}

.actions {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
  padding: 0.25rem 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.15rem;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: transform 0.12s ease, background 0.15s ease, box-shadow 0.15s ease;
}

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

.btn--primary {
  background: linear-gradient(180deg, var(--indigo-600) 0%, var(--indigo-700) 100%);
  color: #fff;
  box-shadow: 0 1px 2px rgb(0 0 0 / 0.08);
}

.btn--primary:hover {
  background: var(--indigo-600);
  box-shadow: 0 4px 14px rgb(79 70 229 / 0.35);
}

.btn--secondary {
  background: var(--slate-100);
  color: var(--slate-800);
  border: 1px solid var(--slate-200);
}

.btn--secondary:hover {
  background: #fff;
  border-color: var(--slate-300);
}

.status {
  min-height: 1.5rem;
  margin: 1rem 0 0;
  font-size: 0.8125rem;
  color: var(--emerald-600);
  text-align: center;
}

.status--error {
  color: #dc2626;
}

.seo-article {
  max-width: 42rem;
  margin: 0 auto 2.5rem;
  padding: 0 0.25rem;
}

.seo-article__title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--slate-900);
  margin: 2rem 0 0.75rem;
  letter-spacing: -0.02em;
}

.seo-article__title:first-of-type {
  margin-top: 0;
}

.seo-article p {
  margin: 0 0 1rem;
  color: var(--slate-600);
  font-size: 0.9375rem;
}

.footer {
  text-align: center;
  padding-top: 1.5rem;
  border-top: 1px solid var(--slate-200);
}

.footer__nav {
  margin-bottom: 0.75rem;
}

.footer__link {
  color: var(--indigo-600);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.875rem;
}

.footer__link:hover {
  text-decoration: underline;
}

.footer__sep {
  color: var(--slate-300);
  margin: 0 0.5rem;
}

.footer__note {
  margin: 0;
  font-size: 0.75rem;
  color: var(--slate-500);
}