:root {
  --color-bg: #ffffff;
  --color-surface: #f8fafc;
  --color-surface-strong: #ffffff;
  --color-text: #1a1a1a;
  --color-accent: #2563eb;
  --color-muted: #64748b;
  --color-border: #e2e8f0;
  --color-success: #22c55e;
  --color-warning: #eab308;
  --color-alert: #f97316;
  --color-danger: #ef4444;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
  --radius-card: 8px;
  --radius-control: 6px;
  --transition: 0.2s ease;
  --max-width: 800px;
  --sidebar-width: 300px;
  --header-height: 64px;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

html[data-theme='dark'] {
  --color-bg: #0f172a;
  --color-surface: #1e293b;
  --color-surface-strong: #111827;
  --color-text: #e2e8f0;
  --color-accent: #3b82f6;
  --color-muted: #94a3b8;
  --color-border: #334155;
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.45);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
select,
textarea {
  font: inherit;
}

button,
select {
  cursor: pointer;
}

img {
  max-width: 100%;
}

.container {
  width: min(100%, var(--max-width));
  margin: 0 auto;
  padding: 0 1rem;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--color-bg) 92%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.nav-shell {
  min-height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-accent);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.language-select,
.theme-toggle,
.button,
.text-input {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-control);
  transition: border-color var(--transition), background var(--transition), color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.language-select,
.theme-toggle {
  min-height: 2.5rem;
  background: var(--color-surface);
  color: var(--color-text);
}

.language-select {
  padding: 0 0.8rem;
}

.theme-toggle {
  width: 2.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.hero,
.page-header {
  padding-top: 2.5rem;
}

.hero h1,
.page-header h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.15;
}

.hero p,
.page-header p,
.section-heading p,
.site-footer p {
  margin: 0;
  color: var(--color-muted);
}

.section-spacing {
  margin-bottom: 1.5rem;
}

.tools-grid {
  display: grid;
  gap: 1rem;
}

.tool-card,
.stat-card,
.section-card,
.ad-slot {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-sm);
}

.tool-card {
  padding: 1.25rem;
}

.tool-card:hover,
.tool-card:focus-visible {
  transform: translateY(-2px);
  border-color: var(--color-accent);
}

.tool-icon {
  font-size: 1.8rem;
  display: inline-flex;
  margin-bottom: 0.75rem;
}

.tool-card h2,
.section-heading h2 {
  margin: 0 0 0.35rem;
  font-size: 1.15rem;
}

.tool-card p {
  margin: 0;
  color: var(--color-muted);
}

.page-shell {
  display: block;
  padding-top: 1rem;
  padding-bottom: 2rem;
}

.text-input {
  width: 100%;
  min-height: 220px;
  padding: 1rem;
  resize: vertical;
  background: var(--color-surface-strong);
  color: var(--color-text);
  line-height: 1.6;
  font-size: 1.1rem;
}

.text-input::placeholder {
  color: var(--color-muted);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.875rem;
}

.stat-card {
  padding: 1rem;
}

.stat-card strong {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 2rem;
  line-height: 1.1;
  color: var(--color-accent);
}

.stat-card span {
  font-size: 0.95rem;
  color: var(--color-muted);
}

.ad-slot {
  min-height: 90px;
  border-style: dashed;
  display: grid;
  place-items: center;
  color: var(--color-muted);
  font-weight: 600;
}

.section-card {
  padding: 1.25rem;
}

.social-limits {
  display: grid;
  gap: 0.95rem;
}

.social-row {
  display: grid;
  gap: 0.55rem;
}

.social-row-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 0.75rem;
}

.social-label {
  font-weight: 600;
}

.social-count {
  font-variant-numeric: tabular-nums;
  color: var(--color-muted);
}

.progress-track {
  height: 0.7rem;
  overflow: hidden;
  border-radius: 999px;
  background: color-mix(in srgb, var(--color-border) 70%, var(--color-bg));
}

.progress-bar {
  height: 100%;
  width: 0%;
  border-radius: inherit;
  background: var(--color-success);
  transition: width var(--transition), background var(--transition);
}

.progress-bar.is-warning { background: var(--color-warning); }
.progress-bar.is-alert { background: var(--color-alert); }
.progress-bar.is-danger { background: var(--color-danger); }
.progress-bar.is-danger {
  background-image: repeating-linear-gradient(
    135deg,
    color-mix(in srgb, var(--color-danger) 88%, #ffffff) 0 10px,
    var(--color-danger) 10px 20px
  );
}
.social-count.is-danger { color: var(--color-danger); }

.table-wrap {
  overflow-x: auto;
}

.keyword-table {
  width: 100%;
  border-collapse: collapse;
}

.keyword-table th,
.keyword-table td {
  padding: 0.75rem 0.5rem;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
}

.keyword-table th {
  color: var(--color-muted);
  font-size: 0.9rem;
  font-weight: 600;
}

.keyword-table tbody tr:last-child td {
  border-bottom: 0;
}

.is-hidden {
  display: none;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.button {
  position: relative;
  overflow: hidden;
  padding: 0.8rem 1rem;
  background: transparent;
  color: var(--color-text);
}

.button::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition);
  z-index: 0;
}

.button span,
.button {
  position: relative;
  z-index: 1;
}

.button:hover,
.button:focus-visible,
.language-select:focus-visible,
.theme-toggle:focus-visible,
.text-input:focus-visible,
.tool-card:focus-visible,
details summary:focus-visible {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-accent) 20%, transparent);
}

.button:hover::before,
.button:focus-visible::before {
  transform: scaleX(1);
}

.button:hover,
.button:focus-visible {
  color: #ffffff;
}

.faq-section details {
  border-top: 1px solid var(--color-border);
  padding: 1rem 0;
}

.faq-section details:first-of-type {
  padding-top: 0.5rem;
}

.faq-section summary {
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

.faq-section summary::-webkit-details-marker {
  display: none;
}

.faq-section summary::after {
  content: '+';
  float: right;
  color: var(--color-accent);
}

.faq-section details[open] summary::after {
  content: '–';
}

.faq-section p {
  margin: 0.75rem 0 0;
  color: var(--color-muted);
}

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
}

.footer-inner {
  display: grid;
  gap: 0.5rem;
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--color-accent);
}

.page-sidebar {
  display: none;
}

.ad-slot-sidebar {
  min-height: 250px;
  width: 100%;
  max-width: 300px;
}

.ad-slot-mobile {
  display: grid;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (min-width: 640px) {
  .stats-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .tools-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .container {
    width: min(100%, calc(var(--max-width) + 2rem));
  }

  .tools-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1024px) {
  .page-shell {
    width: min(100%, calc(var(--max-width) + var(--sidebar-width) + 4rem));
    display: grid;
    grid-template-columns: minmax(0, var(--max-width)) minmax(260px, var(--sidebar-width));
    gap: 2rem;
    align-items: start;
  }

  .page-sidebar {
    display: block;
    position: relative;
    padding-top: 2.5rem;
  }

  .ad-slot-sidebar {
    position: sticky;
    top: calc(var(--header-height) + 1rem);
  }

  .ad-slot-mobile {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}