:root {
  color-scheme: light;
  --bg: #f7f7f4;
  --panel: #ffffff;
  --ink: #1d2327;
  --muted: #68737d;
  --line: #dadfd8;
  --accent: #315c72;
  --accent-strong: #234659;
  --gold: #c28f25;
  --green: #15803d;
  --amber: #b45309;
  --red: #b91c1c;
  --shadow: 0 18px 45px rgba(31, 41, 55, 0.1);
}

[data-theme="dark"] {
  color-scheme: dark;
  --bg: #101412;
  --panel: #181d1a;
  --ink: #f1f5ef;
  --muted: #a8b3ac;
  --line: #303831;
  --accent: #8bc0d1;
  --accent-strong: #b9ddeb;
  --gold: #e1b75a;
  --shadow: 0 18px 45px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    linear-gradient(180deg, rgba(49, 92, 114, 0.1), transparent 360px),
    var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
}

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

button, textarea { font: inherit; }

.site-header {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  min-height: 72px;
  display: flex;
  align-items: center;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.05rem;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: var(--ink);
  color: var(--bg);
  font-family: Georgia, serif;
}

.top-nav {
  margin-left: auto;
  display: flex;
  gap: 6px;
  color: var(--muted);
  font-size: 0.94rem;
}

.top-nav a,
.ghost-button,
.icon-button {
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 8px 10px;
}

.top-nav a:hover,
.ghost-button:hover,
.icon-button:hover {
  border-color: var(--line);
  background: color-mix(in srgb, var(--panel) 72%, transparent);
}

.icon-button {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  background: var(--panel);
  color: var(--ink);
  border-color: var(--line);
  cursor: pointer;
}

.moon, [data-theme="dark"] .sun { display: none; }
[data-theme="dark"] .moon { display: inline; }

main {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
}

.tool-shell {
  padding: 36px 0 48px;
}

.intro {
  max-width: 760px;
  margin-bottom: 28px;
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0;
  font-size: 0.78rem;
}

h1 {
  margin: 0;
  font-size: clamp(2.15rem, 5vw, 4.7rem);
  line-height: 0.98;
  letter-spacing: 0;
  max-width: 820px;
}

.lede {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: clamp(1.02rem, 2vw, 1.22rem);
  max-width: 690px;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 380px;
  gap: 18px;
  align-items: start;
}

.editor-panel,
.result-card,
.empty-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.editor-panel { padding: 16px; }

.panel-head,
.result-actions,
.result-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.panel-head label,
.platform-block h2 {
  font-weight: 800;
}

.editor-actions { display: flex; gap: 8px; }

.ghost-button,
.primary-button {
  cursor: pointer;
  min-height: 38px;
}

.ghost-button {
  background: transparent;
  color: var(--muted);
}

textarea {
  width: 100%;
  min-height: 430px;
  margin-top: 14px;
  resize: vertical;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px;
  background: color-mix(in srgb, var(--panel) 92%, var(--bg));
  color: var(--ink);
  outline: none;
  font-size: 1rem;
}

textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 18%, transparent);
}

.mini-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.92rem;
}

.mini-stats span {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 9px;
}

.results-column {
  display: grid;
  gap: 14px;
  position: sticky;
  top: 16px;
}

.empty-card {
  min-height: 320px;
  display: grid;
  align-content: center;
  justify-items: start;
  padding: 28px;
}

.empty-icon {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  background: color-mix(in srgb, var(--accent) 14%, transparent);
  color: var(--accent);
  font-size: 1.8rem;
}

.empty-card h2 {
  margin: 18px 0 8px;
  font-size: 1.25rem;
}

.empty-card p,
.advice {
  margin: 0;
  color: var(--muted);
}

.result-card {
  padding: 18px;
  animation: cardIn 180ms ease-out;
}

@keyframes cardIn {
  from { opacity: 0; transform: translateY(6px) scale(0.99); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.is-hidden { display: none; }

.result-topline {
  align-items: stretch;
}

.result-topline > div {
  flex: 1;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
}

.metric-label {
  display: block;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0;
}

.result-topline strong {
  display: block;
  margin-top: 4px;
  font-size: 1.25rem;
  line-height: 1.15;
}

.grade-block {
  margin-top: 16px;
  padding: 16px;
  border-radius: 8px;
  background: color-mix(in srgb, var(--accent) 8%, transparent);
}

.grade-copy strong {
  display: block;
  font-size: 1.55rem;
  line-height: 1.15;
}

.grade-bar {
  height: 12px;
  margin: 14px 0 10px;
  overflow: hidden;
  border-radius: 999px;
  background: color-mix(in srgb, var(--ink) 12%, transparent);
}

.grade-bar span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--green);
  transition: width 180ms ease, background 180ms ease;
}

.platform-block {
  margin-top: 18px;
}

.platform-block h2 {
  margin: 0 0 10px;
  font-size: 1rem;
}

.platform-grid {
  display: grid;
  gap: 8px;
}

.platform-item {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 10px;
  align-items: start;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px;
}

.platform-item strong { display: block; }
.platform-item span:last-child { color: var(--muted); font-size: 0.9rem; }
.status-good { color: var(--green); }
.status-warn { color: var(--amber); }
.status-bad { color: var(--red); }

.primary-button {
  border: 0;
  border-radius: 8px;
  padding: 10px 14px;
  color: #fff;
  background: var(--accent-strong);
  font-weight: 800;
}

.result-actions {
  margin-top: 16px;
}

#copyStatus {
  color: var(--muted);
  font-size: 0.9rem;
}

.seo-content {
  display: grid;
  gap: 8px;
  max-width: 860px;
  padding: 42px 0 64px;
}

.seo-content h2,
.seo-content h3 {
  margin: 0;
  line-height: 1.15;
}

.seo-content h2 { font-size: clamp(1.7rem, 3vw, 2.4rem); }
.seo-content h3 { margin-top: 18px; font-size: 1.2rem; }
.seo-content p { margin: 0; color: var(--muted); }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 24px 0 34px;
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  color: var(--muted);
}

.site-footer p { margin: 0; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 14px; }
.site-footer a { color: var(--ink); font-weight: 700; }

@media (max-width: 860px) {
  .site-header { flex-wrap: wrap; padding: 14px 0; }
  .top-nav { order: 3; width: 100%; margin-left: 0; overflow-x: auto; }
  .workspace { grid-template-columns: 1fr; }
  .results-column { position: static; }
  textarea { min-height: 300px; }
  .site-footer { flex-direction: column; }
}

@media (max-width: 520px) {
  main,
  .site-header,
  .site-footer {
    width: min(100% - 20px, 1180px);
  }

  .tool-shell { padding-top: 18px; }
  .panel-head { align-items: flex-start; flex-direction: column; }
  .editor-actions { width: 100%; }
  .ghost-button { flex: 1; }
  .result-topline { flex-direction: column; }
}